Gancheva Veselka, Yordanov Nicola D, Koev Lachezar
Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
Spectrochim Acta A Mol Biomol Spectrosc. 2008 May;69(5):1317-21. doi: 10.1016/j.saa.2007.09.025. Epub 2007 Oct 2.
The spectral properties of bis(diaryl-dithiophosphato)copper(II) complexes, [Cu(S(2)P(OR)(2))(2)], with R = o-cresyl (complex I) and 2,6-dimethylphenyl (complex II) are studied by EPR- and vis spectroscopy. In solid (powder) state both complexes exhibit dark brown colour and are paramagnetic. Room temperature EPR spectra of the complexes dissolved in non-coordinating (C(6)H(5)CH(3), C(5)H(12), C(6)H(14)), acceptor (CHCl(3), CCl(4)) or donor (DMFA, DMSO) solvents have typical features of the chromophore CuS(4). In non-coordinating and acceptor solvents their isotropic EPR parameters are: g(iso)=2.047+/-0.003, (Cu)A(iso) = 7.2+/-0.1 mT and (P)A = 0.95+/-0.1 mT. An absorption band characterizes the vis spectra in these solvents with a maximum at 427 nm, due to a ligand-to-metal charge-transfer transition. One hour after dissolution the absorbance at 427 nm follows Beer's law with molar absorptivity (epsilon) about 11000, which does not change significantly after 24 h staying at room temperature or after 30 min heating at 50 degrees C. Both DMFA and DMSO exhibit specific solute-solvent interaction with the acceptor centre of copper complex yielding an axial adduct, with increased g-factor and decreased (hf)A compared to the initial complex. An additional EPR signal with unresolved hyperfine structure is also detected in DMSO. EPR and vis intensities of both bis(diaryl-dtp)Cu(II) complexes decrease after dissolution in both solvents. Moreover, they are EPR silent in pyridine and do not show any absorption in the vis spectra.
研究了二（二芳基二硫代磷酸酯）铜（II）配合物[Cu(S₂P(OR)₂)₂]（其中R = 邻甲酚基（配合物I）和2,6 - 二甲基苯基（配合物II））的光谱性质，采用电子顺磁共振（EPR）和可见光谱法。在固态（粉末）状态下，两种配合物均呈现深棕色且具有顺磁性。溶解于非配位（苯、正戊烷、正己烷）、受体（氯仿、四氯化碳）或给体（N,N - 二甲基甲酰胺、二甲基亚砜）溶剂中的配合物在室温下的EPR光谱具有发色团CuS₄的典型特征。在非配位和受体溶剂中，它们的各向同性EPR参数为：g(iso)=2.047±0.003，(Cu)A(iso)=7.2±0.1 mT，(P)A = 0.95±0.1 mT。由于配体到金属的电荷转移跃迁，在这些溶剂中的可见光谱由一个吸收带表征，其最大值在427 nm处。溶解一小时后，427 nm处的吸光度符合比尔定律，摩尔吸光系数（ε）约为11000，在室温下放置24小时或在50℃加热30分钟后变化不显著。N,N - 二甲基甲酰胺和二甲基亚砜均与铜配合物的受体中心表现出特定的溶质 - 溶剂相互作用，生成轴向加合物，与初始配合物相比，g因子增加，(hf)A降低。在二甲基亚砜中还检测到具有未解析超精细结构的额外EPR信号。两种二（二芳基 - dtp）铜（II）配合物在两种溶剂中溶解后的EPR和可见光谱强度均降低。此外，它们在吡啶中EPR无信号，在可见光谱中无任何吸收。
