Copper(II) and lead(II) complexes based on 2,3,5,6-tetrakis(2-pyridyl)pyrazine as a polydentate ligand

The Cu(II) complexes [Cu(Tppz)(Dipic)] · 8H₂O (I) and [Pb₂(Tppz)Cl₄] _n (II), where Tppz, H2Dipic are 2,3,5,6-tetrakis(2-pyridyl)pyrazine, dipicolinic acid, respectively, have been synthesized and characterized by elemental analyses, IR, cyclic voltammetry, and electronic spectral studies. Solid state structures of both complexes have been determined by single crystal X-ray crystallography. An ORTEP drawing of two complexes shows that the coordination geometry around the metal center is a distorted octahedron. There are extensive conventional intermolecular O-H…O, N-H…O, and weaker C-H…O and C-H…Cl non-classical hydrogen bonds, which cause the stability of the crystal structure. Crystal data for I: monoclinic, space group: C2/c, a = 35.421(3), b = 8.422(6), c = 22.824(8) Å, β = 101.69(2)°, V = 6668(5) ų, Z = 8. Crystal data for II: triclinic, space group P \(\bar 1\) , a = 7.9534(4), b = 8.8682(5), c = 9.4245(5) Å, β = 95.086(2)°, V = 655.93(6) ų, Z = 2.     

Heteroligand zinc(II) and copper(II) complexes with naphthylacetic acid and monoethanolamine: Syntheses and crystal structures

New heteroligand Cu(II) and Zn(II) complexes with the α-naphthylacetic acid anion (NAA) and monoethanolamine (MEA), [M(NAA)₂(MEA)₂] (M = Cu²⁺, (I), Zn²⁺ (II)), are synthesized. The crystal structures of the obtained complexes are determined by X-ray diffraction analysis (CIF files CCDC 984097 (I) and 930946 (II)). The crystals are monoclinic, for I: a = 18.8140(9) Å, b = 4.82500(14) Å, c = 16.0360(7) Å, β = 115.135(6)°, V = 1317.87(11) ų, space group P2₁/c, Z = 2; for II: a = 32.9760(14) Å, b = 5.0911(3) Å, c = 15.7994(10) Å, β = 94.418(5)°, V = 2644.6(3) ų, space group C2/c, Z = 4. In the structure of complex I, the Cu²⁺ ion arranged in the symmetry center is coordinated at the vertices of the distorted octahedron by the oxygen atoms of two NAA molecules (Cu-O(2) 2.019(4) Å) and two MEA molecules. The latter is the bidentate-chelating ligand and coordinates the metal through the O and N atoms to form the five-membered metallocycle (Cu-O(3) 2.457(5), Cu-N(1) 1.986(5) Å). In complex II, the Zn atom (on axis 2) is coordinated at the vertices of the distorted tetrahedron by the oxygen atoms of two NAA molecules (Zn-O(2) 1.976(4) Å) and the nitrogen atoms of two MEA molecules (Zn-N 2.034(6) Å). The character of the interaction of coordinated NAA and MEA ligands and methods for packing complexes I and II are considered on the basis of the structural data.     

Synthesis and crystal structures of cobalt(III) and zinc(II) complexes derived from 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol with urease inhibitory activity

A new mononuclear cobalt(III) complex, [CoL₂(N₃)]₂ · CH₃OH (I), and a new mononuclear zinc(II) complex, [ZnLCl(CH₃OH)] (II) (HL = 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol), were prepared and structurally characterized by elemental analyses, infrared spectroscopy, and single- crystal X-ray diffraction. The crystal of I is monoclinic: space group P2₁/c, a = 18.742(2) Å, b = 15.197(2) Å, c = 25.646(2) Å, β = 125.996(3)°, V = 5909.8(11) ų, Z = 4. The crystal of II is monoclinic: space group P2₁/c, a = 7.257(1) Å, b = 24.707(2) Å, c = 9.637(1) Å, β = 101.557(2)°, V = 1692.9(3) ų, Z = 4. The Co atom in I is in an octahedral coordination, and the Zn atom in II is in a trigonal-bipyramidal coordination. The urease inhibitory test shows that complex I has strong urease inhibitory activity, while complex II has no activity.     

Hydrothermal synthesis, crystal structure, and photoluminescence of Pb(II) and Mn(II) coordination polymers based on imidazo[4,5-f][1,10]phenanthroline

Two new coordination polymers, [Pb(IDPT)₂(NO₃)₂] (I) and [Mn(IDPT)(SO₄)(H₂O)₂] (II) (IDPT = imidazo[4,5-f][1,10]phenanthroline), were synthesized by hydrothermal method and characterized by elemental analysis and single-crystal X-ray diffraction technique. The results reveal that the complex I belongs to monoclinic crystal system, space group C2/c and complex II belongs to monoclinic crystal system, P2₁/c space group. The cell parameters are: a = 19.1970(13), b = 7.3875(5), c = 17.3825(12) Å, β = 100.47(10)°, V = 2424.0(3) ų, Z = 4, F(000) = 1488 for I; a = 10.9135(6), b = 7.0230(4), c = 19.7034(10) Å, β = 99.32(10)°, V = 1490.25(14) ų, Z = 4, F(000) = 828 for II. In the structure of complex I, the metal center Pb(II) is six-coordinated, displays an octahedral geometry. Each molecule is further connected with neighboring one via π-π interactions into 1D chain. In complex II, Mn(II) is six-coordinated to form a distorted octahedral geometry. Compound II displays 1D supramolecular chain formed through hydrogen bonds. Additionally, the fluorescent properties for the complexes were investigated. Complexes I and II exhibit strong photoluminescence with emission maximum at 583 and 529 nm at room temperature.     

Cadmium(II) iodide molecular coordination compounds with 4-methylpyridine and 4-methylquinoline

The coordination compounds [CdI₂(4-MePy)₂] (I) and [CdI₂(4-MeQuin)₂] (II) where Quin is quinoline have been synthesized, and their structure has been solved. Crystals of complex I are monoclinic, space group C2/c, a = 13.353(1) Å, b = 16.653(1) Å, c = 14.380 (1) Å, β = 103.17(1)°, V = 3113.5(4) ų, ρ_calcd = 2.425 g/cm³, Z = 8. Crystals of complex II are monoclinic, space group P2₁/c, a = 10.647(1) Å, b = 25.264(1) Å, c = 8.610(1) Å, β = 113.73(1)°, V = 2120.1(3) ų, ρ_calcd = 2.044 g/cm³, Z = 4. Polymer [CdI₂(4-MePy)₂]_∞ chains running in the direction [001] are formed in the structure of complex I. Each of the two crystallographically nonequivalent Cd(1) and Cd(2) atoms are octahedrally surrounded by the four iodine and two nitrogen atoms of the 4-MePy ligand. The Cd(1)?Cd(2) distance in a chain is 4.33 Å. The structure of complex II is built of [CdI₂(4-MeQuin)₂] discrete neutral clusters. The two iodine and two nitrogen atoms of the 4-MeQuin ligand participate in the coordination of the Cd²⁺ ion. The cadmium coordination polyhedron is a distorted tetrahedron (Cd-I_avg, 2.72 Å; Cd-N_avg, 2.30 Å; angles N(I)CdN(I), 98.3–121.8°). The minimum and maximum values correspond to the ICdI angle and NCdN angle, respectively. Complex I is photoluminescent in the solid state at room temperature.     

Diaquabromo(18-crown-6)rubidium and triaqua(18-crown-6)barium dibromide monohydrate: Synthesis and crystal structures

Two complexes are synthesized: diaquabromo(18-crown-6)rubidium [RbBr(18-crown-6)(H₂O)₂] (I) and triaqua(18-crown-6)barium dibromide monohydrate [Ba(18-crown-6)(H₂O)₃]²⁺ 2Br^? · H₂O (II). The orthorhombic structure of compound I (space group Pnma, a = 10.124 Å, b = 15.205 Å, c = 12.544 Å, Z = 4) and the monoclinic structure of compound II (space group C 2/c, a = 17.910 Å, b = 10.315 Å, c = 14.879 Å, β = 123.23°, Z = 4) are determined by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.063 (I) and 0.042 (II) for all 2293 (I) and 3363 (II) independent measured reflections (CAD-4 automated diffractometer, λMoK _α). The complex molecule [RbBr(18-crown-6)(H₂O)₂] in compound I and the randomly disordered cation [Ba(18-crown-6)(H₂O)₃]²⁺ in compound II are of the host-guest type: their Rb⁺ or Ba²⁺ cation (its coordination number is nine) is located in the cavity of the 18-crown-6 ligand and coordinated by all six O atoms. In structure I, the coordination polyhedron of Rb⁺ is a distorted hexagonal pyramid with a triple apex at the Br^? ligand and two O atoms of the water molecules. In structure II, the Ba²⁺ polyhedron is a distorted hexagonal bipyramid with one apex at the O atom of the water molecule and the other split apex at two O atoms of water molecules.     

Crystal structures of allyltriphenyl-phosphonium halogenocuprates(I)

Alternating-current electrochemical synthesis is used to obtain for the first time halogenocuprates of an allyl derivative of phosphonium of the composition (CH₂=CHCH₂(C₆H₅)₃P)CuX₂ (X = Br (I), Cl (II)). Compound I crystallizes in the space group P2₁, a = 9.6341(3) Å, b = 12.4167(4) Å, c = 9.9618(4) Å, β = 117.484(5)°, Z = 2. Compound II crystallizes in the space group P2₁/n, a = 9.9725(5) Å, b = 15.4586(8) Å, c = 13.7557(5) Å, β = 90.429(4)°, Z = 4. In the structures of I and II quasilinear CuX ₂ ^? anions are held by C-H…X hydrogen bonds inside a framework formed by the stacking of phenyl groups from CH₂=CHCH₂(C₆P₅)₃P⁺ cations. Allyl groups are not involved in coordination with copper(I) atoms.     

Crystal and molecular structures of ZnPhen(C2H5OCS2)2 and Zn(2,2′-Bipy)(n-C4H9OCS2)2 mixed-ligand coordination compounds

ZnPhen(EtOCS₂)₂ (I) and Zn(2,2′-Bipy)(n-BuOCS₂)₂ (II) mixed-ligand complexes have been synthesized. The structures were solved from X-ray diffraction data (CAD-4 and X8-APEX diffractometers, MoK _α radiation, 1879 and 3637 F _hkl , R = 0.0374 and 0.0315). Crystals I are monoclinic with parameters a = 11.678(3) Å, b = 19.215(3) Å, c = 9.655(1) Å; β = 101.23(1)°; V = 2125.0(7) ų; Z = 4, space group P2₁/c; crystals II are triclinic with parameters a = 8.7875(3) Å, b = 11.833(1) Å, c = 13.3454(6) Å; α = 112.154(2)°, β = 108.503(1)°, γ = 92.787(2)°; V = 1196.2(1) ų; Z = 2, space group 1 $P\bar 1$ . The structures are composed of discrete mononuclear molecules. The polyhedra of the Zn atoms are distorted trigonal bipyramids N₂S₃ formed by coordination of the N atoms of Phen or 2,2′-Bipy molecules and sulfur atoms of the monodentate and cyclic bidentate xanthogenate ligand. In structures I and II, dimer assemblies are formed by π-π interactions of Phen or 2,2′-Bipy molecules.     

Synthesis,crystal structures,and biological property of dinuclear oxovanadium(V) complexes derived from tridentate Schiff bases

A pair of structurally similar dinuclear oxovanadium(V) complexes, [VO₂L¹]₂ (I) and [VO₂L²]₂ (II), where L¹ and L² are the mono-anionic form of 2-[(2-isopropylaminoethylimino)methyl]-4-methylphenol (HL¹) and 4-fluoro-2-[(2-isopropylaminoethylimino)methyl]phenol (HL²), respectively, have been synthesized and characterized by elemental analysis, FT-IR spectra, and single crystal X-ray determination. The crystal of I is monoclinic: space group P2₁/c, a = 12.528(1), b = 12.266(1), c = 9.432(1) Å, β = 104.814(3)°, V = 1401.2(3) ų, Z = 2. The crystal of I is monoclinic: space group P2₁/n, a = 12.3128(5), b = 6.5124(3), c = 17.1272(7) Å, β = 105.863(1)°, V = 1321.1(1) ų, Z = 2. The V…V distances are 3.210(1) Å in I and 3.219(1) Å in II. The V atoms in the complexes are in octahedral coordination. Biological assay indicates that complex II, bearing fluoro-substitute groups, has stronger antimicrobial activity against most bacteria than complex I which bearing methyl-substitute groups.     

Synthesis and crystal structure of zinc(II) and manganese(II) complexes of 2-(diphenylacetyl)indandione-1,3

Zinc(II) and manganese(II) complexes of 2-(diphenylacetyl)indandione-1,3 (HL) were synthesized. Crystals of [M(DMSO)₂L₂] · CHCl₃, where M= Zn^(II) (I) and Mn^(II) (II), obtained from chloroform plus dimethyl sulfoxide (DMSO) mixture were found to be isostructural based on the similarity of their unit cell parameters and unit cell volumes. The crystals are triclinic, Z = 2, space group P \(\bar 1\); a = 10.422(1) Å, b = 11.929(1) Å, c = 20.429(1) Å, α = 73.616(1)°, β = 85.095(1)°, γ = 77.586(1)° for complex I; a = 10.436(1) Å, b = 12.297(1) Å, c = 19.924(2) Å, α = 78.138(2)°, β = 87.625(2)°, γ = 82.048(2)° for complex II. X-ray structural analysis of complex I was carried out. For complex II, the structure was not refined because all of its atoms are each disordered over three to five positions. The two DMSO molecules in complex I coordinate the central metal atoms in the monodentate mode via their donor oxygen atoms to occupy an axial position and an equatorial position in an octahedral polyhedron. The other four positions are occupied by the four oxygen atoms of the two deprotonated ligands L^? coordinated in the bidentate-cyclic mode. The outer sphere of complex I contains the solvating chloroform molecule.     

Hydrothermal synthesis and structural characterization of a new one-dimensional ladder-shaped metal-organic framework Zn(HTci)(4,4′-bipy)0.5 · H2O (H3Tci = tri(2-carboxyethyl)isocyanurate, 4,4′-bipy = 4,4′-bipyridine)

A new metal-organic coordination polymer, namely, Zn(HTci)(4,4′-Bipy)_0.5 · H₂O (I) (H₃Tci = tri(2-carboxyethyl)isocyanurate, 4,4′-Bipy = 4,4′-bipyridine), has been synthesized under hydrothermal conditions by the reaction of zinc nitrate, H₃Tci, and 4,4′-Bipy with the presence of H₂O and characterized by elemental analysis, IR and X-ray single-crystal diffraction. The X-ray diffraction analysis reveals that I crystallizes in the triclinic system, $P\bar 1$ space group. The unit cell parameters for I: a = 5.248(1), b = 12.537(2), c = 14.597(2) Å, α = 91.91(1)°, β = 91.22(2)°, γ = 95.75(1)°, V = 954.8(3) ų, Z = 2.     

Acid Co(II) and Ni(II) trifluoroacetate complexes: Synthesis and crystal structure

Anhydrous and partially hydrated acid trinuclear trifluoroacetates of divalent transition metals of the composition [M₃(CF₃COO)₆(CF₃COOH)₆)](CF₃COOH) and [M₃(CF₃COO)₆(CF₃COOH)₂(H₂O)₄)](CF₃COOH)₂, respectively, where M = Co (I, III) Ni (II, IV), were synthesized and studied by X-ray diffraction. Complexes I and II were obtained by crystallization from solutions of M(CF₃COO)₂ · 4H₂O in trifluoroacetic anhydride; complexes III and IV were synthesized under the same conditions with the use of 99% trifluoroacetic acid as a solvent. Crystals I are triclinic: space group $P\bar 1$ , a = 13.199(6) Å, b = 14.649(6) Å, c = 15.818(6) Å, α = 90.04(4)°, β = 114.32(4)°, γ = 108.55(4)°, V = 2611.3(19) ų, Z = 2, R = 0.0480. Crystals II are trigonal: space group $R\bar 3$ , a = 13.307(2) Å, c = 53.13(1) Å, V = 8148(2) ų, Z = 6, R = 0.1112. Crystals III are triclinic: space group $P\bar 1$ , a = 9.001(8) Å, b = 10.379(9) Å, c = 12.119(9) Å, α = 83.67(5)°, β = 72.33(5)°, γ = 83.44(5)°, V = 1068.3(15) ų, Z = 1 Å, R = 0.1031. Crystals IV are triclinic: space group $P\bar 1$ , a = 9.121(18) Å, b = 10.379(2) Å, c = 12.109(2) Å, α = 84.59(3)°, β = 72.20(3)°, γ = 82.80(3)°, V = 1080.94(40) ų, Z = 1, R = 0.0334.     

Synthesis and crystal structure of the copper(II) valerate complex with nicotinamide

A coordination compound of copper(II) valerate with nicotinamide, [CuL(C₄H₉COO)₂]₂ (I), has been synthesized, and its crystal structure has been determined by X-ray crystallography. The crystals of I are triclinic: a = 9.1245(9) Å, b = 9.8572(6) Å, c = 11.0944(9) Å, α = 73.51(1)°, β = 79.917(6)°, γ = 72.161(7)°, Z = 2, space group $P\bar 1$ . In the centrosymmetric binuclear molecule of I, the copper atoms (Cu...Cu′, 2.621 Å) are linked through four bidentate chelating valerate ligands (av., Cu-O 1.969 Å). The coordination polyhedron of the Cu atom is a tetragonal pyramid with the nitrogen atom of the pyridine ring in the apical position at a longer distance (Cu-N, 2.190 Å).     

Synthesis and crystal structures of dimeric schiff base oxovanadium(V) complexes with antimicrobial activity

Two new dimeric oxovanadium(V) complexes, [VO₂L₁]₂ · 2H₂O (I) and [VO₂L₂]₂ (II), where L¹ and L² are the monoanionic form of 5-methoxy-2-[(2-methylaminoethylimino)methyl]phenol (HL¹) and 5-diethylamino-2-[(2-methylaminoethylimino)methyl]phenol (HL²), respectively, have been synthesized and characterized by elemental analysis, FT-IR spectra, and single crystal X-ray determination. The crystal of I is monoclinic: space group P2₁, a = 6.858(2), b = 16.630(3), c = 12.306(2) Å, β = 103.985(2)°, V = 1361.9(5) ų, Z = 2. The crystal of II is triclinic: space group $P\bar 1$ , a = 7.378(2), b = 8.838(2), c = 13.312(3) Å, α = 102.576(2)°, β = 92.044(2)°, γ = 113.017(2)°, V = 772.7(3) ų, Z = 2. The V...V distances are 3.140(1) Å in I and 3.254(1) Å in II. The V atoms in the complexes are in octahedral coordination. The effect of the complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.     

Structure and characterization of A 2D cobalt(II) complex [Co(L)2] n (L = 3-nitro-5-(pyridine-4-yl)benzoate)

The self-assembly of unsymmetrical tecton 3-nitro-5-(pyridin-4-yl)benzoic acid (HL)with cobalt chloride under hydrothermal conditions affords a new 2D coordination polymer [Co(L)₂] _n (1, L = 3-nitro-5-(pyridin-4-yl)benzoate), which is characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction analysis, and single crystal X-ray diffraction. Compound 1 is of the triclinic system, space group P-1 with a = 9.7857(12) Å, b = 10.3417(13) Å, c = 10.8463(13) Å, α = 85.155(2)°, β = 74.785(2)°, γ = 88.962(2)°, V = 1055.4(2) ų. The crystal structural analysis of complex 1 shows that the cobalt center is six-coordinated in an octahedral geometry by four O atoms from four different L ligands and two N atoms from two different L ligands; the Co(II) cations are bridged by μ₃-L into an interesting two-dimensional network structure. It should be pointed out that the thermal analysis results indicate that complex 1 is quite stable up to 420°C.     

Synthesis and study of tetraamminecobalt hydrogen hexamolybdometalates(III)

Tetraamminecobalt hydrogen hexamolybdoferrate [Co(NH₃)₄] · H[FeMo₆O₁₈(OH)₆] · 6H₂O (I) and tetraamminecobalt hydrogen hexamolybdogallate(III) [Co(NH₃)₄] · H[GaMo₆O₁₈(OH)₆] · 6H₂O (II) were synthesized and studied by mass spectrometry, thermogravimetry, IR spectroscopy, and X-ray diffraction. Crystals of I and II are monoclinic; a = 16.21 Å, b = 5.43 Å, c = 12.32 Å, β = 119.63°, V = 1092.11 ų, ρ_calcd = 2.21 g/cm³, and Z = 1 for I; a = 16.24 Å, b = 5.59 Å, c = 12.29 Å, β = 119.79°, V = 1064.05 ų, ρ_calcd = 2.15 g/cm³, and Z = 1 for II. Compounds I and II were used as catalysts for soft oxidation of natural gas.     

Mixed-ligand complexes based on asymmetric gadolinium β-diketonates: Synthesis, crystal structure, and theoretical modeling

Mixed-ligand complexes of asymmetric gadolinium β-diketonates with 2,2′-bipyridyl (Bipy)—[Gd(Pa)₃(Bipy)] (HPa is pivaloylacetone) (I) and [Gd(Pta)₃(Bipy)] (HPta is pivaloyltrifluoroacetone) (II)-have been obtained by direct interaction of initial reagents and their structures have been studied by X-ray crystallography. Crystals of I are monoclinic: a = 9.536(1) Å, b = 15.037(1) Å, c = 13.280(1) Å, β = 109.56(1)°, V = 1798.7(3) ų, Z = 2, space group P2₁. Crystals of II are triclinic: a = 9.6696(17) Å, b = 12.1348(9) Å, c = 18.243(3) Å, α = 100.257(12)°, β = 103.997(2)°, γ = 101.438(11)°, V = 1977.4(5), Z = 2, space group P $\bar 1$ . The coordination polyhedron of the central gadolinium atom in I and II is a distorted square antiprism formed by six oxygen atoms of the three β-diketonate ligands (av. Gd-O, 2.35(2) and 2.351(5) Å in I and II, respectively) and two nitrogen atoms of the Bipy ligand (av. Gd-N, 2.47(2) and 2.584(7) Å in I and II, respectively). Although the molecular structures of these complexes are similar, they have different crystal packings. In II, the planes of the Bipy ligands of neighboring molecules related by an inversion center are bound by stacking interaction (the distance between the Bipy planes is 3.45 Å). The structure and properties of these mixed-ligand complexes have been discussed based on the results of quantum-chemical density functional theory calculations (DFT/B3PW91). The nature of the substituents in the β-diketonate ligand has an effect on the structure and properties of the complexes. The correlation between the Gd-Dik and Gd (Dik)₃-Bipy bond energies has been studied.     

Dichloro(ethylenediamine-<Emphasis Type="Italic">N,N</Emphasis>-di-3-propionato)zinc: Synthesis and crystal structure

Dichloro(ethylenediamine-N,N-di-3-propionato)zinc (I) has been synthesized for the first time by the reaction between acrylic acid and ethylenediamine coordinated with ZnCl₂ in an aqueous medium. Complex I has been characterized by IR, Raman, and ¹H,¹³C NMR spectroscopy, mass spectrometry, and elemental analysis. The X-ray diffraction analysis of complex I has also been performed. Crystals are monoclinic, а = 9.7792(4) Å, b = 9.9805(4) Å, c = 13.1130(5) Å, β = 101.5620(10)°, space group Р2₁/c, Z = 4, V = 1253.88(9) ų, ρ_calc = 1.804 g/cm³. The coordination polyhedra of Zn atoms in complex I are slightly distorted {ZnCl₂O₂} tetrahedra, each of which are built of two chlorine atoms and the carboxyl oxygen atoms of the two propionic groups of two ligand molecules and form a polymeric layer parallel to crystallographic plant (100). Bond lengths are Zn–О 1.970(1) and 1.976(1); Zn–Cl 2.2600(4) and 2.2693(4) Å. The ligand molecule in complex I has a double betaine structure.     

Coordination compounds of cobalt(II) and cadmium(II) with 2-amino-4-methylpyrimidine: Synthesis, crystal structure, and luminescent properties

The coordination compounds [CoL₂Cl₂] (I) and [CdL₂(H₂O)₂(NO₃)₂] (II) have been synthesized by the reaction of CoCl₂ · 6H₂O and Cd(NO₃)₂ · 4H₂O with L = 2-amino-4-methylpyrimidine (Ampym, C₅H₇N₃), and their structures have been solved. The crystals of complex I are triclinic, space group $P\bar 1$ , a = 5.627(1) Å, b = 11.191(1) Å, c = 12.445(1) Å, α = 81.00(1)°, β = 77.21(1)°, γ = 76.18(1)°, V = 737.7(2) ų, ρ_calcd = 1.567 g/cm³, Z = 2. The crystals of complex II are monoclinic, space group P2₁/c, a = 10.390(1) Å, b = 11.982(1) Å, c = 7.624(1) Å, β = 102.61(1)°, V = 926.1(2) ų, ρ_calcd = 1.760 g/cm³, Z = 2. Discrete [CoL₂Cl₂] moieties are realized in the structure of complex I. The cobalt atom is tetrahedrally coordinated to the two nitrogen atoms of crystallographically nonequivalent ligands L and two chlorine atoms (Co(1)-N_avg, 2.051(4)Å; Co(1)-Cl(1), 2.241(1) Å; Co(1)-Cl(2), 2.263 Å; bond angles at the cobalt atom lie within a range of 102.1°–118.6°). The complexes are linked into supramolecular zigzag chains by N-H...N(Cl) hydrogen bonds. In the structure of complex II, the Cd²⁺ ion (at the inversion center) is coordinated in pairs to the nitrogen atoms of ligand L and the O(NO₃) and O(H₂O) oxygen atoms. The coordination of the Cd²⁺ ion is distorted octahedral (Cd(1)-N(1), 2.341Å; Cd(1)-O(1), 2.340(4) Å; Cd(1)-O(4), 2.327(3) Å; bond angles at the cadmium atom lie within a range of 79.1°–100.9°). N-H...N hydrogen bonds link the complexes into supramolecular chains. These chains are linked into a supramolecular framework by the O-H...O hydrogen bonds between water molecules and NO₃ groups.     

Synthesis and crystal structure of diaquadibenzoatobis(nicotinamide)nickel(II)

A coordination compound of nickel(II) benzoate with nicotinamide [Ni(C₆H₅COO)₂(L)₂(H₂O)₂] (I) (L is nicotinic acid amide) is synthesized and studied by IR spectroscopy. Its crystal structure is solved by X-ray crystallography. The crystals of compound I are monoclinic: a = 7.152 Å, b = 18.266 Å, c = 10.341 Å, β = 109.24°, V = 1275.4 ų, Z = 2, space group P2₁/c. Structural units of a crystal of I are centrosymmetric octahedral complex molecules. The coordination environment of the Ni atom contains two O atoms (Ni-O(1) 2.066(2) Å) and two N atoms (Ni-N(1) 2.091(2) Å) of the monodentate-coordinated benzoate anions and nicotinamide molecules, respectively, as well as two O atoms of the H₂O molecules (Ni-O(1w) 2.110(2) Å).