Synthesis,characterization, crystal structures,and antimicrobial activity of cobalt(II) and iron(III) complexes derived from N'-(2-hydroxybenzylidene)-3-methylbenzohydrazide

A new cobalt(II,III) complex, [Co^IIIL₂]₂[Co ₂ ^II (HL)₂(OH₂)₂(CH₃OH)₂] ? 2H₂O (I) and a new iron(III) complex, [Fe^III(HL)₂](NO₃) (II), where L^2– and HL^– are the dianionic and monoanionic form of N'-(2-hydroxybenzylidene)-3-methylbenzohydrazide, respectively, have been prepared and characterized by elemental analyses, infrared and UV-Vis spectroscopy and single-cyrstal X-ray diffraction (CIF files CCDC nos. 1417971 (I), 1417979 (II)). Complex I crystallizes in the monoclinic space group P2₁/n with unit cell dimensions a = 16.1665(9), b = 14.5692(8), c = 19.086(1) Å, β = 96.347(1)°, V = 4467.9(4) ų, Z = 2, R ₁ = 0.0521, and wR ₂ = 0.1411. Complex II crystallizes in the orthorhombic space group Pbcn with unit cell dimensions a = 12.475(1), b = 12.202(1), c = 18.859(2) Å, V = 2870.8(4) ų, Z = 4, R ₁ = 0.0796, and wR ₂ = 0.1981. The metal atoms in the complexes are in octahedral coordination. Crystals of the complexes are stabilized by hydrogen bonds. The efficiency of the aroylhydrazone and the two complexes was evaluated against B. subtilis, S. aureus, E. coli, P. fluorescence, C. albicans and A. niger, with the complexes demonstrating enhanced activity relatively to the free ligand.     

Hydrothermal Synthesis,Crystal Structures,and Fluorescence Properties of Ni(II)–Ln(III) Complexes (Ln = Sm,Pr, Eu)

Three novel 3d–4f heterometal complexes [Ln(NiL)₃(Btca)(NO₃)] · xH₂O (Ln = Sm(III) (I), Pr(III) (II), Eu(III) (III) (H₂L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien, H₂Btca = benzotriazole-5-carboxylic acid) were solvothermally synthesized and characterized by singlecrystal X-ray diffraction (CIF files CCDC nos. 1555557 (I), 1555555 (II), 1555556 (III)). They crystallized in the monoclinic space group P2₁/n for I (x = 1.5) and C2/c for (II) and (III) (x = 1), respectively. In these complexes, the central Ln(III) and external nickel ions are bridged by macrocyclic oxamide groups. The metal center of Ln(III) resides in a distorted bicapped square antiprism surrounding with six oxygen atoms of three oxamide groups, two oxygen atoms of Btca^2– ion and two oxygen atoms of NO₃^-. Furthermore, there are C–H···O and/or C–H···N hydrogen bond interactions among nitrate, benzotriazole-5-carboxylate, macrocyclic oxamide and water to form three-dimensional superamolecular architecture. The fluorescence properties of the compounds I and II are also discussed.     

Hexa(isothiocyanato)chromates(III) of Some Yttrium Group Lanthanide(III) and Europium Complexes with Nicotinic Acid: Synthesis and Crystal Structures

Double ionic complexes [M(C₅H₅NCOO)₃(H₂O)₂][Cr(NCS)₆] · nH₂O, where M = Eu (I), n = 1.15; Dy (II), Er (III), n = 1.5; M = Yb (IV), n = 2, have been synthesized by the reaction between M(NO₃)₃, M = Eu, Dy, Er, Yb, K₃[Cr(NCS)₆], and nicotinic acid (C₅H₅NCOO) in an aqueous solution and studied by chemical analysis, IR spectroscopy, and X-ray diffraction. Crystals of complexes I–IV are monoclinic, space group P2₁/n, Z = 4; a = 9.5358(2) Å, b = 25.4871(5) Å, c = 15.4303(4) Å, β = 105.513(1)°, V = 3613.6(1) ų, ρ_calcd = 1.799 g/cm³ for I, a = 9.5901(5) Å, b = 25.8599(15) Å, c = 15.6316(9) Å, β = 106.829(2)°, V = 3710.6(4) ų, ρ_calcd = 1.782 g/cm³ for II, a = 9.5640(3) Å, b = 25.8936(11) Å, c = 15.6498(7) Å, β = 106.895(2)°, V = 3708.3(3) ų, ρ_calcd = 1.791 g/cm³ for III, and a = 9.5049(2) Å, b = 25.6378(4) Å, c = 15.5120(3) Å, β = 106.934(1)°, V = 3616.1(1) ų, ρ_calcd = 1.864 g/cm³ for IV.     

Bis(citrato)germanates of bivalent 3<Emphasis Type="Italic">d</Emphasis> metals (Fe,Co, Ni,Cu, Zn): Crystal and molecular structure of [Fe(H<Subscript>2</Subscript>O)<Subscript>6</Subscript>][Ge(HCit)<Subscript>2</Subscript>] · 4H<Subscript>2</Subscript>O

In continuation of a systematic study of bis(citrate)germanates, we synthesized a number of heterometallic germanium(IV) and 3d metal complexes based in citric acid (H₄Cit) with the molecular formula [M(H₂O)₆][Ge(HCit)₂] · nH₂O, where M = Fe, n = 4 (I); Co, n = 2 (II); Ni, n = 2 (III); Cu, n = 1 (IV); Zn, n = 3 (V). The complexes were characterized by elemental analysis, X-ray diffraction, thermogravimetry, and IR spectroscopy. The X-ray diffraction analysis of compound I was performed. Crystals are monoclinic, a = 10.091(4) Å, b = 11.126(4) Å, c = 10.996(4) Å, β = 100.966(6)°, V = 1212.1(8) ų, Z = 4, space group P2₁/n, R1 = 0.0561 for 2266 reflections with I > 2σ(I). Compound I is composed of centrosymmetric octahedral complexes-[Ge(HCit)₂]^2? anions and [Fe(H₂O)₆]²⁺ cations—and crystallization water molecules. Structural units in compound I are combined by a hydrogen bond system.     

Synthesis,crystal structure,and luminescent properties of silver complexes with 2-methylquinoline

The complexes [AgL₂(NO₃)] (I) and [AgL₂(CH₃SO₃)] · H₂O (II) (L is 2-methylquinoline, C₁₀H₉N) have been synthesized and structurally characterized by single-crystal X-ray diffraction. Crystals of I are monoclinic, space group P2₁/n, a = 9.296(1) Å, b = 13.495(1) Å, c = 14.931(1) Å, β = 95.06(1)°, V = 1865.8(3) ų, ρ_calc = 1.624 g/cm³, Z = 4. Crystals of II are monoclinic, space group P2₁/n, a = 13.147(1) Å, b = 11.767(1) Å, c = 13.814(1) Å, β = 96.06(1)°, V = 2124.3(3) ų, ρ_calc = 1.599 g/cm³, Z = 4. Compounds I and II are composed of discrete complexes of similar structure but with different orientation of the methyl groups of ligand L (trans and cis arrangement, respectively). Both anions, NO ₃ ^- and CH₃SO ₃ ^- function as a chelating weakly bound ligand for the Ag⁺ ion. The presence of water molecules in II is favorable for the formation of dimeric supramolecular moieties between the centrosymmetrically arranged Ag⁺ complexes with 2-methylquinoline. The luminescence spectra of solid complexes I and II showed a bathochromic shift as compared to the spectrum of L in acetonitrile. Complexes I and II have been characterized by ¹H and ¹³C{H} NMR spectra in CD₃CN.     

(18-Crown-6)(nitrato-<Emphasis Type="Italic">O,O</Emphasis>′)potassium and (18-crown-6)(nitrato-O,O′)potassium<Subscript>(0.91)</Subscript>silver<Subscript>(0.09)</Subscript>: Synthesis and crystal structures

Two complexes with similar compositions are synthesized: (18-crown-6)(nitrato-O,O′)potassium (I) and (18-crown-6)(nitrato-O,O′)potassium_(0.91)silver_(0.09) (II). Their isomorphic orthorhombic crystals (space group P2₁2₁2₁, Z = 4) are studied by X-ray diffraction analysis. Structure I (a = 8.553 Å, b = 11.967 Å, c = 17.871 Å) and structure II (a = 8.540 Å, b = 11.956 Å, c = 17.867 Å) are solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.044 (I) and 0.055 (II) for all 2385 (I) and 2379 (II) measured independent reflections. Complex molecules [K(NO₃)(18-crown-6)] in structure I and [K_0.91Ag_0.09(NO₃)(18-crown-6)] in compound II are of the host-guest type and rather similar in structure. Their 18-crown-6 and NO ₃ ^? ligands are disordered over two orientations. The K⁺ cation in complex I and the mixed cation (K_0.91Ag_0.09)⁺ in complex II reside in the cavity of the disordered 18-crown-6 ligand and is coordinated by its six O atoms and by two disordered O atoms of the NO ₃ ^? . ligand. The coordination polyhedron (CN = 8) of the K⁺ cation in complex I and that of (K_0.91Ag_0.09)⁺ cation in complex II is a distorted hexagonal pyramid with a base of six O atoms of the 18-crown-6 ligand and a split vertex at two O atoms of the NO ₃ ^? ligand.     

Synthesis and structure of Cu(II) and Pd(II) coordination compounds with chiral α-thiooxime,a derivative of natural terpenoid (−)-α-pinene

The paramagnetic complex Cu(HL)Cl₂(I) (μ_eff = 1.88 μ_B) and the diamagnetic complex Pd(HL)Cl₂(II) with chiral α-thiooxime, a derivative of natural terpenoid (?)-α-pinene (HL), were synthesized. The crystal structures of these complexes were determined from single-crystal X-ray diffraction data (X8 APEX diffractometer, MoK _α radiation, 2975 F _hkl , R = 0.0258 for I and 3270 F _hkl , R = 0.0222 for II). The crystals of complex I are monoclinic, a = 9.3376(3) Å, b = 6.8619(2) Å, c = 14.6540(5) Å, β = 97.814(1)°, V = 930.22(5) ų, Z = 2, ρ_calc = 1.513 g/cm³, space group P2₁. The crystals of complex II are orthorhombic, a = 7.0084(6) Å, b = 9.2113(9) Å, c = 29.081(3) Å, V = 1877.4(3) ų, Z = 4, ρ_calc = 1.651 g/cm³, space group P2₁2₁2₁. The structures are composed of mononuclear molecules. The coordination cores MNSCl₂ (M = Cu, Pd) are tetrahedrally distorted squares. According to NMR data, complex II has a similar structure in a CDCl₃ solution. The intermolecular contacts in structure I generate supramolecular polymeric ribbons lying parallel to axis b. No short intermolecular contacts are present in complex II.     

Self assembly of three new copper coordination polymers based on N-[(3-pyridine)-sulfonyl]aspartate: Synthesis and structure

Three new copper coordination polymers [Cu(L) · 6H₂O] _n (I), [Cu₂(L)₂] _n (II), and [Cu(HL)₂] _n (III), where H₂L is N-[(3-pyridine)-sulfonyl]aspartate, have been synthesized and characterized by singlecrystal X-ray diffraction (CIF files CCDC nos. 1435871 (I), 1435872 (II), 1435873 III), elemental analysis and IR spectra. Moreover, the variable-temperature magnetic susceptibility had been studied for complex I. A structural comparison of these polymers suggests that different reaction temperatures play important role in the construction of resulting architectures for I–III.     

XRD and EXAFS study of nitrato ammine complexes of nitrosyl ruthenium

The structure of trans-[RuNO(NH₃)₄(H₂O)](NO₃)₃ (I) and trans-[RuNO(NH₃)₄(NO₃)](NO₃)₂ (II) was determined by XRD. Crystallographic data are as follows: space group I4₁/a; a = b = 18.280(1) Å, c = 15.129(1) Å, R = 0.0244 (I), and space group Cm, a = 11.5620(3) Å, b = 7.9934(2) Å, c = 7.7864(2) Å, β = 127.124(1)°, R = 0.0139 (II). Interatomic distances for complex particles of fac- and mer- [RuNO(NH₃)₂(NO₃)₃] (III and IV, respectively) were determined by EXAFS.     

Crystal structures of polyphosphates MCs<Subscript>5</Subscript>(PO<Subscript>3</Subscript>)<Subscript>8</Subscript> (M = Pr,Eu, and Gd)

Crystals of double polyphosphates EuCs₅(PO₃)₈ (I) and GdCs₅(PO₃)₈ (II) have been studied by X-ray diffraction. The isostructural crystals of I and II are monoclinic, space group C2. Only unit cell parameters have been determined for the crystals of double Pr and Cs polyphosphate (III). This crystal is isostructural with earlier studied La₃Cs₁₅P₂₄O₇₂ · 6H₂O (IV). The crystals of compounds III and IV are triclinic, space group P1, Z = 1; a = 11.987(2) and 12.178(5) Å, b = 14.754(8) and 14.740(8) Å, c = 14.692(8) and 14.847(9) Å, α = 60.15(4)° and 60.87(5)°, β = 67.04(4)° and 66.35(4)°, γ = 78.76(3)° and 77.54(4)°, respectively. In compounds I and II, the polyphosphate anions exist as infinite chains. The M^IIIO₈ polyhedra are isolated from each other but share edges and faces with the CsO _n polyhedra.     

Synthesis,crystal structures,and antimicrobial activity of copper(II) and zinc(II) complexes derived from 2-bromo-4-chloro-6-[(2-morpholin-4-ylethylimino)methyl]phenol

An end-to-end azido-bridged dinuclear copper(II) complex [Cu₂L₂(μ_1,3-N₃)](NO₃) (I) and a mononuclear zinc(II) complex [ZnCl₂(HL)] ? CH₃OH (II), where L is 2-brom-4-chloro-6-[(2-morpholin- 4-ylethylimino)methyl]phenolate, have been prepared and characterized by elemental analyses, IR, and single crystal X-ray crystallographic determination (CIF files CCDC nos. 1415217 (I), 1415218 for (II)). The crystal of I is monoclinic: space group C2/c, a = 28.684(2), b = 7.1787(5), c = 18.292(1) Å, β = 117.887(3)°, V = 3329.1(4) ų, Z = 4. The crystal of II is monoclinic: space group P2₁/c, a = 10.8207(9), b = 12.3398(7), c = 14.9477(7) Å, β = 93.473(3)°, V = 1992.2(2) ų, Z = 4. The Schiff base ligand in I coordinates to the Cu atom through the phenolate O, imine N, and morpholine N atoms, while the Schiff base ligand in II coordinates to the Zn atom through the phenolate O and imine N atoms, with the morpholine N atom protonated. The effect of these complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.     

Syntheses and luminescence of three lanthanide complexes constructed by flexible carboxylate ligand

Three new complexes, namely {[Ln(L)₃(2,2′-Bipy)] _n · H₂O} (Ln = Pr (I), Sm (II), and Nd (III)) (HL = 3-(2-hydroxyphenyl)propanoic acid), have been synthesized and structurally characterized. The structural determinations indicated (CIF files CCDC nos. 1472729 (I), 1472730 (II), 1472734 (III)) that I–III have similar dinuclear structures, which can be further linked into 2D sheet via the hydrogen bond interactions. Furthermore, the luminescent properties of I–III show the strong emissive power and feature.     

Synthesis and X-ray investigation of Rb<Subscript>2</Subscript>[Pd(NO<Subscript>3</Subscript>)<Subscript>4</Subscript>] and Cs<Subscript>2</Subscript>[Pd(NO<Subscript>3</Subscript>)<Subscript>4</Subscript>]

Powder and single crystal X-ray diffraction studies have been performed for anhydrous nitrate complexes Rb₂[Pd(NO₃)₄] (I) and Cs₂[Pd(NO₃)₄] (II). Crystal data for I: a = 7.843(1) Å, b = 7.970(1) Å, c = 9.725(1) Å; β = 100.39(1)°, V = 597.9(1) Å ³, space group P2₁/c, Z = 2, d _calc = 2.918 g/cm³; for II: a = 10.309(2) Å, b = 10.426(2) Å, c = 11.839(2) Å; β = 108.17(3)°, V = 1209.0(4) ų, space group P2₁/c, Z = 4, d ^calc = 3.408 g/cm³. The structures are formed by isolated [Pd(NO₃)₄]^2? complex anions and alkali metal cations. The plane-square environment of the Pd atom is formed from the oxygen atoms of the monodentate nitrate groups. The geometrical characteristics of the complex anions are analyzed. Compound II has a short contact Pd...Cs 3.252 Å.     

The first cubane-like complex of copper based on <Emphasis Type="Italic">N</Emphasis>-carboxyethyl-tris(hydroxymethyl)aminomethane: Synthesis and crystal structure

The interaction of acrylic acid with tris(hydroxymethyl)aminomethane (I) was studied. A simple method was suggested for preparing N-carboxyethyl-tris(hydroxymethyl)aminomethane (homotricin) (II). On the basis of compound II, the 1:1 Cu complex, [Cu(OCH₂C(CH₂OH)₂NHCH₂CH₂COO)]₄·nH₂O (n = 4–11.25) (III), which is alkoxycarboxylate, was synthesized. The crystal structure of III was found to correspond to a cubane-like tetranuclear cluster (an automated Bruker X8Apex diffractometer with CCD detector (MoK _α radiation, graphite monochromator, ? = 1.11°?27.5°), 8016 reflections, space group P \(\overline 1 \), a = 12.5573(3), b = 19.1012(4), c = 21.2903(5) Å, α = 80.7770(10)°, β = 75.7430(10)°, γ = 75.2260(10)°, V = 4761.62(19) ų, ρ(calcd.) = 1.704 g/cm³, Z = 4). The crystals are unstable due to the large number of water molecules.     

Synthesis and structure of diethylenetriammonium tetrachloroaurates(III)

The (DienH₃)[AuCl₄]₃ · H₂O (I) and (DienH₃)₂[AuCl₄]Cl₅ (II) compounds were obtained by the reaction of HAuCl₄ with diethylenetriamine trihydrochloride (DienH₃Cl₃) in hydrochloric acid. The compounds were characterized by elemental analysis, X-ray diffraction, thermogravimetry, and IR spectroscopy. Crystals of I and II are monoclinic with space group P2₁/n. For I, a = 12.2314(3) Å, b = 14.6077(5) Å, c = 13.2680(5) Å, β = 106.7350(10)°, V = 2270.22(13) ų, Z = 8. For II, a = 6.62990(10) Å, b = 17.9026(5) Å, c = 10.3661(3) Å, β = 101.9230(10)°, V = 1203.83(5) ų, Z = 2. Both structures are ionic. The gold atoms in I and II have a 4 + 2 coordination environment. The Au-Cl bond lengths are within 2.276–2.294 Å, and the axial Au…Cl contacts are within 3.315–3.405 Å. The diethylenetriammonium cation in I and II has different conformations.     

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.     

X-ray study of rhodium(III) sulfates

Compounds with compositions [Rh(H₂O)₆]₂(SO₄)₃·4H₂O (I), (H₃O)[Rh(H₂O)₆](SO₄)₂ (II), [Rh(H₂O)₅OH](SO₄)·0.5H₂O (III), and [Rh(H₂O)₆]₂(SO₄)·(H₂SO₄) _x ·5H₂O (IV) have been studied. The crystal structures of II, III, and IV were determined. All compounds crystallized in the monoclinic crystal system. Crystal data for II: a = 7.279(2) Å, b = 10.512(7) Å, c = 15.806(3) Å, β = 96.71(3)°, space group P2₁/n, Z = 2, d _calc = 2.334 g/cm³; III: a = 20.433(4) Å, b = 7.820(2) c = 11.215(2) Å, β = 114.14(1)°, space group C2/c, Z = 8, d _calc = 2.559 g/cm³; IV: a = 6.2250(4 Å), b = 27.0270(12) Å, c = 7.2674(5) Å, β = 97.04(3)°, space group P2₁/c, Z = 4, d _calc = 2.143 g/cm³. The compounds were studied by IR spectroscopy and powder X-ray diffraction. All of the isolated crystalline phases are sparingly soluble in ethanol and well soluble in water.     

Syntheses,crystal structures,and properties of three two-dimensional complexes constructed by flexible (2,3-pyridylmethyl)amine

Three two-dimensional coordination polymers [Cd(2,3-Pyma)Cl₂] _n (I), {[Cd(2,3-Pyma)(1,4-Chdc)] · 4H₂O}n (II) and {[Zn₂(2,3-Pyma)(1,2,4,5-Bttc)(H₂O)₄] · 6H₂O} _n (III) (2,3-Pyma = (2,3-pyridylmethyl) amine, H₂-1,4-Chdc = 1,4-cyclohexanedicarboxylic acid, and H₄-1,2,4,5-Bttc = 1,2,4,5-benzenetetracarboxylic acid) have been synthesized and structurally characterized by single crystal X-ray crystallography (CIF files CCDC nos. 989461 (I), 1055685 (II) and 1055686 (III)). Three complexes are all twodimensional layer networks bridged by the flexible 2,3-Pyma ligands or the carboxylate ligands. It is noted that the flexible 1,4-Chdc ligands bind the Cd²⁺ ions into a helical chain structure in complex II. The photoluminescence and thermal properties are investigated.     

(18-Crown-6)sodium tribromide and (18-crown-6)potassium triiodide (with an admixture of bromodiiodide): Synthesis and crystal structure

Two crystalline host-guest complexes are synthesized and studied using X-ray diffraction analysis: (18-crown-6)sodium tribromide [Na(18-crown-6)]⁺ · Br ₃ ^? (I) and (18-crown-6)potassium tribromide (with an admixture of bromodiiodide) [K(18-crown-6)]⁺ · (Br_0.25I_2.75)^? (II). The structures of compound I (space group P2₁/_{n, a} = 8.957 Å, b = 8.288 Å, c = 14.054 Å, β = 104.80°, Z = 2) and compound II (space group Cc, a = 8.417 Å, b = 15.147 Å, c = 17.445 Å, β = 99.01°, Z = 4) are solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.098 (I) and 0.036 (II) for all 2311 (I) and 2678 (II) independent measured reflections on a CAD-4 automated diffractometer (λMoK _α). Similar crystalline complexes I and II exist as infinite chains of alternating complex cations and trihalide anions linked to each other through weak Na-Br or K-I coordination bonds. In [Na(18-crown-6)]⁺ and [K(18-crown-6)]⁺ complex cations, the Na⁺ or K⁺ cation (coordination number is eight) is located in the center of the cavity of the 18-crown-6 ligand and coordinated by the six O atoms and two terminal Br or I atoms of two trihalide anions lying on opposite sides of the rms plane of the crown ligand.     

Synthesis and physicochemical properties of the <Emphasis Type="Italic">d</Emphasis> metal complexes with 2-phenyl-4-(piperidyl-1)-pyrido[2,3-a]anthraquinone. The molecular and crystal structures of 2-phenyl-4-(piperidyl-1)-pyrido[2,3-a]anthraquinonium-7,12 tetranitrozincate

Two types of complexes of 2-phenyl-4-(piperidyl-1)-pyrido[2,3-a]anthraquinone (L) with transition metals were isolated from neutral acetonitrile and acidified acetonitrile and ethanol solutions and characterized. Metal complexes synthesized at pH = 7 had the composition MCl₂L · (CH₃CN) _n (M = Cu, Co, Ni). The complexes (HL)₂[Cu₂Cl₆] (I), (HL)₂[CoCl₄] (II), (HL)₂[Zn(NO₃)₄] (III) were obtained at pH = 1–2. The molecular and crystal structure of complex III was determined. Some spectral parameters of L and its complexes were measured.