Photoinduced isomerisation of cis-[M(L-S,O)_2] (M = Pt~(II) and Pd~(II)) complexes of N,N-diethyl-N'-3,4,5-trimethoxybenzoylthiourea:key to preparation of the trans isomer

摘要

In acetonitrile solutions at room temperature,cis-[M(L-S,O)_2] Pt~(II) and Pd~(II) complexes of N,N-diethyl-N'-3,4,5-trimethoxyben-zoylthiourea undergo reversible photoinduced isomerisation to the corresponding trans isomer upon irradiation with visible light in the 320-570 nm range,the rate and extent of isomerisation being significantly higher for the cis-{Pd(L-S,O)_2] complex compared to the Pt~(II) analogue;in the dark trans-[M(L-S,O)_2] cleanly reverts back to the cis complex at a rate dependent on the solution temperature,indicating a thermally controlled reverse process.