一种功能型混配镍配合物的溶剂化显色特性与结构关系

详细报道了新近合成的二氰基二硫纶·邻菲罗啉二酮合镍配合物Ni(mnt) (phen - 5,6-dione) (mnt2 - ∶1,2 -dicyano - 1,2 -ethylenedithiolateormaleonitriledithiolate ;phen - 5,6-dione∶1,10 -phenanthroline - 5,6-dione)的电子吸收光谱 ,着重研究了可见光区中的溶剂化显色吸收带在相关分子轨道能级图中的对应跃迁关系 ,探讨了LL′CT的本质和感光氧化现象。     

THE EPR SPECTRA OF TETRADENTATE SCHIFF BASE COMPLEXES OF COPPER (II) I. N,N'-Bis-(acetylacetone) ethylenediimine and N,N'-Bis-(1,1,1-trifluoroacetylacetone) ethylenediimine

Abstract

The EPR spectrum of N, N'-bis-(acetylacetone)ethylenediimino Cu(II), [Cu-en(acac)₂], and N, N'-bis-(1,1,1-trifluoroacetylacetone)ethylenediimino-Cu(II), [Cu-en(tfacac)₂], have been studied in doped single crystals of the corresponding Ni(II) chelate. The parameters in the usual doublet spin-Hamiltonian are found to be: Cu[en(acac)₂], g_z =2.183 ± 0.003, g_x =2.047 ± 0.004, g_y =2.048 ± 0.004, A_z =204.8 × 10^?4cm^?1, A_x =31.5 × 10^?4cm^?1, A_y =27.1 × 10^?4 cm^?1, A_zN= 12.8 × 10^?4 cm^?1 and A_xN =A_yN =14.3 × 10^?4 cm^?1: Cu[en(tfacac)₂], g_z =2.192 ± 0.002, g_x =2.048 ± 0.004, g_y =2.046 ± 0.004, A_z =200.8 × 10^?4 cm^?1, A_x =31.1 × 10^?4 cm^?1, A_y =28.3 × 10^?4 cm^?1, A_zN =12.8 × 10^?4 cm^?1 and A_xN =A_yN =14.6 × 10^?4 cm^?1. These parameters are related to coefficients in the molecular orbitals of the complex. It is found that the α-bonding is quite covalent and there is significant in-plane σ-bonding. From the nitrogen hyperfine structure it is determined that the hybridization on the nitrogen is sp².     

The infrared spectra (3500—150 cm-1) of aniline complexes of cobalt(II), nickel(II), copper(II) and zinc(II) halides

The IR spectra (3500—150 cm^?1) of the complexes [M(aniline)₂,X₂ (M = Co, Ni, Cu, Zn; X = Cl, Br), [Zn(aniline)₂I₂] are discussed. Assignments of the internal ligand vibrations are based on the band shifts which result from ¹⁵N-labelling of the amino group. The metal—ligand stretching frequencies, ν(M—N) and ν(M—X), are assigned on the basis of the band shifts which occur on ¹⁵N-labelling and metal ion and halogen substitution. Two bands within the range 350–450 cm^?1 are assigned to ν(M—N) while the ν(M—X) bands occur within the range 170–320 cm^?1. The effects of structure and coordination number on ν(M—N) and ν(M—X) are discussed. The spectra of two ethanol adducts, [M(aniline)₂-(ethanol)₂Cl₂] (M = Co, Ni) compared with those of the unsolvated species [M(aniline)₂-Cl₂], exhibit a unique band near 480 cm^?1 which is insensitive to ¹⁵N-labelling and is assigned to ν(M—O).     

An extraction-spectrophotometric determination of palladium with 4-(2-pyridylazo)resorcinol in the presence of diphenylguanidine

A new, sensitive spectrophotometric determination of palladium has been developed, based on the extraction of the red Pd(II) chelate with 4-(2-pyridylazo)resorcinol in the presence of N,N′-diphenylguanidine into n-butanol; the sensitivity of the method according to Sandell is S = 1.12 μg cm^?2, ?₅₃₀ = 9.4 × 10⁴ liters mol^?1 cm^?1, and palladium can be determined at concentrations from 0.21 to 1.91 μg ml^?1.     

Osmium(II)-Phthalocyanine: Darstellung und Eigenschaften von Di(acido)phthalocyaninatoosmaten(II)

Osmium(II) Phthalocyanines: Preparation and Properties of Di(acido)phthalocyaninatoosmates(II) “H[Os(X)₂Pc^2?]” (X = Br, Cl) reacts in basic medium or in the melt with (ⁿBu₄N)X forming less stable, diamagnetic, darkgreen (ⁿBu₄N)₂[Os(X)₂Pc^2?]. Similar dicyano and diimidazolido(Im) complexes are formed by the reaction of “H[Os(Cl)₂Pc^2?]” with excess ligand in the presence of [BH₄]^?. The cyclic voltammograms show up to three quasireversible redoxprocesses: E_1/2(I) = 0.13 V (X = CN), ?0.03 V (Im), ?0.13 V (Br) resp. ?0.18 V (Cl) is metal directed (Os^II/III), E_1/2(II) = 0.69 V (Cl), 0.71 V (Br), 0.83 V (CN), 1.02 V (Im) is ligand directed (Pc^2?/?) and E_1/2(III) = 1.17 V (Cl) resp. 1.23 V (Br) is again metal directed (Os^III/IV). Between the typical “B” (～16.2 kK) and “Q” (～29.4 kK), “N regions” (～34.1 kK) up to seven strong “extra bands” of the phthalocyanine dianion (Pc^2?) are observed in the uv-vis spectrum. Within the row CN > Im > Br > Cl, most of the bands are shifted slightly, the “extra bands” considerably more to lower energy in correlation with E_1/2(I). The vibrational spectra are typical for the Pc^2? ligand with D_4h symmetry. M.i.r. bands at 514, 909, 1 173 and 1 331 cm^?1 are specific for hexa-coordinated low spin Os^II phthalocyanines. In the resonance Raman (r.r.) spectra polarized, depolarized or anomalously polarized deformation and stretching vibrations of the Pc^2? ligand will be selectively enhanced, if the excitation frequency coincides with “extra bands”. With excitation at ～19.5 kK the intensity of the symmetrical Os? X stretching vibration at 295 cm^?1 (X = Cl), 252 cm^?1 (X = Im) and 181 cm^?1 (X = Br) is r.r. enhanced, too. The asymmetrical Os? X stretching vibration is observed in the f.i.r. spectrum at 345 cm^?1 (X = CN), 274 cm^?1 (X = Cl), 261 cm^?1 (X = Im) and 200 cm^?1 (X = Br).     

Ruthenium(II)-Phthalocyaninate(2–): Darstellung und Eigenschaften von Acido(carbonyl)phthalocyaninato(2–)ruthenat(II), [Ru(X)(CO)Pc2−]− (X = Cl,Br, I,NCO, NCS,N3)

Ruthenium(II) Phthalocyaninates(2–): Synthesis and Properties of (Acido)(carbonyl)phthalocyaninato(2–)ruthenate(II), [Ru(X)(CO)Pc^2?]^? (X = Cl, Br, I, NCO, NCS, N₃) (ⁿBu₄N)[Ru(OH)₂Pc^2?] is reduced in acetone with carbonmonoxid to blue-violet [Ru(H₂O)(CO)Pc^2?], which yields in tetrahydrofurane with excess (ⁿBu₄N)X acido(carbonyl)phthalocyaninato(2–)ruthenate(II), [Ru(X)(CO)Pc^2?]^? (X = Cl, Br, I, NCO, NCS, N₃) isolated as red-violet, diamagnetic (ⁿBu₄N) complex salt. The UV-Vis spectra are dominated by the typical π-π* transitions of the Pc^2? ligand at approximately 15100 (B), 28300 (Q₁) und 33500 cm^?1 (Q₂), only fairly dependent of the axial ligands. v(C? O) is observed at 1927 (X = I), 1930 (Cl, Br), 1936 (N₃, NCO) 1948 cm^?1 (NCS), v(C? N) at 2208 cm^?1 (NCO), 2093 cm^?1 (NCS) and v(N? N) at 2030 cm^?1 only in the MIR spectrum. v(Ru? C) coincides in the FIR spectrum with a deformation vibration of the Pc ligand, but is detected in the resonance Raman(RR) spectrum at 516 (X = Cl), 512 (Br), 510 (N₃), 504 (I), 499 (NCO), 498 cm^?1 (NCS). v(Ru? X) is observed in the FIR spectrum at 257 (X = Cl), 191 (Br), 166 (I), 349 (N₃), 336 (NCO) and 224 cm^?1 (NCS). Only v(Ru? I) is RR-enhanced.     

Structure sensitive bands in the vibrational spectra of metal complexes of tetraphenylporphine

The i.r. and RR spectra of twenty Fe(TPP)LL′ type complexes have been measured to locate structure-sensitive bands. In i.r. spectra, band I (1350-1330 cm⁻¹) and band III (469-432 cm⁻¹) are spin-state sensitive whereas band II (806-790 cm⁻¹) is oxidation-state sensitive and slightly spin-state sensitive in the Fe(II) state. To examine the nature of these bands, the i.r. spectra of Co(TPP), (Fe(TPP))₂O and their d₈ and d₂₀ analogs have been measured, and empirical assignments proposed. In RR spectra, band C (1545-1498 cm⁻¹, ap) and band D (1565-1540 cm⁻¹, p) are spin-state sensitive whereas band E (391-376 cm⁻¹, p) is sensitive to both spin and oxidation states. These results on RR spectra are in good agreement with those of previous workers.     

Darstellung und spektroskopische Eigenschaften von Di(phthalocyaninato(1−))-lanthanidpolybromid; Kristallstruktur von α-Di(phthalocyaninato)samariumpolybromid, α-[Sm(Pc)2]Br1,45 und α-Di(phthalocyaninato)samariumperchlorat, α-[Sm(Pc)2](ClO4)0,63

Synthesis and Spectroscopical Properties of Di(phthalocyaninato(1?))lanthanidepolybromide; Crystal Structure of α-Di(phthalocyaninato)samariumpolybromide, α-[Sm(Pc)₂]Br_1.45 and α-Di(phthalocyaninato)samariumperchlorate, α-[Sm(Pc)₂](ClO₄)_0.63 Bronze-coloured di(phthalocyaninato)lanthanidepolybromide, [Ln(Pc^?)₂]Br_y (Ln = La…(? Ce, Pm)…Lu; y > 1.5) is prepared by oxidation of (ⁿBu₄N)[Ln(Pc^2?)₂] with bromine in excess. The UV-VIS-NIR spectra show the typical B and Q₁ bands of the Pc^? ligand at ～ 14 kK and ～ 20 kK. For the [Ln(Pc^?)₂]⁺ cation a NIR(D) band between 9,14 kK (La) and 11,50 kK (Lu) is characteristic for dimeric cofacial Pc^? radicals. Within the row La…Lu, there is a linear relationship of the hypsochromic shift of the strong bands and the Ln^III radius. In the case of La? Nd the D band shifts successively with longer time of bromination to ～ 3 kK as a result of increasing electron delocalisation. Characteristic vibrational bands are at ～ 1350/1450 cm^?1 (IR) and ～ 560/1120/1170/1600 cm^?1 (RR). In the FT-Raman spectra the totally symmetric Ln? N stretching vibration between 141 cm^?1 (La) and 172 cm^?1 (Lu) is selectively enhanced. As shown by α-[Sm(Pc)₂]Br_1,45 and α-[Sm(Pc)₂](ClO₄)_0,63 only partially ringoxidized complexes are obtained by the anodic oxidation. Both crystallize in the tetragonal space group P4/nnc. The [Sm(Pc)₂] molecular building block contains two nearly planar staggered (～41°) Pc rings packed in columns parallel along [001] leading to the quasi-one-dimensional structure. There is a statistical disorder of the Sm^III and the ClO₄^? resp. Br^?/Br₃^? ions over two incompletely filled crystallographic positions for the cation resp. anion. This results in a partial oxidation of the Pc ligand, which in the picture of localized valence states for α-[Sm(Pc)₂](ClO₄)_0,63 corresponds to [SmPc^?Pc^2?] · 2[Sm(Pc^?)₂](ClO₄). Accepting the same valence state for [Sm(Pc)₂]Br_1,45 five positive charges are compensated by two Br^? and three Br₃^?. The spectroscopic differences of the partially and fully oxidized complexes are discussed.     

Heteroleptic ruthenium sensitizers that contain an ancillary bipyridine ligand tethered with hydrocarbon chains for efficient dye-sensitized solar cells

New heteroleptic ruthenium complexes have been synthesized and used as the sensitizers for dye‐sensitized solar cells (DSSCs). The ancillary bipyridine ligand contains rigid aromatic segments (fluorene‐, carbazole‐, or dithieno[3,2‐b:2′,3′‐d]pyrrole‐substituted bipyridine) tethered with a hydrophobic hexyl substituent. The conjugated aromatic segment results in significant bathochromic shift and hyperchromic effects in these complexes compared with Z907 (cis‐[Ru LL′ (NCS)₂]; L =4,4′‐dicarboxylic acid‐2,2′‐bipyridine, L′ =4,4′‐dinonyl‐2,2′‐ bipyridine). The long hydrocarbon chains help to suppress the dark current if appropriately disposed. DSSCs that use these complexes exhibit very impressive conversion efficiencies (5.94 to 6.91 %) that surpass that of Z907 ‐based (6.36 %) DSSCs and are comparable with that of N719 ‐based standard cells (7.13 %; N719 =cis‐di(thiocyanato)bis(2,2′‐bipyridyl‐4,4′‐dicarboxylato)ruthenium(II) bis(tetrabutylammonium)) fabricated and measured under similar conditions (active area: 0.5×0.5 cm²; AM 1.5 sunlight).     

Darstellung,Eigenschaften und elektronische Raman-Spektren von Bis(chloro)phthalocyaninatoferrat(III), -ruthenat(III) und -osmat(III)

Preparation, Properties and Electronic Raman Spectra of Bis(chloro)-phthalocyaninatoferrate(III), -ruthenate(III) and -osmate(III) Bis(chloro)phthalocyaninatometalates of Fe^III, Ru^III and Os^III [MCl₂Pc(2-)]^?, with an electronic low spin ground state are formed by the reaction of [FeClPc(2-)] resp. H[MX₂Pc(2?)] (M = Ru, Os; X = Cl, I) with excess chloride in weakly coordinating solvents (DMF, THF) and are isolated as (n-Bu₄N) salts. The asym. M? Cl stretch (ν_as(MCl)) is observed in the f.i.r. at 288 cm^?1 (Fe), 295 cm^?1 (Ru), 298 cm^?1 (Os), ν_as(MN) at 330 cm^?1 (Fe), 327 cm^?1 (Ru), and 317 cm^?1 (Os); only ν_s(OsCl) at 311 cm^?1 is resonance Raman (r.r.) enhanced with blue excitation. The m.i.r. and FT-Raman spectra are typical for hexacoordinated phthalocyanines of tervalent metal ions. The UV-vis spectra show besides the characteristic π-π* transitions (B, Q, N, L band) of the Pc ligand a number of extra bands at 12–15 kK and 18–24 kK due to trip-doublet and (Pc→M)CT transitions. The effect of metal substitution is discussed. The r.r. spectra obtained by excitation between the B and Q band (λ₀ = 476.5 nm) are dominated by the intraconfigurational transition Γ₇ Γ ₈ arrising from the spin-orbit splitting of the electronic ground state for Fe^III at 536 cm^?1, for Ru^III at 961 cm^?1 and Os^III at 3 028 cm^?1. Thus the spin-orbit coupling constant increases very greatly down the iron group: Fe^III (357 cm^?1)< Ru^III (641 cm^?1)< Os^III (2 019 cm^?1). The Γ₇ Γ ₈-transition is followed by a very pronounced vibrational finestructure being composed in the r.r. spectra by the coupling with ν_s(MCl), δ(MClN) and the most intense fundamental vibrations of the Pc ligand. In absorption only vibronically induced transitions are observed for the Ru and Os complex at 1 700-2800 rsp. 3100-5800 em^?1 instead of the 0-0 phonon transitions. The most intense lines are attributed to combinations of the intense odd vibrational mo-des at ≈ 740 and 1120 cm^?1 with ν₅(MCI), δ(MClN).     

Synthesis and crystal structure of dinuclear nickel (Ⅱ) complex

The crystal structure of Ni(Ⅱ) complex with 3-hydroxyl-1, 5-diazacycloheptane-N, N'-diacetate was determined by X-ray diffraction method. Crystal data for Ni2 (C9H14N2O5)2·2H2O: monoclinic, space group P21/n, a = 1.1717(5), b = 0.9794(3), c = 1.2971(2) nm, β= 96.62(3), V= 1.4786(7) nm3, Dc = 1.377 g/cm3, Z = 2,μ=13.321 cm-1 (Mo-Kα), F(000)=640. The final R and Rw are 0.075 and 0.089 respectively. The Ni(Ⅱ) ion forms 2:2 complex with ligand. Two ligands are bridged by two Ni(Ⅱ) atoms which are bridged by two O atoms. Every Ni(Ⅱ) is coordinated by two N atoms and four 0 atoms. The coordination polyhedron of the Ni(Ⅱ) ion is a distorted octahedron.     

Thermochromie der organischen Lösungen des Nickel-komplexes von N,N′-Bis[3-Aminopropyl] Piperazin

Thermochromism of Organic Solutions of N,N′-Bis-(3-Aminopropyl)Piperazine Nickel Complexes The orange-red planar nickel complex of N,N′-bis-(3-aminopropyl)piperazine (bapp) is thermochromic in solutions of acetonitril and DMF, and becomes blue at low temperature. This change is caused by the formation of the 6-coordinated species [NibappL₂]²⁺ (L = solvent molecule). If Cl^? or Br^? ions coexist, other kinds of thermochromism involving the formation of the 5-coordinated species [NibappX]⁺ (X^? = Cl^? or Br^?) are observed. Spectral data on these phenomena are given, together with those observed in nitromethane, and discussed in terms of the coordination abilities of L and X^?.     

Syntheses,Crystal Structure,and Magnetic Properties of a Self‐assembling Dicopper(II) Helicate with Novel Bipyridine Ligand

A novel double helical dicopper(II) complex was synthesized by reaction of a polydentate ligand L = 2,2′‐bipyridyl‐6,6′‐bis(2‐acetylpyrazinohydrazone) with copper(II) perchlorate in CH₃CN. The self‐assembling process was studied by UV‐Vis spectrometric titration experiments which revealed the formation of dinuclear complexes [Cu₂L₂](ClO₄)₄. The structure of dicopper double‐helicate was confirmed by X‐ray diffractometry. Each copper(II) center occupies a distorted octahedral environment. Variable‐temperature magnetic measurements reveal weak antiferromagnetic interactions between Cu(II) ion centers with J = ?0.63 cm^?1.     

On the 1 μm system of iron hydride

The 987.7 nm system of FeD has been shown by rotational analysis of the (1,0) and (0,0) bands to be due to a ⁴Δ-⁴Δ electronic transition. The bond lengths in the ν = 0 levels of the upper and lower states are r_o⁴ = 0.1705 nm and r_o¹¹=0.1589 nm. respectively and the (ν′= 1) - (ν′ = 0) vibrational interval of the upper state is 1035 cm^?1.     

Some mixed-ligand palladium(II) complexes and comparison of their photosensitizing ability with analogous platinum(II) complexes

Three new palladium(II) complexes of formula [Pd(bipy)(XX)] [where bipy is 2,2′-bipyridine and XX are dianions of catechol (CAT), 4-tert-butylcatechol (BCAT) and 3,4-dimercaptotoluene (DMT)] have been prepared and characterized by physical methods. A ligand-ligand charge-transfer band in each complex was observed between 16–21 kK (ε_max = 1500–2200 1 mol^?1 cm^?1) which is negatively solvochromic. These palladium(II) complexes in dimethylformamide photosensitize the formation of singlet oxygen and their ability to photosensitize triplet oxygen (³O₂) to singlet oxygen (¹O₂) are compared with analogous platinum(II) complexes. In addition, 2,2′-bipyridine-platinum(II) complex of 3,4-dimercaptotoluene also undergoes self-sensitized photooxidation.     

Tetranuclear Copper(II) Complex with N,N′-bis(2-N-Tosylaminobenzylidene)-1,3-Diaminopropan-2-ol: Crystal structure and magnetic properties

Tetranuclear copper(II) complex, [Cu₄L₂(OOCCH₂COO)], where L is triply deprotonated bis-N,N′-(2-N-tosylaminobenzylidene)-1,3-diaminopropan-2-ol, in which two binuclear fragments are linked by the malonate dianion, is synthesized. The exchange interaction in the binuclear clusters is shown to be antiferromagnetic (2J = ?59 cm^?1), whereas the intercluster interaction is ferromagnetic (zJ’ = 7.5 cm^?1). The structure of the DMSO solvate of the complex is determined by X-ray diffraction analysis.     

Ruthenium(II)-Phthalocyanine: Darstellung und Eigenschaften von Di(halogeno)phthalocyaninatoruthenat(II)

Ruthenium(II) Phthalocyanines: Preparation and Properties of Di(halo)phthalocyaninatoruthenate(II) [Ru(Py)₂Pc^2?] reacts with molten (ⁿBu₄N)X forming stable, green (ⁿBu₄N)₂[Ru(X)₂Pc^2?] (X = Cl, Br). The cyclovoltammogram shows a quasireversible redoxprocess for the metal oxidation at E_1/2(I) = ?0.02 V (X = Cl) resp. 0.05 V (X = Br) and for the first ringoxidation at E_1/2(II) = 0.70 V. The typical π-π*-transitions (B < Q < N) of the phthalocyanine dianion (Pc^2?) are observed in the uv-vis spectrum. With respect to Ru^III phthalocyanines B is shifted significantly to higher, Q, N to lower energy. The strong extra-band at 24.2 kK is diagnostic for these Ru^II phthalocyanines. The vibrational spectra are typical for the Pc^2? ligand with D_4h symmetry, too, and bands at 513, 909, 1 171 und 1 329 cm^?1 in the m.i.r. spectrum are specific for hexa-coordinated low spin Ru^II. In the Raman spectrum with excitation at ～480 nm the intensity of the totally symmetrical Ru? X stretching vibration at 266 cm^?1 (X = Cl) resp. 168 cm^?1 (X = Br) together with a progression of up to three overtones is selectively resonance Raman enhanced. The asymmetrical Ru? X stretching vibration is observed in the f.i.r. spectrum at 272 cm^?1 (X = Cl) resp. 215 cm^?1 (X = Br).     

Mixed‐ligand Complexes with 2,6‐Pyridinedicarboxylato(2‐) and 4,7‐Diphenyl‐1,10‐Phenanthroline Ligands, [MII(pdc)(DPphen)(H2O)]·H2O (M = Co or Cu). Synthesis,Crystal Structures and Properties

Iso‐type [M^II(pdc)(DPphen)(H₂O]·H₂O compounds (M = Co or Cu, pdc = 2,6‐pyridinedicarboxylato(2‐) ligand and DPphen = 4,7‐diphenyl‐1,10‐Phenanthroline) were synthesized and studied by X‐ray diffraction, thermal and spectral methods. The N,N′‐equatorial bidentate DPphen‐copper(II) chelation imposes a mer‐N(equatorial)+O₂(apical) conformation to pdc in the coordination polyhedron (type 4+1+1). In the Co(II) derivative, the coordination is of type 1+2+2+1 because of a lesser Jahn‐Teller distortion. In the crystals, π,π‐interligand interactions between phen ligands connect the complex molecules in multi‐stacked chains. Aqua···O(carboxyl) H‐bonding interactions reinforce the stacked chains and build double chains in 1D supramolecular structures parallel to the a axis. Non coordinated water connect these structures by H‐bonds.     

Spectrophotometric studies of the formation of charge transfer complex of iron(III) with N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane di-Schiff base ligand in methanol

The complex formation reaction between N,N′-bis(2-pyridylmethylidene)-1,2-diiminoethane (BPIE) di-Schiff base ligand as an electron donor and iron(III) chloride as an electron acceptor have been studied spectrophometrically in methanol at 28°C. The values of equilibrium constants, K and molar absorptivities, ε were obtained from the Benesi–Hildebrand, Scott and Foster–Hammick–Wardley equations. The results indicate the formation of 1?:?1 charge transfer complex. The absorption band energy of the complex, E _CT, the ionization potential of the BPIE Schiff base ligand, I ^D, and the Gibbs energy changes of the above reaction, ΔG ⁰, were calculated. Finally, the kinetics of the complex formation reaction were studied and was found to be second-order in each reactant. The values of the rate constants of the forward and reverse reactions k ₁ and k _?1 were determined.     

Gemischtligandkomplexbildung durch Thermische Reaktion von Metall(II) - Thioselenocarbamaten EPR- und massenspektrometrische Untersuchungen

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 Cu^II 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.