Crystal structure of (Et4N)[(mu-H)Fe-3(mu(3)-Se)(CO)(9)]

The crystal structure of (Et4N)[(mu-H)Fe-3(mu(3)-Se)(CO)(9)] is determined; the crystals are monoclinic, a = 11.172(2), b = 32.332(5), c = 13.552(3) A ngstrom, beta = 91.86(2)degrees, V-cell = 4893(2) Angstrom(3), space group P2(1)/n, Z = 8 d(calc) =1.710 g/cm(3) CAD-4 diffractometer, MoKalpha radiat ion; the total number of data collected 4395, including 4086 independent re flections (R-int = 0.0701), R(F) = 0.0566, wR(F-2) = 0.1202 for 1963 (F)hkl > 4 sigma(F). The data were corrected for the 37.8% linear drop of intensi ties of the control reflections due to crystal decay. The Fe-H bond lengths are 1.5(1)-1.72(9) Angstrom. As in the case of three-osmium clusters, the presence of the mu-H ligand leads to a lengthening of the Fe-Fe bond by app roximately 0.1 Angstrom and to push-away of the equatorial carbonyl ligands leading to an increase in the FeFeC angle by approximately 5-10 degrees, w hereas the axial CO and (mu(3)-Se) remain unchanged.