Donald L. Tipton

Synthesis and x-ray crystallographic structural determination of the acetylene complex (η5−C5H5)2W2(CO)4(C2H2)

Abstract Reaction of photogenerated (η5−C5H5)2W2(CO)4 with acetylene at 25°C yields a complex of the formula (η5-C5H5)2W2(CO)4(C2H2). The crystal structure of the complex shows it to have a tetrahedrane-like W2C2 core. The C—C bond distance of the C2H2 unit is 1.33 A which is close to that of ethylene, considerably longer than the 1.20 A for acetylenes. The W—W distance is 2.987 A which is ∼0.25 A shorter than the W—W distance in (η5-C5H5)2W2(CO)6 but longer than that expected for (η5-C5H5)2W2(CO)4. By analogy to the parent (η5-C5H5)2M2(CO)6 species, the near-UV absorption in (η5-C5H5)2M2(CO)4(C2H2) is assigned to a σb → σ* transition. Owing to the shorter M—M bond in the C2H2 adducts, the σb → σ* absorption is at higher energy than in the (η5-C5H5)2M2(CO)6 complexes.

Novel transformation of [(η1-C5H5)2SnFe(CO)4]2: the crystal structure of [{(C5H5)Fe(CO)2}2Sn2Fe3(CO)9]

Thermal decomposition of [(η1-C5H5)2SnFe(CO)4]2 affords [{(C5H5)Fe(CO)2}2Sn2Fe3(CO)9], a cluster based on a trigonal bipyramidal arrangement of three equatorial Fe(CO)3 groups and two axial (C5H5)Fe(CO)2Sn units, characterized on the basis of crystallographic, chemical, and spectroscopic data.

Synthesis and structure of HW2(CO)9(NO)

HW2(CO)9NO has been prepared by the reaction of [HW2(CO)10]– with NaNO2–acetic acid and has been found by X-ray crystallography to have a distorted D4d conformation with a bent W–H–W bond.