SYNTHETIC APPROACHES TOWARDS EARLY/LATE HETEROBIMETALLIC COMPLEXES.

摘要

Cp$sb2$Zr(PPh$sb2$)$sb2$ () is shown to be capable of acting as a u27metalloligandu27 in the preparation of early/late transition metal heterobimetallic compounds. reacts with the complex Mo(CO)$sb4$(NHC$sb5$H$sb{10}$)$sb2$ yielding Cp$sb2$Zr($mu$-PPh$sb2$)$sb2$Mo(CO)$sb4$ () which crystallizes in the space group P2$sb1$2$sb1$2$sb1$. reacts with M(PPh$sb3$)$sb4$ to yield Cp$sb2$Zr($mu$-PPh$sb2$)$sb2$MPPh$sb3$ M = Ni (), Pd () and Pt (). Reaction of with the complex (Ph$sb3$P)$sb2$M(CO)$sb2$ M = Ni, Pt gives (C$sb5$H$sb5$)$sb2{m Zr(}mu$-PPh$sb2$)$sb2$Ni(CO)$sb2$ () and respectively. Reactions of with basic phosphines (PEt$sb3$, PCy$sb3$), CS$sb2$, PhNCS and acetylenes were studied. Complexes of the form Cp$sb2$M($mu$-PR$sb2$)$sb2$M$spprime$H(CO)PPh$sb3$, have been prepared. Structural data for compounds in which M$spprime$ = Rh, R = Ph, M$spprime$ = Zr (15) and M = Hf, R = Ph, M$spprime$ = Rh (16) are available. 15 crystallizes in the space group P2$sb1$/n. 16 is isostructural to 15. 15 reacts with basic phosphines (PEt$sb3$, PCy$sb3$), CO, H$sb2$ and alkenes have been studied. 15 is a catalyst precursor for the hydroformylation of 1-hexene. The complex Cp$sb2$Ti(SPCy$sb2$)$sb2$ (24) was prepared and characterized. 24 crystallizes in the space group PI. The Zr or Hf analogues of (24) were prepared by a similar procedure by reacting Cp$sb2$MCl$sb2$ with the appropriate secondary phosphine chalcogenide. These compounds may also be prepared by reacting the appropriate Cp$sb2{m M(PR}sb2$)$sb2$ with S$sb8$. Reactions of Cp$sb2$TiCl$sb2$ with LiXPR$sb2$, X = S, R = Ph; X = Se, R = Ph, Cy; or solutions of 24 on standing yield Ti(III) species by reductive elimination of (XPR$sb2$)$sb2$. These Ti(III) complexes are formulated as u27Cp$sb2$TiXPR$sb2$u27, X = S, R = Ph (29), X = S, Cy (30); X = Se, R = Ph (31), X = Se, R = Cy (32); on the basis of EPR data. These Ti(III) compounds are unstable and slowly convert by chalcogen atom abstraction to the complexes Cp$sb2$TiX$sb2$PR$sb2$, X = S, R = Ph (35), R = Cy (36); X = Se, R = Ph (37), X = Se, R = Cy (38). 36 crystallizes in the space group Pbna. 37 crystallizes in the space group P2$sb1$/c. 16 - 9, as well as the analogs where X = S, R = Me (33). R = Et (34) can also be prepared by photolysis of Cp$sb2$Ti(CO)$sb2$ in the presence of the appropriate (SPR$sb2$)$sb2$ or XPR$sb2$H. Alternatively, 35 - 38 can be prepared by reaction of either LiXPR$sb2$ or LiX$sb2$PR$sb2$ with (Cp$sb2$TiCl) $sb2$. 29 - 32 slowly convert to the complexes (Cp$sb2$M($mu$-X)) $sb2$ M = Zr, X = S (39); M = Zr, X = Se (40); M = Hf, X = S (41); M = Hf, X = Se (43) respectively. The preparation of 39 - 42 can also be achieved by direct reaction of 25 - 28 with Cp$sb2$M(PR$sb2$)$sb2$. Differences between the Ti chemistry and that of Zr and Hf is attributed to the ease of reduction of Ti(IV) to Ti(III).Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses u26 Major Papers - Basement, West Bldg. / Call Number: Thesis1988 .G455. Source: Dissertation Abstracts International, Volume: 48-10, Section: B, page: 2974. Thesis (Ph.D.)--University of Windsor (Canada), 1988.