Selective Detection of Primary Aromatic Amines through Enhanced Luminescence of a 2D + 2D Inclined Polycatenated Microporous Nitro-Functionalized Metal-Organic Framework.

Detection and sensing of amines through enhanced fluorescence emission are always challenging in aqueous solution. The range of different Lewis basicities, shapes, and sizes as well as the different structural arrangements of amines is responsible for their less specificity in aqueous solution. Here, we have designed a highly fluorescent emissive 2D + 2D → 3D inclined polycatenated NO2-functionalized flexible metal-organic framework (MOF) for selective segregation of electron-rich aromatic primary amines from electron-deficient amines in aqueous solution, showing different emission behaviors. The inclined polycatenated 2D + 2D → 3D MOF having an asymmetric unit {[Cd(dim)(2-nta)(H2O)](H2O)(MeOH)}n (1) has been synthesized by a slow diffusion process and characterized thoroughly by single-crystal and powder X-ray diffraction (PXRD) as well as other physicochemical methods. The desolvated species of 1 (Ref. MOF) is found to be stable and has been characterized by PXRD and adsorption study. The fluorescence profile of the Ref. MOF shows selective enhancement in the presence of electron-rich primary aromatic amines, while the same shows quenching for electron-deficient amines in aqueous solution. The Ref. MOF reported here consists of flexible space between two 2D layers that is responsible for different orientations for different analyte primary aromatic amines (PAAs) with different sizes. The above findings are also supported by time-resolved fluorescence spectroscopy. The respective fluorescence enhancement and quenching have been explained by the interaction between the CB of the host MOF and LUMO of guest amines. Therefore, this work presents an operable method for the sensing of PAAs using a single compound, which is a polycatenated MOF.

Solid-State Solvent-Independent Excited-State Intramolecular Proton Transfer in a Coordination Polymer and Its Temperature Dependence.

Increasing demand for futuristic switches and sensors around the world has created an intense interest in smart materials, which can show a rapid but feature-dependent change in the physical properties in the presence of external stimuli. Hitherto such changes in the photophysical property of materials, specifically in the solid state, are projected for the use of smart on-off switches. Materials having an external-stimuli-responsive change in the photophysical properties like excited-state intramolecular proton transfer (ESIPT) can also be utilized for these purposes. Although the event of solid-state ESIPT is not new in the domain of material chemistry, especially for organic molecules, it was never observed for coordination polymers (CPs). Previous instances of ESIPT in CPs have necessitated the presence of a solvent as a suspension medium, driving a solvent-assisted ESIPT phenomenon. However, the emergence of a solvent-independent ESIPT-enabled CP presents unique advantages. The well-defined periodic arrangement ensures reliable property variations, while the robust coordination bonds between the metal nodes and ligands provide durability in harsh environments. Addressing this gap, we present the first ever solid-state, solvent-free, and solvent-independent ESIPT-active CP. Remarkably, this CP exhibits temperature-dependent ESIPT on-off behavior, demonstrating its potential as a cutting-edge material in the field of smart switches and sensors.

Multidirectional Solvent-Induced Structural Transformation in Designing a Series of Polycatenated Cobalt(II) Coordination Polymers: Impact on Carbon Dioxide and Hydrogen Uptake.

Coordination polymers with external stimuli-responsive structural transformation acquired paramount importance in the advanced material research field due to their eye-catching application to deal with the existing challenging issue, and Co(II) metal complex with d7 electronic configuration is a renowned candidate for kinetic accountability and has the potentiality of structural transformation. Bearing these factors in mind, here, a Co(II) congener of a previously reported high hydrogen-adsorbing Cu(II)-based coordination polymer (CP), {[Cu(4-bpe)(2-ntp)]}n [where 2-ntp2- = 2-nitroterephthalate and 4-bpe = 1,2-bis-(4-pyridyl)ethane], has been synthesized to study the metal change impact on hydrogen adsorption and solvent-induced structural transformation with their impact on hydrogen uptake. This modified framework has a 2D + 2D → 3D inclined polycatenated framework as comparable to our previously published Cu(II) framework. Here, on the variation of different solvents, the labile Co(II)-containing framework exhibits a structural change through single-crystal to single-crystal (SC-SC) structural transformation and results in three new framework structures. All four frameworks are structurally characterized by elemental analysis, IR, PXRD, TGA, and single-crystal X-ray diffraction. The desolvated parent framework with exposed metal centers exhibits excellent results of H2 adsorption of 1.3 wt % (145 cc/g) at 77 K and pressure of 1 bar with structural sustainability and CO2 uptake of 130 cc/g at 195 K and 1 bar. For the other three solvent-mediated structural derivatives, H2 and CO2 adsorption have been studied, and the results are correlated with their structure.

Molecular enneanuclear CuII phosphates containing planar hexanuclear and trinuclear sub-units: syntheses, structures, and magnetism.

Highly symmetric enneanuclear copper(ii) phosphates [Cu9(Pz)6(µ-OH)3(µ3-OH)(ArOPO3)4(DMF)3] (PzH = pyrazole, Ar = 2,6-(CHPh2)2-4-R-C6H2; R = Me, 2MeAr; Et, 2EtAr; iPr, 2iPrAr; and Ar = 2,6-iPr2C6H3, 2Dip) comprising nine copper(ii) centers and pyrazole, hydroxide and DMF as ancillary ligands were synthesized by a reaction involving the arylphosphate monoester, 1, copper(i)chloride, pyrazole, and triethylamine in a 4 : 9 : 6 : 14 ratio. All four complexes were characterized by single crystal structural analysis. The complexes contain two distinct structural motifs within the multinuclear copper scaffold: a hexanuclear unit and a trinuclear unit. In the latter, the three Cu(ii) centres are bridged by a µ3-OH. Each pair of Cu(ii) centers in the trinuclear unit are bridged by a pyrazole ligand. The hexanuclear unit is made up of three dinuclear Cu(ii) motifs where the two Cu(ii) centres are bridged by an -OH and a pyrazole ligand. The three dinuclear units are connected to each other by phosphate ligands. The latter also aid the fusion of the trinuclear and the hexanuclear motifs. Magnetic studies reveal a strong antiferromagnetic exchange between the Cu(ii) centres of the dinuclear units in the hexanuclear part and a strong spin frustration in the trinuclear part leading to a degenerate ground state.

A reversible photochemical solid-state transformation in an interpenetrated 3D metal-organic framework with mechanical softness.

We synthesized a two-fold interpenetrated 3D MOF with two crystallographically distinct C[double bond, length as m-dash]C bonds, which undergoes [2+2] photo-cycloaddition and thermal reversible reaction, in a single-crystal-to-single-crystal (SCSC) manner. The softer nature and comparable mechanical properties of the crystals of the parent and cyclized MOFs revealed by nanoindentation allowed rationalizing their structural softness and SCSC transformation behaviour.

Proton Conductivity and Sorption Study in Three Sulfonic Group Functionalized Mixed Ligand Coordination Polymers and the Impact of Structural Dynamicity on Their Property.

Two new mixed ligand coordination polymers (CPs) that are sulfonic group functionalized, namely, {[Cd(bpe)0.5(5-sip)(H2O)]·4H2O(bpeH2)0.5}n (1) and {[Cd1.5(bte)(5-sip)(H2O)3]·3H2O}n (2) [where 5-sip = trinegative 5-sulfoisophthalate salt, bpe = 4,4'-bispyridylethane, bte = 1,2-bis(1,2,4-triazol-1-yl)ethane] have been synthesized through the variation of the N,N'-donor connectors only, at room temperature by using a slow diffusion technique. The structural analyses of both the complexes by single crystal X-ray diffraction studies clearly revealed the formation of 2D sheets containing guest water molecules entrapped in the 1D channel. A structurally similar reported compound {[Cd1.5(btp)(5-sip)(H2O)3]·2H2O}n (3) has also been synthesized to compare the property of the newly synthesized compound. Herein, all the compounds show their humidity dependent proton conductivity as well as gas sorption behavior, which are signatures of their multifunctionality in the field of not only synthetic chemistry but also in material science. It is worth mentioning that the hydrogen bond network by the guest/coordinated waters, dicarboxylic, as well as sulfonic acid group(s) are present in the interlayer spaces, which are basically responsible for showing this high degree of proton conductivity in addition to significant water adsorption. Interesting phase transformation of compound 1 during experimental study perhaps plays a crucial role for its highest conductivity value among the three reported compounds. Herein it has found that the proton conductivity values vary in the range of ∼10-5-10-7 S cm-1 at 65 °C under 95% relative humidity (RH) corroborating the Grotthus mechanism of proton conduction. All the dehydrated frameworks exhibit adsorption of different gases (e.g., CO2 and N2) and solvents (e.g., EtOH and H2O). In the case of compound 1 and 3, selective CO2 uptake has been observed.

Polarity-Induced Excited-State Intramolecular Proton Transfer (ESIPT) in a Pair of Supramolecular Isomeric Multifunctional Dynamic Metal-Organic Frameworks.

A pair of supramolecular isomers of CdII -based MOF have been synthesized by utilizing a flexible N,N'-donor linker and a dicarboxylate with ESIPT (excited-state intramolecular proton transfer) fluorophore by varying the reaction media. One of the MOFs has a 3D four-fold interpenetrating framework with guest solvent in the structure that undergoes a solvent-dependent crystalline-to-crystalline structural transformation, which has been extensively studied by powder XRD and IR spectroscopy. The other MOF is structurally rigid in nature and has a two-fold interpenetrating structure without any guest molecules. Both the compounds show moderate CO2 adsorption and one of them, the MOF with the four-fold interpenetrating structure, also shows moderately high H2 adsorption. Furthermore, both the compounds show interesting luminescence behavior. In the solid state, the two compounds show single-peak spectra, whereas upon suspension of these compounds in polar solvents, the maxima split into two peaks with a large Stokes shift. On the other hand, in nonpolar solvents, only one emission maximum is observed. This solvatochromic dual-emission phenomenon is due to ESIPT, which has been extensively studied.

Set of Multifunctional Azo Functionalized Semiconducting Cd(II)-MOFs Showing Photoswitching Property and Selective CO2 Adsorption.

Syntheses, structural characterizations, photoluminescence, and adsorption properties of three new azo-functionalized Cd(II)-MOFs, namely, {[Cd(azbpy)(msuc)]·2.5(H2O)}n (2), {[Cd(azbpy)(mglu)]·5(H2O)}n (3), and {[Cd1.5(azbpy)2(glu)]·(NO3)·MeOH}n (4) [where msuc2- = methylsuccinate; mglut2- = methylglutarate; glut2- = glutarate; azbpy = 4,4'-azobispyridine] have been reported. The compounds show different structures only with the variation of aliphatic dicarboxylates. The photoswitching behavior for the above-mentioned newly synthesized Cd(II)-MOFs along with one of our previously reported other azo-functionalized Cd(II)-MOF, namely, {[Cd(azbpy)(suc)]·2(H2O)}n (1), has been studied extensively. At photoilluminated condition, the conductivity values can draw a clear structure-property relationship among the structures of compounds 1-4. Single crystal structural analysis reveals that all the compounds exhibit a three-dimensional (3D) framework connected by azbpy linker and respective aliphatic dicarboxylate through their bis-chelating mono/bis oxo-bridging fashion. Compounds 1-3 exhibit an iso-structural honeycomb like 3D framework showing the same coordination environments, where the metal-carboxylate 2D sheets of compounds 1-3 are pillared by N,N'-donor azbpy linkers. On the other hand, compound 4 exhibits a 2-fold interpenetrated 3D framework with a little difference in its coordination environment and the pillaring of 1D metal-carboxylate ladder by azbpy linkers. All the compounds significantly demonstrate their enhanced sensitivity under light rather than the dark condition. The gas and solvent vapor sorption studies have been performed for the synthesized compounds 2-4. Moreover, compound 2 exhibits an enhanced type IV selective CO2 adsorption isotherm over N2 along with the appearance of gate opening phenomena in that.

Sulfonic Group Functionalized Mixed Ligand Coordination Polymers: Synthesis, Characterization, Water Sorption, and Proton Conduction Studies.

Five sulfonic acid group functionalized mixed ligand coordination polymers (CPs), namely, {[Zn(bpeH)(5-sip)(H2O)]·(H2O)}n (1), {[Cu(pyz)(5-Hsip)(H2O)2]·(H2O)2}n (2), {[Cu(bpee)0.5(5-sip)(H2O)2]·(H2O)4(bpeeH2)0.5}n (3), {[Cu(bpy)(5-Hsip)(H2O)]·(H2O)2}n (4), and {[Cu(bpy)2(5-H2sip)2]·(H2O)6}n (5) [where sip3- = 5-sulfoisophthalate; bpe = 4,4'-bispyridylethane; pyz = pyrazine; bpee = 4,4'-bispyridylethylene; bpy = 4,4'-bipyridine], have been synthesized with varying different N,N'-donor linkers using slow diffusion techniques at room temperature. The CPs possess guest water filled 1D channels and noncoordinating sulfonic acid or coordinated sulfonate groups, which are interconnected by means of extended intermolecular H-bonding interaction, which supports the humidity dependent proton conductivity of the samples. Under 95% relative humidity (% RH), the CPs exhibit the temperature dependent proton conductivity which is maximum up to in the range of ∼10-5-10-6 S cm-1 at 65 °C. In most of the cases, the framework shows activation energies with the value ranging from 0.35 to 0.54 eV, suggesting mostly the contribution of the Grotthuss mechanism of the proton conductivity.

Hydrogen Uptake by an Inclined Polycatenated Dynamic Metal-Organic Framework Based Material.

A 2D + 2D → 3D inclined polycatenated dynamic metal-organic framework of {[Cu(4-bpe)(2-ntp)(H2O)2]·2H2O}n [1, where 2-ntp2- = 2-nitroterephthalate and 4-bpe = 1,2-bis-(4-pyridyl)ethane] has been synthesized and characterized. The variable-temperature powder X-ray diffraction study indicates the dynamic nature of the inclined polycatenated framework, and the dehydrated framework with exposed metal centers exhibits excellent type I H2 adsorption of 1.94 wt % at 77 K and 1 bar of pressure.

Eye-Catching Dual-Fluorescent Dynamic Metal-Organic Framework Senses Traces of Water: Experimental Findings and Theoretical Correlation.

A guest-dependent dynamic fivefold interpenetrated 3D porous metal-organic framework (MOF) of ZnII ions has been synthesized that exhibits selective carbon dioxide adsorption. Furthermore, the MOF shows excellent luminescence behavior, which is supported by a systematic study on the guest-responsive multicolor emission of a suspension of the MOF. The dual-emission behavior arises from the excited-state intramolecular proton transfer (ESIPT), and the compound also shows remarkable potential to detect traces of water in various organic solvents. The experimental observations were also painstakingly authenticated by using time-dependent density-functional-theory (DFT) calculations.

Tuned synthesis of two coordination polymers of Cd(II) using substituted bent 3-pyridyl linker and succinate: structures and their applications in anion exchange and sorption properties.

Two new Cd(II) coordination polymers, namely [Cd(3-bpdh)2(ClO4)2]n (1) and {[Cd(3-bpdh)(suc)(H2O)]·3(H2O)}n (2), have been synthesized using a substituted bent N,N'-donor ligand 2,5-bis-(3-pyridyl)-3,4-diaza-2,4-hexadiene (3-bpdh) and aliphatic dicarboxylate disodium succinate (suc) with Cd(II) perchlorate salts at room temperature by a slow diffusion technique for the exploration of our previous reported work. Both the structures were determined by single-crystal X-ray diffraction analysis and also by other physicochemical methods. Structure analysis revealed that complex 1 is a 1D chain structure containing coordinated perchlorate with a metal centre, and complex 2 shows a porous 3D framework with encapsulation of lattice water molecules into the void along the crystallographic a-axis. The PXRD study shows the bulk purity of both the complexes and TGA analysis of 2 exhibits that the structure is thermally stable up to 250 °C. Complex 1 shows a nice anion exchange property with replacement of weakly coordinated perchlorate with the inclusion of new anions; and the anion exchanged solids were characterised by FT-IR, PXRD and photoluminescence properties. The desolvated framework of 2 exhibits sorption of CO2 and water vapor and surface adsorption of N2 corroborating with the nature of the pore environment present in 2. The photoluminescence study has been also done for both complexes in the solid state which exhibits ligand based emissions at room temperature.

Cd(II) based metal-organic framework behaving as a Schottky barrier diode.

A metal-organic framework (MOF) of cadmium(ii) is reported here which is the first example of an experimentally achieved MOF based electronic device, and in the present case it is a Schottky diode.

Porous coordination polymers based on functionalized Schiff base linkers: enhanced CO2 uptake by pore surface modification.

We report the synthesis, structural characterization and adsorption properties of three new porous coordination polymers {[Cu(Meazpy)0.5(glut)](H2O)}n (2), {[Zn(azpy)0.5(terep)](H2O)}n (3), and {[Zn(Meazpy)0.5(terep)]}n (4) [glut = glutarate, terep = terephthalate, azpy = N,N'-bis-(pyridin-4-ylmethylene)hydrazine and Meazpy = N,N'-bis-(1-pyridin-4-ylethylidene)hydrazine] composed of mixed linkers systems. Structure determination reveals that all three compounds have three-dimensional (3D) coordination frameworks bridged by dicarboxylates and Schiff base linkers. In all cases 2D dicarboxylate layers are supported by paddle-wheel M2(CO2)4 SBUs extended in three dimensions by designed Schiff base linkers. Compound 1, which has been reported in a paper earlier by our group, is a robust porous three-dimensional (3D) framework whose pore surface was found to be decorated with the -CH=N- groups of a linear Schiff base (azpy) and it showed reversible single-crystal-to-single-crystal transformation and selective CO2 uptake. By using another linear Schiff base linker Meazpy, we have synthesized compound 2 which is isostructural with 1, having an additional methyl group pointing towards the pore. Like 1 it also shows a reversible single-crystal-to-single-crystal transformation upon dehydration and rehydration. The dehydrated framework of 2 exhibits 50% enhanced CO2 uptake compared to 1. This has been achieved by the pore surface modification effected upon changing the pillar backbone from a -CH=N- to -CMe=N- group. It also adsorbs water vapour at 298 K. In the case of the two isostructural 3D MOFs 3and 4, the use of a rigid carboxylate (terephthalate) linker arrested porosity by three-fold interpenetration. We showed that the use of aliphatic dicarboxylate (glutarate) results in a non-interpenetrated framework rather than the common interpenetrated framework with aromatic dicarboxylates in mixed ligand systems.

Fabrication of metal-organic hybrid architectures using bridging diphenyl phosphate: syntheses, characterization, magnetic properties and the effect of weak interactions on their crystal packing.

Ten different metal-organic hybrids of divalent metal ions have been synthesized using the diphenyl phosphate ligand and three different N,N donor spacers. All the complexes have been characterized by single crystal X-ray crystallography and other physico-chemical methods. For six complexes, the diphenyl phosphate (dpp) ligand acts as a bridge between the metal ions, whereas in four complexes dpp acts as a monodentate ligand. All nine complexes (1-9) show two dimensional coordination structures created by the N,N donor spacers, and, the remaining one (10) has a one dimensional ribbon-like structure. Here the aromatic rings present in the compounds viz. phenyl rings of dpp and the pyridyl rings of N,N donor spacers, have a key role to extend the dimensionality in their solid-state structures. In each instance, the aromatic rings of dpp and N,N donor spacers are nicely involved in the supramolecular structure generation by the help of π-π interactions. In all the cases, the role of weak interactions on the crystal packing and their effect in the generation of different supramolecular architectures has been thoroughly investigated. Variable temperature magnetic measurements of three relevant complexes have been carried out. Compounds 1 and 3 clearly indicate the existence of a weak antiferromagnetic interaction between the metal ions through the bridging dpp ligand. In 5, where dpp acts as a monodentate ligand; the metal ion may be considered as an isolated monomer.

A germanium(II) hydride as an effective reagent for hydrogermylation reactions.

Herein we report on the reactivity of the stable germanium(II) hydride LGeH (L = CH{(CMe)(2,6-iPr(2)C(6)H(3)N)}(2)) (2), which contains a low-valent germanium atom. 2 is prepared from the corresponding germanium(II) chloride LGeCl (1) using H(3)Al x NMe(3) or K[HB(iBu)(3)] in toluene. The reaction of 2 with carbon dioxide in toluene at room temperature affords a germanium(II) ester of formic acid, LGe-O-C(O)H (3), which is formed by insertion of the carbon dioxide into the germylene hydrogen bond. 2 also reacts with alkynes at room temperature to give the first germanium(II)-substituted alkenes (4, 5, and 6). These two reaction types have in common the fact that the hydrogen and germylene from LGeH are transferred to an unsaturated bond: the carbon-oxygen double bond (C=O) in the former case and the carbon-carbon triple bond (C[triple bond]C) in the latter. Moreover, the reaction of 2 with elemental sulfur in toluene at room temperature leads to the germanium dithiocarboxylic acid analogue LGe(S)SH (7). Compound 7 is formed by the unprecedented insertion of elemental sulfur into the germylene hydrogen bond and oxidative addition of elemental sulfur to the germanium(II) atom. This leads to the formal conversion of the GeH hydride to a SH proton. Compounds 3-7 were investigated by microanalysis, multinuclear NMR spectroscopy, and single-crystal X-ray structural analyses.

Structural diversity in manganese squarate frameworks using N,N-donor chelating/bridging ligands: syntheses, crystal structures and magnetic properties.

Three new polymeric squarato-bridged manganese complexes {[Mn(H(2)O)(2)(bpe)(sq)].bpe.H(2)O}(n) (1), [Mn(2)(H(2)O)(4)(phen)(2)(sq)(2)](n) (2) and [Mn(2)(H(2)O)(2)(phen)(4)(sq)].(sq).8(H(2)O) (3) [bpe, 1,2-bis(4-pyridyl)ethane; phen, 1,10-phenanthroline; sq, squarate dianion] have been synthesized and characterized by single crystal X-ray diffraction analysis and variable temperature magnetic studies. Complex 1 is a 2D rectangular grid-like structure, achieved through flexible bpe bridging ligands and squarate dianions. On the other hand the use of chelating phen instead of bpe gives rise to a 1D polymeric chain in complex 2 and to a dinuclear entity in 3. In all the three complexes weak interactions play a vital role in stabilizing the solid-state structure. Variable temperature (2-300 K) magnetic studies indicate weak antiferromagnetic coupling between the metal centres in all the complexes.

Polymeric networks of copper(II) using succinate and aromatic N-N donor ligands: synthesis, crystal structure, magnetic behaviour and the effect of weak interactions on their crystal packing.

Four succinato-bridged complexes of copper(II) have been synthesized. Complex 1, [Cu(2)(mu-OH(2))(2)L(bpy)(2)(NO(3))(2)](n) and 2, [Cu(2)(mu-OH(2))(2)L(phen)(2)(NO(3))(2)](n)(bpy = 2,2[prime or minute]-bipyridine; phen = 1,10-phenanthroline and LH(2)= succinic acid) exhibit 1D coordination polymer structures where both the nitrate ions are directly linked to the copper(ii) producing synthons in a 2D sheet. A novel 2D grid-like network, ([Cu(4)L(2)(bpy)(4)(H(2)O)(2)](ClO(4))(4)(H(2)O))n3, is obtained upon changing the nitrate by perchlorate anion in complex 1, where the channels are occupied by the anions. On changing the nitrate by tetrafluoroborate anion in complex 2, a novel octanuclear complex, [Cu(8)L(4)(phen)(12)](BF(4))(8).8H(2)O 4, is isolated. The coligand bpy and phen in these complexes show face-to-face (in 1,2,3,4) or edge-to-face (in 4 )pi-pi interactions forming the multidimensional supramolecular architectures. Interestingly, the appearance of edge-to-face pi-pi interactions in complex facilitates the formation of discrete octanuclear entities. Variable-temperature (300-2 K) magnetic measurements of complexes have been done. Complexes 1 and 2 show very weak antiferromagnetic (OOC-CH(2)-CH(2)-COO) and ferromagnetic coupling (mu-H(2)O). Complex 3 also shows antiferromagnetic (syn-syn mu-OCO), and ferromagnetic coupling (mu-O of the -COO group). Complex 4 with two types (syn-syn and syn-anti) of binding modes of the carboxylate group shows strong antiferromagnetic interaction.

A heterometallic polymeric complex: [Cu2(N3)2(medpt)2[Ni(CN)4]]n [medptis bis(3-aminopropyl)methylamine].

The structure of the title compound, catena-poly[[di-micro-azido-kappa(4)N(1):N(1)-bis[[bis(3-aminopropyl)methylamine-kappa(3)N]copper(II)]]-micro-cyano-[dicyanonickel(II)]-micro-cyano], [Cu(2)(N(3))(2)(medpt)(2)[Ni(CN)(4)]](n) [medpt is bis(3-aminopropyl)methylamine, C(7)H(19)N(2)] or [Cu(2)Ni(CN)(4)(N(3))(2)(C(7)H(19)N(3))(2)](n), is a one-dimensional heterometallic covalent chain where Ni(CN)(4)(2-) functions as a molecular ion bridge. The Ni atom sits on the centre of inversion. The chain undergoes hydrogen-bonding interactions, forming a three-dimensional supramolecular network.