Abstract

A series of ReBr(2)(MeCN)(NO)(P boolean AND P)] complexes (P boolean AND P = 1,1'-bis(diphenylphosphino)ferrocene (dppfc) (1a), 1,1'-bis(diisopropylphosphino)ferrocene (diprpfc) (1b), 2,2'-bis(diphenylphosphino)diphenyl ether (dpephos) (1c), 10,11-dihydro-4,5-bis(diphenylphosphino)dibenzob,f]oxepine (homoxantphos) (1d), 4,6-bis(diphenylphosphino)-10,10-dimethylphenoxasilin (Sixantphos) (1e)) were prepared with diphosphines varying in the P-Re-P bite angles. 1a,c-e were obtained from the reaction of ReBr5(NO)]NEt(4)](2) with an an excess of the respective diphosphine in MeCN or MeCN/THF mixtures at elevated temperatures. Compound 1b was obtained by an alternative route, cleaving the dinuclear (2)] unit (2b) with MeCN. 2b was prepared from the reaction of ReBr(5)(NO)]NEt(4)](2) with diprpfc in EtOH. The reaction of 1a-d with HSiEt(3) gave the seven-coordinate ReBr(H)(2)(SiEt(3))(NO)(P boolean AND P)] compounds 4a-d, of which 4a,c,d are only stable in solution in the presence of HSiEt(3). The SiMe(3) (4f) and SiCl(3) (4g) derivatives of 4b were also prepared by applying the reaction of lb with HSiMe(3) and HSiCl(3). 1a,c,e, 2b, and 4f,g were structurally characterized. For 1c,e, 2b, and 4f,g NO/Br disorder was observed, which originates from the presence of two isomeric forms in the crystals of the respective compounds. For lc,d fast interconversion of these isomers could be observed in their (31)P NMR spectra at room temperature.