Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807044832/hg2295sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807044832/hg2295Isup2.hkl |
CCDC reference: 663618
While stirring under a nitrogen atmosphere, 2 ml (18.24 mmol) of TiCl4 were added to approximately 60 ml of n-hexane in a Schlenk flask. Next, 0.16 ml (8.90 mmol) of distilled water mixed with 7.54 ml (72.90 mmol) of diethylamine was added dropwise to the solution. After 16 h of stirring, solid white diethylammonium chloride was removed by no-air filtration. The orange filtrate was evaporated to a minimal volume over a period of two days with a slow stream of nitrogen yielding X-ray quality crystals of I.
Hydrogen atoms were positioned geometrically and allowed to ride on their bonding partners with C—H distances = 0.96 Å and Uiso(H) = 1.5Ueq(C) for the methyl H atoms, C—H distances = 0.97 Å and Uiso(H) = 1.2Ueq(C) for the methylene H atoms, and N—H distance = 0.91 Å and Uiso(H) = 1.2Ueq(N) for the amino hydrogen.
The structure of I was determined as part of an investigation into the effects of water on the synthesis of Ti(IV) complexes derived from secondary amines. Because the two titanium atoms in I are related by an inversion center on the bridging oxygen atom, the Ti—O—Ti bond angle is 180° indicating complete sp hybridization of the oxygen atom. This arises from dπpπ bonding through overlap of the px and py orbitals on oxygen with titanium dxy and dyz orbitals. Perfectly linear Ti—O—Ti complexes with oxygen as an inversion center have been reported (Krug & Müller, 1990; Thewalt & Schomburg, 1977). However, µ-oxo homodinuclear titanium species with Ti—O—Ti bond angles slightly less than 180° appear to be more common. (Honzíček et al., 2004; Levason et al., 2003; Mahrwald et al., 2001; Schormann, 2003)
In addition to the bridging oxygen in I, there is one diethylamido (N2) and one diethylamino (N1) group, as well as two chlorides (Cl1 and Cl2) coordinated to the titanium. Each titanium atom is best viewed as having distorted square pyramidal coordination geometry as judged by the τ-descriptor (Addison et al., 1984) which is 0.13 for this molecule. The amido group occupies the axial position, and Cl1, Cl2, N1 and O1 create the equatorial pseudo-square base. One chloride (Cl2) is trans to the bridging oxygen and the other chloride (Cl1) is trans to the amino group.
The diethylamido N atoms are nearly planar (N2 deviates from the Ti–C21–C23 plane by 0.077 (6) Å) as a result of strong pi interactions with the d0 Ti4+. Three of the four bond angles making up the base of the square pyramid in I are smaller than the ideal 90° (O1—Ti1—N1 = 82.49 (10)°, N1—Ti1—Cl2 = 83.20 (11)°, Cl2—Ti1—Cl1 = 89.73 (7)°). The four bond angles from the respective equatorial positions to the axial nitrogen are all larger than the ideal 90° and range from 102.09 (17)° to 108.65 (11)°. Deviation from ideal square pyramidal geometry can be attributed to electrostatic repulsions, particularly from the diethylamido nitrogen, and significant steric crowding around the Ti4+ centers.
For related literature, see: Addison et al. (1984); Honzíček et al. (2004); Krug & Müller (1990); Levason et al. (2003); Mahrwald et al. (2001); Schormann (2003); Thewalt & Schomburg (1977).
Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 2003b); software used to prepare material for publication: SHELXTL (Sheldrick, 2003b).
[Ti2(C4H10N)2Cl4O(C4H11N)2] | F(000) = 1144 |
Mr = 544.14 | Dx = 1.319 Mg m−3 |
Monoclinic, I2/a | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -I 2ya | Cell parameters from 3400 reflections |
a = 13.204 (3) Å | θ = 4.5–49.2° |
b = 10.131 (2) Å | µ = 0.99 mm−1 |
c = 20.795 (5) Å | T = 298 K |
β = 99.973 (3)° | Block, orange |
V = 2739.7 (10) Å3 | 0.40 × 0.35 × 0.20 mm |
Z = 4 |
Bruker SMART APEX diffractometer | 2421 independent reflections |
Radiation source: fine-focus sealed tube | 1446 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.093 |
ω scans | θmax = 25.0°, θmin = 2.0° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003a) | h = −15→15 |
Tmin = 0.693, Tmax = 0.827 | k = −12→12 |
10591 measured reflections | l = −24→24 |
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)] = 0.058 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.153 | H-atom parameters constrained |
S = 0.93 | w = 1/[σ2(Fo2) + (0.0883P)2] where P = (Fo2 + 2Fc2)/3 |
2421 reflections | (Δ/σ)max = 0.004 |
128 parameters | Δρmax = 0.45 e Å−3 |
0 restraints | Δρmin = −0.29 e Å−3 |
[Ti2(C4H10N)2Cl4O(C4H11N)2] | V = 2739.7 (10) Å3 |
Mr = 544.14 | Z = 4 |
Monoclinic, I2/a | Mo Kα radiation |
a = 13.204 (3) Å | µ = 0.99 mm−1 |
b = 10.131 (2) Å | T = 298 K |
c = 20.795 (5) Å | 0.40 × 0.35 × 0.20 mm |
β = 99.973 (3)° |
Bruker SMART APEX diffractometer | 2421 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003a) | 1446 reflections with I > 2σ(I) |
Tmin = 0.693, Tmax = 0.827 | Rint = 0.093 |
10591 measured reflections |
R[F2 > 2σ(F2)] = 0.058 | 0 restraints |
wR(F2) = 0.153 | H-atom parameters constrained |
S = 0.93 | Δρmax = 0.45 e Å−3 |
2421 reflections | Δρmin = −0.29 e Å−3 |
128 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Ti1 | 0.21205 (5) | 0.21280 (9) | 0.32732 (4) | 0.0574 (3) | |
Cl1 | 0.12134 (10) | 0.02633 (18) | 0.28158 (7) | 0.0953 (6) | |
Cl2 | 0.09047 (11) | 0.24341 (17) | 0.39498 (9) | 0.1030 (6) | |
O1 | 0.2500 | 0.2500 | 0.2500 | 0.0595 (11) | |
N1 | 0.2372 (3) | 0.4269 (4) | 0.34308 (18) | 0.0729 (12) | |
H1A | 0.2879 | 0.4479 | 0.3202 | 0.087* | |
C11 | 0.1437 (4) | 0.4984 (6) | 0.3087 (3) | 0.0835 (16) | |
H11A | 0.1142 | 0.4468 | 0.2707 | 0.100* | |
H11B | 0.0935 | 0.5004 | 0.3377 | 0.100* | |
C12 | 0.1579 (6) | 0.6342 (7) | 0.2870 (4) | 0.128 (3) | |
H12A | 0.1932 | 0.6850 | 0.3230 | 0.192* | |
H12B | 0.0920 | 0.6732 | 0.2713 | 0.192* | |
H12C | 0.1978 | 0.6330 | 0.2526 | 0.192* | |
C13 | 0.2737 (5) | 0.4784 (10) | 0.4096 (3) | 0.144 (3) | |
H13A | 0.2316 | 0.5544 | 0.4155 | 0.173* | |
H13B | 0.2593 | 0.4115 | 0.4401 | 0.173* | |
N2 | 0.3284 (2) | 0.1426 (4) | 0.37576 (16) | 0.0595 (10) | |
C21 | 0.3131 (4) | 0.0542 (6) | 0.4290 (2) | 0.0805 (17) | |
H21A | 0.2433 | 0.0646 | 0.4369 | 0.097* | |
H21B | 0.3592 | 0.0806 | 0.4684 | 0.097* | |
C22 | 0.3315 (5) | −0.0908 (7) | 0.4159 (3) | 0.111 (2) | |
H22A | 0.2891 | −0.1168 | 0.3757 | 0.166* | |
H22B | 0.3145 | −0.1433 | 0.4510 | 0.166* | |
H22C | 0.4025 | −0.1039 | 0.4129 | 0.166* | |
C23 | 0.4344 (3) | 0.1478 (7) | 0.3616 (2) | 0.0812 (16) | |
H23A | 0.4377 | 0.2151 | 0.3289 | 0.097* | |
H23B | 0.4505 | 0.0637 | 0.3435 | 0.097* | |
C24 | 0.5138 (4) | 0.1774 (8) | 0.4206 (3) | 0.116 (2) | |
H24A | 0.4975 | 0.2594 | 0.4395 | 0.175* | |
H24B | 0.5802 | 0.1839 | 0.4080 | 0.175* | |
H24C | 0.5146 | 0.1077 | 0.4520 | 0.175* | |
C14 | 0.3706 (6) | 0.5140 (10) | 0.4276 (4) | 0.163 (4) | |
H14A | 0.4143 | 0.4526 | 0.4103 | 0.244* | |
H14B | 0.3876 | 0.5145 | 0.4744 | 0.244* | |
H14C | 0.3804 | 0.6008 | 0.4112 | 0.244* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ti1 | 0.0338 (4) | 0.0910 (7) | 0.0502 (5) | 0.0052 (4) | 0.0148 (3) | 0.0161 (4) |
Cl1 | 0.0633 (8) | 0.1336 (14) | 0.0909 (10) | −0.0350 (8) | 0.0190 (7) | 0.0076 (9) |
Cl2 | 0.0806 (10) | 0.1190 (13) | 0.1287 (12) | 0.0258 (8) | 0.0724 (9) | 0.0354 (10) |
O1 | 0.054 (2) | 0.078 (3) | 0.048 (2) | 0.004 (2) | 0.0136 (19) | 0.009 (2) |
N1 | 0.052 (2) | 0.111 (4) | 0.059 (2) | −0.017 (2) | 0.0183 (18) | −0.014 (2) |
C11 | 0.072 (4) | 0.083 (4) | 0.094 (4) | −0.006 (3) | 0.009 (3) | 0.001 (3) |
C12 | 0.137 (6) | 0.090 (6) | 0.169 (7) | 0.000 (5) | 0.060 (5) | 0.008 (5) |
C13 | 0.084 (4) | 0.261 (10) | 0.092 (5) | −0.041 (6) | 0.023 (4) | −0.076 (6) |
N2 | 0.0385 (18) | 0.096 (3) | 0.045 (2) | 0.0096 (19) | 0.0109 (15) | 0.0081 (19) |
C21 | 0.064 (3) | 0.116 (5) | 0.061 (3) | 0.015 (3) | 0.010 (2) | 0.020 (3) |
C22 | 0.102 (5) | 0.101 (5) | 0.123 (5) | 0.019 (4) | 0.002 (4) | 0.022 (4) |
C23 | 0.038 (2) | 0.143 (5) | 0.064 (3) | 0.009 (3) | 0.011 (2) | 0.001 (3) |
C24 | 0.051 (3) | 0.188 (8) | 0.105 (5) | −0.003 (4) | −0.002 (3) | 0.001 (5) |
C14 | 0.127 (7) | 0.205 (10) | 0.140 (7) | −0.053 (7) | −0.024 (6) | −0.050 (6) |
Ti1—O1 | 1.8048 (8) | N2—C21 | 1.465 (6) |
Ti1—N2 | 1.828 (3) | N2—C23 | 1.480 (5) |
Ti1—N1 | 2.210 (5) | C21—C22 | 1.521 (8) |
Ti1—Cl2 | 2.3314 (14) | C21—H21A | 0.9700 |
Ti1—Cl1 | 2.3480 (18) | C21—H21B | 0.9700 |
O1—Ti1i | 1.8049 (8) | C22—H22A | 0.9600 |
N1—C13 | 1.479 (7) | C22—H22B | 0.9600 |
N1—C11 | 1.502 (6) | C22—H22C | 0.9600 |
N1—H1A | 0.9100 | C23—C24 | 1.499 (7) |
C11—C12 | 1.470 (9) | C23—H23A | 0.9700 |
C11—H11A | 0.9700 | C23—H23B | 0.9700 |
C11—H11B | 0.9700 | C24—H24A | 0.9600 |
C12—H12A | 0.9600 | C24—H24B | 0.9600 |
C12—H12B | 0.9600 | C24—H24C | 0.9600 |
C12—H12C | 0.9600 | C14—H14A | 0.9600 |
C13—C14 | 1.320 (9) | C14—H14B | 0.9600 |
C13—H13A | 0.9700 | C14—H14C | 0.9600 |
C13—H13B | 0.9700 | ||
O1—Ti1—N2 | 103.63 (10) | H13A—C13—H13B | 106.9 |
O1—Ti1—N1 | 82.49 (10) | C21—N2—C23 | 115.5 (4) |
N2—Ti1—N1 | 102.09 (17) | C21—N2—Ti1 | 116.2 (3) |
O1—Ti1—Cl2 | 146.75 (6) | C23—N2—Ti1 | 127.6 (3) |
N2—Ti1—Cl2 | 108.65 (11) | N2—C21—C22 | 114.1 (4) |
N1—Ti1—Cl2 | 83.20 (11) | N2—C21—H21A | 108.7 |
O1—Ti1—Cl1 | 90.46 (5) | C22—C21—H21A | 108.7 |
N2—Ti1—Cl1 | 103.37 (14) | N2—C21—H21B | 108.7 |
N1—Ti1—Cl1 | 154.52 (11) | C22—C21—H21B | 108.7 |
Cl2—Ti1—Cl1 | 89.73 (7) | H21A—C21—H21B | 107.6 |
Ti1—O1—Ti1i | 180.00 | C21—C22—H22A | 109.5 |
C13—N1—C11 | 112.5 (5) | C21—C22—H22B | 109.5 |
C13—N1—Ti1 | 120.1 (5) | H22A—C22—H22B | 109.5 |
C11—N1—Ti1 | 108.2 (3) | C21—C22—H22C | 109.5 |
C13—N1—H1A | 104.9 | H22A—C22—H22C | 109.5 |
C11—N1—H1A | 104.9 | H22B—C22—H22C | 109.5 |
Ti1—N1—H1A | 104.9 | N2—C23—C24 | 113.4 (4) |
C12—C11—N1 | 117.3 (5) | N2—C23—H23A | 108.9 |
C12—C11—H11A | 108.0 | C24—C23—H23A | 108.9 |
N1—C11—H11A | 108.0 | N2—C23—H23B | 108.9 |
C12—C11—H11B | 108.0 | C24—C23—H23B | 108.9 |
N1—C11—H11B | 108.0 | H23A—C23—H23B | 107.7 |
H11A—C11—H11B | 107.2 | C23—C24—H24A | 109.5 |
C11—C12—H12A | 109.5 | C23—C24—H24B | 109.5 |
C11—C12—H12B | 109.5 | H24A—C24—H24B | 109.5 |
H12A—C12—H12B | 109.5 | C23—C24—H24C | 109.5 |
C11—C12—H12C | 109.5 | H24A—C24—H24C | 109.5 |
H12A—C12—H12C | 109.5 | H24B—C24—H24C | 109.5 |
H12B—C12—H12C | 109.5 | C13—C14—H14A | 109.5 |
C14—C13—N1 | 120.3 (6) | C13—C14—H14B | 109.5 |
C14—C13—H13A | 107.3 | H14A—C14—H14B | 109.5 |
N1—C13—H13A | 107.3 | C13—C14—H14C | 109.5 |
C14—C13—H13B | 107.3 | H14A—C14—H14C | 109.5 |
N1—C13—H13B | 107.3 | H14B—C14—H14C | 109.5 |
Symmetry code: (i) −x+1/2, −y+1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | [Ti2(C4H10N)2Cl4O(C4H11N)2] |
Mr | 544.14 |
Crystal system, space group | Monoclinic, I2/a |
Temperature (K) | 298 |
a, b, c (Å) | 13.204 (3), 10.131 (2), 20.795 (5) |
β (°) | 99.973 (3) |
V (Å3) | 2739.7 (10) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.99 |
Crystal size (mm) | 0.40 × 0.35 × 0.20 |
Data collection | |
Diffractometer | Bruker SMART APEX |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2003a) |
Tmin, Tmax | 0.693, 0.827 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10591, 2421, 1446 |
Rint | 0.093 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.058, 0.153, 0.93 |
No. of reflections | 2421 |
No. of parameters | 128 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.45, −0.29 |
Computer programs: SMART (Bruker, 2003), SAINT (Bruker, 2003), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Sheldrick, 2003b).
The structure of I was determined as part of an investigation into the effects of water on the synthesis of Ti(IV) complexes derived from secondary amines. Because the two titanium atoms in I are related by an inversion center on the bridging oxygen atom, the Ti—O—Ti bond angle is 180° indicating complete sp hybridization of the oxygen atom. This arises from dπpπ bonding through overlap of the px and py orbitals on oxygen with titanium dxy and dyz orbitals. Perfectly linear Ti—O—Ti complexes with oxygen as an inversion center have been reported (Krug & Müller, 1990; Thewalt & Schomburg, 1977). However, µ-oxo homodinuclear titanium species with Ti—O—Ti bond angles slightly less than 180° appear to be more common. (Honzíček et al., 2004; Levason et al., 2003; Mahrwald et al., 2001; Schormann, 2003)
In addition to the bridging oxygen in I, there is one diethylamido (N2) and one diethylamino (N1) group, as well as two chlorides (Cl1 and Cl2) coordinated to the titanium. Each titanium atom is best viewed as having distorted square pyramidal coordination geometry as judged by the τ-descriptor (Addison et al., 1984) which is 0.13 for this molecule. The amido group occupies the axial position, and Cl1, Cl2, N1 and O1 create the equatorial pseudo-square base. One chloride (Cl2) is trans to the bridging oxygen and the other chloride (Cl1) is trans to the amino group.
The diethylamido N atoms are nearly planar (N2 deviates from the Ti–C21–C23 plane by 0.077 (6) Å) as a result of strong pi interactions with the d0 Ti4+. Three of the four bond angles making up the base of the square pyramid in I are smaller than the ideal 90° (O1—Ti1—N1 = 82.49 (10)°, N1—Ti1—Cl2 = 83.20 (11)°, Cl2—Ti1—Cl1 = 89.73 (7)°). The four bond angles from the respective equatorial positions to the axial nitrogen are all larger than the ideal 90° and range from 102.09 (17)° to 108.65 (11)°. Deviation from ideal square pyramidal geometry can be attributed to electrostatic repulsions, particularly from the diethylamido nitrogen, and significant steric crowding around the Ti4+ centers.