Reactivity of coordinated Ph 2P(C 5H 5). Preparation of M(CO) 6- n[Ph 2P(C 5H 4Tl)] n complexes (M = Cr, Mo; n = 1, 2)

Abstract

The interaction of C 7H 8Cr(CO) 4 with two equivalents of Ph 2P(C 5H 5) in hexane at 0°C gives trans-Cr(CO) 4[Ph 2P(C 5H 5)] 2 ( I) in high yield (80%). In CDCl 3 at 30°C, I isomerizes to cis-Cr(CO) 4(Ph 2PC 10H 10PPh 2) ( II) quantitatively. Compound II can also be prepared in high yield (85%) by the interaction of trans-Cr(CO) 4(Ph 2PCl) 2 with two equivalents of TI(C 5H 5) in refluxing toluene. Treatment of M(CO) 6 (M = Cr, Mo) with one equivalent of trimethylamine N-oxide in THF followed by the addition of one equivalent of Ph 2P(C 5H 4Tl) affords M(CO) 5[Ph 2P(C 5H 4Tl)] ( III, M = Cr; IV, M = Mo) and M(CO) 4 [Ph 2P(C 5H 4Tl)] 2 ( V, M = Cr; VI, M = Mo). M(CO) 4[Ph 2P(C 5H 4Tl)] 2 adopts a trans- and a cis-configuration for chromium and molybdenum, respectively. The M(CO) 4[Ph 2P(C 5H 4Tl)] 2 complex can also be prepared conveniently either by the interaction of C 7H 8]M(CO) 4 with two equivalents of Ph 2P(C 5H 4Tl) or by the interaction of M(CO) 4[Ph 2P(C 5H 5)] 2 with two equivalents of Tl(OEt) in THF.