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(μ-CO)6(CO) 8(PPh3)] and

Full title: 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(μ-CO)6(CO) 8(PPh3)] and [N(PPh3)2]2[Rh5(μ-CO) 6(CO)8(SCN)]. The reaction of Rh4(CO)12 with 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, β = 114.67 (2)°, Z = 4, final R = 0.041, Rw = 0.050. Crystal data for II: C87H60N3O14P4Rh 5S, 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.