186379-79-3Relevant academic research and scientific papers
Reactions of Doubly Bridged Biscyclopentadienes with Molybdenum (Tungsten) Carbonyl
Wang, Baiquan,Zhu, Bolin,Xu, Shansheng,Zhou, Xiuzhong
, p. 4842 - 4852 (2003)
Dimolybdenum complexes (X)(Y)[(η5-C5H 3)Mo(CO)3]2 [Y = Me2Si, X = Me 2C, (CH2)5C, CH2; Y = Ph 2Si, X = Me2C] and desilylation products (X)[(η 5-C5H4)Mo(CO)3]2 were obtained from the reactions of carbon and silicon doubly bridged biscyclopentadiene ligands (X)(Y)(C5H4)2 with Mo(CO)6 in refluxing xylene. When these ligands reacted with W(CO)6, under similar conditions, in addition to ditungsten complexes (X)(Y)[(η5-C5H3)W(CO) 3]2 [X = Me2C; Y = Me2Si, Ph 2Si] and desilylation products (X)[(η?5-C 5H4)W(CO)3]2, a class of structurally novel complexes (X)(η5-C5H 3)(η5,η1-C5H 3)[(Y)W(CO)3][W(CO)3] [for X = Me2C, (CH2)5C; Y = Me2Si] with a W-Si bond were also isolated. The reactions of carbon and germanium doubly bridged biscyclopentadiene ligands (X)(Me2Ge)(C5H 4)2 [X = Me2C, (CH2)5C] with Mo(CO)6 or W(CO)6 gave similar novel complexes (X)(η5-C5H3)(η5,η 1-C5H3)[(Me2Ge)M(CO) 3][M(CO)3] [X = Me2C, (CH2) 5C; M = Mo, W] with a M-Ge bond. The reactions also produced degermylation products. However, the corresponding dimolybdenum or ditungsten complexes were not isolated in these cases. The molecular structures of 2, 6, 8, 10, 11, 13, 14, 15, 19, 21, 22, 25t, and 26t have been determined by X-ray diffraction. The M-M distances in complexes 2 [3.4328(12) A], 8 [3.453(2) A], and 11 [3.403(2) A] are conspicuously elongated and are in fact the longest ever reported among the biscyclopentadienyl dimolybdenum or ditungsten complexes. The factors affecting the structures of dimolybdenum or ditungsten complexes are discussed.
