Silsesquioxane Chemistry. 12 [1] Preparation and Complexation of a Novel Silsesquioxanyl Phosphine Ligand

The reaction of the monofunctional closo ‐silsesquioxane silanol derivative Cy 7 Si 8 O 12 OH ( 3 , Cy = c ‐C 6 H 11 ) with tris(dimethylamino)phosphine afforded the novel silsesquioxanyl phosphine ligand Cy 7 Si 8 O 12 OP(NMe 2 ) 2 ( 4 ) in virtually quantitative yield. The complexes [Cy 7 Si 8 O 12 OP(NMe 2 ) 2 ] 2 PtCl 2 ( 5 ) and [Cy 7 Si 8 O 12 OP(NMe 2 ) 2 ] 2 Mo(CO) 4 ( 6 ) were obtained in excellent yields upon treatment of 4 with (COD)PtCl 2 (COD = 1, 5‐cyclooctadiene) and (NBD)Mo(CO) 4 (NBD = norbornadiene), respectively. An attempted preparation of the bis(silsesquioxanyl)phosphine (Cy 7 Si 8 O 12 O) 2 P(NMe 2 ) led to the formation of the known disiloxane derivative (Cy 7 Si 8 O 12 ) 2 O ( 7 ), instead.