Organotungsten-selenolato complexes were prepared in moganomonohalides. Moreover, the X-ray crystal structures derate yields by insertion of selenium into the alkali metal-of C6H5CH2W(C0)3cp (l), ~-[m-C6H4(CH2SeW(CO)~cp]2] tungsten bonds of MSeW(CO),cp (M = Li, Na) and subse-(3), ~L -[~-C , H~( C H~S~W ( C O )~C~}~](4), and C6H5CH[SeWquent reactions with the organohalides 0-, m-, and p-(CO)3cp]2 (5) were deJermined. In complex (l), the W-CH2 C6H4(CH2Br)2, C6H5CHBr2, m-C6H4(CHBr2)2 and C6H5CC1,. bond length is 2.374 A; the W-Se bond lengths in the com-The ??Se-NMR data of the new complexes are discussed and plexes 3, 4 , and 5 are all in the range 2.625-2.655 A, correcompared with those of related complexes derived from orsponding to W-Se single bonds.
The reactions of Fe(CO)5 or Fe3(CO)12 with NaBEt3H or KB[CH(CH3)C2H5]3H, respectively and treatment of the resulting carbonylates M2Fe(CO)4, M = Na, K with elemental selenium in appropriate ratios lead to the formation of M2[Fe2(CO)6(μ‐Se)2]. Subsequent reactions with organo halides or the complex fragment cpFe(CO)2+, cp = η5‐C5H5 afforded the selenolato complexes [Fe2(CO)6(μ‐SeR)2], R = CH2SiMe3 (1), CH2Ph (2), p‐CH2C6H4NO2 (3), o‐CH2C6H4CH2 (4) and cpFe(CO)2+ (5) in moderate to good yields. A similar reaction employing Ru3(CO)12, Se and p‐O2NC6H4CH2Br leads to the formation of the corresponding organic diselenide. The X‐ray structures of 1, 3, 4 and 5 were determined and revealed butterfly structures of the Fe2Se2 cores. The substituents in 1, 3 and 5 adopt different conformations depending on their steric demand. In 4, the conformation is fixed because of the chelate effect of the ligand. The Fe–Se bond lengths lie in the range 235 to 240 pm, with corresponding Fe–Fe bond lengths of 254 to 256 pm. The 77Se NMR data of the new complexes are discussed and compared with the corresponding data of related complexes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.