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The new three-dimensional coordination polymer termed {[Na2SDC(H2O)]}n (SDC²-=C16H10O42-) has been synthesized using workstation Easymax 102 while controlling the conditions and monitoring in-situ reagents. The metal complex was obtained in the reaction of sodium hydroxide with a suspension of 4,4'-stilbenedicarboxylic acid in aqueous medium. The compound was characterized by elemental analysis, single crystal, and powder X-ray diffraction methods, ATR-FTIR spectroscopy, SEM and optical microscopy, TG-DSC and TG-FTIR thermal analysis in air and nitrogen atmosphere. In the crystal structure of {[Na2SDC(H2O)]}n appears penta- and hexacoordinated sodium atoms joined by octa- and decadentate SDC2- linkers. Aqua ligand acts as bridge between Na1 and Na2 atoms. The assynthesized sodium complex is thermally stable up to 86°C whereas its dehydrated form has extreme stability up to 491°C. Removal of water molecule leads to the crystal-to-crystal transformation yielded changes in coordination modes of COO groups. Reversibility of the hydration process in the studied complex was also examined. [ABSTRACT FROM AUTHOR]

Reaction of the flexible phenolic carboxylate ligand 2‐(3,5‐dicarboxylbenzyloxy)benzoic acid (H3L) with nickel salts in the presence of 1,2‐bis(pyridin‐4‐yl)ethylene (bpe) leads to the generation of a mixture of the two complexes under solvolthermal conditions, namely poly[[aqua[μ‐1,2‐bis(pyridin‐4‐yl)ethylene‐κ2N:N′]{μ‐5‐[(2‐carboxyphenoxy)methyl]benzene‐1,3‐dicarboxylato‐κ3O1,O1′:O3}nickel(II)] dimethylformamide hemisolvate monohydrate], {[Ni(C16H10O7)(C12H10N2)(H2O)]·0.5C3H7NO·H2O}n or {[Ni(HL)(bpe)(H2O)]·0.5DMF·H2O}n, 1, and poly[[diaquatris[μ‐1,2‐bis(pyridin‐4‐yl)ethylene‐κ2N:N′]bis{μ‐5‐[(2‐carboxyphenoxy)methyl]benzene‐1,3‐dicarboxylato‐κ2O1:O5}nickel(II)] dimethylformamide disolvate hexahydrate], {[Ni2(C16H10O7)2(C12H10N2)3(H2O)2]·2C3H7NO·6H2O}n or {[Ni2(HL)2(bpe)3(H2O)2]·2DMF·6H2O}n, 2. In complex 1, the NiII centres are connected by the carboxylate and bpe ligands to form two‐dimensional (2D) 4‐connected (4,4) layers, which are extended into a 2D+2D→3D (3D is three‐dimensional) supramolecular framework. In complex 2, bpe ligands connect to NiII centres to form 2D layers with Ni6(bpe)6 metallmacrocycles. Interestingly, 2D+2D→3D inclined polycatenation was observed between these layers. The final 5‐connected 3D self‐penetrating structure was generated through further connection of Ni–carboxylate chains with these inclined motifs. Both complexes were fully characterized by single‐crystal analysis, powder X‐ray diffraction analysis, FT–IR spectra, elemental analyses, thermal analysis and UV–Vis spectra. Notably, an interesting metal/ligand‐induced crystal‐to‐crystal transformation was observed between the two complexes. [ABSTRACT FROM AUTHOR]

The combination of strong coordination bonds and hydrogen bonding interactions were used to generate a series of supramolecular coordination materials (SCMs), which was achieved by reacting a bis-pyridyl amide ligand, namely N-(4-pyridyl)nicotinamide (4PNA) with copper(II), zinc(II), and cadmium(II) benzoates. The SCMs were structurally characterized using X-ray diffraction and the key intermolecular interactions were identified via Hirshfeld surface analysis. The role of solvent molecules on the supramolecular architecture was analyzed by synthesizing the SCMs in different solvents/solvent mixtures. A solvent-mediated solid-state structural transformation was observed in copper(II) SCMs and we were able to isolate the intermediate form of the crystal-to-crystal transformation process. The luminescence experiments revealed that complexation enhanced the fluorescence properties of 4PNA in the zinc(II) and cadmium(II) SCMs, but a reverse phenomenon was observed in the copper(II) SCMs. This work demonstrated the tuning of supramolecular assembly in coordination compounds as a function of solvents for generating SCMs with diverse properties.

Protonation of trans-1,2-bis(4-pyridyl)ethylene (4,4′-bpe) with dilute sulfuric acid (33 %) afforded a protonated adduct [{4,4′-bpe⋅2 H+}2{HSO4}−2{SO4}−2{H2O}2] ( 1). The neighboring olefinic bond in 1 is in a suitable range (3.931-4.064 Å) to undergo a photochemical [2+2] cycloaddition reaction. Upon irradiation with UV light (365 nm), 1 undergoes a molecular sliding involving the 4,4′-bpe⋅2 H+ units, affording 2, stabilized through OSO4⋅⋅⋅π interactions. Heating 1 to 50° C leads to a 3D hydrogen-bonded organic framework (HOF) ( 3). This process occurs through thermal dissociation of the bisulfate anion. Diffusion of iodine through the crystal lattice of 1 and 3 enables the reduction of sulfate to bisulfate, affording a 1D hydrogen-bonded chain ( 4). Solid-state 13C CPMAS NMR, IR, DSC, and powder XRD studies further support stimuli-responsive structural tuning through crystal-to-crystal transformation. All these conversions occur with significant translational and rotational movements along with a series of bond-breaking and bond-forming processes. [ABSTRACT FROM AUTHOR]

Reactions of ZnCl 2 with 4′-(2,4-disulfophenyl)-2,2′:6′2″-terpyridine (H 2 DSPT) result to two new compounds with formula, {[Zn(DSPT)(H 2 O) 2 ]·2H 2 O} n ( 1 ) and {[Zn(DSPT)(H 2 O) 2 ]·H 2 O} n ( 2 ), respectively. Compound 1 is a binuclear complex, whereas compound 2 is a mononuclear organozinc compound. The coordination compounds can be controllable synthesized by adjust the pH value. The thermal behavior of 1 was explored by TG and VT-PXRD, which indicated that it undergo crystal-to-crystal transformation manner. Both compounds 1 and 2 show weak luminescence in both solid state and water emulsions compared with H 2 DSPT. The luminescence intensity of compound 1 can strongly enhanced by the addition of diethylchlorophosphonate (DCP), but significant less influenced by dimethylmethylphosphonate (DMMP), diethylcyanophosphonate (DCNP) and other selected organophosphate, which make compound 1 has potential application on nerve-agent detection. [ABSTRACT FROM AUTHOR]

Coordination polymers (CPs) may undergo structural transformations as a result of external stimuli (e.g., heat, light, or mechanochemical force). Structural transformations are accompanied by the movement of atoms or molecules and involve significant rearrangement of CP structures including rotation, bending, swinging, sliding, shrinking, or swelling. Lead(II) CPs display interesting structural features, varying properties and can be employed to investigate such transformations. In the present review, we focus on solid-state reactions of lead(II) CPs from a crystallographic point of view. Structural transformations of lead(II) CPs have been reported by our research group along with relevant examples from the literature. We also demonstrate that lead(II) CPs can create diverse structures with interesting features through such transformations. All the coordination networks have been determined by single-crystal X-ray diffraction before and after the structural transformations. [ABSTRACT FROM AUTHOR]

Supramolecular networks are crystalline materials based on connections between metal ions through organic ligands. In this sense, the combination of polycarboxylate anions and dipyridyl ligands is an effective strategy to produce extended structures. However, sometimes the 3D arrangement results in an ionic network, and this is the case for the novel compounds [Cu((py) 2 C(OH) 2 ) 2 ](H 2 bta) ( 1 ) and [Cu((py) 2 C(OH) 2 ) 2 ](fum) ( 2 ) where (py) 2 C(OH) 2 is the gem-diol of di-2-pyridyl ketone ((py) 2 CO), H 2 bta 2− is the divalent anion of 1,2,4,5-benzenetetracarboxylic acid (H 4 bta), and fum 2− is the divalent anion of fumaric acid (butenedioic acid). Both compounds were synthesized and structurally characterized by means of single crystal X-ray diffraction and IR spectroscopy. The thermal behavior of both compounds was analyzed through TG/DTA and TDX, concluding that the thermal stability is influenced by the dehydration of the coordinated molecules and counter-anions. Additionally, 13 C NMR measurements were performed to analyze the reversible crystal-to-crystal phase transformation observed for 1 . [ABSTRACT FROM AUTHOR]

The one-dimensional coordination polymer catena-poly[diaqua(sulfato-κ O)copper(II)]-μ2-glycine-κ2 O: O′], [Cu(SO4)(C2H5NO2)(H2O)2] n, (I), was synthesized by slow evaporation under vacuum of a saturated aqueous equimolar mixture of copper(II) sulfate and glycine. On heating the same blue crystal of this complex to 435 K in an oven, its aspect changed to a very pale blue and crystal structure analysis indicated that it had transformed into the two-dimensional coordination polymer poly[(μ2-glycine-κ2 O: O′)(μ4-sulfato-κ4 O: O′: O′′: O′′)copper(II)], [Cu(SO4)(C2H5NO2)] n, (II). In (I), the CuII cation has a pentacoordinate square-pyramidal coordination environment. It is coordinated by two water molecules and two O atoms of bridging glycine carboxylate groups in the basal plane, and by a sulfate O atom in the apical position. In complex (II), the CuII cation has an octahedral coordination environment. It is coordinated by four sulfate O atoms, one of which bridges two CuII cations, and two O atoms of bridging glycine carboxylate groups. In the crystal structure of (I), the one-dimensional polymers, extending along [001], are linked via N-H...O, O-H...O and bifurcated N-H...O,O hydrogen bonds, forming a three-dimensional framework. In the crystal structure of (II), the two-dimensional networks are linked via bifurcated N-H...O,O hydrogen bonds involving the sulfate O atoms, forming a three-dimensional framework. In the crystal structures of both compounds, there are C-H...O hydrogen bonds present, which reinforce the three-dimensional frameworks. [ABSTRACT FROM AUTHOR]

The chain polymer [{Cd(μ-X)2py2}g1/∞ ] (X = Cl, Br; py = pyridine) undergoes a fully reversible phase transition between a monoclinic low-temperature and an orthorhombic high-temperature phase. The transformation can be directly monitored in single crystals and can be confirmed for the bulk by powder diffraction. The transition temperature can be adjusted by tuning the composition of the mixed-halide phase: Transition temperatures between 175 K up to the decomposition of the material at ca. 350 K are accessible. Elemental analysis, ion chromatography and site occupancy refinements from single-crystal X-ray diffraction agree with respect to the stoichiometric composition of the samples. [ABSTRACT FROM AUTHOR]

• The formation of a simple planar four-coordinate copper complex actually takes place in two stages, passing through a six-coordinate Jahn-Teller-active intermediate that is isolable in single-crystal form. • The Cu-centered intermediate is formed in solution and then consumed in a solvent-mediated crystal-to-crystal transformation to form the final product in a period of roughly two weeks, depending on initial crystal size and the evaporation rate of the mediating solvent. • Comparison with the isostructural but unreactive Ni-centered analogue of the Cu-centered intermediate points to molecular, as opposed to crystal, factors as the motive force for the further reaction in the case of copper. • These results suggest that analogous intermediates may pertain to the formation of many more four-coordinate Cu complexes. Isolable crystals of the cesium salt of an anionic Jahn-Teller-active Cu complex, initially formed by reaction in solution, are spontaneously consumed in a solvent-mediated crystal-to-crystal transformation that produces a final product with a four-coordinate Cu center. Depending on the size of the crystals of the intermediate and the evaporation rate of the solvent, the transformation from intermediate to final product occurs in a two-week time frame. The crystalline Jahn-Teller Cu intermediate presents a noteworthy difference in stability compared to its non-Jahn-Teller Ni-centered isomorph. It is proposed that a Jahn-Teller intermediate may precede the formation of other four-coordinate Cu complexes. Partial solvent evaporation drives the crystal-to-crystal transformation of (1) to (2) rather than producing greater yield of (1). [Display omitted] [ABSTRACT FROM AUTHOR]

New 2D lead(II) coordination polymers, Pb(4-bpdh)(CH 3 COO)(NO 3)] n (1) and [Pb(4-bpdh)(ClO 4)(NO 3)] n (2), 4-bpdh ​= ​2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene, were prepared and characterized by single-crystal X-ray diffraction. Compound 3 with formula [Pb(4-bpdh)(NO 3) 2 (H 2 O)] n (3) was obtained by solid state mechanochemical reaction of the compounds 1 and 2 via anion-exchange process. These conversions are reversible and the grinding of compound 3 with CH 3 COO¯ and ClO 4 ¯ ions led to the formation of the compounds 1 and 2 , respectively. Thermal decomposition of the compounds 1–3 results in the formation of different metallic composites. The composites were characterized by X-ray powder diffraction (XRD) and size and morphology of them were investigated by scanning electron microscopy (SEM). Solid state crystal-to-crystal transformation of Pb(II) coordination polymers was performed by solid state mechanochemical reaction and anion-exchange process. Also, thermal decomposition of the coordination polymers led to the formation of different metallic nanocomposites. [Display omitted] • Two new Pb(II) coordination polymers were synthesized by thermal gradient method. • Solid state crystal-to-crystal transformation of three coordination polymers was performed. • Anion exchange of the coordination polymers was occurred by mechanochemical method. • Different metallic composites were formed by calcination of the coordination polymers. [ABSTRACT FROM AUTHOR]

Abstract: A new organic–inorganic hybrid solid with 3-D framework, [Mn(DMF)3]2[Re6Se8(CN)6] (1), has been synthesized and transformed to [H][Mn(salen)]3[Re6Se8(CN)6] (2) by a ligand exchange. Hexarhenium chalcocyanide clusters are closest packed in cubic symmetry for 1 and rhombohedral symmetry for 2. The manganese complexes in the interstitial sites are three-coordinated to the rhenium cluster in 1 and two-coordinated in 2. [Copyright &y& Elsevier]

An imide-based O-donor ligand, 4-carboxyphenyl-1,3-dioxoisoindoline-5-carboxylic acid (H 2 In-4-ba), and one Zn(II) coordination polymer, [Zn(In-4-ba)(py) 2 ] n (1 , py ​= ​pyridine), have been synthesized. Single-crystal X-ray diffraction indicates that 1 has a quasi-3 1 helical chain structure, which shows one-dimensional to two-dimensional (1D → 2D) extension to be a homochiral layer of consecutively interweaving poly-helices with the same helicity. Coexistence of such homochiral layers in opposite chirality makes individual crystal of 1 to be in a racemic manner. Thermogravimetric (TG) analysis indicated that 1 shows high thermal stability approaching 440 ​°C. Thermal activation of 1 gives a desolvated phase, [Zn(In-4-ba)] n (1′), as supported by TG trace. Of particular note, reversible crystal-to-crystal transformations between solvated 1 and desolvated 1′ have been achieved upon decoordination and recoordination of the py ligands, as evidenced by XRPD patterns, IR spectra, and TG diagrams. The photoluminescence properties of as-synthesized 1 , desolvated 1′ , and resolvated 1′ /py have also been studied. All of them exhibit an emission band centered at 486, 492, and 486 ​nm, respectively, which is originated from the ligand-centered charge transfer. Further, the emission intensity of 1′ is weaker than that of 1 and 1′ /py, implying the influence of coordinated py ligands and/or structure regulation on photoluminescence. A solvated zinc(II) coordination polymer showing quasi-3 1 helical chain structure and its desolvated phase have exhibited reversible crystal-to-crystal transformations upon solvent decoordination and recoordination. [Display omitted] • Zn(II) coordination polymer 1 has a quasi-3 1 helical chain structure. • Zn(II) coordination polymer 1 shows 1D.→ 2D homochiral layer of poly-helices. • Zn(II) coordination polymer 1 is high thermally stable approaching 440 ​°C. • Zn(II) coordination polymer 1 exhibits ligand-centered fluorescence. • Solvent-induced reversible crystal-to-crystal transformations have been achieved. [ABSTRACT FROM AUTHOR]

The combination of strong coordination bonds and hydrogen bonding interactions were used to generate a series of supramolecular coordination materials (SCMs), which was achieved by reacting a bis-pyridyl amide ligand, namely N-(4-pyridyl)nicotinamide (4PNA) with copper(II), zinc(II), and cadmium(II) benzoates. The SCMs were structurally characterized using X-ray diffraction and the key intermolecular interactions were identified via Hirshfeld surface analysis. The role of solvent molecules on the supramolecular architecture was analyzed by synthesizing the SCMs in different solvents/solvent mixtures. A solvent-mediated solid-state structural transformation was observed in copper(II) SCMs and we were able to isolate the intermediate form of the crystal-to-crystal transformation process. The luminescence experiments revealed that complexation enhanced the fluorescence properties of 4PNA in the zinc(II) and cadmium(II) SCMs, but a reverse phenomenon was observed in the copper(II) SCMs. This work demonstrated the tuning of supramolecular assembly in coordination compounds as a function of solvents for generating SCMs with diverse properties. [ABSTRACT FROM AUTHOR]

The one-dimensional coordination polymer catena-poly[diaqua(sulfato-κO)copper(II)]-μ2-glycine-κ(2)O:O'], [Cu(SO4)(C2H5NO2)(H2O)2]n, (I), was synthesized by slow evaporation under vacuum of a saturated aqueous equimolar mixture of copper(II) sulfate and glycine. On heating the same blue crystal of this complex to 435 K in an oven, its aspect changed to a very pale blue and crystal structure analysis indicated that it had transformed into the two-dimensional coordination polymer poly[(μ2-glycine-κ(2)O:O')(μ4-sulfato-κ(4)O:O':O'':O'')copper(II)], [Cu(SO4)(C2H5NO2)]n, (II). In (I), the Cu(II) cation has a pentacoordinate square-pyramidal coordination environment. It is coordinated by two water molecules and two O atoms of bridging glycine carboxylate groups in the basal plane, and by a sulfate O atom in the apical position. In complex (II), the Cu(II) cation has an octahedral coordination environment. It is coordinated by four sulfate O atoms, one of which bridges two Cu(II) cations, and two O atoms of bridging glycine carboxylate groups. In the crystal structure of (I), the one-dimensional polymers, extending along [001], are linked via N-H···O, O-H···O and bifurcated N-H···O,O hydrogen bonds, forming a three-dimensional framework. In the crystal structure of (II), the two-dimensional networks are linked via bifurcated N-H···O,O hydrogen bonds involving the sulfate O atoms, forming a three-dimensional framework. In the crystal structures of both compounds, there are C-H···O hydrogen bonds present, which reinforce the three-dimensional frameworks.