Novel Reaction of Complex Salts [(μ-RE)(μ-CO)Fe2(CO)6][HNEt3] (E = S, Se) with Phosphaalkene t-Bu(Me3SiO)CPSiMe3. Synthesis and Spectroscopic and Crystallographic Characterization of Butterfly Fe2EP Clusters (μ-RE)[μ-t-Bu(Me3SiO)CHPH]Fe2(CO)6 (E = S, Se)

Reaction of complex salts [(μ-RE)(μ-CO)Fe 2 (CO) 6 ][HNEt 3 ] ( 1, E = S, Se) with phosphaalkene t-Bu(Me 3 SiO)C PSiMe 3 ( 2 ) has been found to afford a series of new butterfly-shaped Fe 2 EP clusters of type [(μ-RE)[μ-t-Bu(Me 3 SiO)CHPH]Fe 2 (CO) 6 ( 3, RE = EtS; 4, n-PrS; 5, n-BuS; 6, t-BuS; 7, PhSe; 8, p -MeC 6 H 4 Se) in quite high yields. This type of cluster may exist as three isomers, namely, e(R)e(H), e(R)a(H), and a(R)a(H), which differ in whether the R group and H atom are attached to E and P atoms with an axial or an equatorial bond. Clusters 3 − 8 have been characterized by elemental analysis and 1 H, 31 P, and 77 Se NMR spectroscopy, as well as for isomers 3 e(R)a(H), 6 e(R)a(H), 8 e(R)e(H), and 8 a(R)a(H) by single-crystal X-ray diffraction analyses. In addition, a possible reaction mechanism has been preliminarily suggested.