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Article

Homometallic 2D Cd2+ and Heterometallic 3D Cd2+/Ca2+, Cd2+/Sr2+ Metal–Organic Frameworks Based on an Angular Tetracarboxylic Ligand

by
Rafail P. Machattos
1,
Nikos Panagiotou
1,
Vasiliki I. Karagianni
2,
Manolis J. Manos
2,
Eleni E. Moushi
3,* and
Anastasios J. Tasiopoulos
1,*
1
Department of Chemistry, University of Cyprus, 1678 Nicosia, Cyprus
2
Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece
3
Department of Life Sciences, European University Cyprus, 2404 Nicosia, Cyprus
*
Authors to whom correspondence should be addressed.
Materials 2025, 18(20), 4647; https://doi.org/10.3390/ma18204647
Submission received: 20 August 2025 / Revised: 1 October 2025 / Accepted: 3 October 2025 / Published: 10 October 2025
(This article belongs to the Special Issue Synthesis and Applications of Metal–Organic Frameworks)

Abstract

This study reports on the synthesis, structural characterization and gas sorption studies of a homometallic 2D Cd2+ MOF and two heterometallic 3D Cd2+/Ca2+ and Cd2+/Sr2+ -MOFs based on the angular tetracarboxylic ligand 3,3′,4,4′-sulfonyltetracarboxylic acid (H4STBA). The homometallic 2D Cd2+ MOF with the formula [NH2(CH3)2]+2[Cd(STBA)]2−n·nDMF·1.5nH2O—(1)n·nDMF·1.5nH2O was synthesized from the reaction of CdCl2·H2O and 3,3′,4,4′-diphthalic sulfonyl dianhydride (3,3′,4,4′-DPSDA) with stoichiometric ratio of 1:1.3 in DMF/H2O (5/2 mL) at 100 °C. The two heterometallic Cd2+/Ca2+ and Cd2+/Sr2+ compounds were prepared from analogous reactions to this afforded (1)n·nDMF·1.5nH2O with the difference that the reaction mixture also contained AE(NO3)2 (AE2+ = Ca2+ or Sr2+) and, in particular, from the reaction of AE(NO3)2, CdCl2·H2O and 3,3′,4,4′-DPSDA with stoichiometric ratio 1:1.1:1.4 in DMF/H2O (5/2 mL) at 100 °C. Notably, compounds [CdCa(STBA)(H2O)2]n·0.5nDMF—(2)n·0.5nDMF and [CdSr(STBA)(H2O)2]n·0.5nDMF—(3)n·0.5nDMF are the first heterometallic compounds Mn+/AE2+ (M = any metal ion) reported containing ligand H4STBA. The structure of (1)n·nDMF·1.5nH2O comprises a 2D network based on helical 1D chain secondary building unit (SBU) [Cd2+(STBA)4−)]2−. The 2D sheets are linked through hydrogen bonding interactions, giving rise to a pseudo-3D structure. On the other hand, compounds (2)n·1.5nH2O and (3)n·1.5nH2O display 3D microporous structures consisting of a helical 1D chain SBU [Cd2+AE2+(STBA)4−)]. All three compounds contain rhombic channels along c axes. The three MOFs exhibit an appreciable thermal stability, up to 350–400 °C. Gas sorption measurements on activated materials (2)n and (3)n revealed moderate BET surface areas of 370 m2/g and 343 m2/g, respectively, along with CO2 uptake capacity of 2.58 mmol/g at 273 K.

Graphical Abstract

1. Introduction

Metal–Organic Frameworks (MOFs) are considered a highly versatile and promising family of materials in the field of inorganic chemistry since their discovery in the late 20th century. MOFs consist of metal ions or clusters linked by organic bridging ligands, forming a porous, crystalline structure with high surface areas. Their unique structures arising from the variety of metal ions, organic ligands, functional groups and resulting network topologies enable tunability and customization [1,2,3,4,5], making them valuable for applications in fields of general interest, such as energy, environment, healthcare, food safety, etc. As a consequence, numerous MOFs have been synthesized and proposed for potential applications in the fields of gas storage/separation [6,7,8,9], catalysis [10,11,12], sensing [13,14,15,16], removal of pollutants from the environment [17,18,19,20], and water harvesting [21].
The construction of functional MOFs requires the judicious selection of not only the metal ions but also the organic linkers. Specifically, there are several factors regarding the identity of the appropriate carboxylate organic ligand, for the construction of MOFs, including the overall size of the molecule, rigidity/flexibility and the number and positions of the carboxylate groups [22,23,24,25,26,27,28]. One category of organic ligands widely used in MOF synthesis comprises semi-rigid, V-shaped multicarboxylic acid molecules that feature two benzoate or phthalate units connected through a central functional group or atom. Generally, the central group/atom can be an etheric -O- group [20,29,30,31,32,33,34,35,36,37,38,39], a thioetheric -S- atom [40], a secondary or tertiary amine; -(NH(R))- (R: H-, Me-, etc.) [41,42,43,44], a ketone group; -(C=O)- [31,45,46,47,48,49,50,51,52,53,54], a hexafluoroisopropylidene group; -C(CF3)2- [20,55,56,57,58,59,60,61,62,63,64], silane groups -(SiR′2)- (R′: Me-, Ph-, etc.) [65,66,67,68] or a sulfonyl group; -S(O)2- [69,70,71,72,73]. The flexibility of these di-/tetracrboxylate linkers stems from the sp3-hybridized central atom connecting the two benzoate or phthalate moieties in most of these linkers, which allows the rotation of the adjacent benzene rings around the central atom. Although there are numerous examples of MOFs based on V-shaped dicarboxylic linkers, including 4,4′-oxybisbenzoic acid and 4,4′-sulfonyl dibenzoic acid (amongst others), the corresponding examples with V-shaped tetracarboxylic ligands are significantly fewer. Among them, the MOF structures with diphthalic ligand derivatives are relatively rare, as revealed by a CCDC search, which returned around 310 examples for this family of ligands. This is possibly because of the incompatibility of the phthalic acid moiety with the common SBUs formed in MOFs. Another common issue with phthalic acid-containing ligands is that they tend to adopt various coordination modes with metal ions, restricting the ability to form targeted MOF structures with specific topological features. As a result, such ligands lead to several new structures with various network topologies, especially when they are used with metal ions possessing flexible coordination spheres (as lanthanide ions, alkaline earth ions, etc.). In addition, because of their multiple binding sites (the four carboxylate groups), they usually bind with several metal ions and, this way, they can stabilize heterometallic MOFs containing two or more different metal ions [36,52]. In recent years, heterometallic MOFs (HMOFs) have attracted significant attention, and have been employed in multiple applications, including H2 sorption and storage [74,75,76,77,78,79], light hydrocarbon sorption [80,81,82,83,84], catalysis [85,86,87,88,89,90], magnetism [91,92,93,94], and sensing [95,96].
Among the diphthalic ligands, 3,3′,4,4′-sulfonyltetracarboxylic acid (H4STBA) has a high bridging capability due to its four carboxylic groups, while the central –SO2– moiety can serve either as a binding site or as a functional group influencing the sorption performance of materials [69,71,97,98]. Therefore, the H4STBA ligand is a promising candidate for the synthesis of multidimensional coordination polymers, especially 3D porous frameworks. The reported coordination polymers containing the STBA4− ligand are all based on individual metal ions with or without auxiliary ligands, and there are no Mn+/AE2+ (M = any metal ion) heterometallic MOFs in the literature.
We herein report three new MOFs, one 2D Cd2+-MOF and two heterometallic microporous 3D Cd2+/Ca2+ and Cd2+/Sr2+ -MOFs with formulae [NH2(CH3)2]+2[Cd(STBA)]2−n·nDMF·1.5nH2O—(1)n·nDMF·1.5nH2O, [CdCa(STBA)(H2O)2]n·0.5nDMF—(2)n·0.5nDMF and [CdSr(STBA)(H2O)2]n·0.5nDMF—(3)n·0.5nDMF. The three compounds were synthesized by analogous synthetic routes involving the reaction of CdCl2·H2O with 3,3′,4,4′-diphthalic sulfonyl dianhydride (3,3′,4,4′-DPSDA), which was hydrolyzed in situ to afford the corresponding tetracarboxylic acid in DMF/H2O 5/2 mL at 100 °C in the presence or not (in the synthesis of (1)n) of Ca(NO3)2·4H2O (in the synthesis of (2)n) or Sr(NO3)2 (in the synthesis of (3)n). Compound (1)n·nDMF·1.5nH2O consists of a homometallic 1D helical Cd2+-chain SBU and exhibits a 2D structure, whereas compounds (2)n·0.5nDMF and (3)n·0.5nDMF feature a heterometallic 1D helical Cd2+AE2+-chain SBU and display 3D structures. In addition, all three MOFs exhibit appreciable thermal stability, retaining their structural integrity and crystallinity even at elevated temperatures (350–400 °C) as confirmed by thermogravimetric analysis (TGA) and variable temperature powder x-ray diffraction (VT-pXRD) measurements. CO2 uptake measurements on activated samples of (2)n and (3)n revealed type I isotherms, typical of microporous materials, with BET surface areas of 370 m2/g and 343 m2/g (Langmuir areas of 403 and 375 m2/g), respectively.

2. Materials and Methods

Details about the synthesis, stability studies, and the physicochemical characterization methods of compounds (1)n, (2)n, and (3)n are provided in the Supplementary Materials.

3. Results and Discussion

3.1. Synthesis

In recent years, our group has explored the use of V-shaped dicarboxylic ligands in MOF chemistry, aiming to develop new functional materials. Several such ligands have been employed in these studies, comprising two benzoic acid units connected via a central linker, etheric -O- (H2OBA), hexafluoroisopropylidene, -C(CF3)2- (H2HFPBBA), carbonyl –(C=O)- (H2BPHD), or sulfonyl -S(O)2- (H2SDBA) functional groups. These efforts have afforded a series of Cu2+ [99], Zr4+ [20] and trivalent rare earth MOFs [34,72] with interesting structural, sorption, and sensing properties. These investigations have been recently extended to tetracarboxylic V-shaped ligands, and, in this work, we report three new compounds synthesized from the use of the diphthalic ligand H4STBA (Scheme S1a in Supplementary Materials). According to a survey of the literature and the CCDC database, MOFs comprising the deprotonated H4−nSTBAn− ligand without auxiliary bridging ligands containing N-donor atoms are relatively rare (a CCDC search returned fewer than 40 structures). This tetracarboxylic ligand has also been utilized in Cd2+-chemistry, yielding only a handful of MOF examples [36,54,64]. As such, we explored the chemistry of the H4STBA ligand in Cd2+- and AE2+-chemistry. These synthetic efforts and, in particular, the reaction of CdCl2·H2O with 3,3′,4,4′-DPSDA in DMF/H2O (5 mL/2 mL) afforded compound [NH2(CH3)2]+2[Cd(STBA)]2−n·nDMF·1.5nH2O—(1)n·nDMF·1.5nH2O, which represents an anionic framework where the negative charge is counterbalanced by two [NH2(CH3)2]+ cations. Considering this result, it was decided to use a second, divalent metal ion in the reaction mixture with the aim of isolating neutral heterometallic MOFs. The exact same reaction that led to (1)n·nDMF·1.5nH2O was repeated with the difference that an AE(NO3)2 salt was employed in the reaction mixture. These efforts led to compounds [CdCa(STBA)(H2O)2]n·0.5nDMF—(2)n·0.5nDMF and [CdSr(STBA)(H2O)2]n·0.5nDMF—(3)n·0.5nDMF, which are neutral MOFs.

3.2. Structural Characterization

Representations of the crystal structure of compound (1)n, crystallizing in the monoclinic space group P2/c, are illustrated in Figure 1, and selected crystal data and bond lengths are listed in Tables S1 and S2, respectively, in the Supplementary Materials. The asymmetric unit comprises a half cadmium ion and a half STBA4− ligand. The coordination environment of Cd1 ion comprises eight O atoms of four carboxylic groups, chelating to the metal ion, of four different STBA4− ligands, adopting a Johnson Gyrobifastigium (J26) geometry [100]. There is one crystallographically independent STBA4− ligand that connects four metal ions in a η111111114 fashion (Scheme S1b in the Supplementary Materials). The connection of the Cd2+ ions through the COO groups of STBA4− ligands leads to a 1D chain along the crystallographic c axis with the formula [Cd(COO)4]2−, which is the secondary building unit (SBU) of (1)n (Figure 1a). The chains are linked through the STBA4− anions, resulting in a 2D network (Figure 1b). A thorough inspection of the packing of (1)n showed the existence of rhombic channels along the c axis, defined by two STBA4− anions and two chain SBUs (Figure 1c). Moreover, soft inter-layer hydrogen-bonding interactions are observed between the hydrogen atom of a benzene ring in one STBA4− ligand (donor) and the O atom of the sulfonyl group, -S(O)2-, in another STBA4− ligand (acceptor) (O···C distance ≈ 3.24 Å) which lead to the parallel packing of the 2D sheets and the formation of a pseudo 3D MOF structure (Figure 1b) [72,99].
The total charge of (1)n is negative and is counterbalanced by two dimethylammonium cations formed from the in situ decomposition of DMF molecules under elevated temperature and pressure conditions. The solvent-accessible volume (SAV) for (1)n was calculated, using program PLATON, to 50% of the unit cell volume.
Representations of the crystal structure of compound (2)n, crystallizing in the tetragonal space group P4122, are illustrated in Figure 2, and selected crystal data and bond lengths are listed in Tables S1 and S3, respectively, in the Supplementary Materials. The asymmetric unit comprises a half cadmium ion, a half calcium ion, and a half STBA4− ligand. Its SBU contains a 1D helical chain with molecular formula [CdCa(COO)4] along the crystallographic c-axis (Figure 2a). The coordination environment of the crystallographically independent Cd2+ center contains six carboxylate O atoms of four different STBA4− ligands, two of which bind to the metal ions in a chelating and the remaining two in a monodentate mode, adopting a distorted octahedral geometry [100], whereas the one of Ca2+ ion consists of four carboxylate O atoms of four different STBA4− anions and two O atoms of terminal water molecules, adopting a distorted octahedral geometry [100]. There is one crystallographically independent STBA4− ligand that connects eight metal centers in a η211121118 fashion (Scheme S1c in the Supplementary Materials). The 1D SBUs are linked to four adjacent ones through STBA4− anions forming, in this way, a 3D network (Figure 2b). A thorough inspection of the packing of (2)n showed the existence of rhombic channels along the c axis (Figure 2b,c). The SAV for (2)n was calculated to ~45% of the unit cell volume.
Representations of the crystal structure of compound (3)n, crystallizing in the tetragonal space group P4322, are illustrated in Figure 3, and selected crystal data and bond lengths are listed in Tables S1 and S4, respectively, in the Supplementary Materials. The asymmetric unit comprises a half cadmium ion, a half strontium ion, and a half STBA4− ligand. Its SBU consists of a 1D helical chain with molecular formula [CdSr(COO)4] along the crystallographic c-axis (Figure 3a). The coordination environment of the crystallographically independent Cd2+ ion consists of six carboxylate O atoms of four STBA4− ligands, two of which bind to the metal ions in a chelating and the remaining two in a monodentate mode, adopting a distorted octahedral geometry [100]. The coordination environment of the Sr2+ center comprises six carboxylate O atoms of four STBA4− ligands and two O atoms of water solvent molecules, adopting a triangular dodecahedral geometry [100]. There is one crystallographically independent STBA4− ligand that connects eight metal ions in a η122112218 fashion (Scheme S1d in the Supplementary Materials). The one-dimensional SBUs are linked to four adjacent ones through STBA4− ligands, resulting in a three-dimensional network (Figure 3b). A thorough inspection of the packing of (3)n showed the existence of rhombic channels along the c-axis (Figure 3b,c). The SAV of (3)n corresponds to ~44% of the unit cell volume.

3.3. Physical Characterization

The stability of the reported MOFs in selected solvents was examined by pXRD. These studies revealed that the MOFs retain their structural integrity and crystallinity upon exposure to air as well as after treatment with most organic solvents, despite their relatively high solvent-accessible volumes (Figures S1–S3). Also, their IR spectra are shown in Figures S4–S6, and the assignment of selected IR bands is summarized in Tables S5–S7.
The thermal stability of microcrystalline samples of the reported MOFs, treated with acetonitrile, was studied with thermogravimetric analysis (Figures S7–S9) and VT-pXRD (Figures S10–S12). Their thermal decomposition includes continuous mass losses. These are attributed to the removal of terminally ligated and guest solvent molecules (H2O/DMF) that is completed at temperatures up to ~290 °C and the combustion of the tetracarboxylic ligand that is completed at ~560–570 °C. The residual mass at 900 °C corresponds to CdO for compound (1)n and an equimolar mixture of CdO/CaO for compound (2)n and CdO/SrO for compound (3)n (Figures S7–S9). A more detailed discussion of the TGA studies for each MOF is included in Supplementary Materials. VT-pXRD studies revealed that compounds (1)n–(3)n retain their crystallinity and structural integrity up to ~350–400 °C, depending on the compound (Figures S10–S12). The morphological features of the compounds were investigated by field-emission scanning electron microscopy (FE-SEM). The results indicate rod-shaped crystals for compound (1)n with an average particle size of 17 μm (Figure S13). Compound (2)n showed larger rod-like aggregates with particle sizes ranging from 40 to 492 μm (Figure S14), whereas compound (3)n displayed needle-like particles with partial aggregation and an average particle size of 46 μm (Figure S15). Energy-dispersive X-ray spectroscopy (EDS) analytical results are in fair agreement with the elemental composition determined from single-crystal X-ray crystallography, yielding a Cd/Ca atomic ratio of ~1.2 for compound (2)n, and a Cd/Sr atomic ratio of ~0.8 for compound (3)n (Figures S14C and S15D).

3.4. Gas Adsorption Measurements

The large SAVs observed in compounds (2)n and (3)n led us to explore their gas adsorption properties. Activation of the two compounds was achieved by replacing both lattice and coordinated solvent molecules with acetonitrile (see experimental part/gas adsorption in the Supplementary Materials). The activated samples of (2)n and (3)n retain their crystallinity and structural integrity as confirmed by pXRD studies (Figures S16 and S17). Carbon dioxide adsorption measurements for activated materials (2)n and (3)n at 195 K exhibited type-I isotherms (Figure 4a,b), typical for microporous materials, from which the apparent BET surface areas were determined to 370 m2/g (Langmuir area, 403 m2/g) and 343 m2/g (Langmuir area, 375 m2/g) (Figures S18–S21), respectively. The total pore volume values calculated at relative pressure, p/p0 = 0.995, are 0.109 cm3/g and 0.102 cm3/g for compounds (2)n and (3)n, respectively. These pore volume values are smaller than those calculated by PoreBlazer [101], most likely due to the partial blockage of the pores by residual organic solvent molecules.
The CO2 uptake of these MOFs at 1 bar was found to be 2.58, 2.32, and 1.90 mmol/g for compound (2)n and 2.58, 2.24, and 1.68 mmol/g for compound (3)n at 273 K, 283 K, and 298 K, respectively (Figure 4c,d). These values are comparable with those reported for other MOFs based on related ligands/or metal ions [8,9]. The isosteric heat of adsorption, Qst, was determined for (2)n and (3)n to 28.4 and 26.2 kJ/mol at zero coverage (Qst0), respectively (Figures S22–S25). These values fall within the expected range for microporous Cd2+-MOFs [102].

4. Conclusions

Summarizing, a homometallic Cd2+-MOF and heterometallic Cd2+/AE2+-MOFs (AE2+ = Ca2+ and Sr2+) are reported. Compound (1)n·nDMF·1.5nH2O is a charged, 2D anionic MOF, counter-balanced by two [NH2(CH3)2]+ cations, based on a homometallic helical Cd2+-chain SBU, whereas compounds (2)n·0.5nDMF and (3)n·0.5nDMF are neutral 3D MOFs, based on heterometallic helical Cd2+/AE2+-chain SBUs. The two heterometallic compounds were targeted after the synthesis and structural characterization of (1)n·nDMF·1.5nH2O was completed due to the existence of two positively charged cations in the structure of (1)n·nDMF·1.5nH2O and polytopic ligands favoring the formation of heterometallic MOFs. Interestingly, compounds (2)n·0.5nDMF and (3)n·0.5nDMF were isolated from the same reaction that afforded (1)n, with the only modification being the inclusion of AE(NO3)2 (AE2+ = Ca2+ (2)n, or Sr2+ (3)n) in the reaction mixture. The structural differences between these three compounds afforded from analogous synthetic procedures highlight the structure-directing capability mainly of the alkaline earth heterometal ions, which is attributed to their flexible coordination sphere. Notably, these compounds are the initial heterometallic Mn+/AE2+ (M = any metal ion) MOFs containing ligand H4STBA or its deprotonated analogs. In addition, all three compounds exhibit appreciable thermal and chemical stability, retaining their crystallinity and structure after exposure to a range of organic solvents and at elevated temperatures (up to 350–400 °C) as evidenced by thermogravimetric analysis and variable temperature powder X-ray diffraction measurements. Gas adsorption measurements on activated materials (2)n and (3)n showed moderate BET areas of 370 m2/g (Langmuir, 403 m2/g) and 343 m2/g (Langmuir, 375 m2/g), respectively, and the capability to adsorb CO2 (2.58 mmol/g), at 273 K/1 bar for both compounds. Overall, this work highlights the capability of diphthalic tetracarboxylic ligands to stabilize homometallic Cd2+ and heterometallic Mn+/AE2+ (M = any metal ion) microporous MOFs. Ongoing work is focused on developing functional materials from this versatile family of ligands.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/ma18204647/s1, Table S1: selected crystal data for (1)n, (2)n and (3)n; Table S2: selected bond lengths of compound (1)n; Table S3: selected bond lengths of compound (2)n; Table S4: selected bond lengths of compound (3)n; Table S5: selected absorption bands of 3,3′,4,4′-DPSDA and compound (1)n; Table S6: selected absorption bands of 3,3′,4,4′-DPSDA and compound (2)n; Table S7: selected absorption bands of 3,3′,4,4′-DPSDA and compound (3)n; Scheme S1: (a) the angular dianhydride that was employed in the reaction mixtures afforded compounds (1)n, (2)n and (3)n (the tetracarboxylic ligand was formed from the in situ hydrolysis of the dianhydride) and the coordination modes of STBA4− ligand in compounds (b) (1)n, (c) (2)n and (d) (3)n; Figure S1: powder X-ray diffraction patterns of the as-synthesized compound (1)n treated in various organic solvents, along with the simulated from single-crystal X-ray data; Figure S2: powder X-ray diffraction patterns of the as-synthesized compound (2)n treated in various organic solvents, along with the simulated from single-crystal X-ray data; Figure S3: powder X-ray diffraction patterns of the as synthesized compound (3)n treated in various organic solvents and H2O, along with the simulated from single-crystal X-ray data; Figure S4: IR spectra of 3,3′,4,4′-DPSDA and the as-synthesized compound (1)n; Figure S5: IR spectra of 3,3′,4,4′-DPSDA and the as-synthesized compound (2)n; Figure S6: IR spectra of 3,3′,4,4′-DPSDA and the as-synthesized compound (3)n; Figure S7: TGA graph of the as-synthesized compound (1)n; Figure S8: TGA graph of the as-synthesized compound (2)n; Figure S9: TGA graph of the as-synthesized compound (3)n; Figure S10: variable temperature powder X-ray diffraction patterns recorded under Ar flow of the compound (1)n treated with acetonitrile; Figure S11: variable temperature powder X-ray diffraction patterns recorded under Ar flow of the compound (2)n treated with acetonitrile; Figure S12: variable temperature powder X-ray diffraction patterns recorded under Ar flow of the compound (3)n treated with acetonitrile; Figure S13: (a,b) FE-SEM images, (c) particle size distribution histogram with the Gaussian fitting (solid red line) and d) EDS spectrum of compound (1)n treated with acetonitrile; Figure S14: (a,b) FE-SEM images and (c) EDS spectrum of as-synthesized compound (2)n treated with acetonitrile; Figure S15: (a,b) FE-SEM images, (c) particle size distribution histogram with the Gaussian fitting (solid red line) and (d) EDS spectrum of compound (3)n treated with acetonitrile; Figure S16: powder X-ray diffraction patterns of the as-synthesized, treated with acetonitrile and activated (collected after the completion of gas sorption studies) compound (2)n; Figure S17: powder X-ray diffraction patterns of the as-synthesized, treated with acetonitrile and activated (collected after the completion of gas sorption studies) compound (3)n; Figure S18: BET plot from CO2 adsorption isotherm at 195 K for compound (2)n; Figure S19: BET plot from CO2 adsorption isotherm at 195 K for compound (3)n; Figure S20: Langmuir plot from CO2 adsorption isotherm at 195 K for compound (2)n; Figure S21: Langmuir plot from CO2 adsorption isotherm at 195 K for compound (3)n; Figure S22: virial-type fitting of CO2 adsorption isotherms of compound (2)n at 273 K, 283 K and 298 K according to Equation (S1); Figure S23: virial-type fitting of CO2 adsorption isotherms of compound (3)n at 273 K, 283 K and 298 K according to Equation (S1); Figure S24: CO2 isosteric heat of adsorption in compound (2)n as a function of surface coverage; Figure S25: CO2 isosteric heat of adsorption in compound (3)n as a function of surface coverage. References [103,104,105,106,107,108,109] are cited in the Supplementary Materials.

Author Contributions

Conceptualization, E.E.M. and A.J.T.; synthetic methodology, R.P.M.; product isolation and characterization, R.P.M. and V.I.K.; data curation, R.P.M., N.P., V.I.K. and M.J.M.; writing—original draft preparation, R.P.M. and N.P.; writing—review and editing, M.J.M., E.E.M. and A.J.T.; supervision and project administration, E.E.M. and A.J.T. All authors have read and agreed to the published version of the manuscript.

Funding

This work was funded under the M-ERA.NET Call 2019 and the Republic of Cyprus through the Research and Innovation Foundation (contract no: P2P/M-ERA.NET/0319/0005; Acronym: SALMOS).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The original contributions presented in this study are included in the article/Supplementary Materials. Further inquiries can be directed to the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Férey, G. Hybrid Porous Solids: Past, Present, Future. Chem. Soc. Rev. 2008, 37, 191–214. [Google Scholar] [CrossRef]
  2. Kalmutzki, M.J.; Hanikel, N.; Yaghi, O.M. Secondary Building Units as the Turning Point in the Development of the Reticular Chemistry of MOFs. Sci. Adv. 2018, 4, eaat9180. [Google Scholar] [CrossRef]
  3. Eddaoudi, M.; Sava, D.F.; Eubank, J.F.; Adil, K.; Guillerm, V. Zeolite-like Metal–Organic Frameworks (ZMOFs): Design, Synthesis, and Properties. Chem. Soc. Rev. 2015, 44, 228–249. [Google Scholar] [CrossRef]
  4. Zhou, H.-C.J.; Kitagawa, S. Metal–Organic Frameworks (MOFs). Chem. Soc. Rev. 2014, 43, 5415–5418. [Google Scholar] [CrossRef]
  5. Valizadeh, B.; Nguyen, T.N.; Stylianou, K.C. Shape Engineering of Metal–Organic Frameworks. Polyhedron 2018, 145, 1–15. [Google Scholar] [CrossRef]
  6. Kumar, A.; Madden, D.G.; Lusi, M.; Chen, K.; Daniels, E.A.; Curtin, T.; Perry, J.J.; Zaworotko, M.J. Direct Air Capture of CO2 by Physisorbent Materials. Angew. Chem. Int. Ed. 2015, 54, 14372–14377. [Google Scholar] [CrossRef] [PubMed]
  7. Gehre, M.; Guo, Z.; Rothenberg, G.; Tanase, S. Sustainable Separations of C4-Hydrocarbons by Using Microporous Materials. ChemSusChem 2017, 10, 3947–3963. [Google Scholar] [CrossRef]
  8. Li, H.; Wang, K.; Sun, Y.; Lollar, C.T.; Li, J.; Zhou, H.-C. Recent Advances in Gas Storage and Separation Using Metal–Organic Frameworks. Mater. Today 2018, 21, 108–121. [Google Scholar] [CrossRef]
  9. Zhao, X.; Wang, Y.; Li, D.; Bu, X.; Feng, P. Metal–Organic Frameworks for Separation. Adv. Mater. 2018, 30, 1705189. [Google Scholar] [CrossRef]
  10. Yang, D.; Gates, B.C. Catalysis by Metal Organic Frameworks: Perspective and Suggestions for Future Research. ACS Catal. 2019, 9, 1779–1798. [Google Scholar] [CrossRef]
  11. Liu, J.; Goetjen, T.A.; Wang, Q.; Knapp, J.G.; Wasson, M.C.; Yang, Y.; Syed, Z.H.; Delferro, M.; Notestein, J.M.; Farha, O.K.; et al. MOF-Enabled Confinement and Related Effects for Chemical Catalyst Presentation and Utilization. Chem. Soc. Rev. 2022, 51, 1045–1097. [Google Scholar] [CrossRef] [PubMed]
  12. Hadjikyprianou, E.; Petrides, S.; Kourtellaris, A.; Tasiopoulos, A.J.; Georgiades, S.N. Catalysis of a Diels–Alder Reaction between Azachalcones and Cyclopentadiene by a Recyclable Copper(II)-PEIP Metal-Organic Framework. Materials 2023, 16, 5298. [Google Scholar] [CrossRef]
  13. Diamantis, S.A.; Margariti, A.; Pournara, A.D.; Papaefstathiou, G.S.; Manos, M.J.; Lazarides, T. Luminescent Metal–Organic Frameworks as Chemical Sensors: Common Pitfalls and Proposed Best Practices. Inorg. Chem. Front. 2018, 5, 1493–1511. [Google Scholar] [CrossRef]
  14. Dolgopolova, E.A.; Rice, A.M.; Martin, C.R.; Shustova, N.B. Photochemistry and Photophysics of MOFs: Steps towards MOF-Based Sensing Enhancements. Chem. Soc. Rev. 2018, 47, 4710–4728. [Google Scholar] [CrossRef] [PubMed]
  15. Olorunyomi, J.F.; Geh, S.T.; Caruso, R.A.; Doherty, C.M. Metal–Organic Frameworks for Chemical Sensing Devices. Mater. Horiz. 2021, 8, 2387–2419. [Google Scholar] [CrossRef]
  16. Wang, H.; Lustig, W.P.; Li, J. Sensing and Capture of Toxic and Hazardous Gases and Vapors by Metal–Organic Frameworks. Chem. Soc. Rev. 2018, 47, 4729–4756. [Google Scholar] [CrossRef]
  17. Li, J.; Wang, X.; Zhao, G.; Chen, C.; Chai, Z.; Alsaedi, A.; Hayat, T.; Wang, X. Metal–Organic Framework-Based Materials: Superior Adsorbents for the Capture of Toxic and Radioactive Metal Ions. Chem. Soc. Rev. 2018, 47, 2322–2356. [Google Scholar] [CrossRef]
  18. Kobielska, P.A.; Howarth, A.J.; Farha, O.K.; Nayak, S. Metal–Organic Frameworks for Heavy Metal Removal from Water. Coord. Chem. Rev. 2018, 358, 92–107. [Google Scholar] [CrossRef]
  19. Kumar, P.; Pournara, A.; Kim, K.-H.; Bansal, V.; Rapti, S.; Manos, M.J. Metal-Organic Frameworks: Challenges and Opportunities for Ion-Exchange/Sorption Applications. Prog. Mater. Sci. 2017, 86, 25–74. [Google Scholar] [CrossRef]
  20. Panagiotou, N.; Liatsou, I.; Pournara, A.; Angeli, G.K.; Giappa, R.M.; Tylianakis, E.; Manos, M.J.; Froudakis, G.E.; Trikalitis, P.N.; Pashalidis, I.; et al. Water-Stable 2-D Zr MOFs with Exceptional UO22+ Sorption Capability. J. Mater. Chem. A 2020, 8, 1849–1857. [Google Scholar] [CrossRef]
  21. Hanikel, N.; Kurandina, D.; Chheda, S.; Zheng, Z.; Rong, Z.; Neumann, S.E.; Sauer, J.; Siepmann, J.I.; Gagliardi, L.; Yaghi, O.M. MOF Linker Extension Strategy for Enhanced Atmospheric Water Harvesting. ACS Cent. Sci. 2023, 9, 551–557. [Google Scholar] [CrossRef]
  22. Huang, J.-J.; Yu, J.-H.; Xu, J.-Q. Structural Characterization of Three Semi-Rigid Tetracarboxylate-Containing Transition-Metal Coordination Polymers. Polyhedron 2016, 117, 126–132. [Google Scholar] [CrossRef]
  23. Bajpai, A.; Chandrasekhar, P.; Govardhan, S.; Banerjee, R.; Moorthy, J.N. Single Crystal-to-Single Crystal Site-Selective Postsynthetic Metal Exchange in a Zn–MOF Based on Semi-Rigid Tricarboxylic Acid and Access to Bimetallic MOFs. Chem. A Eur. J. 2015, 21, 2759–2765. [Google Scholar] [CrossRef]
  24. Fan, Y.; Si, C.-D.; Hou, C.; Yao, X.-Q.; Hu, D.-C.; Yang, Y.-X.; Liu, J.-C. Three Complexes of Manganese(II) Based on a New Semirigid Tetracarboxylate and N-Containing Ligands: Synthesis, Crystal Structures and Magnetic Properties. Polyhedron 2015, 98, 64–70. [Google Scholar] [CrossRef]
  25. Zhou, L.; Zhang, J.; Li, Y.-Z.; Du, H.-B. Synthesis and Properties of Four Coordination Polymers Built from a Semi-Rigid Tripod Carboxylic Acid. CrystEngComm 2013, 15, 8989. [Google Scholar] [CrossRef]
  26. Wang, T.; Zhang, C.; Ju, Z.; Zheng, H. Solvent-Induced Synthesis of Cobalt(II) Coordination Polymers Based on a Rigid Ligand and Flexible Carboxylic Acid Ligands: Syntheses, Structures and Magnetic Properties. Dalton Trans. 2015, 44, 6926–6935. [Google Scholar] [CrossRef] [PubMed]
  27. Mishra, R.; Ahmad, M.; Tripathi, M.R.; Butcher, R.J. Four Novel Coordination Polymers of Transition Metals Built Using a Semi Rigid Oxygen Donor Ligand: Crystal Structures, Novel Topology and Emission Studies. Polyhedron 2013, 50, 169–178. [Google Scholar] [CrossRef]
  28. Hou, X.; Tang, S.-F. Two New Two-Dimensional Layered Uranyl-Bearing Polycarboxylates from Semi-Rigid Tetracarboxylic Acids. RSC Adv. 2014, 4, 34716. [Google Scholar] [CrossRef]
  29. Wang, C.; Guo, G.; Wang, P. Two Sodium and Lanthanide(III) MOFs Based on Oxalate and V-Shaped 4,4′-Oxybis(Benzoate) Ligands: Hydrothermal Synthesis, Crystal Structure, and Luminescence Properties. J. Mol. Struct. 2013, 1032, 93–99. [Google Scholar] [CrossRef]
  30. Cheng, P.-C.; Tseng, F.-S.; Yeh, C.-T.; Chang, T.-G.; Kao, C.-C.; Lin, C.-H.; Liu, W.-R.; Chen, J.-S.; Zima, V. Synthesis, Structures, and Properties of Alkali and Alkaline Earth Coordination Polymers Based on V-Shaped Ligand. CrystEngComm 2012, 14, 6812. [Google Scholar] [CrossRef]
  31. He, J.-H.; Xiao, D.-R.; Yan, S.-W.; Sun, D.-Z.; Chen, H.-Y.; Wang, X.; Yang, J.; Ye, Z.-L.; Yuan, R.; Wang, E.-B. A Series of Novel 1D Coordination Polymers Constructed from Metal–Quinolone Complex Fragments Linked by Aromatic Dicarboxylate Ligands. Solid State Sci. 2012, 14, 1203–1210. [Google Scholar] [CrossRef]
  32. He, J.-H.; Sun, D.-Z.; Xiao, D.-R.; Yan, S.-W.; Chen, H.-Y.; Wang, X.; Yang, J.; Wang, E.-B. Syntheses and Structures of Five 1D Coordination Polymers Based on Quinolone Antibacterial Agents and Aromatic Polycarboxylate Ligands. Polyhedron 2012, 42, 24–29. [Google Scholar] [CrossRef]
  33. Sun, C.-Y.; Zheng, X.-J.; Chen, X.-B.; Li, L.-C.; Jin, L.-P. Assembly and Upconversion Luminescence of Lanthanide–Organic Frameworks with Mixed Acid Ligands. Inorganica Chim. Acta 2009, 362, 325–330. [Google Scholar] [CrossRef]
  34. Panagiotou, N.; Evangelou, K.; Psalti, A.; Varnava, N.; Angeli, G.K.; Trikalitis, P.N.; Plakatouras, J.C.; Lazarides, T.; Tasiopoulos, A.J. Improving the Cd2+ Detection Capability of a New Anionic Rare Earth Metal–Organic Framework Based on a [RE63-OH)8]10+ Secondary Building Unit: An Ion-Exchange Approach towards More Efficient Sensors. Mol. Syst. Des. Eng. 2020, 5, 1077–1087. [Google Scholar] [CrossRef]
  35. Gu, J.; Sun, X.; Kan, L.; Qiao, J.; Li, G.; Liu, Y. Structural Regulation and Light Hydrocarbon Adsorption/Separation of Three Zirconium–Organic Frameworks Based on Different V-Shaped Ligands. ACS Appl. Mater. Interfaces 2021, 13, 41680–41687. [Google Scholar] [CrossRef] [PubMed]
  36. Chen, X.-L.; Zhang, B.; Hu, H.-M.; Fu, F.; Wu, X.-L.; Qin, T.; Yang, M.-L.; Xue, G.-L.; Wang, J.-W. Three Novel Heterobimetallic Cd/Zn−Na Coordination Polymers: Syntheses, Crystal Structure, and Luminescence. Cryst. Growth Des. 2008, 8, 3706–3712. [Google Scholar] [CrossRef]
  37. Zeng, X.-S.; Chen, Y.; Deng, X.-F.; Li, X.; Xu, H.-L.; Yang, Q.; Hu, G.; Qiu, H.-J.; Xiao, D.-R. Two Porous Coordination Polymers Containing Helix-Based Metal-Organic Nanotubes Based on Trigonal N-Donor Ligand. Inorg. Chem. Commun. 2016, 72, 65–68. [Google Scholar] [CrossRef]
  38. Zhang, L.-P.; Ma, J.-F.; Yang, J.; Liu, Y.-Y.; Wei, G.-H. 1D, 2D, and 3D Metal−Organic Frameworks Based on Bis(Imidazole) Ligands and Polycarboxylates: Syntheses, Structures, and Photoluminescent Properties. Cryst. Growth Des. 2009, 9, 4660–4673. [Google Scholar] [CrossRef]
  39. Gong, Y.; Qin, J.; Wu, T.; Li, J.; Yang, L.; Cao, R. Synthesis, Structural Characterization and Anion-Sensing Studies of Metal(II) Complexes Based on 3,3′,4,4′-Oxydiphthalate and N-Donor Ligands. Dalton Trans. 2012, 41, 1961–1970. [Google Scholar] [CrossRef]
  40. Yao, S.; Yi, F.-Y.; Li, G.; Yu, Y.; Wang, J.; Liu, D.; Song, S.-Y. Syntheses, Structures, and Magnetic Properties of Cobalt(II) and Nickel(II) Coordination Polymers Based on a V-Shaped Ligand. J. Solid State Chem. 2017, 250, 6–13. [Google Scholar] [CrossRef]
  41. Kim, T.K.; Lee, J.H.; Moon, D.; Moon, H.R. Luminescent Li-Based Metal–Organic Framework Tailored for the Selective Detection of Explosive Nitroaromatic Compounds: Direct Observation of Interaction Sites. Inorg. Chem. 2013, 52, 589–595. [Google Scholar] [CrossRef]
  42. Zhou, J.-L.; Wang, Y.-Y.; Zhou, M.-J.; Qin, L.; Zhang, M.-D.; Yang, Q.-X.; Zheng, H.-G. A Three-Dimensional Non-Interpenetrated Porous Metal–Organic Framework Based on Cationic 1-D Chains. Inorg. Chem. Commun. 2014, 40, 148–150. [Google Scholar] [CrossRef]
  43. Yang, Q.; Chen, X.; Chen, Z.; Hao, Y.; Li, Y.; Lu, Q.; Zheng, H. Metal–Organic Frameworks Constructed from Flexible V-Shaped Ligands: Adjustment of the Topology, Interpenetration and Porosity via a Solvent System. Chem. Commun. 2012, 48, 10016. [Google Scholar] [CrossRef]
  44. Lee, J.H.; Kim, T.K.; Suh, M.P.; Moon, H.R. Solvent-Induced Single-Crystal to Single-Crystal Transformation of a Zn 4 O-Containing Doubly Interpenetrated Metal–Organic Framework with a Pcu Net. CrystEngComm 2015, 17, 8807–8811. [Google Scholar] [CrossRef]
  45. Eddaoudi, M.; Kim, J.; Vodak, D.; Sudik, A.; Wachter, J.; O’Keeffe, M.; Yaghi, O.M. Geometric Requirements and Examples of Important Structures in the Assembly of Square Building Blocks. Proc. Natl. Acad. Sci. USA 2002, 99, 4900–4904. [Google Scholar] [CrossRef] [PubMed]
  46. Bilgic, M.B.; Kocaarslan, A.; Kaya, K.; Atsay, A.; Svensson Grape, E.; Chen, J.; Yagci, Y. An Unusual Zig-Zag 2D Copper(I) Coordination Polymer as an Outstanding Catalyst for Azide–Alkyne “Click” Chemistry at Room Temperature. Dalton Trans. 2022, 51, 17543–17546. [Google Scholar] [CrossRef]
  47. Winterlich, M.; McHugh, D.; O’Toole, E.; Skordi, K.; O’Malley, C.; Sanii, R.; Tasiopoulos, A.; Erxleben, A.; Mayans, J.; Morrison, L.; et al. Expanding the NUIG MOF Family: Synthesis and Characterization of New MOFs for Selective CO2 Adsorption, Metal Ion Removal from Aqueous Systems, and Drug Delivery Applications. Dalton Trans. 2021, 50, 6997–7006. [Google Scholar] [CrossRef] [PubMed]
  48. Furukawa, H.; Kim, J.; Ockwig, N.W.; O’Keeffe, M.; Yaghi, O.M. Control of Vertex Geometry, Structure Dimensionality, Functionality, and Pore Metrics in the Reticular Synthesis of Crystalline Metal−Organic Frameworks and Polyhedra. J. Am. Chem. Soc. 2008, 130, 11650–11661. [Google Scholar] [CrossRef]
  49. Singh, B.; Mazumder, M.; Balendra; Sundaresan, A.; Pati, S.K.; Ramanan, A. Influence of Noncovalent Interactions on the Magnetic Behavior of Three Isostructural Layered Manganese(II) Dicarboxylate-Based Coordination Polymers. Cryst. Growth Des. 2022, 22, 2534–2546. [Google Scholar] [CrossRef]
  50. Mohmeyer, A.; Schaate, A.; Brechtken, B.; Rode, J.C.; Warwas, D.P.; Zahn, G.; Haug, R.J.; Behrens, P. Delamination and Photochemical Modification of a Novel Two-Dimensional Zr-Based Metal–Organic Frameworks. Chem. A Eur. J. 2018, 24, 12848–12855. [Google Scholar] [CrossRef]
  51. Xiao, D.; Wang, E.; An, H.; Li, Y.; Su, Z.; Sun, C. A Bridge between Pillared-Layer and Helical Structures: A Series of Three-Dimensional Pillared Coordination Polymers with Multiform Helical Chains. Chem. A Eur. J. 2006, 12, 6528–6541. [Google Scholar] [CrossRef]
  52. Zhang, J.; Li, Z.-J.; Kang, Y.; Cheng, J.-K.; Yao, Y.-G. Hydrothermal Syntheses, Crystal Structures, and Properties of a Novel Class of 3,3‘,4,4‘-Benzophenone-Tetracarboxylate (BPTC) Polymers. Inorg. Chem. 2004, 43, 8085–8091. [Google Scholar] [CrossRef]
  53. Wang, H.; Wang, Y.-Y.; Yang, G.-P.; Wang, C.-J.; Wen, G.-L.; Shi, Q.-Z.; Batten, S.R. A Series of Intriguing Metal–Organic Frameworks with 3,3′,4,4′-Benzophenonetetracarboxylic Acid: Structural Adjustment and pH-Dependence. CrystEngComm 2008, 10, 1583. [Google Scholar] [CrossRef]
  54. Chen, S.-M.; Lian, T.-T. Synthesis, Structure and Properties of a Microporous Cd(II) 3,3′,4,4′-Benzophenone-Tetracarboxylate Framework Material. Inorg. Chem. Commun. 2011, 14, 447–449. [Google Scholar] [CrossRef]
  55. Balendra; Banday, A.; Tewari, S.; Singh, B.; Murugavel, S.; Ramanan, A. Alkaline-Earth Metal Based Coordination Polymers Assembled from Two Different V-Shaped Ligands: Synthesis, Structure, and Dielectric Properties. Inorg. Chim. Acta 2019, 495, 118940. [Google Scholar] [CrossRef]
  56. Wang, X.; Liu, L.; Conato, M.; Jacobson, A.J. Amine-Templated Anionic Metal–Organic Frameworks with the 4,4′-(Hexafluoroisopropylidene) Bis(Benzoic Acid) Ligand. Cryst. Growth Des. 2011, 11, 2257–2263. [Google Scholar] [CrossRef]
  57. Bernini, M.C.; De Paz, J.R.; Snejko, N.; Sáez-Puche, R.; Gutierrez-Puebla, E.; Monge, M.Á. Unusual Magnetic Behaviors and Electronic Configurations Driven by Diverse Co(II) or Mn(II) MOF Architectures. Inorg. Chem. 2014, 53, 12885–12895. [Google Scholar] [CrossRef]
  58. Castillo-Blas, C.; López-Salas, N.; Gutiérrez, M.C.; Puente-Orench, I.; Gutiérrez-Puebla, E.; Ferrer, M.L.; Monge, M.Á.; Gándara, F. Encoding Metal–Cation Arrangements in Metal–Organic Frameworks for Programming the Composition of Electrocatalytically Active Multimetal Oxides. J. Am. Chem. Soc. 2019, 141, 1766–1774. [Google Scholar] [CrossRef] [PubMed]
  59. Bernini, M.C.; Platero-Prats, A.E.; Snejko, N.; Gutiérrez-Puebla, E.; Labrador, A.; Sáez-Puche, R.; Romero De Paz, J.; Monge, M.A. Tuning the Magnetic Properties of Transition Metal MOFs by Metal–Oxygen Condensation Control: The Relation between Synthesis Temperature, SBU Nuclearity and Carboxylate Geometry. CrystEngComm 2012, 14, 5493. [Google Scholar] [CrossRef]
  60. Huang, J.-J.; Xu, W.; Wang, Y.-N.; Yu, J.-H.; Zhang, P.; Xu, J.-Q. New 3-D Coordination Polymers Based on Semi-Rigid V-Shape Tetracarboxylates. J. Solid State Chem. 2015, 226, 206–214. [Google Scholar] [CrossRef]
  61. Zhong, R.-Q.; Zou, R.-Q.; Du, M.; Yamada, T.; Maruta, G.; Takeda, S.; Xu, Q. Controllable Preparation, Network Structures and Properties of Unusual Metal–Organic Frameworks Constructed from 4,4′-(Hexafluoroisopropylidene)Diphthalic Acid and 4,4′-Bipyridyl. Dalton Trans. 2008, 17, 2346–2354. [Google Scholar] [CrossRef]
  62. Zhang, L.-P.; Ma, J.-F.; Pang, Y.-Y.; Ma, J.-C.; Yang, J. Four Novel Topological Frameworks Based on 4,4′-(Hexafluoroisopropylidene)Diphthalic Acid and 1,1′-(1,4-Butanediyl)Bis(Imidazole) Ligand. CrystEngComm 2010, 12, 4433. [Google Scholar] [CrossRef]
  63. Thuéry, P.; Masci, B.; Harrowfield, J. Complexation of Uranyl and Rare-Earth Ions by a Fluorinated Tetracarboxylate. Formation of a Layered Assembly and Three-Dimensional Frameworks. Cryst. Growth Des. 2013, 13, 3216–3224. [Google Scholar] [CrossRef]
  64. Jiang, H.; Lin, Q.; Akita, T.; Liu, B.; Ohashi, H.; Oji, H.; Honma, T.; Takei, T.; Haruta, M.; Xu, Q. Ultrafine Gold Clusters Incorporated into a Metal–Organic Framework. Chem. A Eur. J. 2011, 17, 78–81. [Google Scholar] [CrossRef]
  65. Gupta, V.; Mandal, S.K. Design and Construction of a Chiral Cd(II)-MOF from Achiral Precursors: Synthesis, Crystal Structure and Catalytic Activity toward C–C and C–N Bond Forming Reactions. Inorg. Chem. 2019, 58, 3219–3226. [Google Scholar] [CrossRef]
  66. Gupta, V.; Mandal, S.K. Effect of Unsaturated Metal Site Modulation in Highly Stable Microporous Materials on CO2 Capture and Fixation. Inorg. Chem. 2022, 61, 3086–3096. [Google Scholar] [CrossRef]
  67. Turcan-Trofin, G.-O.; Avadanei, M.; Shova, S.; Vlad, A.; Cazacu, M.; Zaltariov, M.-F. Metallo-Supramolecular Assemblies of Dinuclear Zn(II) and Mn(II) Secondary Building Units (SBUs) and a Bent Silicon Dicarboxylate Ligand. Inorganica Chim. Acta 2018, 483, 454–463. [Google Scholar] [CrossRef]
  68. Gavrish, S.P.; Shova, S.; Gazacu, M.; Lampeka, Y.D. A 2D Coordination Polymerassembled from Nickel(II) Tetraazamacrocyclic Cation and 4,4′-(Dimethylsilanediyl)Diphthalate(3-) Linker. Acta Crystallogr. C Struct. Chem. 2020, 76, 419–426. [Google Scholar] [CrossRef]
  69. Senthil Raja, D.; Luo, J.-H.; Wu, C.-Y.; Cheng, Y.-J.; Yeh, C.-T.; Chen, Y.-T.; Lo, S.-H.; Lai, Y.-L.; Lin, C.-H. Solvothermal Synthesis, Structural Diversity, and Properties of Alkali Metal–Organic Frameworks Based on V-Shaped Ligand. Cryst. Growth Des. 2013, 13, 3785–3793. [Google Scholar] [CrossRef]
  70. Yeh, C.-T.; Lin, W.-C.; Lo, S.-H.; Kao, C.-C.; Lin, C.-H.; Yang, C.-C. Microwave Synthesis and Gas Sorption of Calcium and Strontium Metal–Organic Frameworks with High Thermal Stability. CrystEngComm 2012, 14, 1219. [Google Scholar] [CrossRef]
  71. Bhattacharya, S.; Ramanujachary, K.V.; Lofland, S.E.; Magdaleno, T.; Natarajan, S. Stabilization of O–Mn–O Clusters (Mn5) in Three Dimensionally Extended MOF Structures: Synthesis, Structure and Properties. CrystEngComm 2012, 14, 4323. [Google Scholar] [CrossRef]
  72. Panagiotou, N.; Moscoso, F.G.; Lopes-Costa, T.; Pedrosa, J.M.; Tasiopoulos, A.J. 2-Dimensional Rare Earth Metal–Organic Frameworks Based on a Hexanuclear Secondary Building Unit as Efficient Detectors for Vapours of Nitroaromatics and Volatile Organic Compounds. Inorg. Chem. Front. 2022, 9, 4850–4863. [Google Scholar] [CrossRef]
  73. Fu, F.; Li, D.-S.; Wu, Y.-P.; Gao, X.-M.; Du, M.; Tang, L.; Zhang, X.-N.; Meng, C.-X. A Versatile V-Shaped Tetracarboxylate Building Block for Constructing Mixed-Ligand Co(Ii) and Mn(Ii) Complexes Incorporating Various N-Donor Co-Ligands. CrystEngComm 2010, 12, 1227–1237. [Google Scholar] [CrossRef]
  74. Chen, B.; Zhao, X.; Putkham, A.; Hong, K.; Lobkovsky, E.B.; Hurtado, E.J.; Fletcher, A.J.; Thomas, K.M. Surface Interactions and Quantum Kinetic Molecular Sieving for H2 and D2 Adsorption on a Mixed Metal−Organic Framework Material. J. Am. Chem. Soc. 2008, 130, 6411–6423. [Google Scholar] [CrossRef] [PubMed]
  75. Botas, J.A.; Calleja, G.; Sánchez-Sánchez, M.; Orcajo, M.G. Effect of Zn/Co Ratio in MOF-74 Type Materials Containing Exposed Metal Sites on Their Hydrogen Adsorption Behaviour and on Their Band Gap Energy. Int. J. Hydrogen Energy 2011, 36, 10834–10844. [Google Scholar] [CrossRef]
  76. Wang, Y.; Fang, M.; Li, Y.; Liang, J.; Shi, W.; Chen, J.; Cheng, P. A Porous 3d-4f Heterometallic Metal–Organic Framework for Hydrogen Storage. Int. J. Hydrogen Energy 2010, 35, 8166–8170. [Google Scholar] [CrossRef]
  77. Wang, Y.; Cheng, P.; Chen, J.; Liao, D.-Z.; Yan, S.-P. A Heterometallic Porous Material for Hydrogen Adsorption. Inorg. Chem. 2007, 46, 4530–4534. [Google Scholar] [CrossRef]
  78. Wei, W.; Xia, Z.; Wei, Q.; Xie, G.; Chen, S.; Qiao, C.; Zhang, G.; Zhou, C. A Heterometallic Microporous MOF Exhibiting High Hydrogen Uptake. Microporous Mesoporous Mater. 2013, 165, 20–26. [Google Scholar] [CrossRef]
  79. Xu, Y.; Che, Y.; Cheng, F.; Zheng, J. Synthesis, Structures, and Adsorption Properties of Two New La III –Mg II Heterometallic Polymers. Eur. J. Inorg. Chem. 2011, 2011, 5299–5304. [Google Scholar] [CrossRef]
  80. Wang, D.; Liu, Z.; Xu, L.; Li, C.; Zhao, D.; Ge, G.; Wang, Z.; Lin, J. A Heterometallic Metal–Organic Framework Based on Multi-Nuclear Clusters Exhibiting High Stability and Selective Gas Adsorption. Dalton Trans. 2019, 48, 278–284. [Google Scholar] [CrossRef]
  81. Luo, F.; Yan, C.; Dang, L.; Krishna, R.; Zhou, W.; Wu, H.; Dong, X.; Han, Y.; Hu, T.-L.; O’Keeffe, M.; et al. UTSA-74: A MOF-74 Isomer with Two Accessible Binding Sites per Metal Center for Highly Selective Gas Separation. J. Am. Chem. Soc. 2016, 138, 5678–5684. [Google Scholar] [CrossRef] [PubMed]
  82. Chen, F.; Wang, Y.; Bai, D.; He, M.; Gao, X.; He, Y. Selective Adsorption of C2H2 and CO2 from CH4 in an Isoreticular Series of MOFs Constructed from Unsymmetrical Diisophthalate Linkers and the Effect of Alkoxy Group Functionalization on Gas Adsorption. J. Mater. Chem. A 2018, 6, 3471–3478. [Google Scholar] [CrossRef]
  83. Ferrando-Soria, J.; Serra-Crespo, P.; De Lange, M.; Gascon, J.; Kapteijn, F.; Julve, M.; Cano, J.; Lloret, F.; Pasán, J.; Ruiz-Pérez, C.; et al. Selective Gas and Vapor Sorption and Magnetic Sensing by an Isoreticular Mixed-Metal–Organic Framework. J. Am. Chem. Soc. 2012, 134, 15301–15304. [Google Scholar] [CrossRef]
  84. Zhai, Q.-G.; Bu, X.; Zhao, X.; Li, D.-S.; Feng, P. Pore Space Partition in Metal–Organic Frameworks. Acc. Chem. Res. 2017, 50, 407–417. [Google Scholar] [CrossRef]
  85. Takaishi, K.; Nath, B.D.; Yamada, Y.; Kosugi, H.; Ema, T. Unexpected Macrocyclic Multinuclear Zinc and Nickel Complexes That Function as Multitasking Catalysts for CO2 Fixations. Angew. Chem. 2019, 131, 10089–10093. [Google Scholar] [CrossRef]
  86. Gao, Z.; Liang, L.; Zhang, X.; Xu, P.; Sun, J. Facile One-Pot Synthesis of Zn/Mg-MOF-74 with Unsaturated Coordination Metal Centers for Efficient CO2 Adsorption and Conversion to Cyclic Carbonates. ACS Appl. Mater. Interfaces 2021, 13, 61334–61345. [Google Scholar] [CrossRef] [PubMed]
  87. Dong, L.; Zhang, L.; Liu, J.; Huang, Q.; Lu, M.; Ji, W.; Lan, Y. Stable Heterometallic Cluster-Based Organic Framework Catalysts for Artificial Photosynthesis. Angew. Chem. Int. Ed. 2020, 59, 2659–2663. [Google Scholar] [CrossRef] [PubMed]
  88. Xue, Y.-Y.; Zhang, J.-W.; Li, Y.-P.; Li, H.-P.; Wang, Y.; Li, S.-N.; Jiang, Y.-C.; Hu, M.-C.; Zhai, Q.-G. Mimic of Ferroalloy To Develop a Bifunctional Fe–Organic Framework Platform for Enhanced Gas Sorption and Efficient Oxygen Evolution Electrocatalysis. ACS Appl. Mater. Interfaces 2020, 12, 4432–4442. [Google Scholar] [CrossRef]
  89. Zhou, W.; Huang, D.; Wu, Y.; Zhao, J.; Wu, T.; Zhang, J.; Li, D.; Sun, C.; Feng, P.; Bu, X. Stable Hierarchical Bimetal–Organic Nanostructures as HighPerformance Electrocatalysts for the Oxygen Evolution Reaction. Angew. Chem. Int. Ed. 2019, 58, 4227–4231. [Google Scholar] [CrossRef]
  90. Iqbal, B.; Saleem, M.; Arshad, S.N.; Rashid, J.; Hussain, N.; Zaheer, M. One-Pot Synthesis of Heterobimetallic Metal–Organic Frameworks (MOFs) for Multifunctional Catalysis. Chem. A Eur. J. 2019, 25, 10490–10498. [Google Scholar] [CrossRef]
  91. Ouyang, Z.-J.; Mo, X.-Y.; Yang, M.; Zhong, L.; Chen, W.-B.; Gao, S.; Dong, W. High Temperature Fe(III) Spin Crossover Behaviours in Three Unprecedented FeIII–MII–FeIII (M = Fe, Cd) Linear Trinuclear Complexes. Inorg. Chem. Front. 2020, 7, 1526–1531. [Google Scholar] [CrossRef]
  92. Kawabata, S.; Nakabayashi, K.; Imoto, K.; Klimke, S.; Renz, F.; Ohkoshi, S. Second Harmonic Generation on Chiral Cyanido-Bridged FeII–NbIV Spin-Crossover Complexes. Dalton Trans. 2021, 50, 8524–8532. [Google Scholar] [CrossRef]
  93. Wang, R.; Wang, H.; Wang, J.; Bai, F.; Ma, Y.; Li, L.; Wang, Q.; Zhao, B.; Cheng, P. The Different Magnetic Relaxation Behaviors in [Fe(CN)6]3− or [Co(CN)6]3− Bridged 3d–4f Heterometallic Compounds. CrystEngComm 2020, 22, 2998–3004. [Google Scholar] [CrossRef]
  94. Fan, X.-T.; Yang, H.; Li, D.-C.; Tian, H.-Q.; Cao, F.; Dou, J.-M. Three New Heterometallic ZnII–LnIII Complexes with a Windmill-like Framework and Field-Induced SMM Behavior. New J. Chem. 2020, 44, 2555–2560. [Google Scholar] [CrossRef]
  95. Wu, Z.-L.; Dong, J.; Ni, W.-Y.; Zhang, B.-W.; Cui, J.-Z.; Zhao, B. Unique Chiral Interpenetrating d–f Heterometallic MOFs as Luminescent Sensors. Inorg. Chem. 2015, 54, 5266–5272. [Google Scholar] [CrossRef]
  96. Li, J.; Jin, Y.; Yang, Y.-Y.; Song, X.-Q. A Multifunctional CaII–EuIII Heterometallic Organic Framework with Sensing and Selective Adsorption in Water. Inorg. Chem. 2024, 63, 6871–6882. [Google Scholar] [CrossRef]
  97. Wang, X.; Wang, Y.; Silver, M.A.; Gui, D.; Bai, Z.; Wang, Y.; Liu, W.; Chen, L.; Diwu, J.; Chai, Z.; et al. Superprotonic Conduction through One-Dimensional Ordered Alkali Metal Ion Chains in a Lanthanide-Organic Framework. Chem. Commun. 2018, 54, 4429–4432. [Google Scholar] [CrossRef] [PubMed]
  98. Banerjee, D.; Zhang, Z.; Plonka, A.M.; Li, J.; Parise, J.B. A Calcium Coordination Framework Having Permanent Porosity and High CO2/N2 Selectivity. Cryst. Growth Des. 2012, 12, 2162–2165. [Google Scholar] [CrossRef]
  99. Machattos, R.P.; Panagiotou, N.; Tasiopoulos, A.J. Highlighting the Structure—Directing Capability of the Functional Groups of Angular Dicarboxylic Ligands: New 2-Dimensional Cu2+ MOFs from Analogous Synthetic Routes. Polyhedron 2021, 205, 115299. [Google Scholar] [CrossRef]
  100. Alvarez, S.; Alemany, P.; Casanova, D.; Cirera, J.; Llunell, M.; Avnir, D. Shape Maps and Polyhedral Interconversion Paths in Transition Metal Chemistry. Coord. Chem. Rev. 2005, 249, 1693–1708. [Google Scholar] [CrossRef]
  101. Sarkisov, L.; Bueno-Perez, R.; Sutharson, M.; Fairen-Jimenez, D. Materials Informatics with PoreBlazer v4.0 and the CSD MOF Database. Chem. Mater. 2020, 32, 9849–9867. [Google Scholar] [CrossRef]
  102. Lu, Y.-K.; Wang, H.-H.; Hu, Q.-X.; Ma, Y.-Y.; Hou, L.; Wang, Y.-Y. A Stable Cd(II)-Based MOF with Efficient CO2 Capture and Conversion, and Fluorescence Sensing for Ronidazole and Dimetridazole. J. Solid State Chem. 2021, 295, 121890. [Google Scholar] [CrossRef]
  103. Sheldrick, G.M. Crystal Structure Refinement with SHELXL. Acta Crystallogr. C Struct. Chem. 2015, 71, 3–8. [Google Scholar] [CrossRef]
  104. Oxford Diffraction. CrysAlis CCD and CrysAlis RED; Version P171.38.46; Oxford Diffraction Ltd.: Abingdon, UK, 2017. [Google Scholar]
  105. Farrugia, L.J. WinGX and ORTEP for Windows: An Update. J. Appl. Crystallogr. 2012, 45, 849–854. [Google Scholar] [CrossRef]
  106. Dolomanov, O.V.; Bourhis, L.J.; Gildea, R.J.; Howard, J.A.K.; Puschmann, H. OLEX2: A Complete Structure Solution, Refinement and Analysis Program. J. Appl. Crystallogr. 2009, 42, 339–341. [Google Scholar] [CrossRef]
  107. Brandenburg, K. DIAMOND; Version 2003.2001d; Crystal Impact GbR: Bonn, Germany, 2006. [Google Scholar]
  108. Czepirski, L.; Jagiello, J. Virial-Type Thermal Equation of Gas Solid Adsorption. Chem. Eng. Sci. 1988, 44, 787–801. [Google Scholar] [CrossRef]
  109. Sumida, K.; Rogow, D.L.; Mason, J.A.; McDonald, T.M.; Bloch, E.D.; Herm, Z.R.; Bae, T.-H.; Long, J.R. Carbon Dioxide Capture in Metal–Organic Frameworks. Chem. Rev. 2012, 112, 724–781. [Google Scholar] [CrossRef]
Figure 1. Representations of (a) part of the 1D chain SBU, (b) the inter-layer connection of the 2D nanosheets through hydrogen bonds involving the hydrogen atom of a benzene ring and the O atoms of the sulfonyl functional group of the STBA4− ligand along a axis and (c) the 2D nanosheets along the c axis showing the rhombic channels defined by two STBA4− anions and two chain SBUs of (1)n. Color code: Cd, green; S, yellow; O, red; C, gray; H, white.
Figure 1. Representations of (a) part of the 1D chain SBU, (b) the inter-layer connection of the 2D nanosheets through hydrogen bonds involving the hydrogen atom of a benzene ring and the O atoms of the sulfonyl functional group of the STBA4− ligand along a axis and (c) the 2D nanosheets along the c axis showing the rhombic channels defined by two STBA4− anions and two chain SBUs of (1)n. Color code: Cd, green; S, yellow; O, red; C, gray; H, white.
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Figure 2. Representations of (a) the 1D [CdCa(COO)4] helical chain SBU, (b) the connection of [CdCa(COO)4] SBUs via STBA4− ligands along c axis and (c) the space-filling model of compound (2)n along c axis. Color code: Cd, dark blue; Ca, turquoise; S, yellow; O, red; C, gray; H, white.
Figure 2. Representations of (a) the 1D [CdCa(COO)4] helical chain SBU, (b) the connection of [CdCa(COO)4] SBUs via STBA4− ligands along c axis and (c) the space-filling model of compound (2)n along c axis. Color code: Cd, dark blue; Ca, turquoise; S, yellow; O, red; C, gray; H, white.
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Figure 3. Representations of (a) the 1D [CdSr(COO)4] helical chain SBU, (b) the connection of [CdSr(COO)4] SBUs through STBA4− ligands along c axis and (c) the space-filling model of compound (3)n along c axis. Color code: Cd, dark blue; Sr, turquoise; S, yellow; O, red; C, gray; H, white.
Figure 3. Representations of (a) the 1D [CdSr(COO)4] helical chain SBU, (b) the connection of [CdSr(COO)4] SBUs through STBA4− ligands along c axis and (c) the space-filling model of compound (3)n along c axis. Color code: Cd, dark blue; Sr, turquoise; S, yellow; O, red; C, gray; H, white.
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Figure 4. CO2 adsorption isotherms measured at 195 K for (a) (2)n and (b) (3)n, and CO2 adsorption isotherms measured at 273 K, 283 K, and 298 K for (c) (2)n and (d) (3)n.
Figure 4. CO2 adsorption isotherms measured at 195 K for (a) (2)n and (b) (3)n, and CO2 adsorption isotherms measured at 273 K, 283 K, and 298 K for (c) (2)n and (d) (3)n.
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MDPI and ACS Style

Machattos, R.P.; Panagiotou, N.; Karagianni, V.I.; Manos, M.J.; Moushi, E.E.; Tasiopoulos, A.J. Homometallic 2D Cd2+ and Heterometallic 3D Cd2+/Ca2+, Cd2+/Sr2+ Metal–Organic Frameworks Based on an Angular Tetracarboxylic Ligand. Materials 2025, 18, 4647. https://doi.org/10.3390/ma18204647

AMA Style

Machattos RP, Panagiotou N, Karagianni VI, Manos MJ, Moushi EE, Tasiopoulos AJ. Homometallic 2D Cd2+ and Heterometallic 3D Cd2+/Ca2+, Cd2+/Sr2+ Metal–Organic Frameworks Based on an Angular Tetracarboxylic Ligand. Materials. 2025; 18(20):4647. https://doi.org/10.3390/ma18204647

Chicago/Turabian Style

Machattos, Rafail P., Nikos Panagiotou, Vasiliki I. Karagianni, Manolis J. Manos, Eleni E. Moushi, and Anastasios J. Tasiopoulos. 2025. "Homometallic 2D Cd2+ and Heterometallic 3D Cd2+/Ca2+, Cd2+/Sr2+ Metal–Organic Frameworks Based on an Angular Tetracarboxylic Ligand" Materials 18, no. 20: 4647. https://doi.org/10.3390/ma18204647

APA Style

Machattos, R. P., Panagiotou, N., Karagianni, V. I., Manos, M. J., Moushi, E. E., & Tasiopoulos, A. J. (2025). Homometallic 2D Cd2+ and Heterometallic 3D Cd2+/Ca2+, Cd2+/Sr2+ Metal–Organic Frameworks Based on an Angular Tetracarboxylic Ligand. Materials, 18(20), 4647. https://doi.org/10.3390/ma18204647

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