Special Issue "Crystal Structure Analysis of Supramolecular and Porous Solids"

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

Deadline for manuscript submissions: closed (31 December 2017)

Special Issue Editor

Guest Editor
Prof. Dmitriy V Soldatov

Department of Chemistry, University of Guelph, Canada
Website | E-Mail
Interests: supramolecular and nanoporous materials; molecular crystals and cocrystals; natural and synthetic polymers; self-assembly and crystal engineering; reactivity in the solid state

Special Issue Information

Dear Colleagues,

Supramolecular chemistry emerged as a powerful tool for chemists to create new materials from already known molecules. In a supramolecular solid, dissimilar molecules complement each other to build a new, highly organized structure, as seen in host–guest complexes, inclusion compounds, pharmaceutical co-crystals, supramolecular polymers, biomimetic materials, or mechanically interlocked molecular assemblies.

Supramolecular solids are a new target in materials science, where desired properties in a material can be predicted and generated through a specific arrangement of the molecules in the 3D structure. A range of physical (e.g., optical, electrical, magnetic), chemical (thermal stability, reactivity, catalysis) and biomedical (toxicity, bioavailability) properties have been created or tuned in various solids using this approach known as crystal engineering.

Porous solids, with uniform pores on molecular or nano scale, are produced from supramolecular solids. In the first step of this production, a guest template is used to shape a desired topology of pores with specific sorption, catalytic or ion-exchange capabilities. At a later stage, the guest template is removed to yield a zeolite, mesoporous silica, porous metal organic framework material, or porous material based on weaker interactions.

Crystal structure analysis is a primary characterization method in the design and study of supramolecular and porous solids. It provides the most critical information about the spatial arrangement of molecules in the crystal, topology and geometry of the cavity space, intermolecular interactions, as well as any changes in the structure induced by temperature, pressure or guest inclusion/removal. This Special Issue deals with all aspects of such research. The topics include, but are not limited to:

  • Design of new host molecules and host materials

  • Preparation and characterization of inclusion compounds

  • Design and characterization of co-crystals

  • Design of porous frameworks

  • Studies on weak intermolecular interactions in supramolecular solids

  • Studies on molecular disorder and dynamics in molecular crystals

  • Structural studies of phase transitions in supramolecular and porous solids

  • Database studies on supramolecular and porous solids

Prof. Dr. Dmitriy V Soldatov
Guest Editor

Manuscript Submission Information

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Keywords

  • supramolecular chemistry

  • crystal engineering

  • inclusion compounds

  • clathrates

  • cocrystals

  • metal organic frameworks

  • covalent organic frameworks

  • hydrogen-bonded organic frameworks

  • nanoporous materials

  • organic zeolites

  • pseudopolymorphism

  • phase transitions in crystals

Published Papers (13 papers)

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Research

Open AccessArticle Synthesis and Crystal Structures of Cadmium(II) Cyanide with Branched-Butoxyethanol
Crystals 2018, 8(5), 221; https://doi.org/10.3390/cryst8050221
Received: 27 December 2017 / Revised: 12 March 2018 / Accepted: 15 May 2018 / Published: 17 May 2018
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Abstract
Two novel 3D cadmium(II) cyanide coordination polymers with branched-butoxyethanol compounds (iBucel = iso-butoxyethanol, tBucel = tert-butoxyethanol), [{Cd(CN)2(iBucel)2}{Cd(CN)2(H2O)(iBucel)}2{Cd(CN)2}6∙2(iBucel)]nI and [{Cd(CN)2(H2O)1.06(tBucel)0.94
[...] Read more.
Two novel 3D cadmium(II) cyanide coordination polymers with branched-butoxyethanol compounds (iBucel = iso-butoxyethanol, tBucel = tert-butoxyethanol), [{Cd(CN)2(iBucel)2}{Cd(CN)2(H2O)(iBucel)}2{Cd(CN)2}6∙2(iBucel)]n I and [{Cd(CN)2(H2O)1.06(tBucel)0.94}{Cd(CN)2(tBucel)}2{Cd(CN)2}2∙1.06(tBucel)]n II, were synthesized and characterized by structural determination. Complex I contains two distinct Cd(II) coordination geometries: octahedral and tetrahedral. In contrast, complex II contains three distinct Cd(II) coordination geometries: octahedral, square-pyramidal, and tetrahedral. In the two complexes, branched-butoxyethanol molecules behave as both a ligand and a guest in the Cd(CN)2 cavities. The framework in I contains octahedral and tetrahedral Cd(II) in a 3:6 ratio. In I, the coordination environments of octahedral Cd(II) are cis-O-Cd-O. The framework in II contains octahedral, square-pyramidal, and tetrahedral Cd(II) in a 1:2:2 ratio. In II, the coordination environment of octahedral Cd(II) is disordered trans-O-Cd-O and the axial oxygen ligand is either a water or tBucel molecule. In II, the square-pyramidal Cd(II) geometry is formed by one tBucel ligand and four cyanide ligands. The Cd(CN)2 frameworks of the two complexes exhibit different structures. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle Tuning of Luminescent and Magnetic Properties via Metal Doping of Zn-BTC Systems
Crystals 2018, 8(4), 162; https://doi.org/10.3390/cryst8040162
Received: 18 March 2018 / Revised: 2 April 2018 / Accepted: 5 April 2018 / Published: 8 April 2018
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Abstract
In order to assess how metal doping affects the luminescence and magnetic properties of anionic Metal-Organic Frameworks (MOFs), seven single-metal doped MOFs {M-Zn-BTC}{Me2NH2+} (M = Co, Cu, Ni, Mn, Ca, Mg, Cd) and three dual-metal doped MOFs {Zn-M
[...] Read more.
In order to assess how metal doping affects the luminescence and magnetic properties of anionic Metal-Organic Frameworks (MOFs), seven single-metal doped MOFs {M-Zn-BTC}{Me2NH2+} (M = Co, Cu, Ni, Mn, Ca, Mg, Cd) and three dual-metal doped MOFs {Zn-M1-M2-BTC}{Me2NH2+} (M1 = Co, Cu; M2 = Ni, Co) were synthesized. Trace amounts of different metals were doped via addition of another metal salt during the synthetic process. All compounds retained the same crystal structure as that of the parent {Zn-BTC}{Me2NH2+} MOF, which was supported by single crystal and powder X-ray diffraction studies. Thermal Gravimetric Analysis (TGA) of these compounds also revealed that all MOFs had similar stability up to ~450 °C. Solid state photoluminescent studies indicated that {Zn-Mn-BTC}{Me2NH2+}, {Zn-Cd-BTC}{Me2NH2+}, and {Zn-Ca-BTC}{Me2NH2+} had a significant red shifting effect compared to the original {Zn-BTC}{Me2NH2+} MOF. Applications of this doping method to other MOF systems can provide an efficient way to tune the luminescence of such systems, and to obtain a desired wavelength for several applications such as sensors and white light LED materials. Because Zn, Co, Cu, Ni, Mg have magnetic properties, the effect of the doping metal atom on the magnetism of the {Zn-BTC}{Me2NH2+} networks was also studied. To characterize the magnetic behavior of the synthesized MOFs, we conducted low-temperature (10 K) saturation remanence experiments in a 3 Tesla applied field, with the principal goal of identifying the domain state of the synthesized materials (Zn, Zn-Co, Zn-Cu-Co, Zn-Cu-Ni, Zn-Mg, Zn-Mn, Zn-Ni-Co, Zn-Ni). During room/low temperature saturation magnetization experiments, Zn, Zn-Co, Zn-Cu-Co, and Zn-Cu-Ni systems yielded data indicative of superparamagnetic behavior, yet during zero field and field cooled experiments Zn-Co showed a slight paramagnetic effect, Zn showed no temperature dependence on warming and Zn-Cu-Co and Zn-Cu-Ni demonstrated only a slight temperature dependence on warming. These behaviors are consistent with ferromagnetic ordering. Zero field and field cooled experiments indicate that Zn-Mg and Zn-Ni have a ferromagnetic ordering and Zn-Mn and Zn-Ni-Co show paramagnetic ordering behavior. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle Structure and Magnetic Properties of a 1D Alternating Cu(II) Monomer―Paddlewheel Chain
Crystals 2018, 8(3), 114; https://doi.org/10.3390/cryst8030114
Received: 29 January 2018 / Revised: 18 February 2018 / Accepted: 26 February 2018 / Published: 28 February 2018
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Abstract
One-dimensional metal–organic coordination polymers make up a class of compounds with potential towards the development of practical, new magnetic materials. Herein, a rare example of an ABBABB coupled linear chain comprised of alternating dicopper(II) tetraacetate units bridged to copper(II) acetate monomer units via
[...] Read more.
One-dimensional metal–organic coordination polymers make up a class of compounds with potential towards the development of practical, new magnetic materials. Herein, a rare example of an ABBABB coupled linear chain comprised of alternating dicopper(II) tetraacetate units bridged to copper(II) acetate monomer units via axial η212 coordinated acetate is reported. Examination of the structure, determined by small molecule X-ray crystallography, shows that each Cu(II) ion is in a dx2–y2 magnetic ground state. Magnetic susceptibility and magnetization data were collected and, consistent with the structural interpretation, demonstrate that the Cu(II) dimer (paddlewheel) exhibits classic antiferromagnetic exchange, while the S = 1/2 Cu(II) monomer is uncompensated in the ground state (low temperature regime.) Data were therefore fitted to a modified Bleaney-Bowers model, and results were consistent with the only other reported chain in this class for which magnetic data are available. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle Incorporation of Hexanuclear Mn(II,III) Carboxylate Clusters with a {Mn6O2} Core in Polymeric Structures
Crystals 2018, 8(2), 100; https://doi.org/10.3390/cryst8020100
Received: 11 January 2018 / Revised: 12 February 2018 / Accepted: 15 February 2018 / Published: 17 February 2018
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Abstract
A new series of hexanuclear mixed-valent carboxylate coordination clusters of the type [Mn6O2(O2CR)10L4] (R = CMe3; CHMe2) featuring a {MnII4MnIII2(μ4-O)2} core of composition [Mn6O2(O2CCMe3)10(Me3CCO2H)3(EtOH)]•(Me3CCO2H) (1), [Mn6O2(O2CCMe3)10(Me3CCO2H)2 (EtOH)2]•2(EtOH) (2) and [Mn6O2(O2CCMe3)10(Me3CCO2H)2(MeOH)2]•2(MeOH)•H2O (3), and coordination polymers which incorporate such clusters, namely [Mn6O2(O2CCHMe2)10(pyz)(MeOH)2]n (4), {[Mn6O2(O2CCHMe2)10(pyz)1.5(H2O)]•0.5(H2O)}n (5),
[...] Read more.
A new series of hexanuclear mixed-valent carboxylate coordination clusters of the type [Mn6O2(O2CR)10L4] (R = CMe3; CHMe2) featuring a {MnII4MnIII2(μ4-O)2} core of composition [Mn6O2(O2CCMe3)10(Me3CCO2H)3(EtOH)]•(Me3CCO2H) (1), [Mn6O2(O2CCMe3)10(Me3CCO2H)2 (EtOH)2]•2(EtOH) (2) and [Mn6O2(O2CCMe3)10(Me3CCO2H)2(MeOH)2]•2(MeOH)•H2O (3), and coordination polymers which incorporate such clusters, namely [Mn6O2(O2CCHMe2)10(pyz)(MeOH)2]n (4), {[Mn6O2(O2CCHMe2)10(pyz)1.5(H2O)]•0.5(H2O)}n (5), and [Mn6O2(O2CCMe3)10(HO2CCMe3)2(en)]n (6), have been synthesized (where pyz = pyrazine, en = ethyl nicotinate). The modification of the cluster surface by a diverse combination of capped or bridging ligands attached to peripheral MnII atoms results in discrete clusters with a closed hydrophobic exterior shell in 1 and 2, supramolecular chains built through hydrogen bonded solvent molecule clusters in 3, linear coordination polymers in 4 and 6 or a ladder-like coordination polymer in 5. The H-bonded coordination polymers 4 and 5 form supramolecular layers in crystals. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle A Standard Structure for Bile Acids and Derivatives
Crystals 2018, 8(2), 86; https://doi.org/10.3390/cryst8020086
Received: 22 December 2017 / Revised: 31 January 2018 / Accepted: 1 February 2018 / Published: 6 February 2018
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Abstract
The crystal structures of two ester compounds (a monomer in its methyl ester form, with an amino isophthalic group, and a dimer in which the two steroid units are linked by a urea bridge recrystallized from ethyl acetate/methanol) derived from cholic acid are
[...] Read more.
The crystal structures of two ester compounds (a monomer in its methyl ester form, with an amino isophthalic group, and a dimer in which the two steroid units are linked by a urea bridge recrystallized from ethyl acetate/methanol) derived from cholic acid are described. Average bond lengths and bond angles from the crystal structures of 26 monomers and four dimers (some of them in several solvents) of bile acids and esters (and derivatives) are used for proposing a standard steroid nucleus. The hydrogen bond network and conformation of the lateral chain are also discussed. This standard structure was used to compare with the structures of both progesterone and cholesterol. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle Effect of Sorbitol Templates on the Preferential Crystallographic Growth of Isotactic Polypropylene Wax
Crystals 2018, 8(2), 59; https://doi.org/10.3390/cryst8020059
Received: 19 November 2017 / Revised: 11 January 2018 / Accepted: 22 January 2018 / Published: 26 January 2018
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Abstract
The crystallization of isotactic polypropylene wax (iPP) in the presence of different sorbitol structures was studied. Dibenzylidene Sorbitol (DBS), as well as two of its derivatives with one or two methyl groups in the DBS molecule (MDBS and DMDBS, respectively), were tested as
[...] Read more.
The crystallization of isotactic polypropylene wax (iPP) in the presence of different sorbitol structures was studied. Dibenzylidene Sorbitol (DBS), as well as two of its derivatives with one or two methyl groups in the DBS molecule (MDBS and DMDBS, respectively), were tested as nanometer-size fibrillar templates. The early nucleation stage and crystal morphology were analyzed in Real-Time Wide-Angle X-ray Scattering (WAXS) and polarized optical microscopy (POM). It was found that the iPP crystals showed an α-phase unit cell for the three different sorbitols. However, a preferential crystal growth in the plane (040) was observed for iPP–MDBS. The macrostructure morphology of the iPP–DBS and iPP–DMDBS wax compounds was spherulitic, while nodular macrocrystals were observed for the iPP–MDBS compound. It was concluded that the MDBS template promoted a lower interface energy because of its match with the c-axis of the iPP wax crystals, whereas, in the case of the DBS and DMDBS templates, the preferential plane was the (110), characteristic of the iPP spherulitic arrangement. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle Conductive Supramolecular Architecture Constructed from Polyoxovanadate Cluster and Heterocyclic Surfactant
Crystals 2018, 8(2), 57; https://doi.org/10.3390/cryst8020057
Received: 30 December 2017 / Revised: 12 January 2018 / Accepted: 22 January 2018 / Published: 25 January 2018
Cited by 2 | PDF Full-text (3648 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Proton-conductive solid electrolytes are significant for fuel-cell battery technology. Especially for use in motor vehicles, proton conductors which work at intermediate temperatures (373–673 K) under an anhydrous atmosphere are desired to improve the fuel cell stability and efficiency. Inorganic–organic hybrid supramolecular architectures are
[...] Read more.
Proton-conductive solid electrolytes are significant for fuel-cell battery technology. Especially for use in motor vehicles, proton conductors which work at intermediate temperatures (373–673 K) under an anhydrous atmosphere are desired to improve the fuel cell stability and efficiency. Inorganic–organic hybrid supramolecular architectures are a promising option for the realization of highly conductive proton conductors. Here, a hybrid layered crystal was synthesized for the first time by using an proton-containing decavanadate (V10) anion and a heterocyclic surfactant cation. A simple ion-exchange reaction led to the formation of an inorganic–organic hybrid of V10 by using dodecylpyridazinium (C12pda) as the heterocyclic surfactant. Single crystal X-ray analyses revealed that four C12pda cations were associated with one V10 anion, which was a diprotonated species forming a one-dimensional infinite chain structure through hydrogen bonds. Anhydrous proton conductivity was investigated by alternating current (AC) impedance spectroscopy in the range of 313–393 K, exhibiting a maximum value of 1.7 × 10−5 S cm−1 at 373 K. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle Two Supramolecular Inorganic–Organic Hybrid Crystals Based on Keggin Polyoxometalates and Crown Ethers
Crystals 2018, 8(2), 17; https://doi.org/10.3390/cryst8020017
Received: 13 December 2017 / Revised: 18 January 2018 / Accepted: 19 January 2018 / Published: 23 January 2018
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Abstract
New supramolecular structures were designed in this work using large-sized polyoxometalates (POMs) and crown-ether-based supramolecular cations selected as building blocks. Two novel supramolecular inorganic–organic hybrids [(3-F-4-MeAnis)([18]crown-6)]2[SMo12O40]•CH3CN (1) and [(4-IAnis)([18]crown-6)]3[PMo12O
[...] Read more.
New supramolecular structures were designed in this work using large-sized polyoxometalates (POMs) and crown-ether-based supramolecular cations selected as building blocks. Two novel supramolecular inorganic–organic hybrids [(3-F-4-MeAnis)([18]crown-6)]2[SMo12O40]•CH3CN (1) and [(4-IAnis)([18]crown-6)]3[PMo12O40]•4CH3CN (2) (3-F-4-MeAnis = 3-fluoro-4-methylanilinium and 4-IAnis = 4-iodoanilinium) were synthesized. Crystals 1 and 2 have been characterized by infrared spectroscopy (IR) and elemental analysis (EA). Based on X-ray diffraction analysis, Crystals 1 and 2 were constructed through noncovalent bonding interactions and belong to different space groups due to the difference of the building blocks used. Supramolecular cations formed due to strong N–H···O hydrogen bonding interactions between the six oxygen atoms of [18]crown-6 molecules and nitrogen atoms of anilinium derivatives. Crystal 1 has two different supramolecular cations with an anti-paralleled arrangement that forms a dimer through weak hydrogen bonding interactions between adjacent [18]crown-6 molecules. Crystal 2 has three independent supramolecular cations that fill large spaces between the [PMo12O40] polyoxoanions forming a rhombus-shape packing arrangement in the ac plane. Crystals 1 and 2 are unstable at room temperature. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle Salts and Co-Crystalline Assemblies of Tetra(4-Pyridyl)Ethylene with Di-Carboxylic Acids
Crystals 2018, 8(1), 41; https://doi.org/10.3390/cryst8010041
Received: 22 December 2017 / Revised: 9 January 2018 / Accepted: 15 January 2018 / Published: 17 January 2018
Cited by 1 | PDF Full-text (5277 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Tetraarylethylene derivatives are emerging as an increasingly important family of supramolecular building blocks in both solution phase and the solid state. The utility of tetraarylethylenes stems from appealing structural features (rigidity and symmetry) and their propensity to exhibit aggregation induced emission (AIE). In
[...] Read more.
Tetraarylethylene derivatives are emerging as an increasingly important family of supramolecular building blocks in both solution phase and the solid state. The utility of tetraarylethylenes stems from appealing structural features (rigidity and symmetry) and their propensity to exhibit aggregation induced emission (AIE). In an effort to investigate the luminescent sensing ability of heteroaromatic tetraarylethylenes, we previously prepared tetra(4-pyridyl)ethylene and characterized its solution phase AIE properties. We here report the successful incorporation of tetra(4-pyridyl)ethylene into three distinct salts and co-crystalline assemblies with three organic di-carboxylic acids (oxalic acid, malonic acid, and fumaric acid). Interactions between the tetra(pyridyl)ethylene and di-acid components were found to vary from conventional to charge-assisted hydrogen bonding according to the extent of proton transfer between the acid and pyridine groups. Notably, the formation of pyridinium-carboxylate adducts in the salts does not appear to be strongly correlated with acid pKa. Three distinct network topologies were observed, and all featured the bridging of two or three tetra(pyridyl)ethylene groups through di-acid linkers. Crystalline assemblies also retained the AIE activity of tetra(pyridyl)ethylene and were luminescent under UV light. As tetra(4-pyridyl)ethylene features four Lewis basic and potentially metal ligating pyridine rings in a relatively well-defined geometry, this compound represents an attractive building block for the design of additional crystalline organic and metal–organic functional materials. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle A Robust Framework Based on Polymeric Octamolybdate Anions and Copper(II) Complexes of Tetradentate N-donor Ligands
Crystals 2018, 8(1), 20; https://doi.org/10.3390/cryst8010020
Received: 14 December 2017 / Revised: 3 January 2018 / Accepted: 4 January 2018 / Published: 6 January 2018
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Abstract
A new organic-inorganic compound based on octamolybdate building blocks and copper(II) complexes of tetradentate N-donor ligands has been hydrothermally synthesized, namely [Cu(cyclam)]2[Mo8O26]·1.5H2O (1), (cyclam: 1,4,8,11–tetraazacyclotetradecane). Compound 1 has been chemically (elemental and thermal
[...] Read more.
A new organic-inorganic compound based on octamolybdate building blocks and copper(II) complexes of tetradentate N-donor ligands has been hydrothermally synthesized, namely [Cu(cyclam)]2[Mo8O26]·1.5H2O (1), (cyclam: 1,4,8,11–tetraazacyclotetradecane). Compound 1 has been chemically (elemental and thermal analyses), spectroscopically (infrared spectroscopy), and structurally (single crystal and powder X-ray diffraction) characterized. The crystal packing of 1 shows a covalent framework structure formed by [Mo8O26]n4n− chains running along the 100 direction which are linked to each other through the coordination spheres of {Cu(cyclam)}2+ complexes leading to a three-dimensional open network. This structural assembly generates voids that can be described as a succession of cavities communicated through narrow bottlenecks with approximate cross section of 4 × 7 Å2 where the hydration water molecules are hosted. The robust open structure of 1 remains virtually unaltered upon thermal evacuation of guest solvent molecules at 130 °C, resulting in the anhydrous phase [Cu(cyclam)]2[Mo8O26] (1a) with potentially accessible micropores as demonstrated by single-crystal X-ray diffraction measurements. Electron paramagnetic resonance spectroscopy analysis of 1 has also been assessed. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle Synthesis and Luminescence Properties of New Metal-Organic Frameworks Based on Zinc(II) Ions and 2,5-Thiophendicarboxylate Ligands
Crystals 2018, 8(1), 7; https://doi.org/10.3390/cryst8010007
Received: 29 November 2017 / Revised: 21 December 2017 / Accepted: 22 December 2017 / Published: 24 December 2017
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Abstract
Six new metal-organic frameworks based on 2,5-thiophendicarboxylate (tdc2–) and zinc(II) ions were prepared in different reaction conditions, and their crystal structures were determined by XRD analysis. The compound [Zn(tdc)(dabco)(H2O)]∙DMF (1) is based on mononuclear Zn(II) ions connected
[...] Read more.
Six new metal-organic frameworks based on 2,5-thiophendicarboxylate (tdc2–) and zinc(II) ions were prepared in different reaction conditions, and their crystal structures were determined by XRD analysis. The compound [Zn(tdc)(dabco)(H2O)]∙DMF (1) is based on mononuclear Zn(II) ions connected by tdc2– and dabco linkers into square-grid layered nets. The compound [Zn3(tdc)3(dabco)2] (2) is a rare example of monocoordinated dabco ligands in the metal-organic framework chemistry. Its crystal structure contains trinuclear linear carboxylate building units, connected into a distorted primitive cubic net. Similar trinuclear units were also found in [Zn5(tdc)4(Htdc)2(dabco)2]∙4DMF∙14H2O (3), although as a part of more complicated pentanuclear motives. The compound [Na2Zn(tdc)2(DMF)2] (4), quantitatively isolated by the addition of NaOH to the mixture of Zn(NO3)2 and H2tdc, is based on 1D chain motives, interconnected by tdc2– linkers into a three-dimensional framework. The compounds [Zn3(tdc)3(DMF)2]∙0.8DMF∙1.1H2O (5) and [Zn3(tdc)3(DMF)3]∙0.8DMF∙1.3H2O (6) were prepared in very similar reaction conditions, but with different times of heating, indirectly indicating higher thermodynamic stability of the three-dimensional metal-organic framework 6, compared to the two-dimensional metal-organic framework 5. The crystal structures of both 5 and 6 are based on the same trinuclear linear units as in 2. Luminescence properties of the compounds 46 were studied and compared with those for Na2tdc salt. In particular, the luminescence spectra of 4 practically coincide with those for the reference Na2tdc, while 5 and 6 exhibit coherent shifts of peaks to higher energies. Such hypsochromic shifts are likely associated with a different effective charge on the tdc2– anions in Na2tdc and sodium-containing 4, compared to zinc-based 5 and 6. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle Breathing 3D Frameworks with T-Shaped Connecting Ligand Exhibiting Solvent Induction, Metal Ions Effect and Luminescent Properties
Crystals 2017, 7(10), 311; https://doi.org/10.3390/cryst7100311
Received: 18 August 2017 / Revised: 6 October 2017 / Accepted: 13 October 2017 / Published: 17 October 2017
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Abstract
To study the structural effects in three-dimensional porous coordination polymers, three novel flexible porous coordination polymers—[Cd2(bpdc)2](DMF)3(H2O) (1) and [M(bpdc)](DMF)(H2O) (M = Cd (2), Zn (3))—have been synthesized
[...] Read more.
To study the structural effects in three-dimensional porous coordination polymers, three novel flexible porous coordination polymers—[Cd2(bpdc)2](DMF)3(H2O) (1) and [M(bpdc)](DMF)(H2O) (M = Cd (2), Zn (3))—have been synthesized under solvothermal conditions with d10 block metal ions and T-shaped connecting ligand. Complexes 13 crystallize in different space groups, but they display the same ant network. The first two complexes can transform into each other via the alteration of guest, whereas complex 3 shows no structural change. The structural details reveal that the size of metal ions might be responsible for the transformation of porous frameworks. Furthermore, luminescent properties have been explored, and a guest-dependent shift of emission peaks was observed, suggesting potential application of the complexes as a probe. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Open AccessArticle Substituent Effects on the Crystal Structures of Salts Prepared from (R)-2-Methoxy-2-(1-naphthyl)propanoic Acid and (R)-1-Arylethylamines
Crystals 2017, 7(9), 263; https://doi.org/10.3390/cryst7090263
Received: 26 July 2017 / Revised: 15 August 2017 / Accepted: 22 August 2017 / Published: 28 August 2017
Cited by 1 | PDF Full-text (13279 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The crystal structures of salts 69 prepared from (R)-2-methoxy-2-(1-naphthyl)propanoic acid [(R)-MαNP acid, (R)-1] and (R)-1-arylethylamines [salt 6, (R)-1-(4-methoxyphenyl)ethylamine∙(R)-1; salt 7, (R)-1-(4-fluorophenyl)ethylamine∙(
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The crystal structures of salts 69 prepared from (R)-2-methoxy-2-(1-naphthyl)propanoic acid [(R)-MαNP acid, (R)-1] and (R)-1-arylethylamines [salt 6, (R)-1-(4-methoxyphenyl)ethylamine∙(R)-1; salt 7, (R)-1-(4-fluorophenyl)ethylamine∙(R)-1; salt 8, (R)-1-(4-chlorophenyl)ethylamine∙(R)-1; and salt 9, (R)-1-(3-chlorophenyl)ethylamine∙(R)-1] were elucidated by X-ray crystallography. The solid-state associations and conformations of the MαNP salts were defined using the concepts of supramolecular- and planar chirality, respectively, and the crystal structures of salts 69 were interpreted as a three-step hierarchical assembly. The para-substituents of the (R)-1-arylethylammonium cations were found on sheet structures consisting of 21 columns. Thus, salts possessing smaller para-substituents, that is, salt 7 (p-F) and salt 9 (p-H), and larger para-substituents, that is, salt 6 (p-OMe) and salt 8 (p-Cl), crystallized in the space groups P21 and C2, respectively. Additionally, weak intermolecular interactions, that is, aromatic C–H···π, C–H···F, and C–H···O interactions, were examined in crystalline salts 69. Full article
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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