Alternativ-Liganden : XII. Darstellung und charakterisierung von M(CO) n L-komplexen (M = Cr, Mo, W) der chelatliganden Me 2XGeMe 2(CH 2) 2X′Me 2 (Me = CH 3; X, X′ = N, P, As)

Abstract

The reaction of M(CO) 4(NBD) (NBD = norbornadiene; M = Cr, Mo, W) with the ligands Me 2XGeMe 2(CH 2) 2X′Me 2 yields the chelate complexes (CO) 4M[Me 2XGeMe 2(CH 2) 2X′Me 2] for X, X′ = P, As, but not for X and/or X′ = N. The attempt, to synthesize the compound (CO) 4W[Me 2AsGeMe 2(CH 2) 2NMe 2] by replacement of two cis-coordinated piperidine ligands from cis-W(CO) 4(pip) 2, leads to the formation of the cis-disubstituted product W(CO) 4[Me 2AsGeMe 2(CH 2) 2NMe 2] 2 with two As donor atoms. The reaction of Cr(CO) 4(NBD) with Me 2AsGeVi (Vi = vinyl) gives cis-Cr(CO) 4(Me 2AsGeMe 2Vi) 2 and not the possible σ/π-chelate Cr(CO) 4(Me 2AsGeMe 2Vi). For comparison the monosubstituted derivatives Cr(CO) 5L (L = ClGeMe 2(CH 2) 2X′Me 2 (X′ = P, As); Me 2AsGeMe 2Vi) have been prepared from Cr(CO) 5THF or Cr(CO) 5Py and the ligand. The complex Cr(CO) 5(Me 2NGeMe 2Vi) is not formed by analogous reactions. The new compounds are characterized by analytical and spectroscopic (IR, NMR, mass spectral) methods.