The ansa-bridged cyclo­penta­dienyl titanium complex [{η⁵-C₅Me₄CH₂-C(NMe₂)=N}TiCl₂]

Abstract

The title complex, dichlorido[N,N-di­methyl-2-(η⁵-tetra­methyl­cyclo­penta­dien­yl)acetamidinido-κN′]titanium(IV), [Ti(C₁₃H₂₀N₂)Cl₂], exhibits an unusual ansa-bridged conformation. The cyclo­penta­dienyl ring and the mean plane of the Ti—N=C—C—C fragment form a dihedral angle of 88.08 (11)°.

Related literature

For related crystal structures, see: Hughes et al. (1993 ▶); Zhang et al. (2004 ▶). For general background, see: Chen & Marks (1997 ▶); Mahanthappa et al. (2004 ▶).

Experimental

Crystal data

• [Ti(C₁₃H₂₀N₂)Cl₂]

• M _r = 323.11

• Orthorhombic,

• a = 12.600 (5) Å

• b = 15.498 (6) Å

• c = 15.574 (5) Å

• V = 3041.1 (19) ų

• Z = 8

• Mo Kα radiation

• μ = 0.90 mm⁻¹

• T = 213 K

• 0.30 × 0.20 × 0.20 mm

Data collection

• Siemens SMART diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1997 ▶) T _min = 0.774, T _max = 0.841

• 11691 measured reflections

• 2677 independent reflections

• 2554 reflections with I > 2σ(I)

• R _int = 0.037

Refinement

• R[F ² > 2σ(F ²)] = 0.056

• wR(F ²) = 0.117

• S = 1.27

• 2677 reflections

• 169 parameters

• H-atom parameters constrained

• Δρ_max = 0.38 e Å⁻³

• Δρ_min = −0.30 e Å⁻³

Data collection: SMART (Siemens, 1996 ▶); cell refinement: SAINT (Siemens, 1996 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Comment

The homogeneous coordination polymerization catalysts, especially group IV metallocene catalysts, have created new opportunities for the production of ethylene α-olefin copolymers and received extensive attention in recent years (Mahanthappa et al., 2004). The constrained geometry catalysts with a pendant nitrogen or oxygen donor on the cyclopentadienyl ligand, such as Me₂Si-(η⁵-Me₄C₅)(t-BuN)TiCl₂ (Hughes et al., 1993) and 2-tetramethylcyclopentadienyl-4-methylphenoxytitaniumdibenzyl (Zhang et al., 2004) have been developed due to their structural features and good catalytic activities (Chen et al., 1997). Here we present the synthesis and crystal structure of a new ansa-bridged cyclopentadienyl titanium complex (I)

In (I) (Fig. 1), the distance from the central metal atom Ti to the centroid of Cp* is 2.024 (2) Å. The bond lengths Ti—N1, Ti—Cl1 and Ti—Cl2 are 1.823 (3), 2.3104 (12) and 2.3036 (12) Å, respectively. The bond angle Cl1—Ti—Cl2 is 105.40 (5) °. Atoms C1, C6, C7, N1 and Ti are exactly co-planar with a highest deviation of 0.0191 Å. The two planes - Cp* and C1/C6/C7/N1/Ti are almost perpendicular making a dihedral angle of 88.08 (11)°. The bond angles C1—C6—C7, C6—C7—N1 and C7—N1—Ti are 106.7 (3),116.7 (3) and 129.5 (2) °, respectively.

Experimental

(CH₃)₂NCN (0.36 ml, 4.52 mmol) was added to a solution of PhN(Li)SiMe₃(0.386 g, 2.26 mmol) in THF (30 cm³) at -78 °C. The resulting mixture was warmed to ca.25°C and stirred for overnight. CpTiCl₃ (0.99 g, 4.52 mmol) was added at -78°C. The resulting mixture was warmed to ca.25°C and stirred for 24 h. The volatiles were removed in vacuo, and there residue was extracted with dichloromethane and filtered. The filtrate was concentrated to give red crystals of (I)(0.14 g, 13%).

Anal. calcd. for C₁₃H₂₀Cl₂N₂Ti(%): C, 48.33; H, 6.24; N, 8.67. Found: C, 48.25; H, 6.25; N, 8.73. A l l manipulations were performed under argonusing standard Schlenk and vacuum line techniques. THF was dried and distilled over Na underargon prior to use. Elemental analysis and NMR spectra are completely in agreement with the structure of (I). Spectroscopic analysis, ¹HNMR (CDCl₃): d 2.11~2.18 (d, 12 H, Cp—CH₃), d 2.80, 3.10 (d, 6 H, N(CH₃)₂), d 4.09 (s, 2 H, CH₂). ¹³CNMR (CDCl₃): d 10.0, 10.8 (Cp-CH₃), d 28.9 (CH₂), d 33.3, 35.9 (N(CH₃)₂), d 118.5, 123.2, 127.4,128.6, 129.0 (Cp), 171.6 (CH₂-C(NMe₂)-N).

Refinement

The H atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H = 0.93-0.97 Å, and U_iso = 1.2-1.5 U_eq(parent atom).

Figures

Fig. 1.

The molecular structure of (I), showing the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are omitted for clarity.

Crystal data

[Ti(C13H20N2)Cl2]	Dx = 1.411 Mg m−3
Mr = 323.11	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbca	Cell parameters from 4409 reflections
a = 12.600 (5) Å	θ = 2.5–27.0°
b = 15.498 (6) Å	µ = 0.90 mm−1
c = 15.574 (5) Å	T = 213 K
V = 3041.1 (19) Å3	Block, orange
Z = 8	0.30 × 0.20 × 0.20 mm
F(000) = 1344

Data collection

Siemens SMART diffractometer	2677 independent reflections
Radiation source: fine-focus sealed tube	2554 reflections with I > 2σ(I)
graphite	Rint = 0.037
ω scans	θmax = 25.0°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1997)	h = −14→14
Tmin = 0.774, Tmax = 0.841	k = −18→12
11691 measured reflections	l = −18→18

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.056	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.117	H-atom parameters constrained
S = 1.27	w = 1/[σ2(Fo2) + (0.036P)2 + 4.3005P] where P = (Fo2 + 2Fc2)/3
2677 reflections	(Δ/σ)max = 0.001
169 parameters	Δρmax = 0.38 e Å−3
0 restraints	Δρmin = −0.30 e Å−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Ti	0.21528 (5)	0.56734 (4)	0.10562 (4)	0.02449 (19)
Cl1	0.10277 (7)	0.66810 (6)	0.04506 (6)	0.0396 (3)
Cl2	0.11570 (8)	0.49802 (7)	0.20873 (6)	0.0416 (3)
N1	0.3122 (2)	0.63161 (19)	0.16445 (18)	0.0302 (7)
N2	0.4755 (2)	0.69295 (19)	0.19627 (19)	0.0326 (7)
C1	0.3752 (3)	0.5272 (2)	0.0479 (2)	0.0289 (8)
C2	0.3304 (3)	0.4522 (2)	0.0835 (2)	0.0285 (8)
C3	0.2387 (3)	0.4307 (2)	0.0348 (2)	0.0314 (8)
C4	0.2270 (3)	0.4933 (2)	−0.0298 (2)	0.0313 (8)
C5	0.3117 (3)	0.5534 (2)	−0.0221 (2)	0.0299 (8)
C6	0.4650 (3)	0.5788 (2)	0.0867 (2)	0.0347 (9)
H6A	0.5014	0.6123	0.0423	0.042*
H6B	0.5166	0.5403	0.1141	0.042*
C7	0.4158 (3)	0.6384 (2)	0.1528 (2)	0.0282 (8)
C8	0.4285 (3)	0.7477 (3)	0.2621 (3)	0.0458 (10)
H8A	0.3529	0.7362	0.2658	0.069*
H8B	0.4396	0.8078	0.2473	0.069*
H8C	0.4615	0.7356	0.3171	0.069*
C9	0.5892 (3)	0.7047 (3)	0.1806 (3)	0.0447 (10)
H9A	0.6176	0.6536	0.1531	0.067*
H9B	0.6253	0.7141	0.2348	0.067*
H9C	0.5999	0.7544	0.1437	0.067*
C10	0.3711 (3)	0.4014 (3)	0.1590 (2)	0.0421 (10)
H10A	0.4040	0.3486	0.1387	0.063*
H10B	0.3125	0.3872	0.1968	0.063*
H10C	0.4229	0.4355	0.1900	0.063*
C11	0.1708 (3)	0.3522 (2)	0.0475 (3)	0.0442 (10)
H11A	0.0967	0.3678	0.0412	0.066*
H11B	0.1826	0.3290	0.1046	0.066*
H11C	0.1892	0.3090	0.0050	0.066*
C12	0.1436 (3)	0.4946 (3)	−0.0985 (3)	0.0448 (10)
H12A	0.1733	0.4725	−0.1516	0.067*
H12B	0.1194	0.5534	−0.1073	0.067*
H12C	0.0842	0.4588	−0.0812	0.067*
C13	0.3304 (3)	0.6293 (3)	−0.0800 (2)	0.0438 (10)
H13A	0.3836	0.6667	−0.0547	0.066*
H13B	0.2647	0.6611	−0.0872	0.066*
H13C	0.3550	0.6091	−0.1355	0.066*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Ti	0.0217 (3)	0.0269 (3)	0.0249 (3)	0.0006 (3)	0.0008 (2)	−0.0016 (3)
Cl1	0.0328 (5)	0.0388 (5)	0.0471 (6)	0.0091 (4)	−0.0028 (4)	0.0043 (4)
Cl2	0.0404 (5)	0.0474 (6)	0.0370 (5)	−0.0053 (5)	0.0098 (4)	0.0072 (4)
N1	0.0284 (16)	0.0325 (16)	0.0296 (15)	0.0011 (13)	0.0017 (13)	−0.0100 (13)
N2	0.0275 (16)	0.0341 (17)	0.0362 (17)	−0.0027 (13)	−0.0056 (13)	−0.0058 (14)
C1	0.0254 (18)	0.0333 (19)	0.0281 (18)	0.0029 (15)	0.0048 (14)	−0.0097 (16)
C2	0.0273 (18)	0.0292 (18)	0.0292 (18)	0.0055 (15)	0.0010 (15)	−0.0057 (15)
C3	0.0316 (19)	0.0304 (19)	0.0322 (19)	0.0039 (16)	−0.0029 (16)	−0.0050 (16)
C4	0.034 (2)	0.0330 (19)	0.0270 (18)	0.0037 (16)	−0.0009 (15)	−0.0057 (16)
C5	0.0337 (19)	0.0284 (18)	0.0275 (18)	0.0008 (16)	0.0073 (15)	−0.0039 (15)
C6	0.0242 (18)	0.040 (2)	0.040 (2)	−0.0016 (16)	0.0036 (16)	−0.0100 (17)
C7	0.0259 (18)	0.0284 (18)	0.0302 (19)	0.0013 (15)	−0.0026 (15)	−0.0004 (15)
C8	0.049 (2)	0.041 (2)	0.047 (2)	−0.002 (2)	−0.010 (2)	−0.018 (2)
C9	0.035 (2)	0.045 (2)	0.054 (3)	−0.0144 (19)	−0.0090 (19)	0.000 (2)
C10	0.044 (2)	0.041 (2)	0.041 (2)	0.0107 (19)	−0.0116 (19)	0.0001 (19)
C11	0.045 (2)	0.034 (2)	0.054 (3)	−0.0069 (19)	−0.009 (2)	−0.0018 (19)
C12	0.052 (3)	0.049 (2)	0.034 (2)	−0.003 (2)	−0.0164 (19)	−0.0002 (19)
C13	0.053 (3)	0.042 (2)	0.036 (2)	−0.001 (2)	0.0120 (19)	0.0009 (18)

Geometric parameters (Å, °)

Ti—N1	1.823 (3)	C6—C7	1.515 (5)
Ti—C1	2.292 (3)	C6—H6A	0.9800
Ti—Cl2	2.3036 (12)	C6—H6B	0.9800
Ti—Cl1	2.3104 (12)	C8—H8A	0.9700
Ti—C2	2.325 (3)	C8—H8B	0.9700
Ti—C5	2.341 (3)	C8—H8C	0.9700
Ti—C4	2.405 (3)	C9—H9A	0.9700
Ti—C3	2.406 (4)	C9—H9B	0.9700
N1—C7	1.322 (4)	C9—H9C	0.9700
N2—C7	1.319 (4)	C10—H10A	0.9700
N2—C8	1.457 (5)	C10—H10B	0.9700
N2—C9	1.464 (5)	C10—H10C	0.9700
C1—C2	1.406 (5)	C11—H11A	0.9700
C1—C5	1.412 (5)	C11—H11B	0.9700
C1—C6	1.512 (5)	C11—H11C	0.9700
C2—C3	1.422 (5)	C12—H12A	0.9700
C2—C10	1.504 (5)	C12—H12B	0.9700
C3—C4	1.405 (5)	C12—H12C	0.9700
C3—C11	1.500 (5)	C13—H13A	0.9700
C4—C5	1.422 (5)	C13—H13B	0.9700
C4—C12	1.500 (5)	C13—H13C	0.9700
C5—C13	1.500 (5)
N1—Ti—C1	75.92 (13)	C5—C4—Ti	70.10 (19)
N1—Ti—Cl2	105.63 (10)	C12—C4—Ti	125.2 (3)
C1—Ti—Cl2	128.71 (10)	C1—C5—C4	107.5 (3)
N1—Ti—Cl1	104.29 (10)	C1—C5—C13	126.9 (3)
C1—Ti—Cl1	124.25 (10)	C4—C5—C13	125.5 (3)
Cl2—Ti—Cl1	105.40 (5)	C1—C5—Ti	70.40 (19)
N1—Ti—C2	94.34 (13)	C4—C5—Ti	75.1 (2)
C1—Ti—C2	35.44 (13)	C13—C5—Ti	121.3 (2)
Cl2—Ti—C2	94.88 (10)	C1—C6—C7	106.7 (3)
Cl1—Ti—C2	147.26 (9)	C1—C6—H6A	110.4
N1—Ti—C5	97.46 (13)	C7—C6—H6A	110.4
C1—Ti—C5	35.48 (12)	C1—C6—H6B	110.4
Cl2—Ti—C5	146.31 (9)	C7—C6—H6B	110.4
Cl1—Ti—C5	91.94 (10)	H6A—C6—H6B	108.6
C2—Ti—C5	58.66 (12)	N2—C7—N1	122.9 (3)
N1—Ti—C4	131.33 (13)	N2—C7—C6	120.4 (3)
C1—Ti—C4	58.19 (12)	N1—C7—C6	116.7 (3)
Cl2—Ti—C4	114.96 (10)	N2—C8—H8A	109.5
Cl1—Ti—C4	90.13 (9)	N2—C8—H8B	109.5
C2—Ti—C4	57.72 (12)	H8A—C8—H8B	109.5
C5—Ti—C4	34.83 (12)	N2—C8—H8C	109.5
N1—Ti—C3	128.99 (13)	H8A—C8—H8C	109.5
C1—Ti—C3	58.23 (12)	H8B—C8—H8C	109.5
Cl2—Ti—C3	88.61 (10)	N2—C9—H9A	109.5
Cl1—Ti—C3	118.89 (9)	N2—C9—H9B	109.5
C2—Ti—C3	34.93 (12)	H9A—C9—H9B	109.5
C5—Ti—C3	57.70 (12)	N2—C9—H9C	109.5
C4—Ti—C3	33.97 (12)	H9A—C9—H9C	109.5
C7—N1—Ti	129.5 (2)	H9B—C9—H9C	109.5
C7—N2—C8	120.2 (3)	C2—C10—H10A	109.5
C7—N2—C9	123.5 (3)	C2—C10—H10B	109.5
C8—N2—C9	116.3 (3)	H10A—C10—H10B	109.5
C2—C1—C5	108.4 (3)	C2—C10—H10C	109.5
C2—C1—C6	125.4 (3)	H10A—C10—H10C	109.5
C5—C1—C6	125.5 (3)	H10B—C10—H10C	109.5
C2—C1—Ti	73.55 (19)	C3—C11—H11A	109.5
C5—C1—Ti	74.12 (19)	C3—C11—H11B	109.5
C6—C1—Ti	110.9 (2)	H11A—C11—H11B	109.5
C1—C2—C3	108.0 (3)	C3—C11—H11C	109.5
C1—C2—C10	127.2 (3)	H11A—C11—H11C	109.5
C3—C2—C10	124.8 (3)	H11B—C11—H11C	109.5
C1—C2—Ti	71.01 (19)	C4—C12—H12A	109.5
C3—C2—Ti	75.7 (2)	C4—C12—H12B	109.5
C10—C2—Ti	119.9 (2)	H12A—C12—H12B	109.5
C4—C3—C2	107.8 (3)	C4—C12—H12C	109.5
C4—C3—C11	126.4 (3)	H12A—C12—H12C	109.5
C2—C3—C11	125.7 (3)	H12B—C12—H12C	109.5
C4—C3—Ti	73.0 (2)	C5—C13—H13A	109.5
C2—C3—Ti	69.41 (19)	C5—C13—H13B	109.5
C11—C3—Ti	125.7 (3)	H13A—C13—H13B	109.5
C3—C4—C5	108.3 (3)	C5—C13—H13C	109.5
C3—C4—C12	126.4 (3)	H13A—C13—H13C	109.5
C5—C4—C12	125.2 (3)	H13B—C13—H13C	109.5
C3—C4—Ti	73.1 (2)