Reactivities of pi-electron-rich phosphorus-nitrogen ligands toward GroupsVIB and VIIB metal carbonyl complexes

The interaction of (Ph2PN=)C(Ph)[N(SiMe3)(2)] (L-1) with one equivalent of Mn(CO),Br afforded cis-Mn(CO)(4)Br((Ph2PN=)C(Ph)[N(siMe(3))(2)]) (1), which upon boiling in THF gave fac-Mn(CO)(3)Br[(Ph2PNH)C(Ph)(=NSiMe3)] (2), and with one equivalent of Re(CO)(5)X O( = Br or Cl) gave fac-Re(CO)(3)X[(Ph2PN H) C(Ph)(=NH)] [X = Br (3) or Cl (4)] in good yield. Reaction of 1,4-C6H4(C (=NPPh2)[N(SiMe3)(2)])(2), (L-2) with two equivalents of Mn(CO)(5)Br gave t he symmetric dimer [cis-Mn(CO)(4)Br](2)((Ph2PN=)[N(SiMe3)(2)]C)(2)C6H4-1,4 (5), and with two equivalents of Re(CO)(5)Br gave the cyclic dimer cyclo-[f ac-(Me2NCHO)Re(CO)(3)(mu -Ph2PO2)](2) (6) upon recrystallization in DMF. Tr eatment of(NC5H4) ((Ph2PN=)C[N(SiMe3)(2)])-4 (L-3) With one equivalent of ( nbd)M(CO)(4) (M=Mo or Cr, nbd = norbornadiene) in THF produced cis-M(CO)(4) ((NC5H4)-[(Ph2PNH)C(=NSiMe3)]-4) [M = Mo (7) or Cr (8)], and with excess Mn (CO),Br led to the trinuclear complex fac-(cis-Mn(CO)(4)Br[(NC5H4) ((Ph2PN= )C[N(SiMe3)(2)])-4])(2)Mn(CO)(3)Br (9) in good yield. Compound 7, in the pr esence of CdCl2, hydrolyzed to cis-Mo(CO)(4)((NC5H4)[(Ph2PNH)C(=NH)]-4) (10 ). Compound 8 reacted with half an equivalent of Mn(CO)(5)Br to give the tr inuclear complex fac-[cis-Cr(CO)(4)((NC5H4)[(Ph2PNH)C(=NSiMe3)]-4)](2)Mn(CO )(3)Br (11). All the new compounds were characterized by spectroscopic and analytical methods and the structures of compounds 1, 3, 6, 9 and 10 were e stablished by X-ray crystallography. (C) 2000 Elsevier Science B.V. All rig hts resented.