Two 18ē Ti^IVη⁵-Cp-tris(sec-amido)-type complexes derived from 1H-imidazol-2-yl side-chain functionalized cyclopentadienes

Abstract

Achiral {2-[2-(eta(5)-cyclopentadienyl)-2-methylpropyl]-1H-imidazolyl-kappaN(1)}bis(N,N-diethylamido-kappaN)titanium(IV), [Ti(C(4)H(10)N)(2)(C(12)H(14)N(2))], (I), and closely related racemic (SR)-{2-[(eta(5)-cyclopentadienyl)(phenyl)methyl]-1H-imidazolyl-kappaN(1)}bis(N,N-diethylamido-kappaN)titanium(IV), [Ti(C(4)H(10)N)(2)(C(15)H(12)N(2))], (II), have been prepared by direct reactions of Ti(NEt(2))(4) and the corresponding 1H-imidazol-2-yl side-chain functionalized cyclopentadienes. In compound (II), there are two crystallographically independent molecules of very similar geometries connected by a noncrystallographic pseudosymmetry operation akin to a 2(1) screw axis. All Ti-ligating N atoms in both (I) and (II) are in planar environments, which is indicative of an additional N-->Ti ppi-dpi donation. This fact and the 18ē nature of both (I) and (II) are additionally supported by quantum chemical single-point density functional theory (DFT) computations.

Trichlorido{2-[2-(η5-cyclopentadienyl)-2-methylpropyl]-1-trimethylsilyl-1H-imidazole-κN3}titanium(IV) tetrahydrofuran hemisolvate

“…For the geometric parameters of structurally characterized Ti IV complexes of the similar 5 -CpTiCl 3 -NR n type, see: trichloro{2-[2-( 5 -cyclopentadienyl)-2,2-diphenylethyl]-1-methyl-1H-imidazole-N 3 }titanium(IV), C 23 H 21 Cl 3 N 2 Ti (Krut'ko et al, 2006); trichloro{1-[2-( 5 -cyclopentadienyl)ethyl]pyrrolidine-N}titanium(IV), C 11 H 16 Cl 3 -NTi (Herrmann et al, 1995); trichloro [8-( 5 -2,3,4,5-tetramethylcyclopentadienyl)quinoline-N]titanium(IV), C 18 H 18 -Cl 3 NTi (Enders et al, 1997); trichloro[8-( 5 -2,3-dimethylcyclopentadienyl)quinoline-N]titanium(IV), C 16 H 14 Cl 3 NTi (Enders et al, 1996). For the preparation of Wang et al (2009). For a description of the Cambridge Structural Database, see: Allen (2002).…”

Crystal structure of {2-[2-(1H-inden-3-yl)-2-phenylethyl]-1H-imidazolylκN1}- tris[N,N-diethylamido-kN]ti ta nium(IV), C32H47N5Ti

“…The title compound, C 32 H 47 N 5 Ti,(I),presentsaTi(IV) tetrakisamido type mixed-ligated complex with three identical diethylamido ligands and one imidazolido-type ligand [for the asymmetric unit of (I),see the Figure]. Analysis of the Cambridge Structural Database (CSD; version 5.32, release February 2011 [1])reveals only 5entries (5 fragments) for the Group 4transition metal complexes in which the tetrahedral central atom is linked to threea liphatic ando ne hetaryl-type amido-groups (for threeT i complexes, see [2][3][4]; for two Zr complexes, see [2]).…”

“…Analysis of the Cambridge Structural Database (CSD; version 5.32, release February 2011 [1])reveals only 5entries (5 fragments) for the Group 4transition metal complexes in which the tetrahedral central atom is linked to threea liphatic ando ne hetaryl-type amido-groups (for threeT i complexes, see [2][3][4]; for two Zr complexes, see [2]). In complex (I), theTi1-N1 [2.0682(17) Å] and Ti1-N3 to Ti1-N5 distances [1.8773(16) SAINT [6], SADABS [7], SHELX [8], OLEX2 [9] pp-dp donation from each NEt 2 group towards the metal centre and, thus, of the 14e -nature of the complex (or of its 16e -nature, if an analogous additional donation from the imidazolido-group to the Ti-atom is considered; for the discussion of related cases, see [5] …”

2-[(Cyclopenta-1,3-dien-2-yl)diphenylmethyl]-1-methyl-1H-imidazole

“…For the structural parameters of Li, Ti, and Zr complexes derived from 1H-imidazol(in)-2-yl side-chain-functionalized cyclopentadienes, see: Krut'ko et al (2006); Nie et al (2008); Wang et al (2009). For a description of the Cambridge Structural database, see: Allen (2002).…”

“…1H-Imidazol(in)-2-yl side-chain functionalized cyclopentadienes were introduced as ligands into the organometallic chemistry, and, particularly into that of the Group 4 transition metals, not long ago (Krut'ko et al, 2006;Nie et al, 2008;Wang et al, 2009). This contribution reports the first structural characterization of a ligand of question in its CH-acid form.…”