The salts [NO] [XI (X = BF4 or PF6) react with [Rh(l.5-C8Hl2)(NCMe),] [XI or [Rh(l,H,,),][X] in acetonitrite to give [Rh(NCMe),(NO)] [XI, ( I ) , and with [(Rh(l ,5-C8H,,)CI},] or [{Rh(CO),CI},] to give [RhCI(NCMe),-(NO)] [XI (2). Complexes ( I ) , with L, Ph2PCH,CH,PPh2 (dppe), Na[S2CNMe,J-2H,O, and CO afford [Rhand [Rh(CO),(NCMe),] [XI (7) respectively. Complexes (2) reactwith PPh,to give [RhCI(NCMe) (NO) (PPh,),]-[XI (8) which may also be prepared from (3) and CI-. Excess of halide ion with (3). however. yields [RhY,(NO)-(PPh,),] (Y = CI or I), whereas Na[S,CNR,]*nH,O give [Rh(PPh,),(S,CNR,),][X] (R = Me or Et) with loss of the co-ordinated nitrosyl ligand. In the presence of PPh,, (3) reacts with N2H4 to give [Rh(NO)(PPh,),]
!9).The analogous 16N0 species have also been prepared and attempts have been made to assign the ' bent or ' linear ' modes of bonding to the metal-nitrosyl groups on the basis of i.r. and 15N n.m.r. spectroscopy. (NCMe),(NO)L,I [XI, CL = PPh3 (3) or AsPh, (413. [Rh(NO) (dPPe),l[xl, (5). [Rh(NO) (S,CNMe2)31 [XI (6). * Throughout this paper: 1 atm = 101 325 Pa. * This difficulty is underlined by the observation that crystals, which were considered to be (3), were shown by X-ray crystallography to be in fact [Rh(NCMe)3(NO)(PPh3)2]2+, i.e. an Or complex with bent nitrosyl; the additional mol of MeCN is lost only on pumping (N. G. Connelly, I?. T. Draggett, M. Green, B. A.
