The preparation and spectra of [Fe2(η-C5H5)2(CO)4−n(CNAr)n] complexes. The reaction of [Fe(CO)5−m(CNAr)m] with dicyclopentadiene
作者:A.R. Manning、Gerard McNally、Paul Soye
DOI:10.1016/s0020-1693(00)83073-x
日期:1991.2
The relatively elusive [Fe2(eta-C5H5)2(CO)4-n(CNAr)n] complexes where n = 1 or 2 and Ar = C6H5, 2-MeC6H4, 4-MeC6H4, 2,4-Me2C6H3, 2,6-Me2C6H3 and 2,4,6-Me3C6H2 have been prepared by two effective, but not completely general routes. One is the light-catalyzed substitution of [Fe2(eta-C5H5)2(CO)4] by ArNC which gives the derivatives where n = 1 or 2 and, eventually, 4. The other is the reaction at 145-degrees-C of dicyclopentadiene with [Fe(CO)5] and ArNC or with [Fe(CO)4(CNAr)], but not with [Fe(CO)3(CNAr)2] or [Fe(CO)4(CNMe)]. The pathway of the reaction of dicyclopentadiene with [Fe(CO)5]or[Fe(CO)4(CNAr)] is discussed and it is concluded that it does not proceed via cyclopentadine and mononuclear cyclopentadienyl complexes but via species containing dicyclopentadiene and two metal atoms which are formed at an early stage in the reaction and which remain associated throughout the reaction up to the formation of the [Fe2(eta-C5H5)2(CO)4-n(CNAr)n] derivatives. The infrared and H-1 NMR spectra of the complexes are reported and discussed.