Synthesis of Co–Pd alloys by co-electroreduction of aquachloro-cobalt(II) and palladium(II) complexes

The work presents results of the studies on the synthesis of Co–Pd alloys from acid electrolytes containing chloride ions. The main aim of the tests was to identify reactions responsible for alloy formation and to determine an influence of the electrolysis parameters, i.e. working electrode potential, electrolyte composition and temperature on the composition of the resulted alloy coatings. Electrochemical investigations were performed by applying cyclic voltammetry (CV) combined with electrochemical quartz crystal microbalance (EQCM). The electrolyte composition was selected based on a thermodynamic analysis and spectrophotometric tests which were described in our previous papers [1, 2]. They allowed determination of equilibrium distribution of the metals complex forms and a stability analysis of the electrolyte. The alloys were synthesized within the potential range from ?0.7 to ?1.1 V. The tests indicate a possibility of alloys synthesis already at the potential range 相似文献   

X-ray study of volatile Ni(II), Cu(II), and Pd(II) complexes of β-ketoimine pivalyltrifluoroacetone

Synthesis of volatile complexes based on -ketoimine pivalyltrifluoroacetone, C(CH₃)₃C(NH)CH₂COCF₃, is described. The general formula of the complexes is M(L)₂, where M = Cu, Ni, Pd. Complexes of this kind with Ni and Pd were obtained for the first time. The Cu and Pd complexes were found to be isostructural. A comprehensive crystal-chemical study showed that all structures are molecular and built of trans-complexes. The central atom has a square plane environment. The average M-O and M-N distances are nearly equal in all compounds: 1.84 , 1.92 , and 1.98 for Ni, Cu, and Pd complexes, respectively; the mean values of the O-M-N chelate angles are 93.4°, 91.9°, and 92.7°, respectively.Original Russian Text Copyright © 2004 by I. A. Baidina, G. I. Zharkova, N. V. Pervukhina, S. A. Gromilov, and I. K. IgumenovTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 713–722, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Near-infrared-emitting phthalocyanines. A combined experimental and density functional theory study of the structural, optical, and photophysical properties of Pd(II) and Pt(II) α-butoxyphthalocyanines

The structural, optical, and photophysical properties of 1,4,8,11,15,18,22,25-octabutoxyphthalocyaninato-palladium(II), PdPc(OBu)(8), and the newly synthesized platinum analogue PtPc(OBu)(8) are investigated combining X-ray crystallography, static and transient absorption spectroscopy, and relativistic zeroth-order regular approximation (ZORA) Density Functional Theory (DFT)/Time Dependent DFT (TDDFT) calculations where spin-orbit coupling (SOC) effects are explicitly considered. The results are compared to those previously reported for NiPc(OBu)(8) (J. Phys. Chem. A 2005, 109, 2078) in an effort to highlight the effect of the central metal on the structural and photophysical properties of the group 10 transition metal octabutoxyphthalocyanines. Different from the nickel analogue, PdPc(OBu)(8) and PtPc(OBu)(8) show a modest and irregular saddling distortion of the macrocycle, but share with the first member of the group similar UV-vis spectra, with the deep red and intense Q-band absorption experiencing a blue shift down the group, as observed in virtually all tetrapyrrolic complexes of this triad. The blue shift of the Q-band along the MPc(OBu)(8) (M = Ni, Pd, Pt) series is interpreted on the basis of the metal-induced electronic structure changes. Besides the intense deep red absorption, the title complexes exhibit a distinct near-infrared (NIR) absorption due to a transition to the double-group 1E (π,π*) state, which is dominated by the lowest single-group (3)E (π,π*) state. Unlike NiPc(OBu)(8), which is nonluminescent, PdPc(OBu)(8) and PtPc(OBu)(8) show both deep red fluorescence emission and NIR phosphorescence emission. Transient absorption experiments and relativistic spin-orbit TDDFT calculations consistently indicate that fluorescence and phosphorescence emissions occur from the S(1)(π,π*) and T(1)(π,π*) states, respectively, the latter being directly populated from the former, and the triplet state decays directly to the S(0) surface (the triplet lifetime in deaerated benzene solution was 3.04 μs for Pd and 0.55 μs for Pt). Owing to their triplet properties, PdPc(OBu)(8) and PtPc(OBu)(8) have potential for use in photodynamic therapy (PDT) and are potential candidates for NIR light emitting diodes or NIR emitting probes.     

The First Heterometallic Acetate-Bridged Pt(II)–Pd(II) Complex: Synthesis,Structure, and Formation of Bimetallic PtPd2 Nanoparticles

Russian Journal of Coordination Chemistry - The reaction of platinum acetate blue, empirically described as Pt(OOCMe)2.50, with palladium(II) acetate Pd3(μ-OOCMe)6 gave the first...     

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.     

Volatile complexes of Pd(II) with methoxy-β-iminoketones: Synthesis,properties, and crystal and molecular structure

This paper describes a procedure for the synthesis of two new volatile complexes, Pd(L¹)₂ and Pd(L²)₂, from sterically hindered methoxy-β-iminoketones, where HL¹ = C(CH₃)₂(OCH₃)-C(NH)-CH₂-C(O)-C(CH₃)₃; HL² = C(CH₃)₂(OCH₃)-C(NH)-CH₂-C(O)-CH(CH₃)₂. Element analysis and IR spectral data are given. The results of full X-ray crystal structure analysis of the complexes are reported. The compounds have molecular structures; the crystals of the complexes have different symmetry groups and unit cell dimensions. The Pd(L¹)₂ complex molecule has a nonplanar structure; the Pd(L²)₂ complex has a cis-structure. The geometrical characteristics obtained for the coordination units are as follows: the Pd-O and Pd-N bond lengths and N-Pd-O chelate angles were estimated at 1.960 Å, 93.7° for Pd(L¹)₂, and 1.984 Å, 1.976 Å, 92.4° for Pd(L²)₂.     

Synthesis,crystal structure,thermal decomposition,and XPS studies of homo and heterotrinuclear Cu(II)–Cu(II)–Cu(II) and Cu(II)–Ni(II)–Cu(II) complexes obtained from salpn type ligands

In this study, a mononuclear CuL complex was prepared by the use of bis-N,N′-(salicylidene)-1, 3-propanediamine (LH₂) and Cu²⁺ ion. NiCl₂ and NiBr₂ salt were treated with this complex in dioxanewater medium and two new complexes [(CuL)₂NiCl₂(H₂O)₂] and [(CuL)₂NiBr₂(H₂O)₂)] with Cu(II)–Ni(II)–Cu(II) nucleus structure were obtained. In addition to this bis-N,N′-(2-hydroxybenzyl)-1,3-diaminopropane (L^HH₂) was prepared by the reduction of LH₂ with NaBH₄ in MeOH medium. The treatment of this reduced complex with Cu²⁺ ion resulted a complex [(CuL^H)₂CuCl₂] with a structure of Cu(II)–Cu(II)–Cu(II). The complexes prepared were characterized by the use of elemental analysis, IR spectroscopy, thermogravimetric and X-ray diffraction methods. The crystal structures of [(CuL)₂NiBr₂(H₂O)₂] (СIF file CCDC 1448402) and [(CuL^H)₂CuCl₂] (СIF file CCDC 1448401) complexes were elucidated. It was found that halogen ions are coordinated to terminal Cu²⁺ ions which are in a distorted square pyramid coordination sphere. It was determined that the central Cu(II), which joins terminal square pyramidal Cu(II), was coordinated only by the phenolic oxygens of the ligand while the central Ni(II) was coordinated by two phenolic oxygens of the organic ligand and two water molecules. These complexes were investigated by XPS and it was found that the terminal and central Cu²⁺ ions were different in Cu(II)–Cu(II)–Cu(II) complex. Also, the thermal degradation of the CuLH complex unit was observed to exothermic in contrast to the expectations.

     

Synthesis and properties of Cu(II) and Pd(ii) complexes with chiral bis-α-sulfanyl oxymes,the derivatives of natural monoterpene, α-pinene

Coordination compounds Cu₂(H₂L¹)Cl₄ (I), Pd₂(H₂L¹)Cl₄ (II), Cu₂(H₂L²)Cl₄ (III), and Pd₂(H₂L²) Cl₄ (IV) with chiral bis-α-sulfanyloximes, the derivatives of the monoterpenoid (−)-α-pinene, were obtained. The complexes I and III are paramagnetic (μ_eff = 2.45 and 2.67 μ_B, respectively), II and IV are diamagnetic. According to IR spectroscopy, in the compounds I–IV the nearest environment of Cu and Pd atoms includes N, S, and Cl atoms. The values of μ_eff and parameters of ESR spectra of the solid phase and solutions of I and III show a binuclear structure of the Cu(II) complexes. Parameters of the ¹H and ¹³C NMR spectra of compounds II and IV indicate the formation of binuclear Pd(II) complexes of C ₂ symmetry and the closure of fivemembered chelate rings PdNSC₂. The PdCl₂ fragments are in transoid position. H₂L¹ and H₂L² are tetradentate bridging chelating ligands.     

Synthesis of β-ketoenamine donors having O, N, Se/Te donor functionalities and their reaction chemistry with Pd(II) and Pt(II) metal ions

Monoanionic tridentate ligands LH_a and LH_b containing ONSe and ONTe donor sequences and their Pd²⁺ and Pt²⁺ derivatives were synthesized and characterized. The formation of a five- and a six-membered ring around the central metal atom and associative phenomena in solutions provide extra stability to the metal complexes.     

Synthesis,spectral, magnetic,electrochemical and catalytic studies of cyclam-based copper(II) and nickel(II) complexes–effect of N-substitution

New N-substituted cyclam ligands 1,8-[bis(3-formyl-2-hydroxy-5-methyl)benzyl]-1,4,8,11-tetraazacyclotetradecane, 1,8-[bis(3-formyl-2-hydroxy-5-methyl)benzyl]-4,11-dimethyl-1,4,8,11-tetraazacyclotetradecane, 1,8-[bis(3-formyl-2-hydroxy-5-bromo)benzyl]-1,4,8,11-tetraazacyclotetradecane, and 1,8-[bis(3-formyl-2-hydroxy-5-bromo)benzyl]-4,11-dimethyl-1,4,8,11-tetraazacyclotetradecane (L¹–L⁴) were synthesized and mononuclear copper(II) and nickel(II) complexes prepared. The ligands and complexes were characterized by elemental analysis, electronic, IR, ¹H NMR and ¹³C NMR spectral studies. N-alkylation causes red shifts in the λ_max values of the complexes. Copper(II) complexes show one-electron, quasi-reversible reduction waves in the range ?1.04 to ?1.00 V. The nickel(II) complexes show one-electron, quasi-reversible reduction waves in the range ?1.18 to ?1.30 V and one-electron, quasi-reversible oxidation waves in the range +1.20 to +1.40 V. The reduction potential of the copper(II) and nickel(II) complexes of the ligands L¹ to L² and L³ to L⁴ shift anodically on N-alkylation. The ESR spectra of the mononuclear copper(II) complexes show four lines, characteristic of square-planar geometry with nuclear hyperfine spin 3/2. All copper(II) complexes show a normal room temperature magnetic moment value μ_eff?=?1.70–1.74 BM which is close to the spin only value of 1.73 BM. Kinetic studies on the oxidation of pyrocatechol to o-quinone using the copper(II) complexes as catalysts and on the hydrolysis of 4-nitrophenylphosphate using the copper(II) and nickel(II) complexes as catalyst were carried out. The tetra-N-substituted complexes have higher rate constants than the corresponding disubstituted complexes.     

Synthesis, Structure and Properties of Tetrakis (thiourea) mercury (II) Tetrakis (thiocyanato-N) zinc (II)

Introduction In recent years, much attention has been paid to the research of novel, high-quality nonlinear optical (NLO) crystals, especially those metalorganic complex crystals that can generate high efficient second-harmonic blue-violet light using GaAlAs laser diodes. In order to find this type of crystals, much work has been done in our laboratory on the complex crystals of MM'(SCN)4 and MM'(SCN)·nL, where M = Zn, Cd, Mn; M' = Cd, Hg and L = adduct1-6. A 404.5nm blue-violet lig…     

Solvatochromism and piezochromism of pentacyanoferrates(II) and of mixed valence iron(II)—iron(III) and ruthenium(II)—ruthenium(III) species

Pressure effects on the MLCT bands of the pyrazine- and 4-cyanopyridine-pentacyanoferrate(II) anions have been established. The relation of these piezochromic effects to the solvatochromism of each complex is put into the correlation between these parameters developed for other d⁶ ternary complexes. The conformance of piezochromic and solvatochromic efrects on MMCT bands for diiron and diruthenium mixed valence complexes to this correlation is examined.     

Crystal Structures and Characterizations of Bis(pyrrolidinedithiocarbamato) Cu(II) and Zn(II) Complexes

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅａｂｉｌｉｔｙｏｆｄｉｔｈｉｏｃａｒｂａｍａｔｅ(ｄｔｃ)ｂｉｎｄｉｎｇｔｏｍｅｔａｌｓｈａｓｂｅｅｎｋｎｏｗｎｆｏｒｍａｎｙｙｅａｒｓ .Ｉｔｆｏｒｍｓｃｈｅｌａｔｅｓｗｉｔｈｖｉｒｔｕ ａｌｌｙａｌｌｔｒａｎｓｉｔｉｏｎｍｅｔａｌｓ.1Ｔｈｅｂｉｄｅｎｔａｔｅａｎｉｏｎｉｓａｌｓｏｗｅｌｌｋｎｏｗｎａｓａｂｒｉｄｇｅｂｅｔｗｅｅｎｔｗｏｔｒａｎｓｉｔｉｏｎｍｅｔａｌｃｅｎｔｅｒｓ.2 Ｗａ ｔｅｒ ｓｏｌｕｂｌｅｄｉａｌｋｙｌｄｉｔｈｉｏｃａｒｂａｍａｔｅｃｏｍｐｌｅｘｅｓ…     

DNA-binding and photocleavage studies of metallofluorescein–porphyrin complexes of zinc(II) and copper(II)

The DNA-binding behaviors of the fluorescein?Cporphyrinatozinc(II) complex Zn(Fl-PPTPP) (Fl-PPTPP?=?5-(4-fluoresceinpropyloxy)phenyl-10,15,20-triphenylporphyrin) and fluorescein?Cporphyrinatocopper(II) complex Cu(Fl-PPTPP) with calf thymus DNA (CT-DNA) were investigated by UV?CVis absorption titrations, fluorescence spectra, viscosity measurements, thermal denaturation and circular dichroism. The results suggest that both complexes interact with CT-DNA by intercalation. In addition, their photocleavage reactions with pBR322 supercoiled plasmid DNA were investigated. Both complexes exhibit significant DNA cleavage activity, and singlet oxygen may play an important role in these reactions.     

Synthesis, Crystal Structure, Properties and Thermoanalysis of Complexes of Cu(II) and Ni(II) with Taurine-5-chlorosalicylaldelyde Schiff Base

Introduction The complexes of amino acid Schiff base have re-ceived considerable attention because of the interests in the biogical field.1-4 Taurine is a special amino acid in human beings. Recently, the complexes of taurine con-densation salicylaldelyde Schiff base have been re-ported,3-7 but the complexes of taurine condensation derived salicylaldelyde Schiff base have not been re-ported yet. In order to examine its anticancer and antibiosis ac-tivity of the complexes of taurine condensa…     

Coordination reactions of 3,3′-bis(dipyrrolylmethene) with Co(II), Cu(II), and Zn(II) acetylacetonates, valinates, and dipyrrolylmethenates

Using spectrophotometry we found that ligand exchange in the systems of H₂L-[MX₂]-DMF, where M denotes Co²⁺, Cu²⁺, and Zn²⁺; X means Acac^?, Val^?, dpm^?; Hdpm^? is hexamethyldipyrrolylmethene, H₂L is bis(2,4,7,8,9-pentamethyldipyrrolylmethene-3-yl)methane, proceeds through successive stages of formation of hetero- and homoleptic binuclear complexes. Conventional sensitivity of the spectrophotometric determination of Co²⁺, Cu²⁺, and Zn²⁺ reaches 10^?9 M.     

Synthesis,characterization, DFT calculations,and antimicrobial activity of Pd(II) and Co(III) complexes with the condensation derivative of 2-(diphenylphosphino)benzaldehyde and Girard’s T reagent

Complexes of Pd(II) and Co(III) with the condensation derivative of 2-(diphenylphosphino)benzaldehyde and Girard T reagent were synthesized, characterized, and their antimicrobial activities were evaluated. The ligand and the complexes were characterized by elemental analysis, IR and NMR spectroscopies, and X-ray crystallography. In both complexes, the deprotonated ligand was coordinated to the metal through the phosphorus, the imine nitrogen, and the carbonyl oxygen atoms. In the octahedral Co(III) complex, two molecules of ligands were coordinated to metal ion, while square-planar environment of Pd(II) complex was constituted of one tridentate ligand and chloride in the fourth coordination place. The ligand and complexes showed moderate antibacterial activity. The molecular structures of the obtained metal complexes and the relative stabilities of two stereoisomers of the ligand were calculated using density functional theory at the S12g/TZ2P level.     

Synthesis and magnetic properties of copper(II)-cobalt(II) complexes ofN,N′-1,2-propanedisalicylamidatocuprate(II)

Summary The binuclear metal complexes [Cu(sampn)Co(L)₂] (L=bipy, phen), have been prepared by the reaction of sodiumN,N-1,2-propanedisalicylamidatocuprate(II) heptahydrate, Na₂[Cu(sampn)] 7H₂O, with a divalent metalion, and 2,2-bipyridine or 1, 10-phenathroline. The complexes were characterized by variable-temperature magnetic susceptibility measurements; the results indicate that a weak antiferromagnetic spin-exchange interaction operates between the metal ions.     

4,4′-Bipyridine complexes of molybdenum(II) and tungsten(II)

Treatment of [MI₂(CO)₃(NCMe)₂] with two equivalents of 4,4-bipyridine (4,4-bipy) in CH₂Cl₂ at room temperature gave the MeCN displaced products, [MI₂(CO)₃(4,4-bipy-N)₂] (1) and (2). Equimolar amounts of [MI₂(CO)₃(NCMe)₂] and L (L = PPh₃, AsPh₃ or SbPh₃) react to give [MI₂(CO)₃(NCMe)L], which when reacted in situ with 4,4-bipy yield the new complexes, [MI₂(CO)₃(4,4-bipy-N)L] (3)–(8). Reaction of equimolar quantities of [WI₂(CO)(NCMe)( ²-RC₂R)₂] (R = Me or Ph) and 4,4-bipy gave the new bis(alkyne) complexes, [WI₂(CO)(4,4-bipy-N)( ²-RC₂R)₂] (9) and (10). Treatment of [MI₂(CO)₃(NCMe)₂] with two equivalents of (9) or (10) in CH₂Cl₂ at room temperature affords the bimetallic complexes, [MI₂(CO)₃{WI₂(CO)(4,4-bipy-N,N)( ²-RC₂R)₂}₂] (11)–(14). Equimolar quantities of [MI₂(CO)₃(NCMe)(PPh₃)] (prepared in situ) and (9) or (10), react to give the 4,4-bipy-bridged complexes, [MI₂(CO)₃{WI₂(CO)(4,4-bipy-N,N)( ²-RC₂R)₂}(PPh₃)] (15)–(18). All the new complexes, (1)–(18) were characterised by elemental analysis (C, H and N), i.r. and ¹H-n.m.r. spectroscopy.