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1.
Reaction of Cu(ClO4)2·6H2O, SRaaiNR′ (1-alkyl-2-[(o-thioalkyl)phenylazo]imidazole) and NH4SCN (1:1:2 mol ratio) affords distorted square pyramidal, [CuII(SRaaiNR′)(SCN)2] (3) compound while identical reaction with [Cu(MeCN)4](ClO4) yields -SCN- bridged coordination polymer, [CuI(SRaaiNR′)(SCN)]n (4). These two redox states [CuII and CuI] are interconvertible; reduction of [CuII(SRaaiNR′)(SCN)2] by ascorbic acid yields [CuI(SRaaiNR′)(SCN)]n while the oxidation of [CuI(SRaaiNR′)(SCN)]n by H2O2 in presence of excess NH4SCN affords [CuII(SRaaiNR′)(SCN)2]. They are structurally confirmed by single crystal X-ray diffraction study. Cyclic voltammogram of the complexes show Cu(II)/Cu(I) redox couple at ∼0.4 V and azo reductions at negative to SCE. UV light irradiation in MeCN solution of [CuI(SRaaiNR′)(SCN)]n (4) show trans-to-cis isomerisation of coordinated azoimidazole. The reverse transformation, cis-to-trans, is very slow with visible light irradiation while the process is thermally accessible. Quantum yields (?t→c) of trans-to-cis isomerisation are calculated and free ligands show higher ? than their Cu(I) complexes. The activation energy (Ea) of cis-to-trans isomerisation is calculated by controlled temperature experiment. Copper(II) complexes, 3, do not show photochromism. DFT and TDDFT calculation of representative complexes have been used to determine the composition and energy of molecular levels and results have been used to explain the solution spectra, photochromism and redox properties of the complexes.  相似文献   

2.
A kinetic study of the oxidation of (hydroxyethyl)ferrocene (HEF) by [2-pyridylmethylbis(2-ethyl-thioethyl)ainine]copper(II) (Cu(pmas)2+) is reported, with the objective of documenting the influence of the two thioether sulfur ligands on the electron transfer rate. Both reactants exhibit a first-order dependence at pH 6, I = 0.1 M(NaNO3); k(25°C) = 1.3 × 104M−1sec−1, ΔH3 = 10.1 kcal/mole, ΔS3 = −6 eu. The apparent Cu(pmas)2+/+ self-exchange electron transfer rate constant calculated from this reaction on the basis of relative Marcus theory (4.7 × 101M−1 sec−1) agrees well with previous findings on ferrocytochrome c, Fe(CN)64−, and Ru(NH3)5py2+ oxidations. Spectrophotometric titrations of Cu(pmas)2+ and Cu(tmpa)2+ (tmpa = tris(2-pyridylmethyl)amine) with azide ion showed that both Cu(pmas)N3)+ (Kf1 = 3.1 × 103M−1) and Cu(pmas)(N3)2 (Kf2 = 3.5 × 101M−1) but Cu(tmpa)(N3)+ (Kf = 6.6 × 102M−1) are formed up to 0.15 M N3 (25°C, pH 6, I = 0.2 M), suggesting that a thioether sulfur atom is displaced in the uptake of a second N3 ion by Cu(pmas)(N3)+. The effect of thioether sulfur displacement by azide ion on the HEF-Cu(pmas)2+ reaction rate may be understood entirely through the tendency of N3 to shift the position of the redox equilibrium towards the reactant side, without invoking any special role for the sulfur ligand in promoting electron transfer reactivity.  相似文献   

3.
《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 H2NCH2CH2NCHCHNH.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   

4.
A macrocyclic ligand possessing a donor set of {N3S2} synthesised via Cs+-templation, 4-(pyridin-2-ylmethyl)-1,7-dithia-4,10-diazacyclododecane (L) and its Cu(II) complex, [CuL(NCMe)]2+ (6), are described. This Cu(II) complex interacts with a range of anions, F, Cl, Br, I, HCOO, AcO, CO32−, NO3, C2O42−, H2PO4, SCN, CN, BF4. Of the investigated anions, I, SCN, and CN, show strong interaction with the Cu(II) centre as indicated by their spectral variations. The iodide particularly demonstrates distinct change in colour. This change originates from a newly appeared band at 471 nm upon iodide binding, which arises from the ligand (I) to Cu(II) charge transfer (LMCT) in the iodide-substituted Cu(II) complex, [CuLI]+ (7). All organic compounds are characterised by NMR spectroscopy and/or microanalysis. The identities of the two Cu(II) complexes are confirmed by using microanalysis and the complex 6 is crystallographically analysed.  相似文献   

5.
The synthesis, X-ray structures and electrochemical properties of stable five-coordinate, trigonal-bipyramidal CuI complexes of dafone (4,5-diaza-fluoren-9-one) [Cu(dafone)2X] with X=Br (1) or I (2) as ancillary ligands are discussed. The thiocyanate-bridged polymeric CuI complex of dafone, [Cu(dafone)(SCN)]n (3), forms two-dimensional sheets in the crystal, held together by weak interactions involving the dafone ketone group, while the phenanthroline complex, [Cu(phen)(SCN)]n (4), a zigzag arrangement of the phen ligands leads to interchain π-stacking within the lattice. The electrochemical studies reveal that dafone stabilizes the CuI oxidation state more efficiently than phen due to its better π-acceptor ability as indicated by more positive redox potentials for the CuI/CuII couple.  相似文献   

6.
7.
The hydrothermal reaction of CuBr2 and tpyprz in the presence of NH4VO3 and HF for 72 h at 170 °C provided [(tpyprz)3Cu10Br10] (1) in 20% yield. The two-dimensional structure of 1 may be described as Cu(I)-tpyprz chains, linked through {Cu4Br5} clusters in the ac-plane and decorated with {Cu3Br5}2− clusters projecting from one face of the layer in the b-direction. The Cu(I) sites exhibit distorted trigonal coordination {CuBr3} and distorted tetrahedral geometries, {CuBr2N2} and {CuN4}. Crystal data for 1: monoclinic space group C2, a = 12.7561(8) Å, b = 19.359(1) Å, c = 15.860(1) Å, β = 97.178(1)°, V = 3885.8(4) Å3, Z = 2, Dcalc = 2.222 g cm−3, μ(Mo Kα) = 78.75 cm−1.  相似文献   

8.
《Inorganica chimica acta》1988,145(2):225-229
A new molybdenum(0) dithiocarbamato complex [Et4N] [Mo(CO)4(S2CNEt2)] (1) has been synthesized by the reaction of Mo(CO)6, NaS2CNEt2 and Et4NCl in MeCN and characterized by routine elemental analysis, spectroscopy methods. The crystal and molecular structure of 1 was determined from X-ray three dimension data. 1 crystallizes in the orthorhombic, space group Pbc21 with a= 8.148(2), b=19.618(2), c=14.354(2) Å; V=2294 Å3; Z=4; R1=0.052, R2=0.058 for 1308 independent reflections with I ⩾ 3σ(I). The geometry around Mo(0) atom in the anion [Mo(CO)4(S2CNEt2)]- of 1 is distorted octahedral with a small SMoS of 67.70° and a small angle of 3.6° between plane MoSS and MoC(1)C(2). Two groups of MoCO bond distances and the longer MoS bond distance observed in 1 are similar to that in the dinuclear Mo(0) complexes containing SR bridges but very different from those observed in the dithiocarbamato complexes of Mo in higher oxidation states. Different oxidizing products containing Mo in II-V oxidation states Mo(CO)2(S2CNEt2)2, MoO(S2CNEt2)2, Mo2O3(S2CNEt2)4 and Mo2O4(S2CNEt2)2 were isolated from the oxidation of 1 with I2 (or in the presence of traces of air). The electrochemical behavior of 1 in MeCN was investigated by cyclic voltammetry at Pt and C electrodes. The anodic peaks observed at 0.04, 0.14, 0.26 and 0.44 V versus SCE implied that 1 probably underwent oxidation in company with dissociation of dithiocarbamate and substitution of carbonyls resulting in several complexes of Mo in different oxidation states. The relationship between reactivity and structure is also discussed.  相似文献   

9.
The single crystal X-ray structures of (CuICH3CN4·dibenzo-18-crown-6 (I) and (CuICH3CN) (II) have been determined at room temperature [(I) C28H36Cu4I4N4o6, monoclinic space group P21/n, a = 10.116(4), b = 18.092(8), c = 22.211(9) Å, β = 98.66(3)°, Z = 4; (II) C2H3CuIN, orthorhombic pBN21, a = 13.618(8), b =8.742(2), c = 4.298(2), Z = 4]. (I) exists as a distorted cube with copper and iodine at alternate corners, the fourth coordination site copper occupied by an acetonitrile molecule coordinated through nitrogen. The cluster contains no crystallographic symmetry element and CuCu distances average 2.770(5) Å. The dibenzo-18-crown-6 displays only second sphere type interactions with cluster. (II) displays a pleated double chain type structure with distorted rectangles of alternating Cu and I atoms sharing opposite edges in infinite array. Copper displays tetrahedral geometry by coordination to three iodine atoms and a nitrogen bound acetonitrile molecule.  相似文献   

10.
11.
Several new Cu-hippurate derivative-phenanthroline ternary complexes have been prepared. The X-ray structure of one of them, [Cu(hip)(phen)2]+·(hip) (2) (where hip is hippurate and phen is 1,10-phenanthroline) has been solved. The structure of this new compound shows important differences (3D-pattern) to other similar related complexes (2D-pattern). A study of the biological activity of [Cu(hip)(phen)2]+·(hip)·2H2O (2), [Cu(BGG)(phen)2]+·(BGG)·6H2O (3), [Cu(BIGG)2(phen)](H2O) (4) and [Cu(I-hip)(bpy)2]+·(I-hip)·3.5H2O (5) (where I-hip is ortho-iodohippurate, BGG corresponds to benzoylglycilglycine, and BIGG is ortho-iodobenzoylglycilglycine) is included and compared with the anti-proliferative activity of [Cu(I-hip)(phen)2]+·(I-hip)·7H2O (1) previously described, resulting in a greater cytotoxic activity of the compounds with 1,10-phenanthroline instead of those with 2,2′-bipyridyl, in the same way that removing iodine substitution or lengthening the peptidic chain diminishes the activity of compounds compared with 1. The presence of an ortho-iodine group and the direct bond between Ar-CO and glycine moieties yield to the best results.  相似文献   

12.
The lilac pyralid, Palpita nigropunctalis Bremer (Lepidoptera: Crambidae), is a common pest of Oleaceae plants. A crude extract of the female sex pheromone glands was examined by gas chromatography-electroantennogram detection (GC-EAD) and GC coupled to a mass spectrometer (GC/MS). The GC-EAD analysis revealed three EAG-active components (IIII) in a ratio of 1:0.2:0.01 (I: II: III). GC/MS analysis successfully recorded the mass spectra of I and II. For I, ions at m/z 238 (M+) and 220 ([M-18]+) indicated the structure of a monoenyl aldehyde with a 16-carbon chain. For II, M+ was not detected, but ions at m/z 222 ([M-60]+) and 61 ([AcOH+1]+) suggested that II was a monoenyl acetate with a 16-carbon chain. Further GC/MS analysis of the extract treated with dimethyl disulfide revealed that the double bonds in both I and II are located at the same position of 11th-carbon. In addition, the pheromone extract was examined by GC/Fourier transform-infrared spectrophotometer (GC/FT-IR). An IR spectrum of I showed characteristic absorption at 1716 and 966?cm?1, indicating a formyl group and E configuration of the double bond, respectively. In the case of II, absorption at 1745 and 968?cm?1 indicated an ester carbonyl and E configuration, respectively. Taken together and by comparison with authentic standards, I and II were confirmed as (E)-11-hexadecenal and (E)-11-hexadecenyl acetate, respectively; while III was speculated as (E)-11-hexadecen-1-ol. The synthetic I, II and III all coincided well with those of the natural components in chemical data, and elicited strong electroantennographic activity in male P. nigropunctalis.  相似文献   

13.
Two 2D-polymers of Cu(I), [Cu2(μ-tp)(CH3CN)(μ-I)(μ3-I)]n (1) and [Cu2(μ-tp)(μ3-I)2]n (2), both obtained from the reaction between copper iodide and 1,2,4-triazolo[1,5-a]pyrimidine (tp) in the presence of KI are described. While in compound 1, tp acts as bridging ligand via N1 and N3 between chair-like [Cu4I4] units, in compound 2, tp moieties are placed at both sides of a [CunIn] kinked layer, displaying also a bridging mode but, in this case, through its atoms N3 and N4. These structural differences between both compounds seem to be due to the solvent of crystallization, being acetonitrile for 1 and water for 2. These polymers are the first examples of Cu(I) compounds based on the nucleobase-analog ligand tp.  相似文献   

14.
The crystal and molecular structures of the complexes MoO2((SCH2CH2)2NCH2CH2SCH3), I and MoO2((SCH2CH2)2NCH2CH2N(CH3)2), II, have been determined from X-ray intensity data collected by counter methods. Compound I crystallizes in two forms, Ia and Ib. In form Ia the space group is P21/n with cell parameters a = 7.235(2), b = 7.717(2), c = 24.527(6) Å, β = 119.86(2)°, V = 1188(1) Å3, Z = 4. In form Ib the space group is P21/c with cell parameters a = 14.945(5), b = 11.925(5), c = 14.878(4) Å, β = 114.51(2)°, V = 2413(3) Å3, Z = 8. The molecules of I in Ia and Ib are very similar having an octahedral structure with cis oxo groups, trans thiolates (cis to both oxo groups) and N and thioether sulfur atoms trans to oxo groups. Average ditances are MoO = 1.70, MoS (thiolate) = 2.40, MoN = 2.40 and MoS (thioether) = 2.79 Å. Molecule II crystallizes in space group P212121 with a = 7.188(1), b = 22.708(8), c = 7.746(2) Å, V = 1246(1) Å3 and Z = 4. The coordination about Mo is octahedral with cis oxo groups, trans thiolates and N atoms trans to oxo. Distances in the first coordination sphere are MoO = 1.705(2), 1.699(2), MoS = 2.420(1), 2.409(1) and MoN = 2.372(2), 2.510(2) Å. The conformational features of the complexes are discussed. Complex I displays MoO and MoS distances which are very similar to those found by EXAFS in sulfite oxidase. This similarity is discussed.  相似文献   

15.
Denis M  Clore GM 《Plant physiology》1981,68(1):229-235
The reaction of mixed valence state cytochrome oxidase (CuA2+a3+ · CuB+a32+) with O2 at 173 K has been investigated in purified potato mitochondria by low temperature flash photolysis and rad wavelength scanning optical spectrometry in the visible region. The kinetics of the reaction have been analyzed simultaneously at six wavelength pairs (586-630, 590-630, 594-630, 604-630, 607-630, and 610-630 nanometers) by nonlinear optimization techniques, and found to proceed by a two-species sequential mechanism. The “pure” difference spectra of the two species, IM and IIM, relative to unliganded mixed valence state cytochrome oxidase have been obtained. The difference spectrum of species IM is characterized by a peak at 591 nanometers, with a shoulder at 584 nanometers and a trough at 602 nanometers, and that of species IIM by an α band split into a prominent peak at 607 nanometers and a small side peak at 594 nanometers. Evidence is presented to suggest that these two bands arise from O2 → CuB2+ and O2a32+ charge transfer transitions which would imply that O2 forms a bridging ligand between CuB and the iron atom of cytochrome a3 in species IIM. The kinetics of the reaction and the spectral characteristics of species IM and IIM obtained with the potato mitochondrial system are compared and contrasted with data in the literature on the beef heart mitochondrial system.  相似文献   

16.
The effect of copper on the uptake of nitrogen and the tissue contents of inorganic nitrogen, amino acids and proteins were studied in cooper-sensitive Silene vulgaris (Moench) Garcke, grown at different nitrogen sources (NH4 + or NO3 -). All the toxic copper levels tested, i.e. 4, 8, 16 M Cu2+, strongly inhibited the uptake of nitrogen, especially of NO3 -, and decreased the content of NO3 -, amino acids and proteins. Especially at 4 and 8 M Cu2+, NH4 + accumulated in the plants, suggesting that the conversion of NH4 - into amino acids was inhibited.  相似文献   

17.
The structures of [(CuS2CT)2dppm]2 (I) (T = o-tolyl; dppm = bis(diphenylphosphino)methane) and [CuS2CTdppm]2 (II) have been determined by X-ray methods. Crystals of I are monoclinic, space group P21/n, with a = 15.163(4), b = 18.691(5), c = 13.478(4) Å, β = 96.81(3)°, Z = 2; crystals of II are orthorhombic. space group Pccn, with a = 23.267(4), b = 13.016(3), c = 20.731(5) Å, Z = 4. The structures of I and II have been solved by Patterson and Fourier methods and refined by full-matrix least-squares to R = 0.082 for I and 0.092 for II. The structure of I consists of centrosymmetric tetranuclear complexes in which two pairs of Cu atoms are triply bridged by a dppm ligand and two dithiocarboxylate groups from the dithio-o-toluate ligands. These last behave differently: one of them through a sulphur atom is also bonded to a Cu atom of the other pair so forming a tetranuclear complex. The Cu atoms of each pair show different coordination: Cu(1) displays a distorted trigonal and Cu(2) a distorted trigonal pyramidal geometry. The structure of II consists of dimers, in which each copper atom, doubly bridged by two dppm ligands, completes a distorted trigonal pyramidal coordination through two sulphur atoms from dithio-o-toluate anions acting as chelating ligands. In both compounds the phenyl group of the dithio-o-toluate anions is orthogonal to the corresponding CS2 group. Both complexes give methyldithio-o-toluate in high yields by reaction with methyl iodide.  相似文献   

18.
The binuclear mixed valence copper(I/II) compound [CuI(CN)3CuII(tn)2] (1) (tn = propane-1,3-diamine) and its acetonitrile adduct [CuI(CN)3CuII(tn)2] · 2MeCN (2) have been synthesized. Complex 1 crystallizes triclinic, space group , a = 8.117(2) Å, b = 8.389(2) Å, c = 11.920(2) Å, α = 108.728(3)°, β = 100.024(3)°, γ = 104.888(4)°, Z = 2, and compound 2 monoclinic, space group P21/m, a = 8.752(2) Å, b = 13.243(3) Å, c = 9.549(2) Å, β = 114.678(4)°, Z = 2. In both crystal structures, the binuclear [CuI(CN)3CuII(tn)2] complex with slightly different bonding geometries is formed. One of the three nitrogen atoms of a CuI(CN)3 moiety is coordinated to Cu(II) at the apex of a square-pyramid with two chelating ligands tn on its base. The shortest intramolecular CuII?CuII distance in 1 is 5.640(7) Å. The EPR behaviour of 1 has been investigated at room temperature and at 77 K. The magnetic properties were measured in the temperature range 1.8-300 K.  相似文献   

19.
Hydrothermal reaction of copper(II) chloride with 2-hydroxypyrimidine generated double salt of [Cu2Cl(μ4-pymo)] (1) (Hpymo = hydroxylpyrimidine) while hydrothermal treatment of CuCl2, NaN3 and acetonitrile resulted in double salt of [Cu2(mtta)Cl] (2) (Hmtta = 5-methyltetrazole) in which in situ [2 + 3] cycloaddition reactions of acetonitrile with azide formed mtta ligand. X-ray single crystal structural analyses revealed that 1 shows a two-dimensional layer formed by fusion of one-dimensional structural motifs. The two-dimensional layers in 1 are held together by C-H?Cl hydrogen bonds to form three-dimensional supramolecular array. Compound 2 has a three-dimensional framework constructed from ribbons and [Cu8Cl4]4+ units. Uncommon coordination modes of μ4-1,2κO:3κN:4κN′ pymo and μ4-Cl (Cl at the apex of a Cu4Cl square pyramid) in 1 and μ41111 mtta in 2 were also observed. The short Cu(I)?Cu(I) distances were found in 1 and 2, indicating the existence of Cu(I)?Cu(I) interactions.  相似文献   

20.
Three new coordination polymers based on IB metal thiocyanates, [CuII(NCS)2(DMSO)4(meso-dpb)]n (1), (2), [CuI(NCS)(pia)]n (3) (dpb = 2,3-di(4-pyridyl)-2,3-butanediol, bpp = 1,3-bis(4-pyridyl)propane, pia = N,N′-(1,2-phenylene)diisonicotinamide), have been synthesized by the pre-assembly method and characterized by X-ray crystallography. In 1, CuII cations are bridged by meso-dpb ligands to form a one-dimensional (1D) linear chain. Compound 2 consists of 2D undulated layers of (4, 4) topology that show twofold parallel interpenetration. In the case of 3, the MI center adopts tetrahedral coordination geometry and the 2D networks are formed by organic ligand with “folding ruler-shaped” NCS-M chains. The thermal properties of 1-3 were also investigated.  相似文献   

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