New Co(III) dioximates with hexafluorophosphate ion as stimulators of the proteolytic activity of the micromycete Fusarium gibbosum CNMN FD 12

The coordination compounds [Co(DH)₂(An)₂][PF₆] (I) and [Co(NioxH)₂(Thio)₂][PF₆] · 0.5DMF · 0.5H₂O (II), where DH- and NioxH-are dimethylglyoxime and 1,2-cyclohexanedione dioxime monoanions, respectively; An is aniline; and Thio is thiourea, were synthesized. The composition and structure of the complexes were determined by elemental analysis, IR spectroscopy, and X-ray diffraction. Compounds I and II are ionic and consist of complex cations [Co(DioxH)₂(A)₂]⁺, where DioxH is the α-dioxime residue, A is neutral organic molecule (aniline or thiourea), and [PF₆]^? anions. The coordination polyhedra of the Co(III) complex cations are octahedra formed by the set of N6 donor atoms of monodeprotonated DH-residues and two An molecules (in I) or by the N₄S₂ atoms of two NioxH-anions and two Thio molecules (in II). The formation of the crystal structure of I and II is largely determined by the [PF₆]-anions in which the fluorine atoms serve as acceptors in various hydrogen bonds. The compounds were tested as stimulators of biosynthesis of extracellular proteases of the micromycete Fusarium gibbosum CNMN FD 12. The introduction of the test complexes in optimized concentrations into the nutrition medium for cultivation of the producing strain enhances the biosynthesis of acid and neutral proteases by 63.6 and 92.5%, respectively.     

Synthesis, spectroscopic, and thermal investigation of transition and non-transition complexes of metformin as potential insulin-mimetic agents

Complexes of [Mn(MF)₂(Cl)₂]·2H₂O (1), [Fe(MF)₂(Cl)₂]Cl·4H₂O (2), [Ni(MF·HCl)₂(Cl)₂]·6H₂O (3), [Cu(MF·HCl)₂(Cl)₂] (4), [Zn(MF·HCl)₂](NO₃)₂·6H₂O (5), [Cd₂(MF·HCl)(Cl)₄(H₂O)] (6), [Mg(MF·HCl)₂(Cl)₂]·6H₂O (7), [Sr₂(MF·HCl)(Cl)₄(H₂O)] (8), [Ba(MF·HCl)₂(Cl)₂]·2H₂O (9), [Pt(MF)₄] (10), [Au(MF)₃]Cl₃ (11), and [Pd(MF)₂]Cl₂ (12) were synthesized from Legitional behavior of metformin drug as a diabetic agent. The authenticity of the transition and non-transition metal complexes were characterized by elemental analyses, molar conductivity, (infrared, UV–Vis) spectra, effective magnetic moment in Bohr magnetons, electron spin resonance, thermal analysis, X-ray powder diffraction as well as scanning electron microscopy. Infrared spectral studies as well as elemental analyses revealed the existence of metformin in the base or hydrochloride salt forms in the chelation state acts as a bidentate ligand while the platinum(IV) complex is coordinated through the deprotonation of –NH group. The magnetic and electronic spectra of Mn(II), Fe(III), Ni(II), and Cu(II) complexes suggest an octahedral geometry. Antimicrobial screening of metformin and its complexes were determined against the (G⁺ and G^?) bacteria (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa) and fungi (Aspergillus flavus and Candida albicans).     

Synthesis and crystal structure of Co(III) dioximates with the complex anion [SbF6]?

The complexes [Co(DioxH)₂L₂][SbF₆] · nH₂O, where DioxH is dimethylglyoxime monoanion (DioxH^?) or 1,2-cyclohexanedione dioxime (NioxH^?), L is aniline (An) or triphenylphosphine (PPh₃), were isolated from the CoX₂ · nH₂O-NaSbF₆-DioxH₂-L system (X = F or CH₃COO) in aqueous methanol. The complexes were studied by UV, IR, and NMR spectroscopy and by X-ray diffraction. The crystal structure of [Co(DH)₂(An)₂][SbF₆] · H₂O (I) and [Co(NioxH)₂(PPh₃)₂][SbF₆] (II) is stabilized by the electrostatic interactions between the Co(III) complex cations and outer-sphere fluorine-containing anions and by hydrogen bonds between structural units.     

The action of norfloxacin complexes on Tetrahymena investigated by microcalorimetry

Cu(nor)₂·H₂O (1), Zn(nor)₂·4H₂O (2), Ni(nor)₂·2H₂O (3), [Cu(nor)(phen)]NO₃·4H₂O (4), [Zn(nor)(phen)]NO₃·2H₂O (5), and [Ni(nor)(phen)]NO₃·3H₂O (6) were synthesized and their action on Tetrahymena growth was studied by microcalorimetry. The growth constant (k), inhibitory ratio (I), and half-inhibiting concentration (IC₅₀) were calculated, which showed that the complexes had a strong inhibitory effect on Tetrahymena. All these complexes can inhibit the growth of Tetrahymena more strongly than norfloxacin. The norfloxacin?Cmetal complexes exhibited better inhibitory activity than nor?Cphen?Cmetal complexes. The power?Ctime curves of Tetrahymena growth in the presence of norfloxacin were also measured. It was found that all complexes showed higher inhibitory activity than norfloxacin. And the inhibitory mechanism was discussed preliminarily. The diverse inhibition may be due to the ability of the complexes to penetrate into cells and the effect of these complexes on the nucleic acid. Microcalorimetry has been used extensively in many biological and chemical investigations as a universal, non-destructive, continuously running, and highly sensitive tool.     

Copper(II) malonate coordination frameworks with amino-1,2,4-triazole: Crystal structures and magnetic properties of [Cu2(mal)2(datz)2(H2O)]·5H2O and [Cu2(mal)2(atz)2(H2O)]·3H2O

Two new malonato-bridged copper(II) complexes of the composition [Cu₂(mal)₂(datz)₂(H₂O)]·5H₂O (1) and [Cu₂(mal)₂(atz)₂(H₂O)]·3H₂O (2) (mal = malonate, atz = 4-amino-1,2,4-triazole, datz = 3,5-diamino-1,2,4-triazole) are prepared and characterized by X-ray crystal structure determination and magnetic studies. The environment of each copper atom in 1 and 2 has distorted square pyramidal and octahedral geometries. The intrachain copper-copper separation is 6.305 Å and 3.640 Å across the carboxylates and trizolates bridges respectively for complexes 1 and 2. The magnetic properties of 1 and 2 are investigated in the temperature range 2–300 K. The overall antiferromagnetic behavior is observed in both cases.     

Synthesis,structure, and biological properties of mixed cobalt(III) dioximates with guanidine derivatives

Two Co(III) dioximates, cyanoguanidine complex {[Na₂(µ-H₂O)₂(L¹)₂(H₂O)₂]-[Co^III(DmgH)₂(N₃)₂]} _n [Co^III(DmgH)₂(N₃)₂] _n (L¹ = (H₂N)₂C=N–C=N) (I) and aminoguanidine complex [H₃L²][Co(DmgH)₂(N₃)₂] (H₂L² = H₂N–C(=NH)–NH–NH₂) (II), were synthesized from the [CoCl(DmgH)₂(H₂O)] structural unit (DmgH^– is the dimethylglyoxime monoanion). The implementation of the synthesis was confirmed by chemical analysis, IR spectroscopy, and X-ray diffraction (CIF files CCDC 1531845 (I), 1531846 (II)). Both compounds are ionic. Compound I consists of cations representing centrosymmetrical 2D coordination polymers, {[Na₂(µ-H₂O)₂(L¹)₂(H₂O)₂][Co^III(DmgH)₂(N₃)₂]} ⁿ⁺ _n , and monomeric [Co(DmgH)₂(N₃)₂]^– anions, while in II, the charge of the [Co(DmgH)₂(N₃)₂]^– complex anion is counterbalanced by the organic [H₃L²]⁺ cation. In I, L¹ is coordinated to the metal as a monodentate neutral ligand, while in II, H₂L² occurs in the complex as a protonated uncoordinated component. Since L¹ in I and H₂L² in II contain functional amine groups able to form intermolecular hydrogen bonds acting as proton donors, the component packing mode in the crystals was analyzed assuming various types of interactions, apart from electrostatic ones. The biological properties of the complexes were tested considering their effect on the biosynthesis of proteases by the micromycete Fusarium gibbosum CNMN FD 12 strain. Culturing the producer on a culture medium containing complex I in the selected optimal concentrations of 5–10 mg/L was found to increase the acid protease activity by 140–150%.     

Heterometallic complexes of macrocyclic oxamide with polycarboxylates: Syntheses,crystal structures,and magnetic properties

Three complexes with the formula [Co(Ip)(CuL)(H₂O)₂] · H₂O (I), [Co(Ip)(NiL)(H₂O)₂] · H₂O (II), [Co(CuL)₂(Hbtc)(H₂O)] (III), (H₂Ip = m-isophthalic acid; H₂L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien; H₃Btc = 1,3,5-benzenetricarboxylic acid) were synthesized and structurally characterized by elemental analysis, IR and UV spectroscopy. Single-crystal X-ray analyses reveal that the complexes I and II contain neutral heterometallic binuclear CoM (for I and II, M = Cu, Ni, respectively) moieties, and complex III contains discrete neutral trinuclear CoCu₂ moieties. The structures of I–III consist of two-dimensional supramolecular architecture formed by strong O-H…O intermolecular hydrogen bonds. Furthermore, the magnetic properties of complex I were investigated and discussed in detail.     

Mn(II) complexes of N′-(2-methoxybenzoyl)hydrazine carbodithioic acid ethyl ester: synthesis, spectral and structural characterization

Two new Mn(II) complexes [Mn(Hmbhce)₂(o-phen)] (1) and [Mn(Hmbhce)₂(bpy)] (2) based on N??-(2-methoxybenzoyl)hydrazine carbodithioic acid ethyl ester (H₂mbhce) have been synthesized by reacting Mn(OAc)₂·4H₂O with H₂mbhce in the presence of o-phen/bpy. The complexes have been characterized by elemental analyses, magnetic susceptibility measurement, IR, UV?CVis and single crystal X-ray data. Both complexes [Mn(Hmbhce)₂(o-phen)] and [Mn(Hmbhce)₂(bpy)] crystallize in monoclinic system with space group P 21/c and P 21/n, respectively. The single crystal X-ray structures of 1 and 2 show that the Mn(II) center is bonded with two (Hmbhce)^? through carbonyl oxygen and deprotonated hydrazinic nitrogen, plus two nitrogen atoms from one o-phen/bpy co-ligand. The crystal structures of complexes 1 and 2 are stabilized by weak intramolecular N?CH···O hydrogen bonding and C?CH···?? interactions giving supramolecular architectures.     

Syntheses, crystal structures and properties of three novel coordination polymers with tripodal imidazole-containing ligands and benzenetetracarboxylate

Three novel coordination polymers, [Ni₂(tib)₂(btec)]·2H₂O (1), [Co₂(tib)₂(btec)]·2H₂O (2) and [Zn₄(tib)₂(btec)Cl₄]·2H₂O (3), have been synthesized by using mixed ligands of 1,3,5-tris(1-imidazolyl)benzene (tib) and 1,2,4,5-benzenetetracarboxylic acid (H4btec) under hydrothermal conditions. Complexes 1 and 2 have the same structure and are rare three-dimensional (3D) self-penetrating (3,4,5)-connected nets, while complex 3 is an unprecedented (3,4)-connected 3D net. The different structures of 1 (2) and 3 are ascribed to the distinct coordination geometry of the metal centers. The thermal stability and photoluminescence property of the complexes were investigated.     

Thermal behaviour and characterisation of new biologically active Cu(II) complexes with benzimidazole as main ligand

Four coordination compounds of copper(II) were synthesised and characterised in solid state by elemental analysis, infrared, electronic and EPR spectroscopy, as well as by thermal analysis (TG/DTA). The complexes were formulated on the basis of experimental data as: [Cu(BzIm)₂(H₂O)]·H₂O (1), [Cu₂(Acr)₄(HBzIm)₂] (2), [Cu(Acr)₂(HBzIm)₂] (3) and [Cu(Acr)₂(HBzIm)₂(H₂O)]·H₂O (4). IR data are in accordance with the unidentate nature of benzimidazole, in complexes (2), (3) and (4), and bridge bidentate nature of benzimidazole, in complex (1), while acrylato acts as uni- or bridge/chelate ligand. The electronic spectra display the characteristic pattern of square planar, square pyramidal, or octahedral stereochemistry, also confirmed by EPR spectra. Thermal decomposition evidenced several well-defined steps as dehydration of complexes (1) and (4), benzimidazole molecule releases for all complexes and acrylate decomposition in carbonate for complexes (3) and (4). In all four cases, the final residue after thermal treatment in air flow is copper(II) oxide, formed during the decomposition steps for complexes (3) and (4), and, respectively, after the oxidation of the metallic copper for complexes (1) and (2). Antimicrobial activities of the complexes have been determined by in vitro assays, against various Gram-negative and Gram-positive bacterial and fungal strains. Copper(II) complexes were also evaluated for their cytotoxicity on eukaryotic cells.     

Four Ln(III) coordination polymers based on 1H-benzimidazole-5,6-dicarboxylate ligand: Synthesis, crystal structure, and luminescence

Four Ln(III) coordination polymers, [La₂(HBidc)₃(H₂O)] _n (I), [Pr₂(HBidc)₃(H₂O)] _n (II), [Sm₂(HBidc)₃(H₂O)] _n (III), and [Gd₂(HBidc)₃(H₂O)] _n (IV), were synthesized hydrothermally by treating Ln(NO₃)₃ · 6H₂O, NaOH, and H₃Bidc (H₃Bidc = 1H-benzimidazole-5,6-dicarboxylic acid) at 180°C and characterized by elemental analysis, IR spectra, and single-crystal X-ray structure analyses. Complexes I–IV are isostructural, and each complex contains two crystallographically independent Ln(III), one is seven-coordinated, while the other is eight-coordinated. X-ray crystallography reveals that the complex consists of 3D frameworks with the (3⁴·4⁴·5²·6⁶·7¹⁰·8·9)(3·4·5)(3·4·5) topology. Furthermore, the photoluminescence properties of III has been studied.     

Supramolecular assembly of three d10 metal coordination polymers based on the naphthalene-1,8-dicarboxylate ligand: Syntheses, structures and luminescent properties

Three d¹⁰ tetranuclear complexes, [Cd₄(1,8-nap)4(2,2′-bipy)₄(H₂O)8]·6H₂O (1,8-nap = naphthalene-1,8-dicarboxylate and 2,2′-bipy = 2,2′-bipyridine) (1), [Cd₄(1,8-nap)4(2,2′-bipy)₄(H₂O)8]·6H₂O (2) and [Zn₄(1,8-nap)₄(2,2′-bipy)₄(H₂O)4]·2H₂O (3), have been synthesized under hydrothermal conditions and characterized by elemental analyses, IR and X-ray diffraction techniques. Complexes 1 and 2 are isomers showing one-dimensional ribbon-like structures connected by O-H…O hydrogen bonds, and the one-dimensional ribbons are further linked into the three-dimensional network by π-π stacking. In complex 3, the intramolecular O-H…O hydrogen bonds just exist in the inner of the single molecule ring to consolidate its structure, and the single molecules are further linked into a two-dimensional layer structure by the π-π stacking interactions. The luminescent properties reveal that all the complexes display luminescent properties in the violet region.     

Three silver(I) coordination polymers assembled from 2-sulfoterephthalic acid and N-donor ligands: syntheses, crystal structures, and luminescence properties

The reactions of silver nitrate with 2-sulfoisophthalic acid (H₃stp) in the presence of N-donor ligands produced three coordination polymers; [Ag₃(stp)(pyz)_0.5]_n (1), {[Ag₄(dpp)₄]·2(Hstp)·9H₂O}_n (2), and {[Ag(bpe)]₂[Ag₂(bpe)₂]₂·2(stp)·19H₂O}_n (3) [pyz = pyrazine, bpp = 1,2-bis(4-pyridyl)propane, bpe = 1,2-di(4-pyridyl)-ethylene]. The complexes have been characterized by single-crystal X-ray diffraction, physico-chemical, and spectroscopic methods. Single-crystal X-ray diffraction reveals that complex 1 is a 2D silver carboxylate-sulfonate layered structure, in which the 2D layers are further linked by the N-donor atoms of pyz ligands into a 3D supramolecular structure. Complex 2 is an infinite 1D chain arrangement with the [Ag₂(dpp)₂]²⁺ unit in which weak Ag···Ag or Ag···O interactions extend the chains into 2D structures. Complex 3 has a 3D supramolecular structure constructed by hydrogen bonding, π–π stacking, and Ag···O interactions to link the ligands, metal atoms, and water molecules together. The luminescence properties of the complexes were investigated.     

Structural diversity of transition-metal coordination polymers derived from isophthalic acid and bent bis(imidazole) ligands

Four coordination polymers associated with bent bis(imidazole) 1,3-bis(imidazol-l-yl-methyl)benzene (mbix) and isophthalic acid (H₂ip) or 5-methylisophthalic acid (H₂mip) ligands, formulated as {[Cd(mbix)(mip)]·H₂O} _n (1), {[Co(mbix)(mip)]·0.4H₂O} _n (2) [Ni(mbix)(mip)H₂O] _n (3) and [Ni(mbix)(ip)] _n (4), were synthesized under hydrothermal conditions and characterized by physico-chemical and spectroscopic methods. Complexes 1 and 2 are isomorphous and exhibit a 1D loop-like chain. Complex 3 features a 2D (4,4) layer, which further extends into an unusual 2D (3,5)-connected 3,5L2 double-layered supramolecular network via classical O–H···O hydrogen bonding interactions. Complex 4 is a 3D network, which shows a rare binodal (3,5)-connected 3,5T1 framework. Moreover, the luminescence and catalytic properties of the complexes for the degradation of methyl orange by sodium persulfate in a Fenton-like process are reported.     

Assembly of triorganotin chloride with selenite ligands to macrocyclic,zigzag, helical,and linear structures: syntheses,characterizations, and crystal structures of [R3Sn(O2SeC6H4-4-Et)] n and [R3Sn(O2SeC6H4-2-Et)] n (R = Me,C6H5) complexes

Four new triorganotin(IV) complexes, [R₃Sn(O₂SeC₆H₄-4-Et)]₄ (R = Me 1), [R₃Sn(O₂SeC₆H₄-4-Et)] _n (R = Ph 2), [R₃Sn(O₂SeC₆H₄-2-Et)] _n (R = Me 3; Ph 4) have been synthesized by the treatment of 4-ethylbenzeneseleninic acid, 2-ethylbenzeneseleninic acid, and the corresponding triorganotin(IV) chloride with sodium ethoxide in methanol. All of the complexes were characterized by elemental analysis, FT-IR, NMR (¹H, ¹³C, and ¹¹⁹Sn) spectroscopy, TGA, and X-ray crystallography. Crystal structures show that all of the complexes are generated by the bidentate oxygen atoms and the five-coordinated tin centers with trigonal bipyramid geometry. The structural analyses reveal that complex 1 has a centrosymmetric tetranuclear triorganotin selenite with 16-membered macrocycle, which is formed by trimethyltin and ligand alternate linking. A series of C–H···O and π–π stacking interactions in complex 1 play an important function in the supramolecular aggregation. Complex 3 has two 1D spring-like chiral helical chains and crystallizes in the monoclinic space group P2₁, which is chiral. Complex 2 and 4 are both 1D infinite neutral chain polymers and complex 2 forms a 2D supramolecular framework through intermolecular C–H···O interactions.     

Hydrothermal synthesis, crystal structures, and properties of two Co(II) complexes based on 4-bromoisophthalic acid and N-donor ligands

Two new Co(II) complexes, [Co₂(H₂O)(Bipy)₂(Bript)₂] _n (I) and [Co(H₂O)(Phen)(Bript)] · H₂O (II), where H₂Bript = 4-bromoisophthalic acid, Bipy = 2,2??-bipyridine, and Phen = 1,10-phenanthroline, have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Complex I has binuclear units in which two Co²⁺ ions are bridged by two carboxylate groups and a coordinaiod-water molecule, and the binuclear units are connected by Bript to generate a 1D helical chain. These 1D helical chains are further linked by ????? stacking interactions to form a 3D supramolecular network, while complex II has a 2D layer motif. In I and II, there exists extensive hydrogen bonding interactions. The thermal behavior of the two corresponding complexes have briefly been investigated.     

Scorpionate nickel complexes with dicarboxylic acid ligands: influence of different spanning dicarboxylato co-ligands on the structures

Three new scorpionate nickel complexes [Tp*Ni(Hglu)(H₂O)]·EtOH (1), Tp*Ni(Haze)(MeOH) (2), and Tp*Ni(HTA)(H₂O) (3) (Tp*?=?hydrotris(3,5-dimethylpyrazolyl)borate) with different spanning dicarboxylo co-ligands (H₂glu?=?glutaric acid, H₂aze?=?azelaic acid, H₂TA?=?tetradecane diacid) were synthesized by solution methods at room temperature. X-ray crystallographic analyses of complexes 1?C3 demonstrate that these three octahedral Ni scorpionate complexes each contain an anionic chelating dicarboxylic acid, O₂C(CH₂) _n COOH, n?=?3, 7, and 12, respectively. The sixth coordination site is occupied by an ethanol, methanol, or water that is hydrogen bonded to the terminal carboxylic acid end of the anionic dicarboxylic acid ligand from a different Tp*Ni complex in the crystal lattice. Through these abundant hydrogen bond interactions, complexes 1 and 2 form 2D hydrogen bonding network structures, respectively, while complex 3 has a 1D infinite double-chain structure. The results of quantum mechanical calculations and thermogravimetric analyses on these complexes are presented and discussed.     

Synthetic aspects, crystal structures and antibacterial activities of manganese(III) and cobalt(III) complexes containing a tetradentate Schiff base

Three new Schiff base complexes, namely [Mn(L)Cl] · H₂O (1), [Co(L)Cl]₂ · 2CH₃COCH₃ (2) and [Co(L)NCS]₂ (3), where H₂L = 2,2′-[propane-1,2-diylbis(nitriloeth-1-yl-1-ylidene)]diphenol, have been prepared and characterized. The syntheses of 1 and 2 have been achieved by reacting equimolar amounts of the respective metal chloride and the tetradentate Schiff base ligand (H₂L). While the mononuclear Mn(III) complex 1 was obtained with MnCl₂ in acetone medium, the same synthetic system yielded the binuclear Co(III) complex 2 in the presence of CoCl₂. Dissolution of 1 and 2 followed by crystallization with ammonium thiocyanate in methanol yielded two isostructural phenoxo-bridged binuclear complexes, namely [Mn(L)NCS]₂ (previously reported by us) and a new complex [Co(L)NCS]₂ (3), respectively. All the complexes 1–3 have been characterized by microanalytical, spectroscopic, single crystal X-ray diffraction and other physicochemical studies. Structural studies reveal that 1 adopts a distorted tetragonal pyramidal geometry while 2 and 3 comprise dimeric Co(III) units with bridging phenolate oxygen atoms. All the complex units in 1–3 and the respective solvent molecules are held together by weak intermolecular H-bonding to constitute a supramolecular network in the solid state. The antibacterial activity of the complexes has been tested against some Gram(+) and Gram(?) bacteria.     

Coordination polymer with the framework structure [Zn2(DMA)(Atc)] · DMA: Synthesis, structure, and properties

Crystals of a new coordination polymer with the framework structure, [Zn₂(DMA)(Atc)] · DMA (I), were prepared by heating a solution of Zn(NO₃)₂ · 6H₂O and H₄Atc (H₄Atc is 1,3,5,7-adamantanetetracarboxylic acid) in N,N′-dimethylacetamide (DMA). Colorless crystals of Zn₂(Atc) · 2MeOH · 4H₂O (II) were obtained by soaking the crystals of compound I in methanol. The structure of compound I was determined by X-ray diffraction analysis. Compounds I and II were characterized by X-ray powder diffraction, IR spectroscopy, thermal gravimetric analysis, and elemental analysis. The luminescence properties of compound I were studied.     

Syntheses, structures, and properties of the Co(II), Ni(II), and Cu(II) complexes with 5-carboxy- and 5-methoxycarbonylpyrazoles

New cobalt(II), nickel(II), and copper(II) complexes based on 5-methoxycarbonyl-3-me-thylpyrazole (MePzCOOMe), [Co(MePzCOOMe)₂(H₂O)₂](NO₃)₂ (I), [Ni(MePzCOOMe)₂(H₂O)₂] (NO₃)₂ (II), and [Cu(MePzCOO)₂(H₂O)] · 3H₂O (III), were synthesized. The compounds were studied by X-ray diffraction analysis, IR spectroscopy, and static magnetic susceptibility. The molecular and crystal structures of complexes I and III were determined by X-ray structure analysis.