COBALT(II) COMPLEXES WITH PHOSPHINE OXIDES

Abstract

Abstract Solid complexes of tribenzylphosphine oxide (tbpo), dibenzylphenylphosphine oxide (dbppo) and benzyldiphenyl-phosphine oxide (bdppo) with Cobalt(II) chloride, bromide, iodide, thiocyanate, nitrate and perchlorate are reported and characterized. The compounds have the general formulas [CoL2 X2] and [CoL4] (C[tbnd]O4)2, where L is the phosphine oxide and X = Cl, Br, I, NCS or NO3. They are characterized and identified by chemical analysis and physical measurements. Analogous complexes of triphenylphosphine oxide (tppo) reported in the literature were also prepared in order to compare the spectral data. The chloride, bromide, iodide, thiocyanate and perchlorate complexes are tetrahedral and the nitrate ones are octahedral, like those with tppo. The crystal field parameters for the complexes of the four phosphine oxides are very similar and they are placed in a common position in the spectro-chemical and nephelauxetic series. The molar absorptivities measurements of the tetrahedral complexes in dichl...