Synthesis and Crystal Structure of a Novel Double-Chain Coordination Polymer [Zn<Subscript>2</Subscript>(bipy)<Subscript>2</Subscript>(btec)(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>]<Subscript>n</Subscript> (bipy = 2,2′-bipyridine; btec = 1,2,4,5-benzenetetracarboxylate)

Abstract  A novel aromatic polycarboxylate polymer, [Zn₂(bipy)₂(btec)(H₂O)₂]_n (1), has been synthesized and structurally characterized by the single crystal X-ray diffraction. Compound 1 belongs to the triclinic crystal system, space group P-1; a = 7.7449(6) ?, b = 8.9286(8) ?, c = 10.7422(8) ?, α = 80.95(1)°, β = 70.21(1)°, γ = 78.14(1)°, V = 680.93(10) ?³, Z = 2. The coordination geometry of Zn(II) atom is distorted trigonal bipyramidal with two nitrogen atoms of one 2,2′-bipy group, two oxygen atoms from two different btec ligands, and one water. The 16-membered rings are alternately arranged forming an infinite 1-D double-chain structure. A 3-D network was constructed by interlayer C···H–O, O···H–O hydrogen bonds and π–π stacking interactions. Compound 1 exhibits fluorescence at room temperature in the solid state. Graphical Abstract  A 1-D double-chain aromatic polycarboxylate polymer, [Zn₂(bipy)₂(btec)(H₂O)₂]_n (1), has been synthesized and structurally characterized by the single crystal X-ray diffraction. A 3-D network was constructed by intermolecular C···H–O, O···H–O hydrogen bonds and π–π stacking interactions. Compound 1 exhibits fluorescence at room temperature in the solid state.      

Hydrogen-bonded Three-dimensional Supramolecular Network Constructed by Dinuclear Ni(II) Macrocyclic Complex and 1,2,4,5-Benzenetetracarboxylate

Abstract  

A new coordination polymer [Ni₂(L)(H₂btec)]_n, (1) was obtained from the reaction of NiSO₄·6H₂O, macrocyclic ligand 3,6,9,17,20,23-hexaaza-29,30-dihydroxy-13,27-di-tert-butyl-tricyclo[23,3,1,1^11,15]triaconta-1(28),11,13,15(30),25,26-hexaene (H₂L), and 1,2,4,5-benzenetetracarboxylic acid (H₄btec) in methanol. Its structure was determined by X-ray diffraction analysis. The crystal is monoclinic C2/c space group with cell parameters a = 20.4923(3) ?, b = 14.2389(3) ?, c = 14.5130(2) ?, β = 97.441(2)°, V = 4199.05(12) ?³, and Z = 8. The X-ray analysis shows that each Ni (II) cation is six-coordinated by an O₃N₃ donor set. The macrocyclic complex [Ni₂L] ²⁺ are bridged by H₂btec²⁻ anions to form 1D chains, which are further joined via N–H···O hydrogen bonds to yield a 3D supramolecular structure. Thermogravimetric analysis (TGA) for the complex is discussed.     

Syntheses,Crystal Structures and Physical Properties of Cd(II) and Mn(II) Complexes with <Emphasis Type="Italic">Trans</Emphasis>-1,2-di(4-pyrindyl)ethylene and <Emphasis Type="Italic">P</Emphasis>-(carboxyl-methyloxy)-benzenecarboxylic Acid

Abstract  

Two complexes [Cd₂(dpe)₃(H₂O)₈]·(dpe)·(hssal)₂·(H₂O)₂ 1, [Mn(dpe)₂(Hpcmb)₂·(H₂O)₂] 2, (dpe = trans-1,2-di(4-pyrindyl)ethylene; H₂hssal = sulphosalicylic acid; H₂pcmb = p-(carboxyl-methyloxy)-benzenecarboxylic acid) has been prepared, and was characterized by elemental analysis, FT-IR and single-crystal X-ray diffraction. Structure indicates in complex 1 that Cd(II) is a distorted octahedral coordination geometry. The hssal²⁻ anions are localized between 2-D sheets {[Cd(dpe)₂(H₂O)₄]²⁺(dpe)}n and {{[Cd(dpe)₂(H₂O)₄]²⁺}n as count anions and bridge to further connect these 2-D sheets through hydrogen bond O–H···O to form 3-D structure. The complex 2 is a single molecule structure. In 2, Each Mn(II) atom is six-coordinated with a distorted octahedral coordination geometry. The single molecule units are extended into three-dimensional structure via π–π, hydrogen bonding interactions. The thermogravimetric behavior and luminescent property of complex 1 were investigated.     

Synthesis, Crystal Structure and Properties of the Binuclear Complex [Sm2(C10H9N2O4)2(C10H8N2O4)2(H2O)4]

Abstract  A novel binuclear Smarium (III) complex with N-(2-propionic acid)-salicyloyl hydrazone (C₁₀H₁₀N₂O₄, H₃L) was prepared and characterized. The crystal structure of [Sm₂(H₂L)₂(HL)₂(H₂O)₄] (1) was determined by X-ray single crystal diffractometry. 1 crystallizes in the monoclinic systerm, space group P2(1)/c, with a = 0.10229(2), c = 31.549(7), b = 0.70599(15) nm, and Z = 4. In the structure, Sm(III) is nine-coordinated by carboxyl O and acyl O atoms and imido N atoms of two ligands (H₂L and HL forms) and O atoms from two water molecules. H₂L and HL act as tridentate ligands which form two stable five-numbered chelating rings sharing one edge in the keto form for each ligand, and the carboxyl groups of two ligands were coordinated via bidentated bridging form. The coordination polyhedron around Sm (III) was described as a monocapped square antiprism. The inter- and intramolecular hydrogen bonds resulted in a three-dimensional network and provided extra stability for the structure. The complex was researched the interaction with calf thymus DNA by electronic absorption titration and emission titration. The results show that the complex is bound to calf thymus DNA mainly by intercalation .The complex also shows good fluorescence property. Index Abstract  The title compound, [Sm₂(H₂L)₂(HL)₂(H₂O)₄] was synthesized by the treatment of N-(2-propionic acid)-salicyloyl hydrazone (C₁₀H₁₀N₂O₄, H₃L) and Sm(NO₃) · 4H₂O and its crystal structure determined. Single crystal X-ray diffraction analysis reveals that Sm (III) is nine-coordinated by carboxyl O and acyl O atoms and imido N atoms of two ligands (H₂L and HL forms) and O atoms from two water molecules. The carboxyl groups of two ligands were coordinated via bidentated bridging form. The coordination polyhedron around Sm (III) was described as a monocapped square antiprism. The inter- and intramolecular hydrogen bonds resulted in a three-dimensional network and provided extra stability for the structure.      

Self-Assembly of Two Isomorphous Thiocyanate Complexes of Co(II) and Ni(II) with 3-Hydroxypicolinamide

Abstract  

The synthesis, thermal and spectral characterization, and crystal structure of isomorphous thiocyanate cobalt(II) and nickel(II) complexes with 3-hydroxypicolinamide (3-OHpia), [M(C₆H₆N₂O₂)₂(NCS)₂]·2H₂O, are reported. The metal(II) ions are chelated by two cis-oriented 3-OHpia and two thiocyanate ligands in distorted octahedral geometry. The distortion within the coordination sphere is mainly imposed by formation of the chelate rings. The compounds crystallize in monoclinic space group P2/c with two symmetrically independent molecules and a = 14.4945(2) ?, b = 8.5906(1) ?, c = 16.3865(3) ?, β = 105.987(2)°, Z = 4 (1) and a = 14.4927(5) ?, b = 8.5912(3) ?, c = 16.2712(6) ?, β = 105.740(4)°, Z = 4 (2). Commonly observed supramolecular amide synthons are not robust enough to accommodate thiocyanate ions and H₂O molecules. But instead, neutral complexes are linked through hydrogen bonds leading to two different hydrogen bonding ribbon motifs involving amide moieties and H₂O molecules [C(8)R ₂²(12) along c axis] and amide moieties and thiocyanate ions [C(8)R ₂²(16) along b axis] for symmetrically related molecules labelled as 1 [Co1 (1) and Ni1 (2)] and 2 [Co2 (1) and Ni2 (2)], respectively.     

Hydrothermal Syntheses and Structures of Lanthanide Coordination Polymers with 5-Aminoisophthalate and 1,10-Phenthroline

Abstract  

Two new lanthanide coordination polymers, [Ln₂(APA)₂(HAPA)₂(phen)₂] _n [Ln = Pr (1), Eu (2); H₂APA = 5-aminoisophthalic acid, phen = 1,10-Phenanthroline] have been synthesized by hydrothermal method, and characterized by single crystal X-ray diffraction, elemental analysis and IR spectra. Crystallographic data show that complexes 1 and 2 both crystallize in a triclinic system, space group P[`1] P\bar{1} . The titled compounds own 2-D herringbone structures which are further constructed to form 3-D supramolecular structures by N–H···O and O–H···O hydrogen bondings. The thermogravimetric analyses were carried out to examine the thermal stability of the title complexes. And the photoluminescence property of 2 was investigated.     

Self-Assembled Hydrogen-Bonding Chains of Copper(II) 2-Nitrobenzoate with Nicotinamide

Abstract  

The synthesis, spectral characterization and crystal structure of two new nitrobenzoatocopper(II) complexes, namely, [Cu₂(2-O₂Nbz)₄(nia)₂]·ACN (1) and [Cu₂(2-O₂Nbz)₄(ACN)₂] (2) (where 2-O₂Nbz = 2-nitrobenzoate, nia = nicotinamide and ACN = acetonitrile) are reported. The complexes 1 and 2 form dinuclear units of the paddle-wheel type around the crystallographic inversion centers. The copper ions are bridged by four 2-nitrobenzoate anions and the neutral N-donor ligands, viz. nicotinamide in 1 and acetonitrile in 2, are coordinated at apical positions. Selected geometric parameters of both complexes are compared with values for related tetra-2-nitrobenzoate complexes of copper(II) as well as the other dimeric copper(II) carboxylates with apical nicotinamide and acetonitrile ligands. The molecules of 1 are linked with N–H···O and C–H···O hydrogen bonds. The π–π stacking interactions in 1 are observed between benzene rings of 2-nitrobenzoate anions and pyridine rings of nicotinamide and also between acetonitrile molecules and benzene rings of 2-nitrobenzoate anions. The C–H···O hydrogen-bonds and CH/π interactions are observed in crystal structure of 2.     

Two Isostructural Complexes Constructed from Mixed Ligands of Dipyrido[3,2-d:2′,3′-f]quinoxaline and Phthalate with Novel Oxygen Clusters

Abstract Two isostructural dinuclear complexes [M₂(Dpq)₂(phth)₂(H₂O)₄] · 2H₂O [M = Zn(1), Ni(2), Dpq = dipyrido[3,2-d:2′,3′-f]quinoxaline, phth = phthalate] have been synthesized and characterized. Crystal data: (1), Mr = 1031.55, monoclinic, C2/c, a = 27.7948(11), b = 10.5196(4), c = 15.0390(5) ?, β = 110.818(1), Z = 4, V = 4110.2 ?³, R ₁ = 0.0277, wR ₂ = 0.0718 [I > 2σ(I)]; (2), Mr = 1018.19, monoclinic, C2/c, a = 27.675(4), b = 10.3601(15), c = 15.082(2) ?, β = 110.954(2), Z = 4, V = 4038.3 ?³, R ₁ = 0.0248, wR ₂ = 0.0668 [I > 2σ(I)]. The dinuclear units are connected into 2-D supramolecular net through O–H···O hydrogen bonding. Moreover, the 2-D networks are ultimately packed into a 3-D supramolecular structure via interlayer π···π stacking interaction between the aromatic rings of Dpq ligands. Furthermore, the photoluminescence property of compound 1 is also studied. Graphical Abstract Two isostructural dinuclear complexes [M₂(Dpq)₂(phth)₂(H₂O)₄] · 2H₂O [M = Zn(1), Ni(2), Dpq = dipyrido[3,2-d:2′,3′-f]quinoxaline, phth = phthalate] have been synthesized, and the structure study reveals that each dinuclear complex is connected with six other dinuclear units through the O–H···O hydrogen bonding to form 2-D supramolecular networks.      

Three New Complexes Based on a Flexible Bis(benzimidazole) Ligand and Rigid/Flexible Organic Carboxylates

Abstract  

Three new polymeric frameworks, [Ni(bbbm)(L1)₂] _n (1), [Ni(bbbm)(L2)₂] _n (2), and {[Co(bbbm)(L3)]·H₂O} _n (3) (bbbm = 1,4-bis(N-benzimidazolyl) butane, HL1 = 4-bromobenzoic acid, HL2 = 3-methylbenzoic acid, and H₂L3 = glutaric acid) have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 features a one-dimensional (1D) linear chain structure bridged by bbbm ligands, which is further connected into a supramolecular double chain structure through intermolecular π–π stacking interactions. Complex 2 contains 1D zigzag chain, which is further arranged into a 2D supramolecular architecture by hydrogen bonding and π–π stacking interactions. In the structure of 3, there are infinite 1D zigzag Co(II)-bbbm chains linked together by L3 ligands to generate an undulated 2D (4,4) sheet, which is further connected by intermolecular π–π stacking interactions to form a 3D supramolecular network. Furthermore, thermal stability and luminescent property of 1–3 were investigated.     

The Structure and Fluorescence Property of a 3D Supramolecular Network [Cd2(2-mBIM)2Cl2(C4H4O4)(H2O)2(H2O)]n

Abstract  

A cadmium(II) coordination polymer [Cd₂(2-mBIM)₂Cl₂(C₄H₄O₄)(H₂O)₂(H₂O)] _n (1) (wherein 2-mBIM = bis(2-methylimidazo-1-yl) methane, C₄H₄O₄ = succinate anion) has been synthesized and characterized by X-ray diffraction. Complex 1 crystallizes in the monoclinic space group C2/c with a = 23.5265(15) ?, b = 7.3558(5) ?, c = 17.4771(11) ?, β = 90.3560(10)°, V = 3024.5(3) ?³, Z = 4. Each Cd(II) atom is octahedrally coordinated and connected with two adjacent Cd(II) atoms by two individual 2-mBIM ligands in a trans-configuration to form one-dimensional (1D) helical structure. Such 1D helical chain structures were connected to each other via the succinate anion ligands and result in the formation of a two-dimensional (2D) framework. Meanwhile, an overall three-dimensional (3D) supramolecular network was formed via the weak hydrogen bond interactions between metal-coordination and free water molecules.     

Supramolecular Organization in Tetra Aqua (μ-8-Hydroxyquinoline-5-sulfonate) Barium (II) and Ag···I Interactions in a Pseudopolymorphic Form of (7-Iodo-8-hydroxyquinoline-5-sulfonate) Silver (I) Monohydrate

Abstract  

The complexes, Ba (HQS) (H₂O)₄ (HQS = 8-hydroxyquinoline-5-sulfonic acid) (1) and Ag (HIQS) (H₂O) (Ferron = 7-iodo-8-hydroxyquinoline-5-sulfonic acid) (2) have been synthesized and characterized by X-ray diffraction analysis and spectroscopic studies. In compound 1, Ba²⁺ ion has a nine-coordinate monocapped antiprismatic geometry. In compound 2, Ag⁺ has distorted tetrahedral coordination and Ag···I interactions generate the supramolecular architectures. The complexes have been characterized by FT-IR and UV–Visible measurements. In both the structures, the inversion-related organic ligands are stacked over one another leading to three-dimensional networks.     

Grid Constructed by Chain-Like Lanthanide(III) Acetate and Bridging Sulfate Ion: Synthesis, Crystal Structure, Thermal Stability and Luminescent Property

Abstract  

Five complexes of [Ln(OAc)SO₄(H₂O)₂] _n (HOAc = acetic acid, Ln = La-1, Pr-2, Nd-3, Sm-4, Eu-5) were hydrothermally synthesized. The three-dimensional supramolecular frameworks of title compounds are constructed by the layer of [Ln(OAc)SO₄(H₂O)₂] _n via the interlayer hydrogen bonding. The compound 5 exhibits strong red fluorescence in the visible region.     

Syntheses,Structures and Luminescent Properties of Zinc(II) and Cadmium(II) Complexes With the Ditopic Ligand 1,3-Bis(imidazol-1-ylmethyl)benzene

Abstract  

Three new complexes, namely [Zn(mbix)(SO₄)]·CH₃OH (1), Cd(mbix)₂(NO₃)₂ (2) and [Cd(mbix)₂(H₂O)₂]·(NO₃)₂ (3), have been obtained by reactions of flexible bidentate ligand 1,3-bis(imidazol-1-ylmethyl)benzene (mbix) with corresponding zinc(II) and cadmium(II) salts. The structures of these complexes have been determined by the X-ray single crystal diffraction analysis. Complex 1 features a 2D wavy network with (4,4) topology. Complex 2 has a 2D grid network with left- and right-handed helical chains, while complex 3 exhibits twofold parallel interpenetration structure. The differences of three complexes demonstrate that the coordination geometry of metal ions and the ratio of reactants have a great impact on the structure of the supramolecular architectures. The luminescent properties of three complexes are also investigated.     

Synthesis and Crystal Structures of Two Complexes with Carboxylic Derivatives of Nitrogen-containing Heterocycle Ligands

Abstract  

Two new complexes [Zn(pcn)₂(H₂O)₂] (1) and [Cd(inic)₂(H₂O)₄] (2) (pcn = 2-pyrazinecarboxylate, inic = isonicotinic acid) were synthesized by the hydrothermal reaction and characterized by single crystal X-ray diffraction, elemental analysis, IR spectrum and UV spectrum. In complex 1, the Zn(II) central ion is six-coordinated by two oxygen atoms and two nitrogen atoms from pcn ligands and two oxygen atoms from two coordinated water molecules. In complex 2, the Cd(II) central ion is six-coordinated by two nitrogen atoms from isonicotinate ligands and four oxygen atoms from the coordinated water molecules. Both complexes are mononuclear but hydrogen bonds enrich the structural construction. The visible spectra of the complexes between 200 and 300 nm are assigned to intraligand (IL) π–π* transitions of the pyridyl or pyrazine ligands.     

Metal-betaine interactions. IV. Crystal structures of trans-tetraaquabis(betaine)nickel(II) nitrate and trans-diaquatetrakis(pyridine betaine)cobalt(II) bis[trichloro(pyridine betaine)cobaltate(II)]

Two transition metal(II) complexes of betaine (Me₃N⁺CH₂COO^–, designated as BET) and pyridine betaine (C₅H₅N⁺CH₂COO^–, pyBET) have been prepared and investigated by X-ray crystallography and infrared spectroscopy. [Ni(BET)₂(H₂O)₄] (NO₃)₂ (1), (R _F=0.054 for 2518 observed MoK data) comprises slightly distorted octahedral [Ni(BET)₂(H₂O)₄]²⁺ cations in which the Ni(II) atom is centrosymmetrically coordinated by four aqua ligands and twotrans-related unidentate BET ligands, and the uncoordinated carboxy oxygens form intramolecular hydrogen bonds with the aqua ligands. [Co(pyBET)₄(H₂O)₂]·2[Co(pyBET)Cl₃] (2) (R _F=0.029 for 4696 observed data) consists of discrete octahedral [Co(pyBET)₄(H₂O)₂]²⁺ cations and tetrahedral [Co(pyBET)Cl₃]^– anions. In the centrosymmetric cation each of the twotrans-related aqua ligands form a pair of intramolecular hydrogen bonds with the uncoordinated oxygen atoms of two unidentate pyBET ligands. In the anion the cobalt atom is coordinated by one unidentate pyBET ligand and three chloro ligands.     

3D Solid-State Network from Hierarchical Supramolecular Self-Assembly of Transition Metal Complexes of Pyridine Based Ligand

Abstract  The crystal structures of [Cu(py)₄(ClO₄)](ClO₄) (1), [V(pic)₂(OH)](NO₃)₂ · H₂O (2) and [Ni(H₂O)₆][Ni(dpa)₂] · 2H₂O (3) [py = Pyridine, picH = Pyridine-2-carboxylic acid, dpaH₂ = Pyridine-2,6-dicarboxylic acid] was determined by single-crystal X-ray diffraction techniques. Solid-state structural analysis shows that all these complexes from extensive 3D network structure via supramolecular self-assembly. The crystal structures are stabilized by extended hydrogen bonding interactions. The complex 2 forms orange V₂O₅ micro spheroids when heated at ~400 °C for 6 h. Graphical Abstract  Hierarchical supramolecular self-assembly of transition metal complexes of pyridine based ligands in crystal. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Crystal Structure and Photoluminescent Properties of Two Cadmium(II) Complexes with Orotic Acid

Abstract  

Assembly of orotic acid (2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid, H₃dtpc) and Cd(OAc)₂·2H₂O gave rise to two complexes [Cd₂(H₂dtpc)₂(H₂O)₆] (I) and [Cd(H₂dtpc)(bpy)(H₂O)]_n (II) (bpy = 2,2′-bipyridine). Complex (I) and (II) have been characterized by X-ray single crystal diffraction, IR, PXRD, TGA and fluorescence spectra. Structural analyses reveal that (I) is a binuclear structure, and complex (II) possesses a one-dimensional infinite zig-zag chain architecture and the chains are further assembled into 2D supramolecular network by strong hydrogen bonding interactions. Crystal data for (I): Monoclinic, space group P2(1)/n, a = 9.3221(19) ?, b = 6.6315(13) ?, c = 15.322(3) ?, β = 102.31(3)°, V = 925.4(3) ?³, Z = 4, R1 = 0.0269, and wR2 = 0.0604; for (II): Monoclinic, space group P2(1)/c, a = 9.9880(2) ?, b = 14.5085(2) ?, c = 11.6957(2) ?, β = 107.976(2)°, V = 1612.10(5) ?³, Z = 4, R1 = 0.0234 and wR2 = 0.0554.     

Synthesis,Characterziation and SOD Activity of Manganese(II) Complexes with Aza-Macrocyclic Ligand

Abstract  

Two manganese(II) complexes, [Mn₂(L)(H₂O)₄]Cl₂·6H₂O(1) and [Mn₂L(NCS)₂(H₂O)₂]·3H₂O(2) (L is 1,2,4-triazolato)-4,12,17,25-tetramethyl-1,2,5,8,11,14,15,18,21,24-decaza-4,11,17,24-cyclohexaeicosatetraene) have been prepared by template synthesis method. They are characterized by elemental analysis and IR. Single-crystal X-ray analysis reveals that complex (1) crystallizes in space group P 2₁/c with a = 8.710(3), b = 14.720(5), c = 14.301(5) ?, α = 90, β = 105.801(14), γ = 90°. The complex [Mn₂(L)(H₂O)₄]Cl₂·6H₂O consists of two manganese(II) macrocyclic complexes in which two Mn(II) centers are linked by two triazolate units of the macrocyclic framework. Each manganese(II) ion is coordinated by five nitrogen atoms from the macrocycle and two oxygen atoms of the coordinated water. The manganese(II) center is in an approximately pentagonal-bipyramidal environment. The SOD activities of both complexes have also been investigated.     

Synthesis, Crystal Structure and Magnetic Behaviour of {[Yb(1,4-BDC)1.5(H2O)4]·H2O}n (1,4-BDC?=?1,4-benzenedicarboxylate)

Abstract  

The title complex {[Yb(1,4-BDC)_1.5(H₂O)₄]·H₂O}_n (1) (1,4-BDC = 1,4-benzenedicarboxylate) has been hydrothermally synthesized and structurally characterized by the single crystal X-ray diffraction. Crystals of compound 1 belongs to the triclinic crystal system, space group P-1; a = 7.549(3) ?, b = 10.072(4) ?, c = 10.470(4) ?, α = 87.810(4)°, β = 82.531(4)°, γ = 86.306(4)°, V = 787.3(5) ?³, Z = 2. The Yb(III) atoms are linked by the deprotonated 1,4-BDC ligands in two kinds of bridging modes. Four Yb(III) atoms at each corner (nodes) and four 1,4-BDC ligands at each edge (spacers) form a edge–sharing 36-membered rings. The rhombohedral Yb₄(1,4-BDC)₄ arranged in an alternating fashion to construct a 1D ladder-like chain along the c axis. Two neighboring chains are linked to each other in a parallel fashion to construct 3D supramolecular structure by O–H···O hydrogen bonds and π–π stacking interactions. In addition, the properties of thermogravimetric analysis and magnetic behaviors of the complex have been also discussed.     

Syntheses and Structural Characterization of Three New Alkaline Earth Metal Supramolecular Coordination Compounds Based on Atza Ligand (Atza = 5<Emphasis Type="Bold">-</Emphasis>Aminotetrazole<Emphasis Type="Bold">-</Emphasis>1<Emphasis Type="Bold">-</Emphasis>Acetato Anion)

Abstract  

Reactions of alkaline earth metal salts M(NO₃)₂ (M = Mg, Ca, Sr) and ligands 5-aminotetrazole-1-acetic acid (Hatza) in water/methanol solution, respectively, produced three new complexes [Mg(atza)₂(H₂O)₄] (1), [Ca(atza)₂(H₂O)₄] (2) and [Sr(atza)₂(H₂O)₃]^.2H₂O (3). These compounds were structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Compounds 1 and 2 have a mononuclear structure and the same coordination mode. Compound 3 has a 1D polymeric chain structure. In 1–3, amido group (–NH₂) of atza ligand forms hydrogen bond N(5)–H(5)···N(O) with the neighboring carboxylate-O, tetrazolate-N or water molecule which stabilized the supramolecular assemblies.