Synthesis and characterization of a phosphaalkyne-bridged pentairon carbonyl cluster - crystal and molecular-structure of [(fe3se2(co)(8))(mu-pcbu(t))(fe2se(co)(6))]

The new cluster [{Fe3Se2(CO)8(})(mu-PCBu(t)){Fe2Se(CO)(6)}] has been isolated in moderate yield from the photolytic reaction of [Fe-2(CO)(6)(mu-Se-2] and the phosphaalkyne P=CBUt. Its structure has been established by single crystal X-ray diffraction methods: monoclinic, P2(1)/c (No. 14), a = 9.378(1) Angstrom, b = 17.605(3) Angstrom, c = 18.631(2) Angstrom, beta = 93.00(1)degrees, V = 3071.7 Angstrom(3) Z = 4, R = 7.6%, R' = 6.5%. The structure consists of a [Fe3Se2(CO)(8)] unit and a [Fe2Se(CO)(6)(PCBu(t))] unit linked by the phosphorus lone pair electrons of the phosphaalkyne