Linear uranium metallocenes with polydentate aromatic nitrogen ligands

摘要

Treatment of [Cp*_2U(NCMe)_5]X_2 [Cp* = C_5Me_5, X = BPh_4 (1) or I (1′)] or Cp*_2UI_2 in acetonitrile with the polydentate aromatic nitrogen bases phen, terpy and R_4btbp led to the formation of the linear uranium metallocenes [Cp*_2U(NCMe) _3(phen)]X_2 [X = BPh_4 (2), I (2′)], [Cp*_2U(NCMe)_2(terpy)][BPh_4]_2 (4), [Cp*_2U(NCMe)(Me_4btbp)][BPh_4] _2 (5) and [Cp*_2U(NCMe)(CyMe_4btbp)][X] _2, [X = BPh_4 (6), I (6′)], [phen = 1,10-phenanthroline, terpy = 2,2′:6,2′′-terpyridine, Me _4btbp = 6,6′-bis-(3,3,6,6-tetramethyl-1,2,4-triazin-3-yl)-2, 2′-bipyridine, CyMe_4btbp = 6,6′-bis-(3,3,6,6-tetramethyl- cyclohexane-1,2,4-triazin-3-yl)-2,2′-bipyridine]. The bent metallocene [Cp*_2U(phen)_2][BPh_4]_2 (3) was isolated from the reaction of 1 and two molar equivalents of phen in THF. The X-ray crystal structures of 2·2MeCN, 3·2THF, 4 and 6′·2MeCN were determined.