<i>E/Z</i> isomerism in monoalkylated derivatives of [Pt<sub>2</sub>(µ-S)<sub>2</sub>(PPh<sub>3</sub>)<sub>4</sub>] containing 2,4-dinitrophenylhydrazone substituents
作者:Oguejiofo T. Ujam、Sarah M. Devoy、William Henderson、Alistair L. Wilkins、Brian K. Nicholson
DOI:10.1080/00958972.2011.606573
日期:2011.8.20
Alkylation of [Pt-2(mu-S)(2)(PPh3)(4)] with 2,4-dinitrophenylhydrazone-functionalized alkylating agents XC6H4C=NNHC6H3(NO2)(2)} CH2Br (X = H, Ph) gives monoalkylated cations [Pt-2(mu-S)mu-SCH2C=NNHC6H3(NO2)(2)}C6H4X}(PPh3)(4)](+). An X-ray diffraction study on [Pt-2(mu-S)mu-SCH2C=NNHC6H3(NO2)(2)}Ph}(PPh3)(4)]BPh4 shows the crystal to be the Z isomer, with the phenyl ring and NHC6H3(NO2)(2) groups mutually trans. H-1- and P-31H-1} NMR spectroscopic methods indicate a mixture of Z (major) and E (minor) isomers in solution, which slowly convert mainly to the E isomer. Reaction of [Pt-2(mu-S)(2)(PPh3)(4)] with the dinitrophenylhydrazone of chloroacetone [ClCH2C=NNH(C6H3(NO2)(2)}Me] and NaBPh4 gives [Pt-2(mu-S)mu-SCH2C=NNHC6H3(NO2)(2)}Me}(PPh3)(4)]BPh4, which exists as a single (E) isomer.