2-Acetylpyridine- and 2-benzoylpyridine-derived thiosemicarbazones and their antimony(III) complexes exhibit high anti-trypanosomal activity

Complexes [Sb(2Ac4oClPh)Cl₂] (1), [Sb(2Ac4oFPh)Cl₂] (2), [Sb(2Ac4oNO₂Ph)Cl₂] (3), [Sb(2Bz4oClPh)Cl₂] (4), [Sb(2Bz4oFPh)Cl₂] (5) and [Sb(2Bz4oNO₂Ph)Cl₂] (6) were obtained with 2-acetylpyridine-N(4)-ortho-chlorophenyl thiosemicarbazone (H2Ac4oClPh) and its N(4)-ortho-fluor (H2Ac4oFPh) and N(4)-ortho-nitro (H2Ac4oNO₂Ph) analogues, and with the corresponding 2-benzoylpyridine-derived thiosemicarbazones (H2Bz4oClPh, H2Bz4oFPh, H2Bz4oNO₂Ph). The studied compounds are excellent inhibitors of Trypanosoma cruzi growth. H2Bz4oClPh and complexes (4) and (1) were the most trypanosomicidal.Upon coordination of H2Ac4oClPh to antimony(III) in 1, the therapeutic index (TI) goes from 10.58 to 14.35. However, the best values of TI were found for H2Bz4oClPh (TI = 1240) and H2Ac4oNO₂Ph (TI = 773). Structure-activity relationship (SAR) studies did not allow the establishment of correlations between the anti-trypanosomal activity and physico-chemical parameters, but correlations were found between the cytotoxicities and physico-chemical properties.     

Zinc(II) complexes of 2-pyridine-derived N (4)- p -tolyl thiosemicarbazones: study of in vitro antibacterial activity

Reaction of N(4)-p-tolyl-2-formylpyridine thiosemicarbazone (H2Fo4pT), N(4)-p-tolyl-2-acetylpyridine thiosemicarbazone (H2Ac4pT), and N(4)-p-tolyl-2-benzoylpyridine thiosemicarbazone (H2Bz4pT) with ZnCl₂ gave [Zn(H2Fo4pT)Cl₂] (1), [Zn(H2Ac4pT)Cl₂] (2), and [Zn(H2Bz4pT)Cl₂] (3). In the first two complexes a tridentate N_py–N–S thiosemicarbazone binds to the zinc while in the latter N–S coordination occurs. Upon coordination the antibacterial activity against Salmonella typhimurium increases in 1 and 3.     

Increasing the antibacterial activity of gallium(III) against Pseudomonas aeruginosa upon coordination to pyridine-derived thiosemicarbazones

Reaction of N(4)-phenyl-2-formylpyridine thiosemicarbazone (H2Fo4Ph), N(4)-phenyl-2-acetylpyridine thiosemicarbazone (H2Ac4Ph) and N(4)-phenyl-2-benzoylpyridine thiosemicarbazone (H2Bz4Ph) with gallium nitrate gave [Ga(H2Fo4Ph)₂](NO₃)₃ (1), [Ga(2Ac4Ph)₂]NO₃ (2) and [Ga(2Bz4Ph)₂]NO₃ (3). In all complexes coordination of the thiosemicarbazone via the N_py–N–S chelating system occurs. In 1 the thiosemicarbazone acts as a neutral ligand while in 2 and 3 the ligand is anionic. Upon slow diffusion of 2 in DMSO [Ga(2Ac4Ph)₂]NO₃·DMSO (2a) was formed. The crystal structure of 2a was determined. Upon coordination the antibacterial activity of both gallium and thiosemicarbazones against Pseudomonas aeruginosa significantly increases.     

Synthesis and Characterization of Zinc(II) Complexes with 3,4-Dimethoxybenzaldehyde Thiosemicarbazone: The Crystal Structure of [Zn(34-MBTSC)2Cl2]

Abstract

The synthesis and characterization of three zinc(II) complexes [Zn(34-MBTSC)₂Cl₂] (1), [Zn(34-MBTSC)₂Br₂] (2), and [Zn(34-MBTSC)₂I₂] (3) of 3,4-dimethoxybenzaldehyde thiosemicarbazone (34-MBTSC) are reported. Elemental analysis (CHN) and spectral (FT-IR and ¹H-NMR) measurements have been used to characterize the complexes. In addition, the structure of the complex 1 has been determined by X-ray diffraction methods. In these complexes, the zinc(II) ion is bonded to two thioketonic sulfur donors in η¹-S bonding mode and to two halide ions in tetrahedral geometry.

Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional figures.     

Synthesis,Characterization, Antimicrobial Activities,and Structural Studies of Lanthanide (III) Complexes with 1-(4-Chlorophenyl)-3-(4-fluoro/hydroxyphenyl)prop-2-en-1-thiosemicarbazone

Twelve coordinate lanthanide (III) complexes with the general composition [Ln L₃X_n(H₂O)_n] where Ln = Pr(III), Sm(III), Eu (III), Gd (III), Tb (III), Dy (III), X = Cl^?1, NO₃ ^?2, n = 2–7, and L is 1-(4-chlorophenyl)-3-(4-fluoro/hydroxyphenyl)prop-2-en-1- thiosemicarbazone have been prepared. The lanthanide complexes (5) were derived from the reaction between 1-(4-chlorophenyl)-3-(4-fluoro/hydroxyphenyl)prop-2-en-1-thiosemicarbazone (4) with an aqueous solution of lanthanide salt. Chalcone thiosemicarbazone ligand (4) was prepared by the reaction of [1-(4-chlorophenyl)-3-(4-fluoro/hydroxyphenyl)]prop-2-enone (chalcone) (3) with thiosemicarbazide in the presence of hot ethanol. All the lanthanide-ligand 1:3 complexes have been isolated in the solid state, are stable in air, and characterized on the basis of their elemental and spectral data.

Thiosemicarbazone ligands behave as bidentate ligands by coordinating through the sulfur of the isocyanide group and nitrogen of the cyanide residue. The probable structure for all the lanthanide complexes is also proposed. The chalcone thiosemicarbazone ligands and their lanthanide complexes have been screened for their antifungal and antibacterial studies. Some of the synthesized lanthanide complexes have shown enhanced activity compared with that of the free ligand.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Spectral and electrochemical studies of ruthenium(II) complexes with N-methyl-4-nitrobenzaldehyde and N-methyl-4-nitrobenzophenone thiosemicarbazone: Potential anti-trypanosomal agents

N⁴-Methyl-4-nitrobenzaldehyde thiosemicarbazone (H4NO₂Fo4M), N⁴-methyl-4-nitrobenzophenone thiosemicarbazone (H4NO₂Bz4M) and their ruthenium(II) complexes [Ru(4NO₂Fo4M)₂(PPh₃)₂] (1), [Ru(4NO₂Bz4M)₂(PPh₃)₂] (2), [Ru(4NO₂Fo4M)₂(dppb)] (3) and [Ru(4NO₂Bz4M)₂(dppb)] (4) (dppb = 1,4-bis(diphenylphospine)butane) were obtained and characterized. The crystal structure of H4NO₂Fo4M has been determined. Electrochemical studies have shown that the nitro anion radical, one of the proposed intermediates in the mechanism of action of nitro-containing anti-trypanosomal drugs, is formed at approximately −1.00 V in the free thiosemicarbazones as well as in their corresponding ruthenium(II) complexes, suggesting their potential to act as antitrypanosomal drugs. The natural fluorescence of H4NO₂Fo4M, H4NO₂Bz4M and complexes (1)–(4) provides a way to identify and to monitor their concentration in biological systems.     

含不同芳香取代基的肼基二硫代甲酸甲酯-Ga3+配合物的合成及抑菌活性

设计合成了4种含不同芳香取代基团的肼基二硫代甲酸甲酯配体（2-乙酰基吡啶肼基二硫代甲酸甲酯（L¹-H）、2-甲酰基吡啶肼基二硫代甲酸甲酯（L²-H）、2-甲酰基噻吩肼基二硫代甲酸甲酯（L³-H）、2-甲酰基水杨醛肼基二硫代甲酸甲酯（L⁴-H））的镓配合物,对它们的抑菌活性进行了测试,并讨论了配体分子中不同芳香取代基对配合物抑菌活性的影响。在模拟生理条件下,L与Ga³⁺生成较稳定的单核配合物[Ga（L¹）₂]NO₃（1）、[Ga（L²）₂]NO₃（2）、[Ga（L³）₂]NO₃（3）、[Ga（L⁴）₂]NO₃（4）,各配合物对金黄色葡萄球菌和大肠杆菌表现出比Ga（NO₃）₃·9H₂O强的抑制活性,抑制金黄色葡萄球菌的能力高于大肠杆菌,其中,1和2的活性比相应配体高,其余2个配合物与其配体之间无明显活性差异。L¹和L²分子中吡啶基的较强吸电子效应可能是1和2具有较强抑菌活性的主要原因。4种配合物抑制黑曲霉生长的活性同样高于Ga（NO₃）₃·9H₂O,其中3最强,并显著高于L³,其余配合物与相应配体间无活性差异。     

Group III quinaldates: synthesis,structure and photoluminescence

The reactions of Al(III), Ga(III) and In(III) nitrates with 2-quinaldic acid (qaH) afforded [Al₂(OH)₂(qa)₄]·2H₂O (1), [Ga(qa)₂(H₂O)₂]NO₃ (2) and [In(qa)₂(NO₃)(H₂O)] (3), respectively, in high yields. The crystal structures of 1, 2 and 3 have been determined by single-crystal X-ray crystallography. The structure of 1 features a di-hydroxo bridged [Al₂(μ-OH)₂]⁴⁺ dimer in which each Al(III) is further ligated by two bidentate chelate qa^? ligands. Complexes 2 and 3 are mononuclear with the M(III) ions in octahedral environments surrounded by two bidentate chelate qa^? and two H₂O in 2 or one H₂O and a terminal NO₃^? in 3. Characteristic IR as well as thermal analysis and solid-state fluorescence are discussed.     

Synthesis,spectral and thermal properties of macrocyclic zinc(II) complexes

The new zinc ternary complexes [Zn(cyclen)NO₃]ClO4 (I), [Zn₂(cyclen)₂(m-nic)](ClO₄)₃ (II), [Zn₂(cyclen)₂(m-pic)](ClO₄)₃ (III) (cyclen=1,4,7,10-tetraazacyclododecane; nic=nicotinic acid; pic=picolinic acid) were synthesized and their spectral and thermal properties were investigated. The compounds were characterized by elemental analysis, IR spectroscopy and TG/DTG, DTA methods. Moreover, the way of coordination of pyridinecarboxylate anions was proposed on the basis of the spectral data and consequently proved with results of X-ray structure analysis. This revised version was published online in August 2006 with corrections to the Cover Date.     

Zinc(II) and mercury(II) complexes with Schiff bases: syntheses,spectral, and structural characterization

Schiff bases o-vanilidene-1-aminobenzene (HL¹) and o-vanilidene-2-methyl-1-aminobenzene (HL²) lead to the formation of mono- and bis-[(Cl)Zn(L¹)] (1), [(Cl)Zn(L²)] (2), [(Cl)Hg(L¹)] (3), [(Cl)Hg(L²)] (4), [Zn(L¹)₂] (5), [Zn(L²)₂] (6), [Hg(L¹)₂] (7), and [Hg(L²)₂] (8) complexes by reactions of zinc(II) and mercury(II) chlorides in different mole ratio(s). Complexes 1–8 have been characterized by elemental analyses (Zn, Hg, C, H, Cl, and N), melting point and spectral (IR, ¹H-NMR), PXRD, molar conductivity measurement, and TGA. Conductivity measurements suggest non-electrolytes. Structural compositions have been assigned by mass spectral studies. Four-coordinate geometry may be assigned to these complexes tentatively. Structural study reveals that in 1–4 two metal centers are held together by two bridged (μ₂-Cl) chlorides, whereas 5–8 contain two bidentate Schiff-base ligands around one metal-producing monomers.     

Synthesis,spectral characterization,properties and structures of copper(I) complexes containing novel bidentate iminopyridine ligands

Four new ligands, (4-methyl-phenyl)-pyridin-2-ylmethylene-amine (A), (2,3-dimethyl-phenyl)-pyridin-2-ylmethylene-amine (B), (2,4-dimethyl-phenyl)-pyridin-2-ylmethylene-amine (C) and (2,5-dimethyl-phenyl)-pyridin-2-ylmethylene-amine (D), and their corresponding copper(I) complexes, [Cu(A)₂]ClO₄ (1a), [Cu(B)₂]ClO₄ (1b), [Cu(C)₂]ClO₄ (1c), [Cu(D)₂]ClO₄ (1d), [Cu(A)(PPh₃)₂]ClO₄ (2a), [Cu(B)(PPh₃)₂]ClO₄ (2b), [Cu(C)(PPh₃)₂]ClO₄ (2c) and [Cu(D)(PPh₃)₂]ClO₄ (2d), have been synthesized and characterized by CHN analyses, ¹H and ¹³C NMR, IR and UV–Vis spectroscopy. The crystal structures of [Cu(B)₂]ClO₄ (1b), [Cu(C)₂]ClO₄ (1c) and [Cu(A)(PPh₃)₂]ClO₄ · 1/2CH₃CN (2a) were determined from single crystal X-ray diffraction. The coordination polyhedron about the copper(I) center in the three complexes is best described as a distorted tetrahedron. A quasireversible redox behavior is observed for the complexes.     

Synthesis,crystal structures,and fluorescence properties of (RS)-2-methylglutarato Zn(II), Cd(II) complexes

Reactions of fresh M(OH)₂ (M = Zn²⁺, Cd²⁺) precipitate and (RS)-2-methylglutaric acid (H₂MGL), 2,2′-bipyridine (bipy), or 1,10-phenanthroline (phen) in aqueous solution at 50°C afforded four new metal–organic complexes [Zn₂(bipy)₂(H₂O)₂(MGL)₂] (1), [Zn₂(phen)₂(H₂O)(MGL)₂] (2), [Cd(bipy)(H₂O)(MGL)] · 3H₂O (3), and [Cd(phen)(H₂O)(MGL)] · 2H₂O (4), which were characterized by single crystal X-ray diffraction, IR spectra, TG/DTA analysis as well as fluorescence spectra. In 1, the [Zn(bipy)(H₂O)]²⁺ moieties are linked by R- and S-2-methylglutarate anions to build up the centrosymmetric dinuclear [Zn₂(bipy)₂(H₂O)₂(MGL)₂] molecules. In 2, the 1-D ribbon-like chains [Zn₂(phen)₂(H₂O)(MGL)₂] _n can be visualized as from centrosymmetric dinuclear [Zn₂(phen)₂(H₂O)₂(MGL)₂] units sharing common aqua ligands. Both 3 and 4 exhibit 1-D chains resulting from [Cd(bipy)(H₂O)]²⁺ and [Cd(phen)(H₂O)]²⁺, respectively, bridged alternately by R- and S-2-methylglutarate anions in bis-chelating fashion. The intermolecular and interchain π···π stacking interactions form supramolecular assemblies in 1 and 1-D chains in 2–4 into 2-D layers. The hydrogen bonded lattice H₂O molecules are sandwiched between 2-D layers in 3 and 4. Fluorescence spectra of 1–4 exhibit LLCT π → π* transitions.     

Syntheses,structures, and fluorescent properties of three Zn(II) and Cu(II) complexes of different ligands derived from 3,6-bis(2-pyridyl)-1,2-dihydro-1,2,4,5-tetrazine

Three supramolecular complexes [Zn(HL₁ )₂(H₂O)₂(ZnCl₄)₂] (1), [Cu(L₂ )₂Cl₂] (2), and [Zn(L₃ )Cl₂] (3) have been synthesized and characterized by single crystal X-ray diffraction analysis (L₁ = 3,5-di(2-pyridyl)-4-amino-1,2,4-triazole, L₂ = 3,5-di(2-pyridyl)-1,2,4-triazole, and L₃ = 2-pyridinecarboxylic acid (pyridin-2-ylmethylene)-hydrazide). In 1, anion–π interactions between Cl^? and the π-systems of L₁ are observed and anion–π, hydrogen bonding and π–π stacking interactions link the two complex units of [Zn(HL₁ )₂(H₂O)₂]⁴⁺ and [ZnCl₄]^2? to form a 3-D supramolecular network. In 2, π–π stacking interactions between aromatic rings of 1,2,4-triazole and pyridine rings are observed; in 3, hydrogen bonding of Cl ··· H–N and π–π stacking interactions between parallel pyridine rings of L ₃ are observed. The mechanisms of rearrangement reactions of L to L₁ –L₃ are discussed. The fluorescent properties for solid 1 and 3 are also investigated.     

Transition metal complexes of 3-acetylpyridine 4 N-(2-pyridyl)thiosemicarbazone (HAPS); structural,spectroscopic, and biological studies

This work examines transition metal ion complexes which have been synthesized from 3-acetylpyridine ⁴ N-(2-pyridyl)thiosemicarbazone (HAPS) (1). [Cu(HAPS)₂Cl₂]?·?H₂O (2), [Hg(HAPS)₂Cl₂] (3), [Ni(HAPS)Cl₂]?·?2H₂O (4), [UO₂(APS)₂]?·?2H₂O (5), [VO(HAPS)₂]SO₄?·?H₂O (6), and [Zn(HAPS)₂Cl₂] (7) were characterized by elemental analysis, spectral (IR, ¹H-NMR, and UV-Vis), magnetic, and molar conductance measurements. The biochemical studies showed that 2 and 3 have powerful and complete degradation on both DNA and protein. Complexes 2, 4, and 7 showed significant antioxidant properties, especially scavenging on superoxide and hydroxyl radicals. The antibacterial screening demonstrated that all studied complexes have maximum and broad range activities against Gram-positive and Gram-negative bacterial strains.     

Cytotoxic activity of iron(III), cobalt(III), nickel(II), zinc(II), and cadmium(II) complexes of 2-acetylpyrazine thiosemicarbazone: crystal structure of the cobalt(III) complex

Transition metal complexes [Fe(HL)₂]Cl₃ ? 1.5H₂O (1), [Co(L)₂] ? ClO₄ ? H₂O (2), Ni(HL)₂(ClO₄)₂ ? 2H₂O (3), Zn(HL)L ? BF₄ ? 2H₂O (4), and Cd(HL)₂(ClO₄)₂ ? 2H₂O (5), where HL = C₇H₉N₅S, 2-acetylpyrazine thiosemicarbazone, have been synthesized. Complex 2 was characterized by elemental analysis, infrared spectra, mass spectra, and single-crystal X-ray diffraction. Preliminary in vitro screening showed that 1, 4, and 5 exhibit higher antitumor activity than 2 and 3 against K562 leucocythemia cancer cell line.     

Synthesis,characterization, crystal structures,and superoxide dismutase activity of copper(II) octahedral complexes containing tri- and monodentate ligands

Three new copper(II) complexes [Cu(PSBP)₂](NO₃)(BF₄) (1), [Cu(DAPBMA)₂](BF₄)₂ (2), and [Cu(ImH)₄(NO₃)₂] (3), where PSBP = 4-phenylsemicarbazide-2-benzoylpyridine, DAPBMA = 2,6-diacetylpyridine-bis-4-methoxyaniline, and ImH = Imidazole, have been synthesized and characterized by elemental analysis, FAB mass spectrometry, magnetic susceptibility, X-band electron paramagnetic resonance (EPR), electronic spectroscopy, and cyclic voltammetry. Frozen solution EPR spectra of the complexes have axial features with g _∥ > g _⊥ > 2.003 suggesting the presence of a d _{x ²? y ²} ground state. Single crystal X-ray analyses of 1–3 reveal the presence of distorted octahedral geometry. All complexes exhibit significant superoxide dismutase activity.     

Synthesis,characterization and antimicrobial activity of zinc(II) ibuprofen complexes with nitrogen-based ligands

Metal carboxylate complexes possess different carboxylate coordination modes, e.g. monodentate, bidentate, and bridging bidentate. Five Zn(II) complexes were prepared and characterized in order to examine their coordination modes in addition to their biological activity. The syntheses were started by preparation of [Zn(ibup)₂(H₂O)₂] (1). Then, different nitrogen-donor ligands reacted with 1 to produce [Zn(ibup)₂(2-ampy)₂] (2), [Zn(ibup)(2-ammethylpy)] (3), [Zn(ibup)(2,2′-bipy)] (4), and [Zn₂(ibup)₄(2-methylampy)₂] (5) (ibup = ibuprofen, 2-ampy = 2-aminopyridine, 2-ammethylpy = 2-aminomethylpyridine, 2,2′-bipy = 2,2′-bipyridine, 2-methylampy = 2-(methylamino)pyridine). IR, ¹H NMR, ¹³C{¹H}-NMR and UV–vis spectroscopies were used for characterization. The crystal structures of 2 and 5 were determined by single-crystal X-ray diffraction. Investigation of in vitro antibacterial activities for the complexes against Gram-positive (Micrococcus luteus, Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis) bacteria were done using agar well-diffusion method. Complex 1 showed antibacterial activity against Gram-positive bacteria. Complexes 2 and 3 did not exhibit antibacterial activity. Complex 4 showed antibacterial activity and was chosen for further studies to determine the inhibition zone diameter for different concentrations and to set the minimum inhibitory concentration. The antibacterial activity against most of the bacteria was minimized as a result of the complexation of zinc ibuprofen with 2,2′-bipy in 4.     

Synthesis,characterization, crystal structure,and DNA-binding of ruthenium(II) complexes of heterocyclic nitrogen ligands resulting from a benzimidazole-based quinazoline derivative

The reaction of cis-[RuCl₂(dmso)₄] with [6-(2-pyridinyl)-5,6-dihydrobenzimidazo[1,2-c]quinazoline] (L) afforded in pure form a blue ruthenium(II) complex, [Ru(L¹)₂] (1), where the original L changed to [2-(1H-benzoimidazol-2-yl)-phenyl]-pyridin-2-ylmethylene-amine (HL¹ ). Treatment of RuCl₃?·?3H₂O with L in dry tetrahydrofuran in inert atmosphere led to a green ruthenium(II) complex, trans-[RuCl₂(L²)₂] (2), where L was oxidized in situ to the neutral species 6-pyridin-yl-benzo[4,5]imidazo[1,2-c]quinazoline (L² ). Complex 2 was also obtained from the reaction of RuCl₃?·?3H₂O with L² in dry ethanol. Complexes 1 and 2 have been characterized by physico-chemical and spectroscopic tools, and 1 has been structurally characterized by single-crystal X-ray crystallography. The electrochemical behavior of the complexes shows the Ru(III)/Ru(II) couple at different potentials with quasi-reversible voltammograms. The interaction of these complexes with calf thymus DNA by using absorption and emission spectral studies allowed determination of the binding constant K _b and the linear Stern–Volmer quenching constant K _SV.     

Manganese(II) complexes with N-methyl-4-nitrobenzaldehyde, N-methyl-4-nitroacetofenone,and N-methyl-4-nitrobenzophenone thiosemicarbazone: Investigation of in vitro activity against Trypanosoma cruzi

Thiosemicarbazones are known to be active against different pathogenic microorganisms including Trypanosoma cruzi, the etiological agent of Chagas disease. In the search for new therapeutic drugs against this illness, the complexes [Mn(H4NO₂Fo4M)₂Cl₂] (1), [Mn(H4NO₂Ac4M)₂Cl₂] (2) and [Mn(H4NO₂Bz4M)₂Cl₂] (3) of N⁴-methyl-4-nitrobenzaldehyde thiosemicarbazone (H4NO₂Fo4M), N⁴-methyl-4-nitroacetophenone thiosemicarbazone (H4NO₂Ac4M) and N⁴-methyl-4-nitrobenzophenone thiosemicarbazone (H4NO₂Bz4M) were obtained and screened in vitro against bloodstream and intracellular forms of T. cruzi. H4NO₂Fo4M, H4NO₂Ac4M and their Mn(II) complexes displayed poor effect on bloodstream trypomastigotes, with IC₅₀ values ranging from 68 to >200 μM. However, although H4NO₂Bz4M was also not active, its corresponding Mn(II) complex presented high effect on this T. cruzi form, with an IC₅₀ value of 19 μM. The effect of complex (3), against trypomastigotes of T. cruzi supports further in vitro as well as in vivo studies.     

Synthesis and characterization of [Cu(mb2en)2]ClO4 and [Cu(mb2en)(PPh3)2]BPh4: crystal structure of [Cu(mb2en)2]ClO4

The ligand, N,N′-bis-(4-methoxy-benzylidene)-ethane-1,2-diamine (mb₂en), and its corresponding copper(I) complexes, [Cu(mb₂en)₂]ClO₄ (1), and [Cu(mb₂en)(PPh₃)₂]BPh₄ (2), have been synthesized and characterized by CHN analyses, ¹H and ¹³C-NMR, IR, and UV-Vis spectroscopies. The crystal and molecular structure of [Cu(mb₂en)₂]ClO₄ (1), were determined by X-ray crystallography from a single-crystal. The coordination polyhedron about copper(I) is best described as a distorted tetrahedron. Quasi-irreversible redox behavior was observed for 1 and 2 (E _1/2?=?0.55 and 0.95?V, respectively).