COMPLEXES OF THE BIDENTATE LIGANDS Z-PPH2CH2C(BU(T))=NNR2 (R=ME OR H) WITH RHODIUM AND IRIDIUM

Treatment of 0.5 equivalent of [{RhCl(CO)2}2] with the phosphino dimethylhydrazone Z-PPh2CH2C(Bu(t))=NNMe2(L1) or the phosphino hydrazone Z-PPh2CH2C(Bu(t))=NNH2 (L2) gave the chelate complexes [RhCl(CO){PPh2CH2C(Bu(t))=NNR2}] (R = Me 1a or H 1b). Complex 1a reacts with another mole of L1 to give the bis(phosphine)rhodium(I) complex trans-[RhCl(CO)-{PPh2CH2C(Bu(t))=NNMe2}2] 2a. The analogous iridium(I) complex 2b was prepared by treating [IrCl(CO)2(H2NC6H4Me-p)] with 2 mol equivalents of L1. Complex 2a reacts with [PtCl2(cod)] (cod = cycloocta-1,5-diene) to give a 1:1 mixture of the chelate 1a and [PtCl2{PPh2CH2C(Bu(t))=NN-Me2}]. Treatment of [IrCl(CO)2(H2NC6H4Me-p)] with 2 equivalents of L2 gave the hydridoridium(III) complex cis-[IrH(Cl){PPh2CH2C(Bu(t))=NNH2}2]Cl 3a. Treatment of [{MCl(cod)}2] (M = Rh or Ir) with two equivalents of L1 in methanol in the presence of NH4PF6 gave the cationic complexes [M(cod){PPh2CH2C(Bu(t))=NNMe2}]PF6 (M = Rh 4a or Ir 4b) in which L1 is bidentate. When [{MCl(cod)}2] was treated with 2 equivalents of L1 in benzene it yielded the neutral complexes [MCl(cod){PPh2CH2C(Bu(t))=NNMe2}] (M = Rh 5a or Ir 5b) in which L1 is monodentate through phosphorus. Treatment of [{MCl(cod)}2] with 2 equivalents of L2 in CD2Cl2 gave the cationic chelate complexes [M(cod){PPh2CH2C(Bu(t))=NNH2}]Cl (M = Rh 4c or Ir 4d). Treatment of [{RhCl(cod)}2] or [{RhCl(C8H14)2}2] (C8H14 = cyclooctene) with 2 equivalents of L2 per rhodium atom gave the cationic bis(phosphine)rhodium(I) complex [Rh{PPh2CH2C(Bu(t))=NNH2}2]Cl 6. Treatment of [RhCl(PPh3)3] with 1 equivalent of L1 in C6D6 gave the Wilkinson-type complex [RhCl(PPh3){PPh2CH2C(Bu(t))=NNMe2}] 7, which readily reacts with dioxygen to give the adduct cis-[RhCl(O2)(PPh3){PPh2CH2C(Bu(t))=NNMe2}] 8. The rhodium(III) complex 8 reacts with sulfur dioxide to give the rhodium(III) sulfate cis-[RhCl(SO4)(PPh3){PPh2CH2C(Bu(t))=NNMe2}] 9. Treatment of [{MCl(C8H14)2}2] with 2 equivalents of L1 per rhodium atom gave the bis(phosphine) complexes cis-[MCl{PPh2CH2C(Bu(t))=NNMe2}{PPh2CH2C(Bu(t))=NNMe2}] (M = Rh 10a or Ir 10b), containing one chelate and one monodentate phosphine ligand. These complexes reacted rapidly with dioxygen to give corresponding dioxygen adducts cis-[MCl(O2){PPh2CH2C(Bu(t))=NNMe2}{PPh2CH2C(Bu(t))=NNMe2}] (M = Rh 11a or Ir 11b). Proton, P-31-{H-1} and some C-13-{H-1} NMR data are given.