Reactivities of π-electron-rich phosphorusnitrogen ligands toward Groups VIB and VIIB metal carbonyl complexes

Abstract

The interaction of (Ph 2PN)C(Ph)[N(SiMe 3) 2] ( L 1 ) with one equivalent of Mn(CO) 5Br afforded cis-Mn(CO) 4Br{(Ph 2PN)C(Ph)[N(SiMe 3) 2]} ( 1), which upon boiling in THF gave fac-Mn(CO) 3Br[(Ph 2PNH)C(Ph)(NSiMe 3)] ( 2), and with one equivalent of Re(CO) 5X (X=Br or Cl) gave fac-Re(CO) 3X[(Ph 2PNH)C(Ph)(NH)] [X=Br ( 3) or Cl ( 4)] in good yield. Reaction of 1,4-C 6H 4{C(NPPh 2)[N(SiMe 3) 2]} 2 ( L 2 ) with two equivalents of Mn(CO) 5Br gave the symmetric dimer [ cis-Mn(CO) 4Br] 2{(Ph 2PN)[N(SiMe 3) 2]C} 2C 6H 4-1,4 ( 5), and with two equivalents of Re(CO) 5Br gave the cyclic dimer cyclo-[ fac-(Me 2NCHO)Re(CO) 3(μ-Ph 2PO 2)] 2 ( 6) upon recrystallization in DMF. Treatment of (NC 5H 4){(Ph 2PN)C[N(SiMe 3) 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{(NC 5H 4)[(Ph 2PNH)C(NSiMe 3)]-4} [M=Mo ( 7) or Cr ( 8)], and with excess Mn(CO) 5Br led to the trinuclear complex fac-{ cis-Mn(CO) 4Br[(NC 5H 4){(Ph 2PN)C[N(SiMe 3) 2]}-4]} 2Mn(CO) 3Br ( 9) in good yield. Compound 7, in the presence of CdCl 2, hydrolyzed to cis-Mo(CO) 4{(NC 5H 4)[(Ph 2PNH)C(NH)]-4} ( 10). Compound 8 reacted with half an equivalent of Mn(CO) 5Br to give the trinuclear complex fac-[ cis-Cr(CO) 4{(NC 5H 4)[(Ph 2PNH)C(NSiMe 3)]-4}] 2Mn(CO) 3Br ( 11). All the new compounds were characterized by spectroscopic and analytical methods and the structures of compounds 1, 3, 6, 9 and 10 were established by X-ray crystallography.