SYNTHESIS AND REACTIVITY OF RUTHENIUM AMIDE PHOSPHINE COMPLEXES - FACILE CONVERSION OF A RUTHENIUM AMIDE TO A RUTHENIUM AMINE VIA DIHYDROGEN ACTIVATION AND ORTHO METALATION - X-RAY STRUCTURE OF RUCL(C6H4PPH2)[NH(SIME2CH2PPH2)2]

The reaction of LiN(SiMe2CH2PPh2)2 with RuCl2(PPh3)3 leads to the formation of the ruthenium amide complex RuCl(PPh3)[N(SiMe2CH2PPh2)2]. This complex reacts with H2 to form two isomeric amine-hydride derivatives of the formula RuCl(PPh3)H[NH(SiMe2CH2PPh2)2]. Reaction of RuCl(PPh3)[N-(SiMe2CH2PPh2)2] with MeLi, Me3SiCH2Li, or H2C = CHCH2MgCl does not lead to the expected hydrocarbyl derivative; rather, ortho metalation occurs to generate Ru(C6H4PPh2)[N(SiMe2CH2PPh2)2]. Attempts to displace the PPh3 ligand of RuCl(PPh3)[N(SiMe2CH2PPh2)2] with PEt3 lead to the formation of RuCl(C6H4PPh2)[NH(SiMe2PPh2)2], having an amine ligand and the ortho-metalated phenyl group. The complex RuCl(C6H4PPh2)[NH(SiMe2CH2PPh2)2] crystallizes in space group P2(1)/n with a = 9.8385 (5) angstrom, b = 29.561 (1) angstrom, c = 20.8665 (9) angstrom, beta = 101.683 (4)-degrees, V = 5942.2 (5) angstrom3, and Z = 4. Transformation of an amide linkage to an amide via H2 activation or ortho metalation is apparently driven by the formation of an intramolecular hydrogen bond between the amine hydrogen and the coordinated chloride; the N-H...Cl distance is 2.76 (6) angstrom, which is shorter than the expected van der Waals separation of 3.0 angstrom.