Guest Solvent Molecules Research Articles

A Robust Framework Based on Polymeric Octamolybdate Anions and Copper(II) Complexes of Tetradentate N-donor Ligands

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.

Solvent Dependent Disorder in M2(BzOip)2(H2O)·Solvate (M = Co or Zn)

Coordination polymers derived from 5-benzyloxy isophthalic acid (H2BzOip) are rare, with only three reported that do not contain additional bridging ligands, of which two M2(BzOip)2(H2O) (M = Co and Zn) are isomorphous. It was hoped that by varying the solvent system in a reaction between H2BzOip and M(OAc)2 (M = Co and Zn), from water to a water/alcohol mixture, coordination polymers of different topology could be formed. Instead, two polymorphs of the existing M2(BzOip)2(H2O) (M = Co and Zn) were isolated from aqueous methanol and aqueous ethanol, in which a small number of guest solvent molecules are present in the crystals. These guest water molecules disrupt the hexaphenyl embrace motif, leading to varying degrees of disorder of the benzyl groups.

Heterometallic Hybrid Open Frameworks: Synthesis and Application for Selective Detection of Nitro Explosives

Three inorganic–organic hybrid open frameworks based on heterometallic cluster building blocks, formulated as Cd2Cs3(NDC)3(OAc)(DMA)2(H2O) (1), [NH2(CH3)2]2·Cd2Mg(NDC)4·Gx (2), and [NH2(CH3)2]3·Cd2K(NDC)4·Gx (3) (H2NDC = 2,6-naphthalenedicarboxylic acid, G = guest solvent molecule), were synthesized under solvothermal conditions. Compound 1 has a pillared layered structure featuring inorganic hcb-type layers with 14-ring windows and simultaneously exhibits a 3D open framework constructed from two types of heterometallic clusters, i.e., {Cd2Cs2O18} and {CdCs4O18}, and the NDC2– ligand. Compounds 2 and 3 are constructed from linear trinuclear {Cd2M} (M = Mg and K) building blocks and the NDC2– ligand, featuring 1D square channels with rld-z topology. Of the three heterometallic hybrid open frameworks, compounds 1 and 2 exhibited strong blue-light emission due to the presence of fluorescent organic ligands in the anionic frameworks, and more importantly, their strong fluorescence could be selectively quenche...

Synthesis, crystal structure and magnetic properties of a dinuclear dysprosium single-molecule magnet

To seek novel dysprosium based single-molecule magnets, a dinuclear dysprosium complex, namely [Dy2(L)2(DBM)2(DMF)2]·2DMF (1) was successfully obtained by employing tridentate Schiff base ligand (where H2L=2-hydroxy-N′’-(2-hydroxy-3-methoxybenzylidene) benzohydrazide), HDBM=dibenzoylmethane, DMF=dimethylformamide). Single-crystal X-ray structural analysis reveals that the key feature of 1 is neutral dinuclear complex, in which two Dy(III) ions with eight-coordinated environment are bridged by two phenoxido oxygen atoms from two Schiff base ligands. Interestingly, complex 1 could be regarded as the structurally related derivatives to our previous reported complex of [Dy2(L)2(DBM)2(DMF)2] (1a) but adding two guest DMF solvents. More importantly, the energy barrier to magnetic relaxation of 1 is slightly higher, with a value of 33K, when compared to the corresponding complex 1a of 24K, which provides a good example towards regulating magnetization dynamics in dinuclear dysprosium (III) single-molecule magnets by guest solvent molecules.

Solvatomorphs of 25,26,27,28-tetrahydroxycalix[4]arene and 5,11,17,23-tetramino-25,26,27,28-tetrabutoxycalix[4]arene: quenching photoluminescence through switching the guest

Here, we have disclosed two solid state forms of 5,11,17,23-tetramino-25,26,27,28-tetrabutoxycalix[4]arene (1) and two solid state forms of the non-functionalized 25,26,27,28-tetrahydroxycalix[4]arene (2). This is the first structural knowledge of a tetra-amino functionalized calixarene derivative, even though this compound is well known and used as a precursor of several other functionalized calix[4]arenes. The two solid forms of 1 differ by the presence of either water or water/dimethylsulfoxide (DMSO) solvent molecules entrapped in the major calixarene cavity, even though the pinched conformation is adopted in both forms as a consequence of the contacts between solvent molecules and phenyl rings. Likewise, the switch from water to DMSO in the cone cavity of 1 has abrogated the photoluminescence (PL) found only in the dihydrate form. Frontier molecular orbital calculations at the B3LYP/6-31G* level of theory support a short-range electron transfer between guest (DMSO) and host (1) molecules quenching the solid state photoluminescence when DMSO is entrapped in the cone. This solvatomorphism approach for PL search in calixarenes opens a perspective on tuning and even increasing the performance of calixarenes through changing the guest solvent molecule. Similarly, the two crystal forms of 2 entrap either methyl alcohol or DMSO in their cones, which, as well as both crystal forms of 1, are packed into sheets through different fashions and contact patterns.

Flexible Porous Coordination Polymers from Divergent Photoluminescent 4-Oxo-1,8-naphthalimide Ligands.

Two new luminescent ditopic naphthalimide-derived ligands, N-(4-cyanophenylmethylene)-4-(4-cyanophenoxy)-1,8-naphthalimide (L3) and N-(4-carboxyphenylmethylene)-4-(4-carboxyphenoxy)-1,8-naphthalimide (H2L4), have been prepared, and their coordination chemistry has been explored in the synthesis of three new coordination polymer materials. Complex poly-[Ag(L3)2]BF4·4.5H2O·0.5THF (1) is a 3-fold 2D → 2D parallel interpenetrated coordination polymer in which three interwoven sheets define inter- and intralayer channels containing anions and solvent molecules. Molecules of L3 interact in 1 through dominant head-to-head π-π stacking interactions, in an opposite aggregation mode to that observed in the free ligand in the crystalline phase. Complexes poly-[Cu(L4)(OH2)]·2DMF·0.5H2O (2) and poly-[Cd2(L4)2(OH2)2]·1.5DMF·3H2O (3) are related noninterpenetrated two-dimensional coordination polymers defined by one-dimensional metal-carboxylate chains, forming layers that interdigitate with adjacent networks through naphthalimide π-π interactions. Both materials undergo structural rearrangements on solvent exchange with acetonitrile; in the case of 3, this transformation can be followed by single-crystal X-ray diffraction, revealing the structure of the acetonitrile solvate poly-[Cd2(OH2)2(L4)2]·2MeCN (4), which shows a significant compression of the primary channels to accommodate the solvent guest molecules. Both materials display modest CO2 adsorption after complete evacuation, and the original expanded phases can be regenerated by reimmersion in DMF. The photophysical properties of each ligand and complex were also explored, which revealed variations in emission wavelength, based on solid-state interactions, including a notable shift in the fluorescence emission band of 3 upon structural rearrangement to 4.

Solvent-Controlled Assembly of Ionic Metal–Organic Frameworks Based on Indium and Tetracarboxylate Ligand: Topology Variety and Gas Sorption Properties

Four metal–organic frameworks (MOFs) based on indium and a tetracarboxylate ligand have been synthesized through regulation of the reaction solvent conditions. The resultant compounds exhibited not only rich structural topologies (pts, soc, and unique topologies) but also interesting charge reversal framework features. By regulating the solvent, different building units (indium monomer, trimer) have been generated in situ, and they are connected with the ligand to form ionic frameworks 1–4, respectively. Among the synthesized four ionic frameworks, compounds 3 and 4 maintained keep their crystallinity upon heating temperature up to 300 °C and full removal of solvent guest molecules. Particularly, they also exhibit the charge reversal framework features (3 adopts an overall cationic framework, whereas 4 has an anionic framework). Both compounds 3 and 4 exhibit a notable significant uptake capacity for CO2 and H2; besides that, compounds 3 and 4 also offer excellent selective adsorption of CO2 over N2 and CH4.

(113)Cd Nuclear Magnetic Resonance as a Probe of Structural Dynamics in a Flexible Porous Framework Showing Selective O2/N2 and CO2/N2 Adsorption.

Two new isomorphous three-dimensional porous coordination polymers, {[Cd(bpe)0.5(bdc)(H2O)]·EtOH}n (1) and {[Cd(bpe)0.5(bdc)(H2O)]·2H2O}n (2) [bpe = 1,2-bis(4-pyridyl)ethane, and H2bdc = 1,4-benzenedicarboxylic acid], have been synthesized by altering the solvent media. Both structures contain one-dimensional channels filled with metal-bound water and guest solvent molecules, and desolvated frameworks show significant changes in structure. However, exposure to the solvent vapors (water and methanol) reverts the structure back to the as-synthesized structure, and thus, the reversible flexible nature of the structure was elucidated. The flexibility and permanent porosity were further reinforced from the CO2 adsorption profiles (195 and 273 K) that show stepwise uptake. Moreover, a high selectivity for O2 over N2 at 77 K was realized. The framework exhibits interesting solvent vapor adsorption behavior with dynamic structural transformation depending upon the size, polarity, and coordination ability of the solvent molecules. Further investigation was conducted by solid state (113)Cd nuclear magnetic resonance (NMR) spectroscopy that unambiguously advocates the reversible transformation "pentagonal-bipyramidal CdO6N → octahedral CdO5N" geometry in the desolvated state. For the first time, (113)Cd NMR has been used as a probe of structural flexibility in a porous coordination polymer system.

Study on four polymorphs of bifendate based on X-ray crystallography

Bifendate, a synthetic anti-hepatitis drug, exhibits polycrystalline mode phenomena with 2 polymorphs reported (forms A and B). Single crystals of the known crystalline form B and 3 new crystallosolvates involving bifendate solvated with tetrahydrofuran (C), dioxane (D), and pyridine (E) in a stoichiometric ratio of 1:1 were obtained and characterized by X-ray crystallography, thermal analysis, and Fourier transform infrared (FT-IR) spectroscopy. The differences in molecular conformation, intermolecular interaction and crystal packing arrangement for the four polymorphs were determined and the basis for the polymorphisms was investigated. The rotation of single bonds resulted in different orientations for the biphenyl, methyl ester and methoxyl groups. All guest solvent molecules interacted with the host molecule via an interesting intercalative mode along the [1 0 0] direction in the channel formed by the host molecules through weak aromatic stacking interactions or non-classical hydrogen bonds, of which the volume and planarity played an important role in the intercalation of the host with the guest. The incorporation of solvent-augmented rotation of the C–C bond of the biphenyl group had a striking effect on the host molecular conformation and contributed to the formation of bifendate polymorphs. Moreover, the simulated powder X-ray diffraction (PXRD) patterns for each form were calculated on the basis of the single-crystal data and proved to be unique. The single-crystal structures of the four crystalline forms are reported in this paper.

A Versatile CuII Metal–Organic Framework Exhibiting High Gas Storage Capacity with Selectivity for CO2: Conversion of CO2 to Cyclic Carbonate and Other Catalytic Abilities

A linear tetracarboxylic acid ligand, H4 L, with a pendent amine moiety solvothermally forms two isostructural metal-organic frameworks (MOFs) LM (M=ZnII , CuII ). Framework LCu can also be obtained from LZn by post- synthetic metathesis without losing crystallinity. Compared with LZn , the LCu framework exhibits high thermal stability and allows removal of guest solvent and metal-bound water molecules to afford the highly porous, LCu '. At 77 K, LCu ' absorbs 2.57 wt % of H2 at 1 bar, which increases significantly to 4.67 wt % at 36 bar. The framework absorbs substantially high amounts of methane (238.38 cm3 g-1 , 17.03 wt %) at 303 K and 60 bar. The CH4 absorption at 303 K gives a total volumetric capacity of 166 cm3 (STP) cm-3 at 35 bar (223.25 cm3 g-1 , 15.95 wt %). Interestingly, the NH2 groups in the linker, which decorate the channel surface, allow a remarkable 39.0 wt % of CO2 to be absorbed at 1 bar and 273 K, which comes within the dominion of the most famous MOFs for CO2 absorption. Also, LCu ' shows pronounced selectivity for CO2 absorption over CH4 , N2 , and H2 at 273 K. The absorbed CO2 can be converted to value-added cyclic carbonates under relatively mild reaction conditions (20 bar, 120 °C). Finally, LCu ' is found to be an excellent heterogeneous catalyst in regioselective 1,3-dipolar cycloaddition reactions ("click" reactions) and provides an efficient, economic route for the one-pot synthesis of structurally divergent propargylamines through three-component coupling of alkynes, amines, and aldehydes.

Effects of ligand and guest solvent molecules on the luminescence properties of Tb : Eu-codoped indium-based MOFs.

Luminescent lanthanide MOF materials are good sensors for analyzing some specific gas or volatile small molecules. However, some potential interference factors coming from the material itself, such as bridging ligands or guest solvent molecules entrapped in the channel of a MOF, were usually ignored during the sensing process. Here, two Tb : Eu-codoped indium-based MOFs with different bridging ligands were obtained for exploring the effects of ligand and guest solvent molecules on their luminescence properties. The current studies demonstrated that a ligand in the triplet state located between the excited states of Tb and Eu and polar guest solvent molecules encapsulated in the lanthanide MOF with such a type of ligand as the linker can interfere with the sensing process since they can substantially facilitate the energy transfer between Tb and Eu.

A comparative study of graphite electrodes using the co-intercalation phenomenon for rechargeable Li, Na and K batteries.

Here, we demonstrate that graphite can serve as a versatile electrode for various rechargeable battery types by reversibly accommodating solvated alkali ions (such as K, Na, and Li) through co-intercalation in its galleries. The co-intercalation of alkali ions is observed to occur via staging reactions. Notably, their insertion behaviors, including their specific capacity, are remarkably similar regardless of the alkali ion species despite the different solubility limits of K, Na, and Li ions in graphite. Nevertheless, the insertion potentials of the solvated alkali ions differ from each other and are observed to be correlated with the interlayer distance in the intercalated graphite gallery.

Guest-dependent single-ion magnet behaviour in a cobalt(ii) metal-organic framework.

Single-ion magnets (SIMs) are the smallest possible magnetic devices for potential applications in quantum computing and high-density information storage. Both, their addressing in surfaces and their organization in metal-organic frameworks (MOFs) are thus current challenges in molecular chemistry. Here we report a two-dimensional 2D MOF with a square grid topology built from cobalt(ii) SIMs as nodes and long rod-like aromatic bipyridine ligands as linkers, and exhibiting large square channels capable to host a large number of different guest molecules. The organization of the cobalt(ii) nodes in the square layers improves the magnetic properties by minimizing the intermolecular interactions between the cobalt(ii) centres. Moreover, the SIM behaviour was found to be dependent on the nature of the aromatic guest molecules. The whole process could be followed by single-crystal X-ray diffraction, providing comprehensive evidence of the putative role of the solvent guest molecules that leave a "fingerprint" on the 2D structures and thus, on the cobalt environment.

Hierarchical Metal-Organic Framework Hybrids: Perturbation-Assisted Nanofusion Synthesis.

Metal-organic frameworks (MOFs) represent a new family of microporous materials; however, microporous-mesoporous hierarchical MOF materials have been less investigated because of the lack of simple, reliable methods to introduce mesopores to the crystalline microporous particles. State-of-the-art MOF hierarchical materials have been prepared by ligand extension methods or by using a template, resulting in intrinsic mesopores of longer ligands or replicated pores from template agents, respectively. However, mesoporous MOF materials obtained through ligand extension often collapse in the absence of guest molecules, which dramatically reduces the size of the pore aperture. Although the template-directed strategy allows for the preparation of hierarchical materials with larger mesopores, the latter requires a template removal step, which may result in the collapse of the implemented mesopores. Recently, a general template-free synthesis of hierarchical microporous crystalline frameworks, such as MOFs and Prussian blue analogues (PBAs), has been reported. This new method is based on the kinetically controlled precipitation (perturbation), with simultaneous condensation and redissolution of polymorphic nanocrystallites in the mother liquor. This method further eliminates the use of extended organic ligands and the micropores do not collapse upon removal of trapped guest solvent molecules, thus yielding hierarchical MOF materials with intriguing porosity in the gram scale. The hierarchical MOF materials prepared in this way exhibited exceptional properties when tested for the adsorption of large organic dyes over their corresponding microporous frameworks, due to the enhanced pore accessibility and electrolyte diffusion within the mesopores. As for PBAs, the pore size distribution of these materials can be tailored by changing the metals substituting Fe cations in the PB lattice. For these, the textural mesopores increased from approximately 10 nm for Cu analogue (mesoCuHCF), to 16 nm in Co substituted compound (mesoCoHCF), and to as large as 30 nm for the Ni derivative (mesoNiHCF). While bulk PB and analogues have a higher capacitance than hierarchical analogues for Na-batteries, the increased accessibility to the microporous channels of PBAs allow for faster intercalated ion exchange and diffusion than in bulk PBA crystals. Thus, hierarchical PBAs are promising candidates for electrodes in future electrochemical energy storage devices with faster charge-discharge rates than batteries, namely pseudocapacitors. Finally, this new synthetic method opens the possibility to prepare hierarchical materials having bimodal distribution of mesopores, and to tailor the structural properties of MOFs for different applications, including contrasting agents for MRI, and drug delivery.

Gas sorption and transition-metal cation separation with a thienothiophene based zirconium metal–organic framework

The modulated synthesis of the thienothiophene based zirconium metal–organic framework (MOF) material having formula [Zr6O4(OH)4(DMTDC)6]·4.8DMF·10H2O (1) (H2DMTDC=3,4-dimethylthieno[2,3-b]thiophene-2,5-dicarboxylic acid; DMF=N,N'-dimethylformamide) was carried out by heating a mixture of ZrCl4, H2DMTDC linker and benzoic acid (used as a modulator) with a molar ratio of 1:1:30 in DMF at 150°C for 24h. Systematic investigations have been performed in order to realize the effect of ZrCl4/benzoic acid molar ratio on the crystallinity of the material. The activation (i.e., the removal of the guest solvent molecules from the pores) of as-synthesized compound was achieved by stirring it with methanol and subsequently heating under vacuum. A combination of X-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermogravimetric (TG) and elemental analysis was used to examine the phase purity of the as-synthesized and thermally activated 1. The material displays high thermal stability up to 310°C in an air atmosphere. As revealed from the XRD measurements, the compound retains its crystallinity when treated with water, acetic acid and 1M HCl solutions. The N2 and CO2 sorption analyses suggest that the material possesses remarkably high microporosity (SBET=1236m2g−1; CO2 uptake=3.5mmolg−1 at 1bar and 0°C). The compound also shows selective adsorption behavior for Cu2+ over Co2+ and Ni2+ ions.

Structural Insight into Guest Binding Sites in a Porous Homochiral Metal-Organic Material.

An enantiomeric pair of chiral metal-organic materials (CMOMs) based upon mandelate (man) and 4,4'-bipyridine (bpy) ligands, [Co2(S-man)2(bpy)3](NO3)2·guest (1S·guest) and [Co2(R-man)2(bpy)3](NO3)2·guest (1R·guest), have been prepared. The cationic frameworks exhibit one-dimensional chiral channels with dimensions of 8.0 Å × 8.0 Å. The pore chemistry is such that chiral surfaces lined with nitrate anions and phenyl groups create multiple binding sites for guest and/or solvent molecules. The performance of 1S and 1R with respect to resolution of racemic mixtures of 1-phenyl-1-propanol (PP) was studied by varying time, temperature, and the use of additives. Selectivity toward PP was determined by chiral HPLC with ee values of up to 60%. The binding sites and host-guest interactions were investigated through single-crystal X-ray structural analyses of guest-exchanged 1S and 1R. Crystallographically observed structural changes (e.g., the absolute configurations of the three PP binding sites switch from R, R, and S to R, R, and R/S) correlate with experimentally observed ee values of 33% and 60% for variants of 1S that contain PP and different solvent molecules, 1S·PPex and 1S·PPex', respectively. The fact that manipulation of guest solvent molecules, which in effect serve as cofactors, can modify chiral sites and increase enantioselectivity is likely to aid in the design of more effective CMOMs and processes for chiral separations.

3D Metal–Organic Framework Based on a Lower-Rim Acid-Functionalized Calix[4]arene: Crystal-to-Crystal Transformation upon Lattice Solvent Removal

A rare three-dimensional (3D) calix[4]arene-based metal–organic framework (calixMOF) {[Pb2@L]·2DMF}n (1) was obtained by the solvothermal reaction between a lower-rim acid-functionalized calix[4]arene (H4L) and Pb(NO3)2 in N,N-dimethylformamide; 1 exhibited ths topology, in which Pb(II) atoms accommodated inside the calixarene unit adopted hemidirected coordination geometry. Interestingly, upon the removal of guest solvent molecules, the 3D framework of 1 readily converted to a shrunken 3D framework [Pb2@L]n (1a) via a single-crystal to single-crystal transformation. However, the resolvation of the guest molecules was not observed when 1a was immersed into DMF at room temperature or at 110 °C. Furthermore, 1a exhibited interesting CO2 sorption behavior: Its CO2 isotherm curves exhibited looped patterns of linear adsorption and nonlinear desorption. The thermal behavior and solid-state photoluminescence properties of 1 and 1a were also reported.

Synthesis, Characterization, Stability, and Gas Adsorption Characteristics of a Highly Stable Zirconium Mesaconate Framework Material

AbstractA new ZrIV mesaconate framework material was synthesized by heating a mixture of ZrCl4, mesaconic acid, and acetic acid in a molar ratio of 1:1:30 in DMF at 150 °C for 24 h. The influence of the molar ratio of ZrCl4/acetic acid on the crystallinity of the compound was examined. The as‐synthesized compound was Soxhlet‐extracted with ethanol and subsequently heated under vacuum to remove guest solvent molecules from the pores. Both the as‐synthesized sample and the thermally activated sample of this new material were characterized by X‐ray powder diffraction (XRPD), FTIR spectroscopy, thermogravimetry, and elemental analysis. The compound is thermally stable up to 320 °C under air. XRPD experiments indicate that the compound maintains its crystallinity upon exposure to water, acetic acid, and 1 M HCl. According to the N2 sorption analyses, the compound possesses a BET surface area of 662 m2 g–1. Thus, the material is a promising candidate for gas storage and separation owing to its high physiochemical stability and considerable porosity.

Isostructurality Among Solvates of Cabazitaxel: X-ray Structures and New Solvates Preparation

Cabazitaxel is an anticancer drug and its marketed product (form A) is acetone solvate (1:1) (Didier E, Perrin MA. 2005. Patent WO2005/028462 A1). This work describes three crystal structures of cabazitaxel 1:1 solvates with isopropyl alcohol (B), 2-butanol (C), and dioxane (D). These solvates are isostructural with cabazitaxel forming a host framework through hydrogen bonds and the guest solvent molecules located in channels from which they can escape. The host is hydrogen bonded to each other through hydroxyl O1 and sec-amide N3 ', whereas the hydroxyl O2 ' plays an important role in connecting the host to the guest. Moreover, because of the existence of channels in the crystal structure, the solvent-replacement method was established to prepare four new solvates of cabazitaxel with dimethyl formamide (E), cyclohexane (F), n-hexane (G), and ethyl ether (H). All the seven solvates involved in this work were proven to be isostructural by methods of X-ray crystallography and contain the same amount of solvents by thermogravimetric analysis. The single-crystal structures of solvate C-E and the solvates prepared by solvent-replacement method have been reported for the first time.

A Microporous Co2+ Metal Organic Framework with Single-Crystal to Single-Crystal Transformation Properties and High CO2 Uptake

The synthesis and characterization of {[Co9(INA)18(H2O)6]·11DMF·15H2O}∞ (Co9-INA·11DMF·15H2O) (INA– = the anion of isonicotinic acid) is reported. It exhibits a rigid 3D-porous structure with a Co9 repeating unit consisting of four [CoII2(μ-O2CR)2(μ-H2O)] subunits (two unique) linked through bridging INA– ligands to an isolated CoII ion (half unique). The [CoII2] dimers and the isolated CoII ion have assembled to create a trinodal (6,7,8)-coordinated network with point symbol (32.411.56.62)2(32.418.54.64)2(34.44.54.63). Gas sorption studies revealed that Co9-INA exhibits 910 m2 g–1 BET area, 4.2 mmol g–1 CO2 uptake at 273 K/1 bar, and 6.7 CO2/CH4 selectivity at zero coverage. Furthermore, Co9-INA displays capability for exchange of the guest solvent molecules by various organic molecules in a single-crystal to single-crystal fashion. Direct and alternating current magnetic susceptibility studies revealed the existence of dominant antiferromagnetic interactions between the Co2+ ions that result in a parama...