Coordination Complexes: Synthesis, Characterization and Application

A special issue of Crystals (ISSN 2073-4352). This special issue belongs to the section "Crystal Engineering".

Deadline for manuscript submissions: closed (30 April 2024) | Viewed by 14070

Special Issue Editors


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"C. D. Nenitzescu" Institute of Organic and Supramolecular Chemistry, Splaiul Independentei 202 B, 060023 Bucharest, Romania
Interests: crystal engineering; cocrystals; organic cages; coordination polymers; photoswitches; supramolecular chemistry

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Guest Editor
Organic Chemistry Department Chemistry Institute, Universidade Federal Fluminense, Niteroi, Brazil
Interests: quinolones; triazoles; fluorescent probes; photosensitizers; coordination polymers; anti-prion compounds; anti-cancer agents; water splitting; organic synthesis

Special Issue Information

Dear Colleagues,

Coordination polymers are solid-state structures constructed from metal ions (commonly d- or f- block metals) and bridging ligands, extending in one (1D), two (2D) or three dimensions (3D). The resulting networks are strongly influenced by the employed organic ligand(s) through the number, nature and position of the donor atoms, as well as the stereochemical preferences of the metal ions. When possessing voids able to accommodate guest molecules, two- and three-dimensional polymers are often referred to as metal-organic networks (MOFs). Following Robson’s seminal paper in the early 1990s, significant synthetic developments have been made that allowed isolation of specific structural topologies. The judicious selection of assembly units allows fine-tuning of properties or even the combination of multiple properties within the material. Thus, coordination polymers have promising applications in fields ranging from adsorption and separation processes to catalysis, sensor technologies, luminescence, magnetism, drug delivery, proton conductivity, non-linear optics, etc.

Dr. Simona Nica
Prof. Dr. Pedro Netto Batalha
Guest Editors

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Keywords

  • metal-organic frameworks
  • luminescence
  • magnetism
  • conducting materials
  • sensors

Published Papers (13 papers)

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Research

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19 pages, 4999 KiB  
Article
Energetic Features of H-Bonded and π-Stacked Assemblies in Pyrazole-Based Coordination Compounds of Mn(II) and Cu(II): Experimental and Theoretical Studies
by Mridul Boro, Trishnajyoti Baishya, Antonio Frontera, Miquel Barceló-Oliver and Manjit K. Bhattacharyya
Crystals 2024, 14(4), 318; https://doi.org/10.3390/cryst14040318 - 29 Mar 2024
Viewed by 680
Abstract
Two new coordination compounds comprising Mn(II) and Cu(II) viz. [Mn(bz)2(Hdmpz)2(H2O)] (1) and [Cu(crot)2(Hdmpz)2] (2) (where, bz = benzoate; crot = crotonate; Hdmpz = 3, 5-dimethyl pyrazole) were synthesized and [...] Read more.
Two new coordination compounds comprising Mn(II) and Cu(II) viz. [Mn(bz)2(Hdmpz)2(H2O)] (1) and [Cu(crot)2(Hdmpz)2] (2) (where, bz = benzoate; crot = crotonate; Hdmpz = 3, 5-dimethyl pyrazole) were synthesized and characterized. The characterization involved a single crystal X-ray diffraction technique, FT-IR spectroscopy, electronic spectroscopy, TGA, and elemental analyses. Compounds 1 and 2 crystallize as mononuclear entities of Hdmpz with penta-coordinated Mn(II) and hexa-coordinated Cu(II), respectively. These complexes exhibit distorted trigonal bipyramidal and distorted octahedral geometries, respectively. A crystal structure analysis of compound 1 elucidates the existence of C–H⋯π and π-stacking interactions alongside O–H⋯O, N–H⋯O, and C–H⋯O H-bonding interactions contributing to the stabilization of the compound’s layered assembly. Similarly, in compound 2, the crystal structure stability is attributed to the presence of hydrogen bonding in conjugation with π-stacking interactions. We conducted theoretical investigations to analyze π⋯π, H-bonding, and antiparallel CH···π non-covalent interactions observed in compounds 1 and 2. DFT calculations were performed to find out the strength of these interactions energetically. Moreover, QTAIM and non-covalent interaction (NCI) plot index theoretical tools were employed to characterize them and evaluate the contribution of the H-bonds. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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16 pages, 3479 KiB  
Article
Crystal and Molecular Structures of Two Phthalocyanines, Chloro(phthalocyaninato)gallium(III) (ClGaPc) and µ-Oxobis(phthalocyaninato)gallium(III) (PcGaOGaPc)
by Peter Zugenmaier
Crystals 2024, 14(2), 182; https://doi.org/10.3390/cryst14020182 - 12 Feb 2024
Viewed by 796
Abstract
The structure of µ-oxobis(phthalocyaninato)gallium(III) (PcGaOGaPc) and the structure of a second modification of chloro(phthalocyaninato)gallium(III) (ClGaPc) has been determined by single-crystal X-ray analysis. Sublimation of the respective compounds led to single crystals suitable for an X-ray study. Both compounds crystallize in the triclinic space [...] Read more.
The structure of µ-oxobis(phthalocyaninato)gallium(III) (PcGaOGaPc) and the structure of a second modification of chloro(phthalocyaninato)gallium(III) (ClGaPc) has been determined by single-crystal X-ray analysis. Sublimation of the respective compounds led to single crystals suitable for an X-ray study. Both compounds crystallize in the triclinic space group P1¯, with a unit cell for ClGaPc a = 13.770 Å, b = 13.770 Å, c = 14.039 Å, α = 98.32°, β = 108.64°, γ = 90.01°, containing four disordered molecules (Z = 4). The unit cell of the dimeric PcGaOGaPc contains one molecule, with half a molecule as an asymmetric moiety (Z = 2) and a = 7.848 Å, b = 12.529 Å, c = 12.720 Å, α = 91.03°, β = 94.94°, γ = 89.98°. The Ga atoms for the two ClGaPc molecules are placed 0.44 Å above the plane formed by the respective isoindole nitrogen N1 to N4. The two rings of the asymmetric unit (molecule 1 and 2) are arranged in parallel, with ca. 3.4 Å distance within the unit cell. The Ga-Cl bond distances are ca. 2.20 Å for the two molecules. The gallium of PcGaOGaPc is placed 0.49 Å above the respective isoindole nitrogen plane and the Ga-O bond amounts to 1.734 Å. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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11 pages, 2267 KiB  
Article
Synthesis, Crystal Structure, and Electrochemistry of Mono- and Bis-Homoannular Ferrocene Derivatives
by Uttam R. Pokharel, Derek P. Daigle, Stone D. Naquin, Gwyneth S. Engeron, Mary A. Lo and Frank R. Fronczek
Crystals 2024, 14(2), 141; https://doi.org/10.3390/cryst14020141 - 30 Jan 2024
Viewed by 1767
Abstract
Two ferrocene derivatives, namely, 1,2-(tetramethylene)-ferrocene and 1,2,1′,2′-bis(tetramethylene)-ferrocene, were synthesized in a four-step reaction sequence starting from ferrocene. Friedel–Crafts acylation of ferrocene using succinic anhydride gave mono- or bis(3-carboxypropinoyl)-ferrocene depending on the stoichiometry of succinic anhydride. The reduction of the keto groups to methylene [...] Read more.
Two ferrocene derivatives, namely, 1,2-(tetramethylene)-ferrocene and 1,2,1′,2′-bis(tetramethylene)-ferrocene, were synthesized in a four-step reaction sequence starting from ferrocene. Friedel–Crafts acylation of ferrocene using succinic anhydride gave mono- or bis(3-carboxypropinoyl)-ferrocene depending on the stoichiometry of succinic anhydride. The reduction of the keto groups to methylene followed by ring-closing using trifluoroacetic anhydride gave 1,2-(α-ketotetramethylene)-ferrocene or 1,2,1′,2′-bis(α-ketotetramethylene)-ferrocene. The diastereomeric mixture of the latter diketones was separated using column chromatography, characterized via single-crystal X-ray analysis, and assigned its stereochemistry. Reduction of the keto groups to methylene under Clemmensen conditions gave homoannular mono- or bis(tetramethylene)-ferrocene derivatives. The molecular structure of 1,2-(tetramethylene)-ferrocene revealed that the ipso carbon atoms of the cyclopentadienyl group are 0.023(3) Å farther away from Fe(II) compared to the remaining three carbon atoms. Both complexes exhibit lower half-wave oxidation potentials than ferrocene, possibly due to the electron-releasing effects of the tetramethylene bridges. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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17 pages, 3046 KiB  
Article
Mammalian Cell Cytotoxicity, Antibacterial Activity and the Properties of Methylenebis(Hydroxybenzoic Acid) and Its Related Zinc(II) Complex
by Ayman H. Ahmed, Ibrahim O. Althobaiti, Marwah Aljohani, Ehab S. Gad, Yazeed M. Asiri and Omar A. Hussein
Crystals 2024, 14(1), 88; https://doi.org/10.3390/cryst14010088 - 17 Jan 2024
Viewed by 936
Abstract
Formaldehyde, sulfuric acid and salicylic acid were combined to create a 3,3′-methylenebis(2-hydroxybenzoic acid) (MHB) ligand, which was subsequently permitted to bind with zinc(II) ions. The ligand and its zinc(II) complex (Zn–MHB) have been described by a combination of elemental analyses, spectral analyses (UV–Vis, [...] Read more.
Formaldehyde, sulfuric acid and salicylic acid were combined to create a 3,3′-methylenebis(2-hydroxybenzoic acid) (MHB) ligand, which was subsequently permitted to bind with zinc(II) ions. The ligand and its zinc(II) complex (Zn–MHB) have been described by a combination of elemental analyses, spectral analyses (UV–Vis, IR, MS and NMR), XRD, TEM, as well as TGA measurement. The ligand has been suggested to coordinate to the zinc center in a tetradentate manner forming the binuclear tetrahedral complex. An X-ray analysis indicated a considerable difference between MHB (crystalline) and Zn–MHB (amorphous). The UV–Vis spectra were used to determine the optical properties such as bandgap, refractive index, optical conductivity and penetration depth. The possibility of employing the samples for optoelectronic applications was indicated from the band gap values which underlie the range of semiconductors. TEM revealed the spherical shapes and mutation of ligand particles into the nano-scale by complexation. The antimicrobial potential of the MHB towards Gram-positive and Gram-negative bacterial growths has been investigated. The results suggested that it would be possible to employ MHB to prevent bacterial development, particularly that of salmonella typhimurium. The cytotoxicity of the MHB was assessed against two types of mammalian cells: VERO (the kidney of an African green monkey) and HFB4 (human skin melanocytes). Lower sensitivity was observed in VERO cells. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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8 pages, 2056 KiB  
Communication
Building Manganese Halide Hybrid Materials with 0D, 1D, and 2D Dimensionalities
by Anna Peoble, Kandee Gallegos, Michael O. Ozide and Raúl Castañeda
Crystals 2023, 13(12), 1634; https://doi.org/10.3390/cryst13121634 - 25 Nov 2023
Viewed by 979
Abstract
In recent years, metal-halide hybrid materials have attracted considerable attention because materials, such as lead-iodide perovskites, can have excellent properties as photovoltaics, light-emitting devices, and photodetectors. These materials can be obtained in different dimensionalities (1D, 2D, and 3D), which directly affects their properties. [...] Read more.
In recent years, metal-halide hybrid materials have attracted considerable attention because materials, such as lead-iodide perovskites, can have excellent properties as photovoltaics, light-emitting devices, and photodetectors. These materials can be obtained in different dimensionalities (1D, 2D, and 3D), which directly affects their properties. In this article, we built 0D, 1D, and 2D manganese halide materials with 3-aminopyridine (3AP) or 4-ethylpyridine (4EtP). Two isomorphic complexes with 3AP and manganese chloride ([MnCl2(3AP)4]) or manganese bromide ([MnBr2(3AP)4]) were obtained with the amino group in 3AP assisting in the formation of 0D structures via hydrogen bonding. By modifying the reaction conditions, 3AP can also be used to build a 2D coordination polymer with manganese chloride ([MnCl33AP] [3APH]+). Unlike 3AP, 4EtP does not provide the opportunity for hydrogen bonding, leading to the formation of two additional isomorphic compounds built of individual 1D chains with manganese chloride ({MnCl3(4EtP)2}n) and manganese bromide ({MnBr2(4EtP)2}n). In the visible region, the 0D and 1D manganese halide compounds have similar photoluminescence properties; however, 0D and 1D have different near-IR emissions. In conclusion, hydrogen-bonding groups can play a role in the formation of discrete manganese-halide units, 1D halide chains, or 2D polymeric sheets. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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11 pages, 3959 KiB  
Communication
Construction of Energetic Complexes Based on LLM-105 and Transition Metal Cations (Ni, Co, Mn, and Cu)
by Yiyi Xiao, Hui Huang, Jinkun Guo, Mi Yan, Liyuan Wei, Yu Liu, Shiliang Huang, Rufang Peng and Bo Jin
Crystals 2023, 13(11), 1587; https://doi.org/10.3390/cryst13111587 - 15 Nov 2023
Viewed by 914
Abstract
Energetic complexes represent a crucial research direction for the design and synthesis of novel energetic materials. In this work, 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105), a significant explosive compound with exceptional comprehensive properties, was selected as the ligand for coordinating with various metal ions. Four novel energetic [...] Read more.
Energetic complexes represent a crucial research direction for the design and synthesis of novel energetic materials. In this work, 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105), a significant explosive compound with exceptional comprehensive properties, was selected as the ligand for coordinating with various metal ions. Four novel energetic complexes, Ni(C4H3N6O5)2·DMF (1), Co(C4H3N6O5)2·2DMF (2), Mn(C4H3N6O5)3·3/2DMF (3), and Cu3(C4H2N6O5)3·3DMF (4) were successfully synthesized, and their crystal structures were identified by a single-crystal X-ray diffraction technique. The structural analyses illustrated that LLM-105 can form either a mononuclear metal complex after the deprotonation of one amino group or a trinuclear metal complex after the deprotonation of two amino groups. Compound 1 exhibits a planar quadrilateral geometry, while both compounds 2 and 3 display distorted octahedral configurations. Compound 4 has three metal centers and exhibits two coordination configurations of distorted tetragonal pyramid geometry and planar quadrilateral geometry. The detonation performances of compounds 14 were also theoretically calculated, revealing their favorable explosive properties. These findings emphasize the diverse coordination modes of LLM-105 and the structural variability and adjustability of its complexes, offering valuable insights for regulating both the structure and performance of the LLM-105 complex as well as researching its deprotonation. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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16 pages, 5574 KiB  
Article
Single-Crystal Structure Analysis of Three Novel Iron(II) Coordination Polymers with Bridging 1,3,5-Tris((1H-1,2,4-triazol-1-yl)methyl)benzene
by Aysenur Limon, Dustin N. Jordan, Till Strothmann, Laure P. Cuignet, Yann Garcia and Christoph Janiak
Crystals 2023, 13(11), 1574; https://doi.org/10.3390/cryst13111574 - 7 Nov 2023
Viewed by 1176
Abstract
Three novel iron(II) coordination polymers, namely [Fe(H2O)2(ttmb)2](ClO4)2·4H2O (1), [Fe(H2O)2(ttmb)2](BF4)2·4H2O (2) and [Fe(NCS)2(ttmb)2 [...] Read more.
Three novel iron(II) coordination polymers, namely [Fe(H2O)2(ttmb)2](ClO4)2·4H2O (1), [Fe(H2O)2(ttmb)2](BF4)2·4H2O (2) and [Fe(NCS)2(ttmb)2] (3), were synthesized with the linker 1,3,5-tris((1H-1,2,4-triazol-1-yl)methyl)benzene (ttmb). The single-crystal structures show that all three compounds form a double-chain structure with the adjacent iron atoms being bridged by two ttmb linkers. The iron(II) ions are octahedrally surrounded by four N4 donor atoms from the 1,2,4-triazol-1-yl groups of four different ttmb linkers which form an equatorial plane and two trans-coordinated aqua ligands in 1 and 2 or isothiocyanato ligands in 3 in the axial positions. In view of the neutral bridging ttmb linker, there is a non-coordinated counter-anion in 1 and 2 (ClO4 and BF4, respectively), and a coordinated NCS anion in 3. Compounds 1 and 2 are isostructural. Interestingly, the ttmb linker only utilizes two of its three potentially coordinating triazole groups. All iron(II) coordination networks are colorless or have a light-yellow color, being indicative of the high-spin state. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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10 pages, 4707 KiB  
Article
Synthesis, Crystal Structure, and Optical Properties of Mononuclear Eu(III) and Tb(III) Complexes Containing a Chalcone Ligand
by Valentin L. Virgil, Anamaria Hanganu and Augustin M. Mădălan
Crystals 2023, 13(9), 1406; https://doi.org/10.3390/cryst13091406 - 21 Sep 2023
Viewed by 710
Abstract
Chalcones are α,β-unsaturated ketones with great structural diversity and various applications. A chalcone produced by condensation of 2-acetylpyridine with 2-naphthaldehyde (L) was employed for synthesis of two mononuclear complexes: [Eu(L)(hfac)3(H2O)]·0.5CHCl3 and [Tb(L)(hfac)3], where [...] Read more.
Chalcones are α,β-unsaturated ketones with great structural diversity and various applications. A chalcone produced by condensation of 2-acetylpyridine with 2-naphthaldehyde (L) was employed for synthesis of two mononuclear complexes: [Eu(L)(hfac)3(H2O)]·0.5CHCl3 and [Tb(L)(hfac)3], where hfac is the hexafluoroacetylacetonate anion. The chalcone and complexes were structurally characterized by single-crystal X-ray diffraction. The chalcone acts as a chelating bidentate ligand. Luminescent properties of the ligand L and the complexes were investigated in the solid state. For these heteroleptic mononuclear complexes, the emission of the Eu(III) and Tb(III) ions was influenced by the excitation wavelength. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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10 pages, 2545 KiB  
Article
Synthesis, Crystal Structure, and Antifungal Activity of Quinazolinone Derivatives
by Rong Zeng, Cong Huang, Jie Wang, Yuan Zhong, Qingwen Fang, Shuzhen Xiao, Xuliang Nie, Shangxing Chen and Dayong Peng
Crystals 2023, 13(8), 1254; https://doi.org/10.3390/cryst13081254 - 14 Aug 2023
Cited by 1 | Viewed by 969
Abstract
In this paper, four new compounds with quinazolinone structure were designed and synthesized based on the special biological activity of quinazolinone. The four new compounds containing quinazolinone structures were synthesized using a one-pot method after intramolecular cyclization and dehydration catalyzed by aqueous methylamine [...] Read more.
In this paper, four new compounds with quinazolinone structure were designed and synthesized based on the special biological activity of quinazolinone. The four new compounds containing quinazolinone structures were synthesized using a one-pot method after intramolecular cyclization and dehydration catalyzed by aqueous methylamine solution. Their structures were characterized using 1H NMR, 13C NMR, FT-IR, and HRMS, and the crystal structure of 2a was characterized using X-ray diffraction. In their potential antifungal activity tests, it was found that the four newly synthesized compounds exhibited significant antifungal activity against all seven phytopathogenic fungi at concentrations of 150 and 300 mg/L. Among them, the target compound 2c showed the best inhibitory effect against Fusarium oxysporum f. sp. Niveum fungus, with 62.42% inhibition at a concentration of 300 mg/L. Compound 2c is expected to be a leading compound for the treatment of watermelon Fusarium wilt in the future, which is worth further study. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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20 pages, 8869 KiB  
Article
Crystal Nanoarchitectonics and Characterization of the Octahedral Iron(III)–Nitrate Complexes with Isomer Dimethylurea Ligands
by Kende Attila Béres, Zoltán Homonnay, Laura Bereczki, Zsolt Dürvanger, Vladimir M. Petruševski, Attila Farkas and László Kótai
Crystals 2023, 13(7), 1019; https://doi.org/10.3390/cryst13071019 - 27 Jun 2023
Cited by 2 | Viewed by 886
Abstract
Three octahedral iron(III) nitrate complexes with dimethylated urea ligand isomers, [hexakis(N,N’-dimethylurea-O)iron(III)] nitrate (compound 1), trans-[diaquatetrakis(N,N-dimethylurea-O)iron(III)] nitrate (compound 2), and [hexakis(N,N-dimethylurea-O)iron(III)] nitrate trihydrate (compound 3) were prepared and characterized [...] Read more.
Three octahedral iron(III) nitrate complexes with dimethylated urea ligand isomers, [hexakis(N,N’-dimethylurea-O)iron(III)] nitrate (compound 1), trans-[diaquatetrakis(N,N-dimethylurea-O)iron(III)] nitrate (compound 2), and [hexakis(N,N-dimethylurea-O)iron(III)] nitrate trihydrate (compound 3) were prepared and characterized with single crystal X-ray diffraction, IR, Raman and UV–Vis methods. In compounds 1 and 3, six dimethylurea ligands coordinate to the central FeIII ion via the oxygen in octahedral geometry and the ligands are arranged in a propeller-like manner, dividing the complex cations into two sides. In compound 1, the dimethylurea propellers screw in the opposite direction on the two sides of the complex and in compound 3, they are arranged with the same handedness on the two sides. The complexes have helical chirality. The two sides of the complex cations differ not only in the rotation direction of the ligands but also in the hydrogen bond formation. On one side of the complex cation, the ligands form intermolecular hydrogen bonds only with the crystal waters, meanwhile on the other side of the complex, the ligands form hydrogen bonds only with the nitrate ions. In compound 2, [Fe(N,N-dimethylurea)4(H2O)2]3+ cations form layers that are separated by interconnected NO3 ions forming a hydrogen bonding system and connecting the complex cations A-s and B-s. The three crystallographically different nitrate ions each form four hydrogen bonds in a way that they have one bidentate O atom and two monodentate O atoms; however, the anions differ in their hydrogen bonding. The spectroscopic characteristics of compound 2 were determined by IR measurements on the deuterated compound 2 as well. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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11 pages, 1589 KiB  
Article
Two-Dimensional Lattices with Lanthanoids, Anilato Ligands and Formamide
by Samia Benmansour, Antonio Hernández-Paredes, Kilian Defez-Aznar and Carlos J. Gómez-García
Crystals 2023, 13(6), 939; https://doi.org/10.3390/cryst13060939 - 11 Jun 2023
Cited by 1 | Viewed by 1922
Abstract
Here, we illustrate the use of formamide (fma) and anilato-type ligands to build two-dimensional lattices with lanthanoids. Thus, we describe the synthesis and crystal structure of four lattices formulated as [Ln2(C6O4X2)3(fma)6]·6fma [...] Read more.
Here, we illustrate the use of formamide (fma) and anilato-type ligands to build two-dimensional lattices with lanthanoids. Thus, we describe the synthesis and crystal structure of four lattices formulated as [Ln2(C6O4X2)3(fma)6]·6fma with Ln/X = La/Cl (1), La/Br (2), Eu/Cl (3), and Eu/Br (4), where C6O4X22− = dianion of 3,6-disubstituted-2,5-dihydroxy-1,4-benzoquinone with X = Cl (chloranilato) and X = Br (bromanilato). Single crystal X-ray analysis shows that the four compounds crystallize in the triclinic P-1 space group and present two-dimensional, very distorted hexagonal lattices with the lanthanoids ions in the vertex coordinated by three anilato ligands forming the sides of the distorted hexagons that appear as rectangles. The rectangles are disposed parallel to their long sides in a brick wall fashion. The nona-coordination of the lanthanoids is completed by three formamide molecules. These layered compounds include three additional formamide molecules per lanthanoid atom, located in the interlayer space inside the channels formed by the eclipsed packing of the layers. We discuss the differences observed among these compounds due to the change of the lanthanoid ion (La and Eu) and of the substituent group X in the anilato ligand (Cl and Br). Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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17 pages, 4874 KiB  
Article
Electrochemical Properties and Perspectives of Nickel(II) and Cobalt(II) Coordination Polymers-Aspects and an Application in Electrocatalytic Oxidation of Methanol
by Ivana Škugor Rončević, Marijo Buzuk, Boris-Marko Kukovec, Vesna Sokol, Maša Buljac and Nives Vladislavić
Crystals 2023, 13(5), 718; https://doi.org/10.3390/cryst13050718 - 24 Apr 2023
Viewed by 997
Abstract
The electrochemical sensing potential of two isostructural one-dimensional nickel(II) and cobalt(II) coordination polymers with 4,4′-bipyridine (4,4′-bpy) and 6-oxonicotinate (6-Onic), namely, {[Ni(4,4′-bpy)(H2O)4](6-Onic)2×2H2O}n and {[Co(4,4′-bpy)(H2O)4](6-Onic)2×2H2O}n, was [...] Read more.
The electrochemical sensing potential of two isostructural one-dimensional nickel(II) and cobalt(II) coordination polymers with 4,4′-bipyridine (4,4′-bpy) and 6-oxonicotinate (6-Onic), namely, {[Ni(4,4′-bpy)(H2O)4](6-Onic)2×2H2O}n and {[Co(4,4′-bpy)(H2O)4](6-Onic)2×2H2O}n, was investigated along with the polymers’ potential applications in the catalytic oxidation of methanol. The highly oxidative species from redox pairs Ni(II)/Ni(III) and Co(II)/Co(III) in these compounds represent catalytically active centres for oxidation of small molecules. A glassy carbon electrode (GCE) modified with a Ni polymer showed stability and reproducibility in 0.1 M NaOH, while the oxidation current inc 2reased with the increasing methanol concentration, suggesting that the Ni-polymer-modified electrode possess good sensing ability with respect to methanol. The GC electrode modified with the Co polymer is not reproducible and cannot be used for electroanalytical purposes under these experimental conditions. The GC electrode modified with the Ni polymer was successfully applied in the determination of methanol. This method showed favourable linear concentration dependence with a good sensitivity of 2.65 and 11.0 mA mM−1, a wide concentration range (0.001–4 mM), and a detection limit of 0.8 μM, which indicates its excellent application potential for methanol oxidation and thus its determination. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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Review

Jump to: Research

21 pages, 2123 KiB  
Review
Structural Aspects of Pt(η3–P1C2X1C2P2)(Y) Derivative Types
by Milan Melník, Veronika Mikušová and Peter Mikuš
Crystals 2023, 13(9), 1340; https://doi.org/10.3390/cryst13091340 - 1 Sep 2023
Viewed by 589
Abstract
In this structural study, structural data are classified and analyzed for almost seventy complexes of the general formula Pt(η3–P1X1P2)(Y) (X1 = O, N, C, S, Si) and (Y = various monodentate ligands), in which [...] Read more.
In this structural study, structural data are classified and analyzed for almost seventy complexes of the general formula Pt(η3–P1X1P2)(Y) (X1 = O, N, C, S, Si) and (Y = various monodentate ligands), in which the respective η3–P1X1P2 ligand forms a pair of five-membered metallocyclic rings with a common X1 atom of the P1C2X1C2P2 type. The present complexes crystallize in five crystal systems: trigonal (1×), tetragonal (1×), orthorhombic (11×), triclinic (18×), and monoclinic (39×). In 69 complexes, a η3 ligand with monodentate Y constructs a distorted square planar geometry around each Pt(II) atom. There is only one complex in which Pt(η3–P1Si1P2)(P3Ph3) constructs a trigonal–pyramidal geometry around a Pt(II) atom. The three P atoms construct a trigonal plane, and the Si atom occupies a pyramid. The structural data are discussed from various points of view, including the covalent radii of the atoms, the degree of distortion, and trans-influence. The trans-effect on the Pt-L bond distance also affects the L-PT-L bond angles, as well as the distortion of square planar geometry around Pt(II) atoms. Full article
(This article belongs to the Special Issue Coordination Complexes: Synthesis, Characterization and Application)
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