MACROPOLYHEDRAL BORON-CONTAINING CLUSTER CHEMISTRY - ISOLATION AND CHARACTERIZATION OF 21-VERTEX [(PME(2)PH)(3)HREB(20)H(15)PH(PHME(2))]

Reaction of B20H16 With [ReH5(PMe(2)Ph)(3)] yields the twenty-one-vert ex metallaborane [(PMe(2)Ph)(3)HReB(20)H(15)Ph(PHMe(2))] which consist s of a close twelve-vertex {B-12} unit and a nide eleven-vertex {B-11} unit fused with a common triangular face, with the {(PMe(2)Ph)(3)HRe} moiety capping exo to the nido {B-11} unit with three Re-H-B bonds; a n unusual reductive P-phenyl cleavage of a PMe(2)Ph moiety to give B-p endant exo PHMe(2) and exo Ph moieties on the open face of the eleven- vertex subcluster is also apparent.