THE X-RAY CRYSTAL-STRUCTURES OF CLPH(2)SNFE(CO)(3)(NO) AND PH(3)SNFE(CO)(3)(NO) AND A REINVESTIGATION OF THE IR-SPECTRA OF XR(2)SNFE(CO)(3)(NO) SPECIES

A range of complexes Cl(3-n)R(n)SnFe(CO)(3)(NO) (R = Ph, Me; n = 0-3) has been prepared, and the X-ray crystal structures of Ph(3)SnFe(CO)(3 )(NO) (Sn-Fe 2.619 Angstrom) and ClPh(2)SnFe(CO)(3)(NO) (Sn-Fe 2.582 A ngstrom) have been determined. The complex IR spectra of the species w ith mixed substituents on tin are discussed in terms of conformers rel ated by rotation about the Sn-Fe bond, which gives rise to different d elocalised pi-bonding interactions. Comparison with earlier work sugge sts the previously reported germanium complexes R(2)Ge(mu-X)Fe(CO)(2)( NO) do not exist.