The First Organic–Inorganic Hybrid Compound Based on Polyoxotungstates and Alkali-tris(imidazolyl) Segments with Electrocatalytic Activity

The first organic–inorganic hybrid compound based on the Keggin polyoxometalate and alkali-N-heterocycle ligand [Na₄(tib)₂(H₂O)₂(α-HBW₁₂O₄₀)]·2H₂O (1) (tib = 1,3,5-tris(1-imidazoly)benzene) was hydrothermally synthesized by utilizing a pH-dependent approach in the POM/Cu/tib reaction systems. X-ray structural analyses reveal that compound 1, formed in pH 5.2, possesses a (3,4,6)-connected 2D net with the (4²·5)(4⁶)(3³·4⁶·5²·6⁴) topology. In addition, electrochemical and electrocatalytic properties of compound 1 were studied by cyclic voltammograms. Compound 1 displayed electrocatalytic activities toward reduction of nitrite.     

Three New Cadmium Complexes Based on 3-Nitrophthalic Acid: Syntheses,Crystal Structures and Fluorescent Properties

Three metal–organic coordinate complexes based on 3-nitrophthalic acid (H₂NPA), namely Cd₂(H₂O)(OH)₂(NPA) (1), Cd₂(Im)₄(NPA)₂ (2) and Cd₂(Bim)₄(H₂O)(NPA)₂ (3) (Im = imidazole, Bim = benzimidazole), have been obtained by hydrothermal method and characterized by X-ray single crystal structure determination. Structural analysis reveals that complex 1 exhibits 2D layers constructed by polyhedral aggregates. Complex 2 exhibits a dinuclear cadmium structural unit and assembles by hydrogen bonds into a 2D supramolecular architecture. Complex 3 is assembled by NPA^2? into layers of a (3,4)-connected dinodal net topology of (4·5₂)(4·5₃·7₂). The fluorescent properties of complexes 1–3 have been investigated.     

Influence of anions on copper(II) complexes of a flexible bis-pyridyltrazole ligand: identification of a discrete water–chloride cluster [(H<Subscript>2</Subscript>O)<Subscript>10</Subscript>(Cl)<Subscript>8</Subscript>]<Superscript>8−</Superscript>

Three Cu(II) complexes, [Cu(H₂L)(ClO₄)₂] (1), [Cu(H₂L)_0.5(µ-SO₄)(H₂O)]·H₂O (2) and [{Cu(H₂L)(H₂O)}{Cu(H₂L)(Cl)]Cl₃·4H₂O (3), with a flexible ligand 1,2-bis(5-(pyridine-2-yl)-1,2,4-triazole-3-yl)ethane (H₂L) were synthesized from various Cu(II) salts. X-ray crystal structure analysis reveals that the H₂L ligand demonstrates different coordination modes in each of these complexes. Complex 1 shows a mononuclear structure with ClO₄ ^? anions weakly coordinated to the metal center, which is further extended into a 1-D assembly through hydrogen bonds. Complex 2 is a polymeric species in which the dinuclear units [Cu₂(H₂L)(H₂O)₂] are linked through SO₄ ^2? anions to form 1-D chains, which are further associated into a 2-D assembly through a self-assembled decameric water cluster. Complex 3 features an interesting 3-D coordination architecture assembled through extensive hydrogen interactions between chloride anions and water molecules. Notably, a unique discrete water–chloride cluster [(H₂O)₁₀(Cl)₈]^8? built around a chair-like water–chloride octameric core is identified in the crystal matrix of complex 3. The choice of counteranion plays a key role in the diverse structures of these complexes. The spectroscopic properties of the complexes have also been investigated.     

Topological insights in polynuclear Ni/Na coordination clusters derived from a schiff base ligand

This article presents the syntheses, crystal structures, topological features and magnetic properties of two Ni^II/Na^I coordination clusters formulated [Ni ₃ ^II Na(L1)₃(HL1)(MeOH)₂] (1) and [Ni ₆ ^II Na(L1)₅(CO₃)(MeO)(MeOH)₃(H₂O)₃]·4(MeOH) 2(H₂O) [2 4(MeOH) 2(H₂O)] where H₂L1 is the semi-rigid Schiff base ligand (E)-2-(2-hydroxy-3-methoxybenzylideneamino)-phenol). Compound 1 possesses a rare Ni ₃ ^II Na^I cubane (3M4-1) topology, and compound 2 is the first example in polynuclear Ni/Na chemistry that exhibits a 2,3,4M7-1 topology.     

Synthesis,crystal structures,and properties of copper(II) dicarboxylate complexes with [bis(2-pyridylcarbonyl)amido]

Four new complexes, [Cu₂(Bpca)₂(L¹)(H₂O)₂] · 3H₂O (I), [Cu₂(Bpca)₂(L²)(H₂O)₂] (II), [Cu₂(Bpca)₂(L³)] · 2H₂O (III), [Cu₂(Bpca)₂(L¹)(H₂O)] · 2H₂O (IV) (Bpca = bis(2-pyridylcarbonyl)amido, H₂L¹ = glutaric acid, H₂L² = adipic acid, H₂L³ = suberic acid, H₂L⁴ = azelaic acid) have been synthesized and characterized by single-crystal X-ray diffraction methods (CIF files CCDC nos. 1432836 (I), 1432835 (II), 817411 (III), and 817412 (IV)), elemental analyses, IR spectra. Structural analyses reveal that compounds I, II, and IV have similar structures [Cu(Bpca)]⁺ units bridged by dicarboxylate forming dinuclear units, whereas the dinuclear of compound III are edge-shared through two carboxylate oxygen atoms of different suberate anions. Hydrogen bonds are response for the supramolecular assembly of compounds I to IV. The temperature-dependent magnetic property of III was also investigated in the temperature range of 2 to 300 K, and the magnetic behaviour suggests weak antiferromagnetic coupling exchange.     

Two novel coordination polymers: Synthesis,structure, luminescent properties,and selective sensing of Cu<Superscript>2+</Superscript> and Mn<Superscript>2+</Superscript> ions

Two novel coordination polymers, namely {[Co(Ttac)_0.5(1,4-Bib)(H₂O)] · H₂O}_n (I) and {[La(HTtac)₂(2H₂O)] · H₂O}n (II) (H4Ttac = 4,5-di(3'-carboxylphenyl)-phthalic acid, 1,4-Bib = 1,4-bis(1-imidazoly) benzene), have been designed and successfully prepared via hydrothermal process, and characterized by elemental analyses, IR spectroscopy, and single crystal X-ray diffraction (CIF files CCDC nos. 1039298 (I), 1039300 (II)). Structural analysis reveals that the H₄Ttac ligands adopt different coordination modes in the as-synthesized I and II, and thus give rise to the targeted coordination polymers with different configurations. It is worth mentioning that, coordination polymer I is assembled from low-dimensional structures into three-dimensional (3D) via π···π stacking interactions, while three-dimensional coordination polymer II is formed by covalent bonds. Luminescent properties of coordination polymer II have been studied at ambient temperature. Significantly, luminescent measurement indicates that coordination polymer II may be acted as potential luminescent recognition sensors towards Cu²⁺ and Mn²⁺ ions.     

Helical Coordination Polymers Based on A Tripodal N‐donor Ligand

The coordination polymers [Cu₂(tpim)₂] · 2H₂O ( 1 ) and [Co(H₂tpim)₂(MoO₄)₂] ( 2 ) [Htpim = 2,4,5‐tri(4‐pyridyl)‐imidazole] were synthesized. Their structures were determined by single‐crystal X‐ray diffraction and further characterized by elemental analyses, IR spectroscopy, and TG analyses. Compounds 1 and 2 both contain chiral helical‐layer structures. Compound 1 exhibits a novel 3D (3,3,4)‐connected framework with (4 · 6 · 8)(6 · 8²)(4 · 6 · 8³ · 10) topology, which is constructed from left‐ and right‐ helices. Compound 2 displays a 2D chiral helical‐layer structure which can be rationalized as a (3,6)‐connected 2D kgd (kagome dual) net, and these 2D layers are further extended by hydrogen‐bonding interactions to form a 3D supramolecular network. By comparing compounds 1 and 2 , it is believed that the tripodal N‐containing ligand (Htpim) plays a key role in the construction of helical coordination polymers. In addition, the photoluminescence property of compound 1 and the magnetic property of compound 2 were studied.     

Cobalt(II) complexes with pentadentate Schiff bases 2,6-diacetylpyridine hydrazones: Syntheses and structures

Seven new cobalt(II) complexes based on the Schiff bases, 2,6-diacetylpyridine bis(isonicotinoylhydrazone) (H₂L¹) and 2,6-diacetylpyridine bis(nicotinoylhydrazone) (H₂L²), are synthesized and studied by X-ray diffraction analysis: [Co(H₂L¹)(NCS)₂] · 2.25H₂O (I), [Co(H₂L²)(NCS)₂] · CH₃OH (II), [Co(H₂L²)(NCS)(H₂O)]NCS (III), [Co(H₄L¹)(NCS)₂](NO₃)₂ · 2H₂O (IV), [Co(H₄L¹)(NCS)₂][Co(NCS)₄] · 0.75H₂O (V), [Co(H₄L²)(NCS)₂][Co(NCS)₄] · 1.75H₂O (VI), and [Co(H₂L²)(NCS)(CH₃OH)]₂[Co(NCS)₄] · 2CH₃OH (VII) (CIF files CCDC 941186 (I), 1457906 (Ia), 1457905 (II), 941187 (III), 1457907 (IV), 1457908 (V), 1457909 (VI), and 941188 (VII)). The organic ligands in the complexes act as pentadentate neutral H₂L or doubly protonated (H₄L)²⁺ coordinated through the same set of donor atoms N₃O₂. In all compounds I–VII, the coordination polyhedron of the Co²⁺ ion in a complex with the Schiff bases has a shape of a pentagonal bipyramid. The hydrazones are arranged in the equatorial plane of the bipyramid. Its axial vertices are occupied by the nitrogen atoms of the NCS￣ anions in compounds I, II, and IV–VI and by the nitrogen atoms of NCS￣ and oxygen of the water molecule in compound III or methanol in compound VII. The NO ₃ ^- anions or [Co(NCS)₄]^2￣ complex anions obtained by the reactions are involved along with the NCS￣ anions in the formation of compounds IV–VII.     

A multi-functional 3D polymolybdate-based copper(II) complex based on an asymmetric pyridyl-amide ligand: synthesis,structure and properties

A polymolybdate-based metal–organic compound {H₂[Cu₂(L)₂(Mo₈O₂₇)(H₂O)₄]} (1) [L = N-(pyridin-3-yl)isonicotinamide] has been synthesized under solvothermal (methanol–water mixed solvent) conditions and structurally characterized by single-crystal X-ray diffraction. Compound 1 exhibits a 3D metal–organic network containing unusual 1D [Mo₈O₂₇] _n ^6n? inorganic chains, with adjacent 1D chains connected by Cu(II) atoms and L ligands to form a 3D framework with a trinodal 4,4,6-connected {4².6³.8}₂{4⁴.6⁸.8³} topology. The electrocatalytic activities of compound 1 and its photocatalytic properties for the degradation of organic dyes have also been investigated.     

Use of symmetrical and pendant pyrazole derivatives for the construction of two polyoxometalate-based complexes as electrochemical sensors

Through the use of two pyrazole derivatives, one symmetrical, namely 1,1′-bis(3,5-dimethyl-1H-pyrazol-4-yl)methane (H₂bdpm), and one asymmetrical, namely 4-propyl-4,5-dihydro-1H-pyrazole (pdp), two polyoxometalate (POM)-based complexes constructed from saturated Wells–Dawson and mono-Cu(II)-substituted Keggin anions, respectively, were hydrothermally synthesized and structurally characterized as [(Cu₂(H₂bdpm)₂)[H₂P₂W₁₈O₆₂]_0.5]·2H₂O (1) and [(Cu₃(pdp)₆Cl₂)(H₅PMo₁₁CuO₃₉)₂]·12H₂O (2). In complex 1, the bidentate H₂bdpm ligands link Cu^I centers to form a 1D wave-like metal–organic chain. Adjacent chains are parallel with each other, with Wells–Dawson anions occupying the gaps. In complex 2, six pdp ligands are coordinated to three Cu^II centers to form a trinuclear cluster. Two Cl^? anions are also coordinated to the copper centers. The mono-Cu(II)-substituted Keggin anions connect the trinuclear clusters to construct a 2D grid-like structure. Both 1 and 2 are semiconducting in nature, with Eg valves of 2.61 and 2.81, respectively. The electrochemical behavior of both complexes has been studied. Carbon paste electrodes of both can be used as electrochemical sensors for the detection of hydrogen peroxide, bromate and nitrite.     

Zinc(II), nickel(II) and cadmium(II) coordination polymers based on the ligand oxamide <Emphasis Type="Italic">N,N</Emphasis>-bis(4-phthalic acid): synthesis,structural characterization and magnetic properties

Three coordination polymers based on the new ligand oxamide N,N-bis(4-phthalic acid), namely [Zn(L)_0.5-(2,2′-bpy)] _n (1), [Ni₂(2,2′-bpy)₄(µ ²-Ox)]L·3H₂O (2) and [Cd(L)(1,10-phen)] (3) [L = oxamide N,N-bis(4-phthalic acid)], (2,2′-bpy = 2,2′-bipyridine), (1,10-phen = 1,10-phenanthroline), have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction: compound 1 is one-dimensional ladder-like coordination polymer, compound 2 exhibits a three-dimensional structure resulting in extensive hydrogen bonds built with the help of lattice water molecules, compound 3 also exhibits a three-dimensional supramolecular structure. All compounds were also characterized by elemental analysis, IR spectra and thermogravimetric analysis; furthermore, the magnetic measurements for 2 reveal antiferromagnetic coupling between the nickel(II) ions.     

Hydroxyl Ammonium and Diethyl Ammonium Glutaratouranylates: Synthesis and Structure

The structures of two new coordination polymers, namely, hydroxyl ammonium glutaratouranylate NH₃OH[UO₂(C₅H₆O₄)(C₅H₇O₄)] · H₂O (I) and diethyl ammonium glutaratouranylate NH₂(C₂H₅)₂[UO₂(C₅H₆O₄) (C₅H₇O₄)] · 2H₂O (II), have been characterized by single-crystal X-ray diffraction. It has been established that the structures of complexes I and II contain [UO₂(C₅H₆O₄)(C₅H₇O₄)]–infinite chains with the crystallochemical formula AQ⁰²B⁰¹ (\(\rm{A = UO_2^{2+}}, Q^{02} = C_5H_6O_4^{2-}, B^{01} = C_5H_7O_4^{-}\)). Despite the identical compositions, uranyl glutarate chains in the studied structures appreciably differ from each other by their geometry and linking. The specific features of nonbonded interactions in the structures of complexes I and II have been characterized by the Voronoi–Dirichlet method of molecular polyhedra.     

Construction and catalytic activities of polyoxometalate-based compound containing helical chains

A polyoxometalate-based, inorganic–organic hybrid compound containing a helical structure along the a axis, [Ag(pyttz)₂][H₂PW₁₂O₄₀]·2H₂O (p-pyttz = 3-(pyrid-4-yl)-5-(1H-1,2,4-triazol-3-yl)-1,2,4-triazolyl), has been isolated and structurally characterized. Single-crystal X-ray diffraction analysis reveals that the new compound possesses two helical channels constructed by the left- and right-handed helical chains, respectively, which are fused together through sharing POMs dimer fabricating a 3-D framework with {4⁴·5³·6³} {4⁴·5³·6³} topolopy. The new compound displays good acid-catalytic activity toward the synthesis of Aspirin and good oxidation-catalytic activity to the decomposition of Rhodamine B dye; the catalytic reaction kinetics are discussed.     

Hydrogen Bonding and Iodine Bonding Interactions in Sustaining Two Coordination Polymers Base on Square Grids and Tetranuclear Cobalt Clusters

Two new coordination polymers [Co(H₂O)₂(bpy)₂]·2(Adi) (1) and [Co₄(OH)₂(Adi)₆(bpe)₂] (2) (HAdi = 4-amino-3,5-diiodobenzoic acid, bpy = 4,4′-bipyridine, bpe = 1,2-bis(4-pyridyl)ethylene) have been synthesized by methods of hydrothermal reactions and their crystal structures determined. In 1, the mononuclear Co atoms are linked by bpy ligands forming cationic two-dimensional square grids, which are connected by the intercalated Adi guest molecules through significant hydrogen-bonding interactions to give a three-dimensional supramolecular porous network with one-dimensional channels. 2 has a one-dimensional chain structure based on rhombic tetranuclear Co^II clusters, connected by bpe ligands. Through special I···I interactions, adjacent chains are extended into a three-dimensional supramolecular structure. The structure versatility indicates that the amino and iodo groups of Adi ligands play a crucial role in modulating the coordination polymers. A discussion of the crystal structures, thermal stabilities, as well as the noncovalent interactions of Adi molecules is provided. IR, elemental analysis and XRPD confirmed the phase purity of the bulk materials. Magnetic properties of 2 in the 300–2 K have been discussed, which reveal the occurrence of antiferromagnetic interactions between Co^II ions.     

Synthesis,crystal structures,and luminescent properties of three cluster-based heterometallic and monometallic compounds

Two heterometallic cluster compounds and one monometallic cluster compound, namely [Ni₉Co₆(PMIDA)₆(BTC)₂(H₂O)₁₂]·6H₂O (1), [Co₁₃Zn₂(PMIDA)₆(H₂O)₁₈]·6NO₃·15H₂O (2), and [Fe₁₅(PMIDA)₆(BTC)₂(H₂O)₂₂]·38H₂O (3), have been obtained under hydrothermal conditions using N-(phosphonomethyl)imino-diacetic acid (H₄PMIDA) and 1,3,5-benzenetricarboxylate acid (H₃BTC) as ligands, and structurally characterized by X-ray crystallography. Compound 1 exhibits a 3D open framework constructed from [Ni₉Co₆(PMIDA)₆(H₂O)₁₂]⁶⁺ heteronuclear clusters and BTC^3? ligands. Compounds 2 and 3 are both zero-dimensional polynuclear clusters, further extended into 3D supramolecular structures via hydrogen-bonding interactions. However, there are some differences in their crystal structures; compound 2 features an isolated spherical heteronuclear cation cluster based on PMIDA^4? ligands, such that the NO₃ ^? anions only balance the charge, whereas compound 3 is characterized as a neutral monometallic cluster incorporating two different types of organic acid ligands, namely PMIDA^4? and BTC^3?, and the two BTC^3? ligands exhibit regular distribution in each cluster. The luminescence properties of all three compounds have been investigated at room temperature.     

The Cu(II) complexes with bis(pyrazole-1-yl)methane and its derivatives: Synthesis,crystal structure,and magnetic properties

The procedures for the synthesis of the Cu(II) complexes with bis(pyrazole-1-yl)methane (L¹), bis(3,5-dimethyl-4-bromopyrazole-1-yl)methane (L²), and bis(3,5-dimethyl-4-iodopyrazole-1-yl)methane (L³) of the composition Cu₂(L¹)₂Br₄ (I), Cu₂(L²)₂Cl₄ (II), Cu(L³)(NO₃)₂ (III), and Cu(L³)(H₂O)(NO₃)₂ · 2H₂O (IV) were developed. The organic ligands in the above complexes are coordinated to Cu(II) in a bidentate cyclic type through the N(2), N(2′) atoms of the pyrazole rings. The molecular and crystal structures of L², L³, II, III, and IV were determined by X-ray diffraction. The study of the μ_eff(T) function in a temperature interval 2–300 K showed that compound I, which exhibited ferromagnetic exchange interactions in the chains, undergoes transition to antiferromagnetic state with weak ferromagnetism. The exchange antiferromagnetic interactions predominate in compound II.     

Examples of cation exchange in new ionic oxovanadium(IV) complexes with anions of cyclobutane-1,1-dicarboxylic acid

The results on the synthesis and study of the crystal structures of compounds based on anionic fragments {VO(Cbdc)₂}^2– formed by oxovanadium(IV) (vanadyl, VO²⁺) and two chelate-bound anions of cyclobutane-1,1-dicarboxylic acid (H₂Cbdc = C₄H₆(COOH)₂) are presented. The use of ammonium cation NH₄⁺ as a counterion in the synthesis leads to the formation of the mononuclear complex (NH₄)₂[VO(Сbdc)₂(H₂O)] · 2H₂O (I). In the case of K⁺ cation, compound [K₄(VO)₂(Сbdc)₄(H₂O)₄] _n (II) with the 3D polymeric crystal structure is formed. The reaction of compound II with Mg(NO3)2 · 6H₂O in an aqueous solution involves the partial substitution of K⁺ by Mg²⁺ cations to form 1D polymeric compound {[KMg_0.5(VO)(Сbdc)₂(H₂O)_6.5] · 3H₂O} _n (III), while a similar reaction of compound I does not afford the product of substitution of NH₄⁺ by Mg²⁺ cations (CIF files CCDC 1551021–1551023 for compounds I–III, respectively).     

Syntheses,Crystal Structures and Properties of Organic–Inorganic Hybrid Compounds of 4,4′-Bipyridine–Decorated Ni/Cu-Substituted Molybdophosphates

Organic–inorganic hybrid compounds of transition metal mono-substituted molybdophosphates, (H₂bipy)₂[PNi(Hbipy)Mo₁₁O₃₉]·4H₂O (1), (H₂bipy)_1.5[HPCu(Hbipy)Mo₁₁O₃₉]·4H₂O (2) (bipy = 4,4′-bipyridine), were synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy, TGA, fluorescent spectroscopy, powder and single crystal X-ray diffraction methods. In 1 and 2 the transition metal atom (Ni and Cu) occupies one site of twelve molybdenum atoms of Keggin anion and combines a monoprotonated bipyridine molecular cation, Hbipy⁺, forming a 4,4′-bipyridine–decorated M-substituted molybdophosphate anion (M = Ni and Cu). In 1 two anions form a dimer through hydrogen bonds, in 2 the anions form a chain through hydrogen bonds. The dimers or the chains, H₂bipy²⁺ cations and lattice water molecules are connected by hydrogen bonds, giving supramolecular compounds. The two kinds of bipy molecules, coordinated and uncoordinated, in 1 and 2 give two emission peaks in their photoluminescent spectra.     

Structure Modulation in Four New Coordination Polymers by In Situ Ligands Synthesis of Anthracene Derivatives and Various Auxiliary N-donor Ligands

Four novel coordination polymers, [Zn(HL¹)₂(phen)₂]·2CH₃OH·2H₂O (1), [ZnCl(HL¹)(4,4′-bipy)_0.5] _n (2), [Cd(HL¹)(L²)_0.5(2,2′-bipy)₂]·3H₂O (3), [Zn(L³)_0.5(N₃)_1.5(phen)] _n (4) (H₂L¹ = 9-(1H-tetrazole-5-yl)-10-carboxyl anthracene, H₂L² = 9,10-di-(1H-tetrazole-5-yl) anthracene, HL³ = 9-(1H-tetrazole-5-yl)-10-cyan anthracene, 1,10-phen = 1,10-phenanthroline, 4,4′-bipy = 4,4′-bipyridine, 2,2′-bipy = 2,2′-bipyridine), have been constructed by in situ ligands synthesis system. The formation of tetrazole-based ligands H₂L¹, H₂L² and H₂L³ involves the in situ Sharpless [2 + 3] cycloaddition reaction between 9,10-dicyanoanthracene (DCA) and NaN₃ in the presence of Zn²⁺/Cd²⁺ ions as Lewis-acid catalysts under hydro/solvothermal conditions. At the same time, there is also another in situ carboxyl ligand synthesis reaction by hydrolysis from nitrile in compounds 1 and 2. The four compounds have been characterized by elemental analysis, IR and single-crystal X-ray diffraction analysis. Compound 1 exhibits a butterfly-shaped mononuclear structure. Compound 2 represents a 2D framework constructed by six-membered {Zn₆} rings as secondary building units (SBUs). Compound 3 presents a dinuclear {Cd₂} structure with two butterflies “flying side by side” fashion. While compound 4 displays a 1D chain structure based on a dinuclear {Zn₂} SBUs. Moreover, the luminescence properties of 1–4 have been also investigated.     

Coordination assemblies of rigid–flexible 1,3-bis(5-(pyridine-2-yl)-1,2,4-triazole-3-yl)propane ligands with MCl<Subscript>2</Subscript> (M = Fe,Co, Cu or Zn): structural diversity and mass spectra

Reactions of the rigid–flexible N-heterocycle 1,3-bis(5-(pyridine-2-yl)-1,2,4-triazole-3-yl) propane (H₂L) with MCl₂ (M = Fe, Co, Cu or Zn) gave coordination complexes, {[Fe ₂ ^III Cl₄(H₂L)₂]·2Cl}·EtOH·H₂O (1), {[Co₃Cl₅(HL)]·H₂O} _n (2), {[Co₄Cl₄(H₂L)₂(H₂O)₄]·[CoCl₄]₂}·H₂O (3), [Cu₂Cl₃(HL)(H₂O)]₆·5H₂O (4), [Cu ₂ ^II Cu^ICl₄(HL)] _n (5), {[Zn₂Cl₂(L)H₂O]·H₂O} _n (6) and [Zn₄Cl₆(HL)₂] (7), which have been characterized by single-crystal X-ray diffraction. Structural analysis reveals that the pyridine triazole ligand attains versatile coordination modes in these complexes. Complexes 1, 3, 4 and 7 consist of 0D clusters with binuclear or tetranuclear units; complex 2 presents a 2D network accompanied by HL^? and chloride bridges; complexes 5 and 6 show 1D chains with [Cu₃] and [Zn₂] subunits. In addition, the electrospray ionization mass spectrometry properties of selected complexes were investigated, revealing the stabilities and structural states of these complexes in solution. These results indicate that H₂L is an excellent multiconnection linker for the construction of diverse coordination complexes.