Linear uranium metallocenes with polydentate aromatic nitrogen ligands

Treatment of [Cp-2*U(NCMe)(5)]X-2 [Cp* = C5Me5, X = BPh4 (1) or I (1')] or Cp-2*UI2 in acetonitrile with the polydentate aromatic nitrogen bases phen, terpy and R(4)btbp led to the formation of the linear uranium metallocenes [Cp-2*U(NCMe)(3)(phen)]X-2 [X = BPh4 (2), I (2')], [Cp-2*U(NCMe)(2)(terpy)][BPh4](2) (4), [Cp-2*U(NCMe)(Me(4)btbp)][BPh4](2) (5) and [Cp-2*U(NCMe)(CyMe(4)btbp)][X](2), [X = BPh4 (6), I (6')], [phen = 1,10-phenanthroline, terpy = 2,2':6,2 ''-terpyridine, Me(4)btbp = 6,6'-bis-(3,3,6,6-tetramethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine, CyMe(4)btbp = 6,6'-bis-(3,3,6,6-tetramethyl-cyclohexane-1,2,4-triazin-3-yl)-2,2'-bipyridine]. The bent metallocene [Cp-2*U(phen)(2)][BPh4](2) (3) was isolated from the reaction of 1 and two molar equivalents of phen in THF. The X-ray crystal structures of 2 center dot 2MeCN, 3 center dot 2THF, 4 and 6'center dot 2MeCN were determined.