REACTIVITY OF RH4(CO)12 WITH HALIDES OR PSEUDOHALIDES - SYNTHESIS OF THE PENTANUCLEAR CARBONYL CLUSTERS [RH5(CO)14X]N- (X = CL, BR, I, SCN, N = 2, X = PPH3, N = 1) - CRYSTAL-STRUCTURES OF [N(PPH3)2][RH5(MU-CO)6(CO)8(PPH3)] AND [N(PPH3)2]2[RH5(MU-CO)6(CO)8(SCN)]

The reaction of Rh4(CO)12with salts of [X]-(X = Cl, Br, I, SCN) under CO yields salts of the dianionic species [Rh5(CO)14X]2-. These can also be produced, together with salts of [Rh5(CO)14(PPh3)]-, by nucleophilic substitution on salts of the anionic substrate [Rh5(CO)15]-. All of these 76 cluster valence electron derivatives are stable under 1 atm of CO but decompose under nitrogen or in a vacuum, the X-ray structural analysis of the [PPN]+, (μ-nitrido)bis(triphenylphosphorus)(1+), salts of [Rh5(CO)14(PPh3)]-(1) and [Rh5(CO)14(SCN)]2-(II), revealed in both anions an elongated trigonal-bipyramidal metallic frame, with eight terminal and six edge-bridging carbonyls; the entering group is bond to an apical rhodium. Crystal data for I: C68H45NO14P3Rh5, fw = 1707.6, monoclinic, P21/c (No. 14), a = 21.707 (4) Å, b = 17.054 (2) Å, c = 19.815 (4) Å, 0 = 114.67 (2)°, Z = 4, final R = 0.041, Rw= 0.050. Crystal data for II: C87H60N3O14P4Rh5S, fw = 2041.9, monoclinic, P21/c (No. 14), a = 25.877 (6) Å, b = 15.115 (3) Å, c = 22.776 (6) Å, β = 93.95 (2)°, Z = 4, final R = 0.069,Rw= 0.092. © 1990, American Chemical Society. All rights reserved.