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1.
The interaction of Cu(II)(dtc)2 and Cu(I)(dtc) complexes with haloalkanes were studied by the EPR method. It was found that the Cu(II)(dtc)2 complex reacted with haloalkanes only in the presence of weak Lewis bases which formed adducts with it. The intermediate reaction product is the mixed-ligand complex Cu(II)(dtc)Xn (X = Cl, Br, n = 1 or 2); the final products being CuX2Bn (B = Lewis bases, n = 1 or 2) and unstable resin-like residue. Cu(I)(dtc) reacted with haloalkanes without any promoters giving the mixed-ligand complex Cu(II)(dtc)Xn as product. Free radicals were detected in the reaction of Cu(I)(dtc) using the method of “radical scavenger” and were not found in the reaction of Cu(II)(dtc)2. The reported results confirmed one of the two reaction mechanisms proposed in the previous studies. The role of the solvent on the EPR parameters of the mixed-ligand Cu(II)(dtc)X complex is also discussed.  相似文献   

2.
The intermediate products of the reaction between copper(II) dithiocarbamate complex and some Lewis acids (HgI2, HgBr2, GeCl4, AsBr3, CoCl2, C(NO2)4) as well as some organometallic compounds (SnEt4 and PbEt4) were studied using EPR spectroscopy. In non-polar and non-coordinating solvents HgI2, HgBr2 and GeCl4 formed adducts with Cu(dtc)2, whereas in polar and coordinating solvents the mixed-ligand complexes of the type Cu(dtc)+…A?(A = HgX3) were obtained with a complex counterion in the second coordination sphere of copper(II). With C(NO2)4 the intermediate reaction product in non-polar solvents was assumed to be Cu(dtc)·NO2 which dissociates to Cu(dtc)+…NO2? in polar solvents. Similar EPR spectra were obtained with SnEt4 and PbEt4. The reaction of Cu(dtc)2 with CoCl2, AsBr3 and SbCl3 yielded the mixed-ligand complexes of the type Cu(dtc)Xn (n = 1 or 2) exhibiting well resolved superhyperfine splitting from one or two halogen nuclei. The influence of the medium on the above interaction is also discussed.  相似文献   

3.
The reaction of bis (acetylacetonato) copper(II) with SO2 yields CuSo4 as a final product. Using e.p.r. technique mixed-ligand complexes of the type Cu(acac) (acacSO2) have been detected at 100 K. The e.p.r. spectrum of the latter complex disappeared under passing argon through the sample. Lewis bases accelerated the reaction. No interaction of SO2 with other complexes containing CuO2N2, CuN2S2, CuS4 chromophores has been detected. In a common solution of Cu(acac)2 and Cu(dtc)2 the reaction proceeded only with Cu(acac)2 though a mixed-ligand complex Cu(acac) (dtc) was formed. The addition of bases accelerated the reaction, all spectra disappeared and only CuI(dtc) has been found as a final product.  相似文献   

4.
Summary Starting from Fe(CO)4I2, octahedral FeII carbonyl derivatives of the types Fe(CO)2(xan)2, Fe(CO)3(xan)I and Fe(CO)3(dtc)I were prepared (xan = xanthate, dtc = dithiocarbamate). Infrared evidence was obtained for the formation of Fe(CO)2(dtp)2 complexes (dtp = dithiophosphate). The dixanthate complexes are also formed from FeII salts and potassium xanthates by CO absorption in MeOH/H2O solution.  相似文献   

5.
《Polyhedron》1987,6(6):1497-1502
Using ESR the exchange of ligands was studied between mononitrosyl chelate complexes of iron and chelate complexes of nickel with the following ligands: dithiocarbamate (dtc), dithiophosphate (dtp), dithiocarbonate (xant), 8-quinolinethiolate, 8-hydroxyquinoline, acetylacetonate and o-hydroxy- benzylideneaniline. For some mixed-ligand complexes the exchange of the covalency of the metal—ligand bond was evaluated. The interaction of the mononitrosyl complexes with Lewis acids (I2 and Br2) and bases (pyridine, DMFA and DMSO) was studied in the cases of Fe(NO)(dtc)2, Fe(NO)(dtp)2 and Fe(NO)(xant)2. In both of the latter cases the interactions with Lewis acids and bases led to the formation of paramagnetic dinitrosyl complexes, while with Fe(NO)(dtc)2 hexacoordinated mononitrosyl complexes were formed. A reaction pathway is suggested and discussed for the formation of the dinitrosyl complexes and their composition.  相似文献   

6.
Planar nickel(II) complexes involving N,N′-dibutyldithiocarbamate, such as [Ni(bu2dtc)(PPh3)(NC)] (1) and [Ni(bu2dtc)(PPh3)(NCS)] (2) (where bu2dtc = N,N′-dibutyldithiocarbamate anion) have been prepared, characterized by electronic, IR and NMR spectra and their structures determined by single crystal X-ray crystallography. Cyclic voltammetric characterizations of the complexes are also reported. IR spectra of the two complexes indicate the isobidentate coordination (νc-s ? 1095 cm?1 without splitting) of the dithiocarbamate moiety. The important stretching mode characteristic of the thioureide bond (νC–N) occurs at higher wave numbers compared to that of the parent dithiocarbamate complex [Ni(bu2dtc)2]. The electronic spectra of 1 and 2 show signature bands at 426 nm and 478 nm, respectively. NMR spectra show large 31P chemical shifts in both compounds and the most important N13CS2 chemical shift appears at 204.86 ppm and 203.23 ppm for 1 and 2, respectively. The CV studies clearly show the presence of reduced electron density on the nickel ions in mixed-ligand complexes 1 and 2 compared to the parent dithiocarbamate. Single crystal X-ray structure studies show that 2 crystallizes as a new triclinic polymorph, whose molecular structure closely resembles that of the previously reported monoclinic form. Both complexes contain a planar NiS2PN chromophore in keeping with the observed diamagnetism. In both complexes the Ni-S distances are significantly different. The thioureide C–N distances of the complexes are shorter than those observed in the parent [Ni(bu2dtc)2]. The two compounds allow comparison of the influence of NCS? in place of NC?.  相似文献   

7.
Equilibrium studies of the mixed-ligand complexes of the copper(II) ion with pentamethyldiethylenetriamine (N,N,N′,N″,N″-pentamethyl-[bis(2-aminoethyl)amine], Me5dien) as a primary ligand and methioninehydroxamic acid (2-amino-4-(methylthio)butanehydroxamic acid, Metha) or histidinehydroxamic acid (2-amino-3-(4′-imidazolyl)propanehydroxamicacid, Hisha) as a secondary ligand L were performed by potentiometric titration, UV–Vis and EPR spectroscopy. The results show that in these ternary systems the dinuclear [Cu2(Me5dien)L2H−1]+ mixed-ligand species is formed as a predominant one in the basic solution. The monouclear [Cu(Me5dien)L]+ species is formed in low concentration. Our spectroscopic results indicate that the geometry of these mixed-ligand five-coordinate complexes is strongly distorted towards trigonal-bipyramidal.  相似文献   

8.
The EPR technique has been used to study the photolysis of the mixed-ligand complex CuII(Et2dtc)Br in a 1:1 solvent mixture of chloroalkane and alcohol, where the chloroalkane is CCl4, CHCl3 or CH2Cl2 and the alcohol is MeOH, EtOH, i-PrOH or i-BuOH, in comparison with CuII(Et2dtc)Cl photolysis in CHBr3:ROH. It was found that while CuII(Et2dtc)Br photolysis in chloroalkane:ROH yielded CuII(Et2dtc)Cl as an intermediate, the opposite conversion of CuII(Et2dtc)Cl to CuII(Et2dtc)Br proceeded via CuII(Et2dtc)Cl photolysis in CHBr3:ROH. The final photolytic products in both cases were tetraethylthiuramdisulphide and the corresponding copper(II) salt (CuCl2 or CuBr2, respectively). The results obtained by EPR allowed to get some insight into the behaviour of the primary photolytic products towards both components of the mixed solvent.  相似文献   

9.
[Mo3S(S2)3(dtc)3]I, [Mo3S(SeS)3(dtc)3](dtc), and [Mo3Se(Se2)3(dtc)3](dtc) (dtc = N,N-diethyldithiocarbamate) were investigated by liquid SIMS-FTMS. The fragmentation pathways were essentially the same for the three compounds and can be explained by two types of fragmentation processes: stepwise abstraction of S/Se atoms as exemplified by the series [Mo3Xz(dtc)3]+ (4 ? z ? 7, X = S, Se), and ligand dissociation, as indicated by the generation of [Mo3Xz(dtc)2]+ (5 ? z ? 7, X = S, Se). The exclusive elimination of the Se-atoms from [Mo3S(Sax-Seeq)3(dtc)3]+ confirmed the inequivalent reactivity of the bridging atoms in axial and equatorial position as observed in previous studies. Collision-induced decomposition (CID) of [Mo3S7(dtc)3]+ ( 1 ), [Mo3S6(dtc)3]+ ( 2 ), [Mo3S(Sax–Seeq)3(dtc)3]+ ( 3 ), and [Mo3Se7(dtc)3]+ ( 4 ) revealed distinctly different fragmentation reactions for the SIMS and CID mode. CID of 1, 3 , and 4 resulted in a two-step reaction with the exclusive elimination of diatomic molecules XY (X,Y = S/Se). In the case of 3 , the selective elimination of Se2 indicated the abstraction of two Se-atoms located in equatorial positions of two different bridging groups. This result is discussed in terms of mechanisms, based on labile M? Xeq and inert M? Xax bonds with an intramolecular formation of a X4 fragment prior to the elimination of X2.  相似文献   

10.
A series of complexes of fullerenes C60 and C70 with metal dithiocarbamates {MII(R2dtc)2}·Cm (m = 60 or 70) and metal dithiocarbamates coordinated to nitrogen-containing ligands (L), {MII(R2dtc)2)x·L}·C60 (x = 1 or 2), where M = Cu, Zn, Cd, Hg, Mn, or Fe, R = Me, Et, Prn, Pri, or Bun, L is 1,4-diazabicyclo[2.2.2]octane (DABCO), N,N′-dimethylpiperazine, or hexamethylenetetramine, were synthesized. The shape of dithiocarbamate molecules is sterically compatible with the spherical shape of C60, resulting in an efficient interaction between their π systems. The resulting compounds are characterized by a layered or three-dimensional packing of the fullerene molecules. In the C60 complexes, iron(II) and manganese(II) dithiocarbamates exist in the high-spin states (S = 2 and 5/2). The magnetic susceptibility of {MII(Et2dtc)2}2·Cm (M = Fe or Mn, m = 60 or 70) in the temperature range of 200–300 K is described by the Curie-Weiss law with Θ = −250 and −96 K and with maxima at 110 and 46 K, respectively, which is indicative of a strong antiferromagnetic spin coupling between MII. The Weiss constants for the [{MII(Et2dtc)2}2·DABCO]·C60·(DABCO)2 complexes (M = Fe or Mn) are 1.7 and 0.3 K, respectively. The magnetic moments of the complexes containing Fe and Mn dithiocarbamates slightly increase at temperatures below 50 and 35 K, respectively, which is evidence of the ferromagnetic spin coupling between MII in {MII(Et2dtc)2}2·DABCO. Single crystals of the complexes exhibit low dark conductivity (10−10–10−11 S cm−1). The visible light irradiation of these crystals leads to an increase in the photocurrent by two–three orders of magnitude. The photogeneration of free charge carriers in the complexes occurs both due to the photoexcitation of metal dithiocarbamate (CuII(Et2dtc)2) and through the charge transfer from metal dithiocarbamate (MII(Et2dtc)2, M = Zn or Cd) to C60. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2072–2087, November, 2007.  相似文献   

11.
The equilibrium structures and vibrational frequencies of the iron complexes [Fe0(CN)n(CO)5?n]n? and [FeII(CN)n(CO)5?n]2?n (n = 0–5) have been calculated at the BP86 level of theory. The Fe0 complexes adopt trigonal bipyramidal structures with the cyano ligands occupying the axial positions, whereas corresponding Fe2+ complexes adopt square pyramidal structures with the cyano ligands in the equatorial positions. The calculated geometries and vibrational frequencies of the mixed iron Fe0 carbonyl cyanide complexes are in a very good agreement with the available experimental data. The nature of the Fe? CN and Fe? CO bonds has been analyzed with both charge decomposition and energy partitioning analysis. The results of energy partitioning analysis of the Fe? CO bonds shows that the binding interactions in Fe0 complexes have 50–55% electrostatic and 45–50% covalent character, whereas in Fe2+ 45–50% electrostatic and 50–55% covalent character. There is a significant contribution of the π‐ orbital interaction to the Fe? CO covalent bonding which increases as the number of the cyano groups increases, and the complexes become more negatively charged. This contribution decreases in going from Fe0 to Fe2+ complexes. Also, this contribution correlates very well with the C? O stretching frequencies. The Fe? CN bonds have much less π‐character (12–30%) than the Fe? CO bonds. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010  相似文献   

12.
《Polyhedron》1999,18(26):3401-3406
Four copper(II) complexes of bis(dialkyldithiocarbamate) [Cd(R2dtc)2] (R=Me, Et, Pr, i-Pr; dtc=dithiocarbamate) have been prepared and characterized by elemental analysis, IR and ESR spectra studies. Their equilibrium constants (K), determined by a UV–vis spectrometry in EtOH, were influenced by the alkyl groups in the following order: i-Pr>n-Pr≈Et>Me. The single crystal structures of complex [Cu2(R2dtc)4] have been determined using X-ray diffraction methods. The compounds [Cu2(Et2dtc)4] and [Cu2(Pr2dtc)4] are built of centrosymmetric neutral dimeric [Cu2(R2dtc)4] entities. The copper atom lies in a distorted square–pyramidal environment. The four equatorial donors are two bidentate chelate sulfur atoms from two dtc ligands. One of the sulfur atoms from the third dtc ligand acts as a bridging ligand occupying the apical position of the symmetry-related copper atom in the dimer structure, which is viewed as two edge-sharing distorted square–pyramids. The structure of [Cu2(i-Pr2dtc)4] is square planar with an exactly planar CuS4 unit and nearly planar NCS2 moieties. The Cu–S distances shows small decreases along the series n-Pr>Et>i-Pr, the biggest change being for the diisopropyl complex. The alkyl substituents at the nitrogen atom affect their coordination number and Cu⋯Cu distance. In the solid, [Cu2(n-Pr2dtc)4] has the shortest Cu⋯Cu distance and [Cu(i-Pr2dtc)2] has the longest one.  相似文献   

13.
The photochemical properties of bis(dithiocarbamato)CuII, Cu(R1dtc)2, and bis(dithiophosphato)CuII, Cu(R2 2dtp)2, complexes with different remote ligand substituents (R1 = piperidine, morpholine, pyrrolidine and 4-phenylpiperazine; R2 = Me, Et and i-Pr) have been studied in chloromethanes (CCl4, CHCl3, CH2Cl2), chloromethanes/EtOH and PhMe. The monomeric species CuII(R1dtc)Cl and its chloride-bridged dimeric form Cu2(R1dtc)2Cl2 were subsequently obtained during Cu(R1dtc)2 photolysis in chloromethane/EtOH mixtures and the steady-state concentration of Cu2(R1dtc)2Cl2 was found to depend on the EtOH content in the mixed solvents as well as on the nature of R1 and the oxidising ability of the chloromethane. The appearance of the mixed-ligand complex CuII(R2 2dtp)Cl has been observed as an intermediate photoproduct after longer u.v.-irradiation of Cu(R2 2dtp)2 in chloromethanes/EtOH.  相似文献   

14.
Mixed Ligand Complex Formation by Thermal Reactions of Metal(II) Thioselenocarbamate Chelates. EPR and Mass Spectrometric Investigations At higher temperatures metal(II) thioselenocarbamates M(R2tsc)2 (M = Cu, Ni, Pd, Pt) react to form M(R2tsc)(R2dsc) and M(R2tsc)(R2dtc) (dtc = dithiocarbamate, dsc = diselenocarbamate) mixed-ligand chelates. If CuII species are participated the mixed-ligand complex formation can be the followed by EPR spectroscopy. The reaction is irreversible, and the rate depends on the temperature, the substituent R, and the solvent used. The complexes M(Et2tsc)(Et2dsc) and M(Et2tsc)(Et2dtc) formed during the thermal reaction of M(Et2tsc)2 chelates (M = Ni, Pd, Pt) can be detected by EPR spectroscopy using the ligand-exchange reaction with [Cu(mnt)2]2?(mnt = maleonitriledithiolate). As results the spectra of [Cu(mnt)(Et2tsc)]?, [Cu(mnt)(Et2dsc)]? and [Cu(mnt)(Et2dtc)]? are observed.  相似文献   

15.
A series of half-sandwich ruthenium(II) complexes containing κ3(N,N,N)-hydridotris(pyrazolyl)borate (κ3(N,N,N)-Tp) and the water-soluble phosphane 1,3,5-triaza-7-phosphaadamantane (PTA) [RuX{κ3(N,N,N)-Tp}(PPh3)2−n(PTA)n] (n = 2, X = Cl (1), n = 1, X = Cl (2), I (3), NCS (4), H (5)) and [Ru{κ3(N,N,N)-Tp}(PPh3)(PTA)L][PF6] (L = NCMe (6), PTA (7)) have been synthesized. Complexes containing 1-methyl-3,5-diaza-1-azonia-7-phosphaadamantane(m-PTA) triflate [RuCl{κ3(N,N,N)-Tp}(m-PTA)2][CF3SO3]2 (8) and [RuX{κ3(N,N,N)-Tp}(PPh3)(m-PTA)][CF3SO3] (X = Cl (9), H (10)) have been obtained by treatment, respectively, of complexes 1, 2 and 5 with methyl triflate. Single crystal X-ray diffraction analysis for complexes 1, 2 and 4 have been carried out. DNA binding properties by using a mobility shift assay and antimicrobial activity of selected complexes have been evaluated.  相似文献   

16.
The EPR technics has been used to study the effect of solvent composition on the photochemical conversion of Cu(II) dithiocarbamate mixed-ligand complexes Cu(Et2dtc)X (X=Cl, Br) and Cu(Et2dtc)+…Y (Y=ClO4, NO3) in chloroalkane/alcohol solutions, where chloroalkane=CCl4, CHCl3 or CH2Cl2 and alcohol=MeOH, EtOH, i-PrOH or i-BuOH. The obtained results allow to get some insight into the behaviour of the mixed-ligand complexes towards the halogen donation power of chloroalkanes and the co-ordination abilities of alcohols. The paper deals with the nature of the complexes obtained as intermediate products of photolysis.  相似文献   

17.
A series of fourteen octahedral nickel(IV) dithiocarbamato complexes of the general formula [Ni(ndtc)3]X·yH2O {ndtc stands for the appropriate dithiocarbamate anion, X stands for ClO4 (1-8; y = 0) or [FeCl4] (9-14; y = 0 for 9-12, 1 for 13 and 0.5 for 14} was prepared by the oxidation of the corresponding nickel(II) complexes, i.e. [Ni(ndtc)2], with NOClO4 or FeCl3. The complexes, involving a high-valent NiIVS6 core, were characterized by elemental analysis (C, H, N, Cl and Ni), UV-Vis and FTIR spectroscopy, thermal analysis and magnetochemical and conductivity measurements. The X-ray structure of [Ni(hmidtc)3][FeCl4] (9) was determined {it consists of covalently discrete complex [Ni(hmidtc)3]+ cations and [FeCl4] anions} and this revealed slightly distorted octahedral and tetrahedral geometries within the complex cations, and anions, respectively. The Ni(IV) atom is six-coordinated by three bidentate S-donor hexamethyleneiminedithiocarbamate anions (hmidtc), with Ni-S bond lengths ranging from 2.2597(5) to 2.2652(5) Å, while the shortest Ni···Cl and Ni···Fe distances equal 4.1043(12), and 6.2862(6) Å, respectively. Moreover, the formal oxidation state of iron in [FeCl4] as well as the coordination geometry in its vicinity was also proved by 57Fe Mössbauer spectroscopy in the case of 9.  相似文献   

18.
Two series of di and trinuclear chlorodiorganotin(IV) complexes derived from bis- and tris-dithiocarbamate ligands have been prepared and structurally characterized. The dinuclear complexes 1-2 of the composition {(R2SnCl)2(bis-dtc)} (1, R = Me; 2, R = nBu) have been obtained from R2SnCl2 (R = Me, nBu) and the triethylammonium salt of N,N′-dibenzyl-1,2-ethylene-bis(dithiocarbamate). The trinuclear complexes 3-9 with the general formula {(R2SnCl)3(tris-dtc)} 3, R = Me, tris-dtc = tris-dtc-Me; 4, R = Me, tris-dtc = tris-dtc-iPr; 5, R = Me, tris-dtc = tris-dtc-Bn; 6, R = nBu, tris-dtc = tris-dtc-Me; 7, R = nBu, tris-dtc = tris-dtc- iPr; 8, R = nBu, tris-dtc = tris-dtc-Bn; 9, R = tBu, tris-dtc = tris-dtc-Me) were prepared from R2SnCl2 (R = Me, nBu, tBu) and the potassium dithiocarbamate salts of (tris[2-(methylamino)ethyl]amine) (tris-dtc-Me), (tris[2-(isopropylamino)ethyl]amine) (=tris-dtc-iPr) and (tris[2-(benzylamino)ethyl]amine) (=tris-dtc-Bn). Compounds 1-9 have been analyzed as far as possible by elemental analysis, FAB+ mass spectrometry, IR and NMR (1H, 13C, 119Sn) spectroscopy, and single-crystal X-ray diffraction analysis. The solid state and solution studies showed that the dtc ligands are coordinated to the tin atoms in the anisobidentate manner. In all cases the metal centers are five-coordinate. The coordination geometry is intermediate between square-pyramidal and trigonal-bipyramidal coordination polyhedra with τ-values in the range of 0.32-0.53. For the members of each series characterized in the solid state by X-ray diffraction analysis, different molecular conformations were found. The crystal structures show the presence of C-H?Cl, C-H?S, C-H?π, S?Cl, S?S, Cl?Sn and S?Sn contacts.  相似文献   

19.
The heat capacities of Ln(Me2dtc)3(C12H8N2) (Ln = La, Pr, Nd, Sm, Me2dtc = dimethyldithiocarbamate) have been measured by the adiabatic method within the temperature range 78–404 K. The temperature dependencies of the heat capacities, C p,m [La(Me2dtc)3(C12H8N2)] = 542.097 + 229.576 X ? 27.169 X 2 + 14.596 X 3 ? 7.135 X 4 (J K?1 mol?1), C p,m [Pr(Me2dtc)3(C12H8N2)] = 500.252 + 314.114 X ? 17.596 X 2 ? 0.131 X 3 + 16.627 X 4 (J K?1 mol?1), C p,m [Nd(Me2dtc)3(C12H8N2)] = 543.586 + 213.876 X ? 68.040 X 2 + 1.173 X 3 + 2.563 X 4 (J K?1 mol?1) and C p,m [Sm(Me2dtc)3(C12H8N2)] = 528.650 + 216.408 X ? 16.492 X 2 + 12.076 X 3 + 4.912 X 4 (J K?1 mol?1), were derived by the least-squares method from the experimental data. The heat capacities of Ce(Me2dtc)3(C12H8N2) and Pm(Me2dtc)3(C12H8N2) at 298.15 K were evaluated to be 617.99 and 610.09 J K?1 mol?1, respectively. Furthermore, the thermodynamic functions (entropy, enthalpy and Gibbs free energy) have been calculated using the obtained experimental heat capacity data.  相似文献   

20.
Reaction of a ligand N-(3,5-di-2-pyrazinyl-4H-1,2,4-triazol-4-yl)-2-pyrazinecarboxamide (Hpztp) with CuSO4 and Cu(acac)2 (acac = acetylacetonate), respectively, yields two distinct CuII coordination polymers {[Cu3(pztp)2(SO4)2(H2O)2]·3H2O} n and {[Cu(pztp)(acac)]·0.5H2O} n . Both complexes have been structurally determined and also characterized by physicochemical and spectroscopic methods. The results reveal that by using different anions (SO4 2? versus acac?), the dimensionality (from 2D to 1D) of the resulting coordination architectures as well as conformations and binding fashions of the pztp ligand are significantly changed. That is to say, the selection of anions will play a key role in inducing the formation of the crystalline materials. The thermal stabilities of both complexes have also been explored and discussed.  相似文献   

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