Organometallic imido, sulfido and oxo complexes of osmium(VI)

Abstract

Transition metal-mediated oxygen, nitrogen, and sulfur transfer reactions to olefins and acetylenes were reviewed in Chapter 1. The alkylosmium(VI) complexes (Y) (Os(N)(R)$\sb2$Cl$\sb2$), Os(N)(CH$\sb2$SiMe$\sb3)\sb2$Cl, Os(N)(CH$\sb2$SiMe$\sb3)\sb2$Cl(NC$\sb5$H$\sb5)$, Os (N)(CH$\sb2$SiMe$\sb3)\sb3$(Z) and (Os(N)(CH$\sb2$SiMe$\sb3)\sb2$(X)$\sb2$) (BF$\sb4$) where Y = NBu$\sp{\rm n}\sb4,$ PPh$\sb4;$ R = CH$\sb2$SiMe$\sb3,$ Me; Z = NC$\sb5$H$\sb5$, PMe$\sb3,$ PPh$\sb3;$ X = NC$\sb5$H$\sb5,$ NCCH$\sb3,$ were synthesized in Chapter 2. Nitrido and imidoosmium(VI) complexes were prepared and their reaction chemistry was studied in Chapter 3. Improved syntheses of $(\eta\sp5$-C$\sb5$H$\sb5$)Os(N)(CH$\sb2$SiMe$\sb3)\sb2$ and $(\eta\sp5$-C$\sb5$Me$\sb5$)Os(N)(CH$\sb2$SiMe$\sb3)\sb2$ where described, while that of $(\eta\sp5$-C$\sb5$H$\sb5$)Os(N)Me$\sb2$ was newly developed. The corresponding imido complexes were prepared using methyl trifluoromethanesulfonate. The imide, (($\eta\sp5$-C$\sb5$H$\sb5$)Os(N)(CH$\sb2$SiMe$\sb3)\sb2$) (OSO$\sb2$CF$\sb3$), was deprotonated with triphenylphosphine, pyridine or water forming $(\eta\sp5$-C$\sb5$H$\sb5$)Os(N=CH$\sb2$)(CH$\sb2$SiMe$\sb3)\sb 2.$ This compound can be reprotonated with strong acids. The reaction of (($\eta\sp5$-C$\sb5$H$\sb5$)Os(N)(CH$\sb2$SiMe$\sb3)\sb2$) (OSO$\sb2$CF$\sb3$) with ethylene produced ($(\eta\sp5$-C$\sb5$H$\sb5$)Os(HN=CH$\sb2$)(C$\sb2$H$\sb4)\sb2$) (OSO$\sb2$CF$\sb3$). Under pressures of ethylene, (($\eta\sp5$-C$\sb5$H$\sb5$)Os(N)(CH$\sb2$SiMe$\sb3)\sb2$) (OSO$\sb2$CF$\sb3$) yielded a nitrogen-containing organic compound. Oxygen- and sulfur-containing osmium(VI) complexes were prepared in Chapter 4. The $\mu\sb3$-sulfidoosmium(VI) cluster (NBu$\sp{\rm n}\sb4$) ((Os(N)(CH$\sb2$SiMe$\sb3)\sb2)\sb3$(S)$\sb2$) was synthesized and its x-ray structure was obtained. The sulfido cluster reacts with (Cu(NCCH$\sb3)\sb4$) (PF$\sb6$) and triphenylphosphine to give a copper-sulfur adduct and triphenylphosphine sulfide. The oxoosmium complex ((Os(N)(CH$\sb2$SiMe$\sb3)\sb2)\sb4$(O)$\sb2$) was synthesized and reacted with triphenylphosphine giving triphenylphosphine oxide. The three complexes ((Os(N)(CH$\sb2$SiMe$\sb3)\sb2$(OH)) $\sb2,$ (NBu$\sp{\rm n}\sb4$) ((Os(N)(CH$\sb2$SiMe$\sb3)\sb3$(OH)) and (NBu$\sp{\rm n}\sb4$) ((Os(N)(CH$\sb2$SiMe$\sb3)\sb2$(OH)$\sb2$) were prepared. Nitridoosmium(VI)amino and amido complexes were synthesized in Chapter 5. The amino complexes included Os(N)(CH$\sb2$Si(CH$\sb3)\sb3)\sb2$(NH$\sb2$CH$\sb3)\sb2$C1, (Os(N)(CH$\sb2$Si(CH$\sb3)\sb3$)$\sb2$(NH$\sb2$CH$\sb3)\sb2$) (BF$\sb4$), (Os(N)Cl$\sb2$(NH$\sb2$CH$\sb3)\sb3$) (Cl), Os(N)(CH$\sb2$SiMe$\sb3)\sb3$(NH$\sb2$Bu$\sp{\rm t})$ and (Os(N)(CH$\sb2$Si(CH$\sb3)\sb3$)$\sb2$(NC$\sb5$H$\sb5$)(NH$\sb2$Bu$\sp{\rm t})$) (BF$\sb4$), while the amido compounds included (NBu$\sp{\rm n}\sb4$) (Os(N)Cl$\sb3$(NHBu$\sp{\rm t}$)) and (NBu$\sp{\rm n}\sb4$) (Os(N)(CH$\sb2$SiMe$\sb3)\sb2$Cl(NHBu$\sp{\rm t}$)).