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1.
Copper(II) cations coordinated with PMDTA (pentamethyldiethylenetriamine) and TMEDA (tetramethylethylenediamine) possess a high synthetic potential. The synthesis of these cations was carried out by metathesis reactions with silver salts. The cationic copper(II) complexes, [Cu(PMDTA)(Me2CO)Cl]+, [Cu(PMDTA)(H2O)Cl]+, [Cu(PMDTA)(DMF)]+, [Cu(PMDTA)Cl]+, [Cu(PMDTA)OAc]+, [Cu(PMDTA)(MeCN)2]2+, [Cu2(TMEDA)2Cl3]+ and [Cu(TMEDA)(MeCN)3]2+ were synthesised as PF6 salts, crystallised and characterised by single-crystal X-ray diffraction. 相似文献
2.
Nirmal K. Shee F.A. Oluwafunmilayo Adekunle Michael G.B. Drew 《Inorganica chimica acta》2011,366(1):198-202
Reaction of 5,6-dihydro-5,6-epoxy-1,10-phenanthroline (L) with Cu(ClO4)2·6H2O in methanol in 3:1 M ratio at room temperature yields light green [CuL3](ClO4)2·H2O (1). The X-ray crystal structure of the hemi acetonitrile solvate [CuL3](ClO4)2·0.5CH3CN has been determined which shows Jahn-Teller distortion in the CuN6 core present in the cation [CuL3]2+. Complex 1 gives an axial EPR spectrum in acetonitrile-toluene glass with g|| = 2.262 (A|| = 169 × 10−4 cm−1) and g⊥ = 2.069. The Cu(II/I) potential in 1 in CH2Cl2 at a glassy carbon electrode is 0.32 V versus NHE. This potential does not change with the addition of extra L in the medium implicating generation of a six-coordinate copper(I) species [CuL3]+ in solution. B3LYP/LanL2DZ calculations show that the six Cu-N bond distances in [CuL3]+ are 2.33, 2.25, 2.32, 2.25, 2.28 and 2.25 Å while the ideal Cu(I)-N bond length in a symmetric Cu(I)N6 moiety is estimated as 2.25 Å. Reaction of L with Cu(CH3CN)4ClO4 in dehydrated methanol at room temperature even in 4:1 M proportion yields [CuL2]ClO4 (2). Its 1H NMR spectrum indicates that the metal in [CuL2]+ is tetrahedral. The Cu(II/I) potential in 2 is found to be 0.68 V versus NHE in CH2Cl2 at a glassy carbon electrode. In presence of excess L, 2 yields the cyclic voltammogram of 1. From 1H NMR titration, the free energy of binding of L to [CuL2]+ to produce [CuL3]+ in CD2Cl2 at 298 K is estimated as −11.7 (±0.2) kJ mol−1. 相似文献
3.
Clifford A. L. Becker 《Inorganica chimica acta》1985,100(2):227-233
Equilibrium constants, Kdis, for the solvent- dependent, solution-phase disproportionation equilibria of monosubstituted pentakis(arlisocyanide)cobalt(I) complexes: 2[Co(CNR)4L]+?[Co(CNR)3L2]+ + [Co(CNR)5]+, Kdis = are measured by planimeter-integration of proton- NMR spectra at ambient temperature. The complexes, [Co(CNR)4L]ClO4, R = 2,6-Me2C6H3, L = P(C6H5)3, P(C6H4Cl-p)3, P(OC6H5)3, P(OC6H4Cl-p)3; R = o-MeC6H4, L = P(C6H4Cl-p)3, P(OC6H5)3, P(OC6H4Cl-p)3; R = 2,4,6-Me3C6H2, L = P(C6H5)3; R = 2,6-Et2C6H3, L = P(C6H5)3; are investigated in the deuterated solvents, CDCl3, CD3CN, (CD3)2CO, C5D5N, CD3NO2, and (CD3)2SO. Disproportionation seems to occur in all [Co(CNR)4L]+, but NMR study is facilitated by utilizing equivalent alkyl protons (i.e., Me-groups) on the RNC ligands.Correlation of Kdis values with steric-hindrance of the RNC in sets of complexes with the same P-ligand is evident in all solvents: Kdis decreases with increased steric-hindrance in RNC. The Kdis values for complexes with the same RNC and analogous triarylphosphine, triarylphosphite ligands (i.e., PR3, P(OR)3, same R) are approximately equal. The Kdis values for complexes of P-ligands with Cl-substituent are significantly larger than Kdis values for complexes with the corresponding unsubstituted P-ligands (e.g., [Co(CNR)4P(C6H4Clp)3]ClO4vs. [Co(CNR)4P(C6H5)3]ClO4) in (CD3)2CO and C5D5N solution, but are smaller in CDCl3 and CD3CN, and approximately equal in CD3NO2 and (CD3)2SO. Properties of the solvents are also considered. 相似文献
4.
Neutral and cationic platinum(IV) isocyanide complexes of the type [PtCl4(CNR)2], [PtCl4(CNR) (PMe2Ph)], [PtCl3(CNR)(PMe2Ph)2]+, [PtCl2(CNR)2 (PMe2Ph)2]2+, where R = methyl, t-butyl, cyclohexyl, p-tolyl, have been prepared by chlorine addition to the corresponding platinum(II) derivatives. The complexes [PtCl2(CN)2(CNR)2] and [PtCl2(CN)(CNR) (PMe2Ph)2]+ (R = t-butyl), are also reported. The cationic t-butylisocyanide derivatives are noteworthy in the way they readily lose the t-butyl cation at room temperature to give the corresponding cyano complexes. The compounds have been characterized by elemental analysis, molecular weights and conductivity measurements, and their i.r. and n.m.r. data are discussed in relation to structures and to the nature of the platinum-isocyanide bond. 相似文献
5.
Javier Arias 《Inorganica chimica acta》2011,365(1):501-504
The crown ether isocyanide CNR (R = benzo-15-crown-5) reacts with silver(I) salts in the appropriate molar ratio to give [Ag(CNR)n]X (n = 1, 2; X = CF3SO3, BF4). X-ray diffraction studies of [Ag(CF3SO3)(CNR)] show the molecules associated in a dinuclear manner with an antiparallel orientation. The silver centers are tetracoordinated to the isocyanide and to three oxygens, one from the triflate anion and two from the second crown ether in the dimer. The molecular structure displays five cycles: the two 15-crown ether rings, two five-membered argentacycles and a 22-membered diargentacycle. The crown ether in these complexes is able to detect alkaline cations from M(CF3SO3) (M = Li, Na, K) by NMR in d6-acetone solutions, and to distinguish Li+-Na+ from K+. 相似文献
6.
Santini C Pellei M Papini G Morresi B Galassi R Ricci S Tisato F Porchia M Rigobello MP Gandin V Marzano C 《Journal of inorganic biochemistry》2011,105(2):232-240
Hydrophilic, monocationic [M(L)4]PF6 complexes (M = Cu or Ag; L: thp = tris(hydroxymethyl)phosphine, L: PTA = 1,3,5-triaza-7-phosphaadamantane, L: thpp = tris(hydroxypropyl)phosphine) were synthesized by ligand exchange reaction starting from [Cu(CH3CN)4]PF6 or AgPF6 precursors at room temperature in the presence of an excess of the relevant phosphine. The related [Au(L)4]PF6 complexes (L = thp, PTA or thpp) were synthesized by metathesis reactions starting from [Au(L)4]Cl at room temperature in the presence of equimolar quantity of TlPF6. The three series of complexes [M(L)4]PF6 were tested as cytotoxic agents against a panel of several human tumour cell lines also including a defined cisplatin resistant cell line. These investigations have been carried out in comparison with the clinically used metallodrug cisplatin and preliminary structure-activity relationships are presented. The best results in terms of in vitro antitumour activity were achieved with metal-thp species and, among the coinage metal complexes, copper derivatives were found to be the most efficient drugs. Preliminary studies concerning the mechanism of action of these [M(L)4]PF6 species pointed to thioredoxin reductase as one of the putative cellular targets of gold and silver complexes and provided evidence that copper derivatives mediated their cytotoxic effect through proteasome inhibition. 相似文献
7.
The copper(II), nickel(II) and silver(I) complexes of the pentadentate 17-membered macrocycle 1, 12, 15-triaza-3, 4:9, 10-dibenzo-5,8-dithiacycloheptadecane (L1) have been prepared as perchlorates and characterized by X-ray crystallography. The N3S2 ligand uses all donor atoms for complexation. The copper coordination is square pyramidal with one sulfur atom in the axial site. Ni(II) displays an octahedral coordination by an interaction with a water molecule. The Ag(I) coordination is best described as a distorted pentagonal bipyramid. In [CuL1]2+ the 1, 4, 7-triazaheptane fragment of L1 is meridionally coordinated, but facially in [NiL1(H2O)]2+ and intermediate in [AgL1](ClO4). Crystal data for [CuL1](ClO4)2: monoclinic, space group P21/n, a = 13.153(8), b = 11.951(5), c = 17.880(8)Å, β = 110.29(4)°, Z = 4, R = 0.086 for 2732 independent reflections with I 2σ(I); [NiL1(H2O)](ClO4)2: monoclinic, P21/a, a = 10.771(2), b= 16.157(2), c = 15.286(2) Å, β =93.08(1)°, Z = 4, R = 0.085 for 1464 independent reflections with I 2σ(I); [AgL1](ClO4): monoclinic, P21/n, a = 12.708(9), b = 9.483(7), c = 19.569(13) Å, β= 103.95(6)°, Z = 4, R = 0.039 for 3600 independent reflections with I 2σ(I). 相似文献
8.
New copper(II) complexes [CuL2]2+ (L2=7,7,9-trimethyl-1,3,6,10,13-pentaazabicyclo[11,2,11.13]hexadec-9-ene) and [Cu2(L3)(H2O)2]4+ have been prepared by the reaction of [CuL1]2+ (L1=5,5,7-trimethyl-1,4,8,11,14-pentaazatetradce-7-ene) and formaldehyde. The mononuclear complex [CuL2]2+ has a square-planar coordination geometry with a 5-6-5-6 chelate ring sequence and is relatively stable even in low pH at room temperature. The dinuclear complex [Cu2(L3)(H2O)2]4+ consists of two unsaturated 15-membered pentaaza macrocyclic units (7,7,9-trimethyl-1,3,6,10,13-pentaazacyclopentadec-9-ene) that are linked together by a methylene group in a tilted face-to-face arrangement [Cu?Cu distance: 7.413(2) Å ]. Each macrocyclic unit of [Cu2(L3)(H2O)2]4+ contains one four-membered chelate ring and has a severely distorted octahedral coordination polyhedron. The dinuclear complex is quite stable in aqueous solutions containing an excess of formaldehyde or in dry acetonitrile but is decomposed to [CuL1]2+ and [CuL2]2+ in pure water. 相似文献
9.
Maura Pellei Mercedes Camalli Giancarlo Gioia Lobbia Grazia Papini Carlo Santini 《Inorganica chimica acta》2008,361(5):1456-1462
Copper(I) complexes have been synthesized from the reaction of CuCl, monodentate tertiary phosphines PR3 (PR3 = P(C6H5)3; P(C6H5)2(4-C6H4COOH); P(C6H5)2(2-C6H4COOH); PTA, 1,3,5-triaza-7-phosphaadamantane; P(CH2OH)3, tris(hydroxymethyl)phosphine) and lithium bis(3,5-dimethylpyrazolyl)dithioacetate, Li[LCS2]. Mono-nuclear complexes of the type [LCS2]Cu[PR3] have been obtained and characterized by elemental analyses, FT-IR, ESI-MS and multinuclear (1H, 13C and 31P) NMR spectral data; in these complexes the ligand behaves as a κ3-N,N,S scorpionate system. One exception to this stoichiometry was observed in the complex [LCS2]Cu[P(CH2OH)3]2, where two phosphine co-ligands are coordinated to the copper(I) centre. The solid-state X-ray crystal structure of [LCS2]Cu[P(C6H5)3] has been determined. The [LCS2]Cu[P(C6H5)3] complex has a pseudo tetrahedral copper site where the bis(3,5-dimethylpyrazolyl)dithioacetate ligand acts as a κ3-N,N,S donor. 相似文献
10.
The disproportionation reaction between the copper(II) complexes, Cu(ClO4)2 · 6H2O and [Cu(S2CNR2)2] is a well-established route to copper(III) complexes [Cu(S2CNR2)2][ClO4] but to date the nature of the copper(I) species generated has remained a mystery. We now show that with [Cu(S2CNPr2)2] this is the copper(I) cluster, [Cu8(μ2,μ2-S2CNPr2)6][ClO4]2, which contains a cubic array of copper atoms, each face cube being capped by a dithiocarbamate ligand such that the sulfur atoms define an icosahedron and the backbone carbons an octahedron around the cube centroid. A crystal structure of [Cu4(μ2,η1-S2CNBu2)4] is also presented for comparison. 相似文献
11.
《Inorganica chimica acta》1986,120(1):77-80
63Cu and 31P NMR spectra of [CuL3Cl] (L=triethylphosphite (1)in various nonaqueous solvents have been measured. It has been demonstrated that ligand-dissociation of 1 occurs to give [CuL4]Cl (2) and low coordination copper(I) species. It has also been found that the formation of copper(I) species greatly depends on the solvent used. 1 and 2 give 63Cu NMR signals while 63Cu signals of other species are hardly observed due to significant line- broadening. By use of a dual NMR tube, 1 and 2 were determined quantitatively. It was found in a series of alcohols that 2 is preferred increasing solvent polarity. This is significantly associated with the cleavage of the CuCl bond. 相似文献
12.
Marina Porchia Franco Benetollo Francesco Tisato Valentina Gandin 《Journal of inorganic biochemistry》2009,103(12):1644-1651
New copper(I) complexes containing the water soluble N-methyl-1,3,5-triaza-7-phosphaadamantane (mPTA) phosphine have been synthesized by ligand-exchange reactions starting from [Cu(CH3CN)4][BF4] or [Cu(CH3CN)4][PF6] precursors and (mPTA)X (X = CF3SO3, I). Depending on the ligand counter ion, the hydrophilic [Cu(mPTA)4][(CF3SO3)4(BF4)] 3a and [Cu(mPTA)4][(CF3SO3)4(PF6)] 3c complexes or the iodine-coordinated [Cu(mPTA)3I]I34 species were obtained respectively and fully characterized by spectroscopic methods. Single crystal structural characterization was undertaken for [Cu(mPTA)3I]I3·H2O, 4·H2O, and [Cu(mPTA)4][(CF3SO3)2(BF4)3] ·0.25H2O, 3b·0.25H2O, the latter obtained by crystallization of [Cu(mPTA)4][(CF3SO3)4(BF4)] 3a. The cytotoxicity of analogous tetrahedral homoleptic Cu(I) derivatives [Cu(PTA)4](BF4) 1, [Cu(PTAH)4][Cl4(BF4)] 2, [Cu(mPTA)4][(CF3SO3)4(BF4)] 3a and [Cu(mPTA)4][(CF3SO3)4(PF6)] 3c was evaluated against a panel of several human tumor cell lines. All the complexes showed in vitro antitumor activity comparable to that of the reference metallodrug cisplatin. Tests performed on cisplatin sensitive and resistant cell lines showed that against human ovarian 2008/C13* cell line pair, the resistance factor of copper derivatives was roughly 7-fold lower than that of cisplatin, whereas against human cervix cancer A431/A431-Pt cell line pair it was about 2.5-fold lower. These results, confirming the circumvention of cisplatin resistance, support the hypothesis that phosphine copper(I) complexes follow different cytotoxic mechanisms than do platinum drugs. 相似文献
13.
Matthew F. Cain Brian J. Anderson James A. Golen Arnold L. Rheingold 《Inorganica chimica acta》2011,369(1):55-61
Phosphinoquinoxalines were prepared by treatment of 2,3-dichloroquinoxaline (3) with phosphorus nucleophiles. The Arbuzov reaction of 3 with PPh(O-i-Pr)2 gave a mixture of diastereomers of 2,3-(PPh(O)(O-i-Pr))2quinoxaline (6); the crystal structure of rac-6 was determined, but attempts at reduction to yield bis(phenylphosphino)quinoxaline 7 resulted in P-C cleavage and formation of phenylphosphine. The bis(secondary phosphine) 7 could be generated from 3 and LiPHPh(BH3), but was not isolated in pure form. Copper-catalyzed coupling of PHPh2 with 3 gave 2,3-bis(diphenylphosphino)quinoxaline (4, dppQx), whose coordination chemistry was investigated, with comparison to data for the analogous 1,2-bis(diphenylphosphino)benzene (dppBz) complexes. Reaction of dppQx with [Cu(NCMe)4][PF6] gave [Cu(dppQx)2][PF6] (8); CuCl yielded [Cu(dppQx)Cl]2 (9). Reaction of [Cu(NCMe)4][PF6] with one equiv of DPEphos, followed by one equiv of dppQx, gave [Cu(dppQx)(DPEphos)][PF6] (10). Ligand 4 and copper complexes 8 and 9 were crystallographically characterized. The UV-Vis spectra of dppQx and its copper complexes were red-shifted from those of the dppBz analogs; in contrast to results for the dppBz complexes, those of dppQx were not luminescent in solution. 相似文献
14.
《Inorganica chimica acta》2006,359(15):4723-4729
Copper(I) and silver(I) complexes of formulae [Cu(NCCH3)4]+[A]− ([A]− = [B(C6F5)4]− (1), {B[C6H3(CF3)2]4}− (2), [(C6F5)3B–C3H3N2–B(C6F5)3]− (3), and [Ag(NCCH3)4]+[B(C6F5)4]− (4) are examined with particular emphasis on the strength of their M–N bond and its influence on the catalytic performance of these complexes in cyclopropanation and aziridination. To examine the strength of the M–N interactions, vibrational spectra of the related hydrogenated and deuterated species [Cu(NCCH3)4]+, [Cu(NCCD3)4]+, [Ag(NCCH3)4]+, and [Ag(NCCD3)4]+ are also determined. It is found that the metal–nitrile bond strength is an important factor for the catalytic activity of the respective complexes. 相似文献
15.
An equimolecular mixture of [Pd(RNC)2Cl2] (R = Ph, p-Me C6H4) and [Pd(MeCN)2Cl2] reacts in boiling, 1,2-dichloroethane to give the binuclear complexes [Pd(RNC)Cl2]2.These compounds undergo a variety of bridge-splitting reactions with neutral or anionic ligands yielding complexes of the type cis and trans [Pd(RNC)LX2] or [Pd(RNC)X3]− (L = PPh3, pyridine, C6H11NC; X = CL, Br).By reaction of [Pd(PhNC)Cl3]− with MeOH the anionic carbene complex [Pd{C(NHPh)OMe}Cl3]− is obtained.[Pd(PhNC)Cl2]2 reacts with p-toluidine (excess) or o-aminopyridine to give the corresponding mononuclear carbene derivatives.In the case of the mixed derivative [Pd(p-MeC6H4NC)(C6H11NC)Cl2], only the more activated p-tolylisocyanide was found to react with p-toluidine.The complexes have been characterized by elemental analysis, conductivity measurements, i.r. and 1H n.m.r. spectra where possible. 相似文献
16.
Reactions between XPd(μ-dmp)2PdX′ (X = X′ = Cl, Br, I, NCO, SCN, N3 or C6F5; X = C6F5, X′ = Cl, Br, I, NCO) with 1,4-diisocyanobenzene lead to the tetranuclear complexes [(μ,μ′-CNC6H4NC){XPd(μ-dpm)2PdX′}2], where both ends of the diisocyanide are inserted in a metalmetal bond. The cationic derivatives [(μ,μ′-CNC6H4NC){(RNC)Pd(μ-dpm)2(CNR)}2](BPh4)4 and [(μ,μ′-CNC6H4NC){(RNC)Pd(μ-dpm)2Pd(C6F5)}2] (BPh4)2 (R = p-Tol, Cy, or tBu) are obtained by reacting [(μ,μ′-CNC6H4NC){ClPd(μ-dpm)2PdX}2] (X= Cl or C6F5) with RNC in the presence of NaBPh4. Treatment of [(μ,μ′-CNC6H4NC){ClPd(μ-dpm)2Pd(C6F5)}]2 with NaBPh4 causes the di-insertion and subsequent coordination of the isocyanide, yielding [(C6F5)Pd(CN-C6H4NC) Pd(μ-dpm)2Pd(C6F5)](BPh4)2. 相似文献
17.
Gold(III) compounds have been recognized as anticancer agents due to their structural and electronic similarities with currently employed platinum(II) species. An added benefit to gold(III) agents is the ability to overcome cisplatin resistance. This work identified four gold(III) compounds, [Au(Phen)Cl2]PF6, [Au(DPQ)Cl2]PF6, [Au(DPPZ)Cl2]PF6, and [Au(DPQC)Cl2]PF6, (Phen = 1,10-phenanthroline, DPQ = dipyrido[3,2-d:2′,3′-f]quinoxaline, DPPZ = dipyrido[3,2-a:2′,3′-c] phenazine, DPQC = dipyrido[3,2-d:2′,3′-f] cyclohexyl quinoxaline) that exhibited anticancer activity in both cisplatin sensitive and cisplatin resistant ovarian cancer cells. Two of these compounds, [Au(DPQ)Cl2]PF6 (AQ) and [Au(DPPZ)Cl2]PF6 (AZ), displayed exceptional anticancer activity and were the focus of more intensive mechanistic study. At the molecular level, AQ and AZ formed DNA adducts, generated free radicals, and upregulated pro-apoptotic signaling molecules (p53, caspases, PARP, death effectors). Taken together, these two novel gold(III) polypyridyl complexes exhibit potent antitumor activity in cisplatin resistant cancer cells. These activities may be mediated, in part, by the activation of apoptotic signaling. 相似文献
18.
A series of chiral Ag(I) and Cu(II) complexes have been prepared from the reaction between AgX (X = NO3, PF6, OTf) or CuX2 (X = Cl, ClO4) and chiral biaryl-based N-ligands. The rigidity of the ligand plays an important role in the Ag(I) complex formation. For example, treatment of chiral N3-ligands 1-3 with half equiv of AgX (X = NO3, PF6, OTf) gives the chiral bis-ligated four-coordinated Ag(I) complexes, while ligand 4 affords the two-coordinated Ag(I) complexes. Reaction of AgX with 1 equiv of chiral N4-ligands 5, 7, 8 and 10 gives the chiral, binuclear double helicate Ag(I) complexes, while chiral mono-nuclear single helicate Ag(I) complexes are obtained with N4-ligands 6 and 9. Treatment of either N3-ligand 1 or N4-ligand 9 or 10 with 1 equiv of CuX2 (X = Cl, ClO4) gives the mono-ligated Cu(II) complexes. All the complexes have been characterized by various spectroscopic techniques, and elemental analyses. Seventeen of them have further been confirmed by X-ray diffraction analyses. The Cu(II) complexes do not show catalytic activity for allylation reaction, in contrast to Ag(I) complexes, but they do exhibit catalytic activity for Henry reaction (nitroaldol reaction) that Ag(I) complexes do not. 相似文献
19.
The tripod ligands tris(2-alkylthioethyl)amine, with alkyl = ethyl, iso-propyl, and tert-butyl, give with cobalt(II) and nickel(II) halides high-spin complexes with formulae [MLX2], [MLX]Y, and [MLX]2[MX4] (where X = Cl, Br, I; Y = BPh4, PF6). The nickel complexes are either six- or five-coordinate: the coordination number decreases as the bulkiness of the alkyl group bound to the sulfur is increased. All the cobalt complexes contain the five-coordinate cation [CoLX]+. The crystal and molecular structure of the [Co(NS3-t-Bu)Br]PF6 complex has been determined by standard X-ray methods, and refined to R = 0.061. The crystals are monoclinic, space group P21/n. The unit cell dimensions are: a = 27.420 (2), b = 11.923 (4), c = 17.082 (1) Å, β = 102.40 (1)°, Z = 8. The complex cation has a trigonal bipyramidal geometry with the nitrogen and bromine atoms at the apexes, and the three sulfur atoms in the equatorial plane. The tetrahedral distortion is relatively small (mean BrCoS angle = 98.5°), and similar to that found for the [Co (Me6tren)Br]Br complex [Me6tren = tris(2-dimethylaminoethyl)amine). 相似文献
20.
《Inorganica chimica acta》1988,149(1):139-145
The stoichiometry and kinetics of the reaction between [Cu(dien)(OH)]+ and [Fe(CN)6]3− in aqueous alkaline medium are described. The rate equation − (d[Fe(III)]/dt = {k1[OH−]2[[Cu(dien)(OH)]+] + k2[OH−] × [[Cu(dien)(OH)]+]2}([Fe(III)]/[Fe(II)]) (Fe(III) = [Fe(CN)6]3−; Fe(II) = [Fe(CN)6]4−, the 4:4:1 OH−/Fe(III)/[Cu(dien)(OH)]+ stoichiometric ratio and the nature of the ultimate products identified in the reaction solution suggest the fast formation of a doubly deprotonated Cu(III)-diamido complex which slowly undergoes an internal redox process where the ligand is oxidised to the Schiff base H2NCH2CH2NCHCHNH.The [[Cu(dien)(OH)]+]2 term in the rate equation is explained with the formation of a transient μ-hydroxo mixed-valence Cu dimer. A two-electron internal reduction of the Cu(III) complex yielding a Cu(I) intermediate is suggested to account for the presence of monovalent copper in a precipitate which forms at relatively high reactant concentrations and in the absence of dioxygen. 相似文献