CRYSTAL-STRUCTURE AND REACTIVITY OF [RU(C6H4(NH)2-1,2)-(PPH3)3] WITH PI-ACID LIGANDS

The structure of the compound [Ru{C6H4(NH)2-1,2)(PPh3)3] 1 has been established from X-ray analysis by direct and Fourier methods and refined by full-matrix least squares to R = 0.071 for 3288 observed reflections: monoclinic, space group P2(1)/n, a = 18.70(1), b = 13.171 (6), c = 23.06(2) angstrom, beta 99.86(6)-degrees and Z = 4. This complex reacts with an excess of ethylene or styrene and with P(OMe), (molar ratio 1 : 1 ) in hot toluene to yield the complexes [Ru{C6H4(NH)2-1,2}L(PPh3)2] [L = C2H4 3, CH2CHPh 4 or P(OMe)3, 5]. With a slight excess of the diphosphines (Ph2P)2X [X = CH2 (dppm), C2H4 (dppe), 1,2-C6H4 (dppbz), cis-C2H2 (dppen) and C3H6 (dppp)], refluxed in toluene, the complexes [Ru{C6H4(NH)2-1,2}] (PPh3) (diphosphine)] 6-10 were obtained as dark purple crystalline solids. An excess of PMe3 in hot toluene solutions of compound 1 afforded brown prismatic crystals of [Ru{C6H4(NH)2-1,2)](PMe3)3] 11, whereas with PEt3 under the same conditions only partial substitution products are obtained, [Ru{C6H4(NH)2-1,2}](PEt3)(PPh3)2] 12 and [Ru{C6H4(NH)2-1,2}(PEt3)2(PPh2)] 13. When toluene solutions of [Ru{C6H4(NH)2-1,2}](CO)(PPh3)2] 2 were boiled with diphosphines the complexes [Ru{C6H4(NH)2-1,2}(CO)(diphosphine)] [dppe 14, dppbz 15, dppen 16, dppp 17 or dppb (X = C4H8) 18] were isolated. The complex [Ru{C6H4(NH)2-1,2)] (CO)2(PPh3)] 19 was also detected as a reaction product of carbonylation of toluene solutions of 1. All complexes have been characterized by elemental analysis and by IR and NMR spectroscopy.