7-COORDINATE IRIDIUM(V) POLYHYDRIDES WITH CHELATING BIS(SILYL) LIGANDS

The pentahydride IrH5(PPh(3))(2) reacts with chelating silanes with lo ss of H-2 to form the classical seven-coordinate distorted pentagonal bipyramidal silyl polyhydride complexes IrH3(disil)(PPh(3))(2)(disil: dmsb, 3a; tids, 3b) with monodentate silanes to give IrH4(SiR(3))(PPh( 3))(2)(R: Et, 4a; Ph, 4b) and with triphenyltin hydride to give IrH3(S nPh(3))(2)(PPh(3))(2) (5), all rare examples of Ir(V). A crystal struc ture was obtained for 3a. Crystal data: orthorhombic;space group Pbca (No. 61); a = 17.1534(6) Angstrom; b = 25.688(2) Angstrom; c = 19.0641 (9) Angstrom; V = 8400(1) Angstrom(3); Z = 8.