Structure and magnetism of .mu.-dinitrogen-bis(bis(pentamethylcyclopentadienyl)titanium(II)), {(.eta.5-C5(CH3)5)2Ti}2N2

Activation of nitrogen for organic synthesis

“…Synthesis of a titanium-nitrogen complex from molecular nitrogen was first reported by Yamamoto [4], and several groups have since reported the syntheses of various titanium-nitrogen complexes [15,[32][33][34][35][36]. Bercaw reported the syntheses of titanium-nitrogen complexes XIIa [35], whose structure was confirmed by X-ray crystallography [36]. In 1991, Gambarotta synthesized complex XIIb from trans-(TMEDA) 2 TiCl 2 and (Me 3 Si) 2 NLi under nitrogen [37].…”

Spectroscopic Comparison of Dinuclear Ti+ and Ti2+ μ‐η1:η1 Dinitrogen Complexes with Cp*/Pentafulvene and Amine/Amide Ligation: Moderate versus Strong Activation of N2

“…[6] Moderately activated dinitrogen complexes are generally found for titanocene-based systems with N-N bond lengths in the range of 1.15-1.20 Å. [7][8][9][10][11][12] Strong activation, on the other hand, is observed for titanium complexes with ligand sets that are different from cyclopentadienyl, exhibiting N-N bond lengths of 1.25-1.30 Å. [13][14][15] A collection of N-N bond lengths of different dinitrogen complexes is given in Table 1.…”

“…At first sight this observation appears to be contradictory. 1.160(3) [7] 2 1.160(5) [7] [{(η 5 -C 5 Me 5 ) 2 Ti} 2 (μ-η 1 :η 1 -N 2 )] 1.165(14) [8] [{(η 5 -C 5 Me 4 H) 2 Ti} 2 (μ-η 1 :η 1 -N 2 )] 1.170(4) [9] [{(η 5 -C 5 H 5 ) 2 Ti(PMe 3 )} 2 (μ-η 1 :η 1 -N 2 )] 1.191(8) [10] [{(η 5 -C 5 H 5 ) 2 Ti(p-tolyl)} 2 (μ-η 1 :η 1 -N 2 )] 1.162(12) [11] [{[η 5 1.289(9) [13] [{(Me 3 Si) 2 NTiCl(py) 2 } 2 (μ-η 1 :η 1 -N 2 )] 1.263(7) [14] [{[(Me 2 N)C(NiPr) 2 ] 2 Ti} 2 (μ-η 1 :η 1 -N 2 )] 1.280(8) [15] In order to address the above statement we investigated compounds 1, 2, and 3 with resonance Raman spec- Scheme 1. troscopy. The vibrational analysis was assisted by DFT calculations performed on structures I and III, which are models of complexes 1/2 and 3, respectively.…”

Unusual addition of but-2-yne to a permethyltitanocene species

“…The titanocene complexes with diphenylethyne containing one molecule of CO [4a] or PMe 3 are known [4b], however, they are converted to titanacyclopentadienes by excess of the alkyne [1d,1g,4a]. The reactivity of more stable decamethylmetallocene [5] toward reactive internal alkynes has been much studied through its complex with molecular nitrogen ½fNTiðg 5 -C 5 Me 5 Þ 2 g 2 [6,7]. It has been found that this complex reacts with diphenylethyne and but-2-yne to give only 1:1 complexes even when the alkynes are used in excess [8].…”