The synthesis and stereodynamics of platinum(II) chloride complexes of 1,1′-bis(methylthio)ferrocene, 1,1′-bis(methylseleno)ferrocene and 1,1′-bis(methylthio)ruthenocene

Abstract

The complexes [PtCl 2(LL)] (LL  [(C 5H 4SCH 3) 2Fe)], [(C 5H 4SeCH 3) 2Fe], [(C 5H 4SCH 3) 2Ru]) have been synthesised. A 1H NMR study of their solution properties showed that at high temperatures pyramidal inversion of the chalogen atoms is rapid on the NMR timescale. At low temperatures (ca. −10°C) the motion was arrested and the selenium complex existed as a mixture of meso and dl species in approximately equal proportions, whereas the sulphur complexes were predominantly (85%) in the dl form. Variable temperature bandshape analyses of the complexes yielded sulphur inversion ( dl → dl) values of Δ G ≠ (298 K) of 64.18±0.03 and 66.29±0.09 kJ mol −1 for the iron and ruthenium compounds respectively and a selenium inversion ( meso → dl) value of Δ G ≠ (298 K) of 78.8±0.6 kJ mol −1.