The synthesis of dimetallic thioalkyne complexes of cobalt and molybdenum
摘要:
Treatment of [Co2(mu-HOCR2'C=CCR2'OH)(CO)6] With an excess of RSH in the presence of HBF4.OEt2 affords [Co2(mu-RSCR2'C=CCR2'SR)(CO)6] (R'= H, R = Et, (n)Bu, (t)Bu, Ph, Bz; R'= Me, R = Et), which undergo substitution with bis(diphenylphosphino)methane (dppm) to give [Co2(mu-RSCR2'C=CCR2'SR)(mu-dppm)(CO)4]. Similar treatment of [MoCo(mu-HOCH2C=CCH2OH)(CO)5Cp] and [Mo2(mu-HOCH2C=CCH2OH)(CO)4Cp2] with EtSH gives [MoCo(mu-EtSCH2C=CCH2SEt)(CO)5-Cp] and [Mo2(mu-EtSCH2C=CCH2SEt)(CO)4Cp2], respectively. Reaction of [Co2(mu-HOCH2C=CCH2-OH)(CO)6] with a small excess of RSH (R=Et or Ph), ca. two equivalents, affords [Co2(mu-HOCH2C=CCH2-SR)(CO)6], while reaction with only one equivalent of EtSH additionally gives an ether-bridged system containing two hexacarbonyldicobalt units, [Co2(CO)6(HOCH2C= CCH2OCH2C=CCH2SEt)-Co2(CO)6]. Treatment of [Co2(mu-HOCH2C=CCH2SEt)(CO)6] with half an equivalent of HBF4.OEt2 affords [Co2(CO)6(EtSCH2C=CCH2OCH2C=CCH2SEt)Co2(CO)6]. Attempted preparation of mixed thioether complexes results in a mixture of products, and a mechanism is proposed for thioether scrambling. The IR, NMR and mass spectra of the new compounds are reported and discussed.
The synthesis of dimetallic thioalkyne complexes of cobalt and molybdenum
摘要:
Treatment of [Co2(mu-HOCR2'C=CCR2'OH)(CO)6] With an excess of RSH in the presence of HBF4.OEt2 affords [Co2(mu-RSCR2'C=CCR2'SR)(CO)6] (R'= H, R = Et, (n)Bu, (t)Bu, Ph, Bz; R'= Me, R = Et), which undergo substitution with bis(diphenylphosphino)methane (dppm) to give [Co2(mu-RSCR2'C=CCR2'SR)(mu-dppm)(CO)4]. Similar treatment of [MoCo(mu-HOCH2C=CCH2OH)(CO)5Cp] and [Mo2(mu-HOCH2C=CCH2OH)(CO)4Cp2] with EtSH gives [MoCo(mu-EtSCH2C=CCH2SEt)(CO)5-Cp] and [Mo2(mu-EtSCH2C=CCH2SEt)(CO)4Cp2], respectively. Reaction of [Co2(mu-HOCH2C=CCH2-OH)(CO)6] with a small excess of RSH (R=Et or Ph), ca. two equivalents, affords [Co2(mu-HOCH2C=CCH2-SR)(CO)6], while reaction with only one equivalent of EtSH additionally gives an ether-bridged system containing two hexacarbonyldicobalt units, [Co2(CO)6(HOCH2C= CCH2OCH2C=CCH2SEt)-Co2(CO)6]. Treatment of [Co2(mu-HOCH2C=CCH2SEt)(CO)6] with half an equivalent of HBF4.OEt2 affords [Co2(CO)6(EtSCH2C=CCH2OCH2C=CCH2SEt)Co2(CO)6]. Attempted preparation of mixed thioether complexes results in a mixture of products, and a mechanism is proposed for thioether scrambling. The IR, NMR and mass spectra of the new compounds are reported and discussed.