Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102022072/fg1670sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102022072/fg1670Isup2.hkl |
CCDC reference: 205292
The title compound was synthesized as described by Jayaratne et al. (1996) from the reaction on TaCl5 with iPrNH2. Recrystallization by slow evaporation of toluene from a solution of the compound afforded colourless crystals suitable for X-ray analysis. 1H NMR spectroscopy of the crystals showed that little or no decomposition had occurred during the recrystallization.
NMR data: 1H, 13C and 15N NMR spectra were recorded with a Bruker AF500 or AF300 NMR spectrometer. Chemical shifts for 1H and 13C are referenced to the residual protio impurity in the deuterated solvent. 15N chemical shifts are referenced to formamide used as an external standard. 14N NMR spectra were recorded by Dr M. Minelli, Grinnell College, Iowa. They were measured on a Bruker AC 300 MHz NMR spectrometer with a 10 mm broadband probehead (109 A g-31P) with digital tuning. Nitromethane neat was used as external reference (0 p.p.m.).
1H NMR (300.13 MHz, C6D6, 25°C): δ 0.83 (d, 6H, 3JHH = 6.00 Hz, NH2CH(C~H3)2), 0.86 (d, 6H, 3JHH = 6.00 Hz, NH2CH(C~H3)2), 1.10 (d, 6H, 3JHH = 6.00 Hz, NHCH(C~H3)2), 1.30 (d, 6H, 3JHH = 6.00 Hz, NCH(C~H3)2), 3.38 (br, 6H, N~H2CH(CH3)2, NH2C~H(CH3)2), 4.52 (sept, 1H, 6.00 Hz, NC~H(CH3)2), 4.70 (m, 1H, NHC~H(CH3)2), 7.80 (d, 1H, 3JHH = 10.00 Hz, N~HCH(CH3)2). 13C {1H} NMR (75.4 MHz, CDCl3, 25°C): δ 24.9 (NH2CH(~CH3)2, 26.5 (NHCH(~CH3)2), 27.8 (NCH(~CH3)2), 49.5 (NH2~CH(CH3)2, 60.0 (N~CH(CH3)2), 60.2 (NH~CH(CH3)2). 14N {1H} NMR (21.69 MHz, CH2Cl2, 25°C): δ −31 (ÑCH(CH3)2), −122 (ÑHCH(CH3)2), −321 (ÑH2CH(CH3)2), −335 (ÑH2CH(CH3)2). 15N NMR (50.68 MHz, C6D6, 25°C): δ −30.0 (s, ÑCH(CH3)2), −115 (d, ÑHCH(CH3)2, JNH=66 Hz), −314 (t, ÑH2CH(CH3)2, JNH = 66 Hz).
The compound crystallized in the triclinic system; space group P1 chosen and confirmed by the successful refinement. It became obvious during the refinement that two of the isopropyl groups (C4,C5,C6 and C10,C11,C12) were disordered. This was dealt with by generating models (C4,C5,C6/C4',C5',C6' and C10,C11,C12/C10',C11',C12') using appropriate DFIX restraints (Csp3—Csp3 1.52 (1), Csp3—N 1.48 (1), CH3···CH3 2.54 (1) Å). Initially tied occupancy free-variables were refined for each disordered isopropyl group, but as the refined values were not significantly different from 1/2, these occupancies were subsequently fixed at 0.5. Difference map plots clearly revealed the amino- and amido-H atoms. In the final refinement cycles all H atoms were allowed for as riding atoms using the SHELXL HFIX commands (N—H 0.90, C—H 0.96 and 0.98 Å). The maxima and minima in the final difference map are within 1 Å of the Ta atom.
Data collection: Siemens P3/PC (Siemens 1990); cell refinement: Siemens P3/PC (Siemens 1990); data reduction: SHELXTL (version 5.10) (Sheldrick, 1997a); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997b); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997b); molecular graphics: PLATON (Spek 2002); software used to prepare material for publication: SHELXTL (version 5.10) (Sheldrick 1997a).
[Ta(C3H7N)(C3H8N)(C3H9N)2Cl2] | Z = 2 |
Mr = 485.27 | F(000) = 480 |
Triclinic, P1 | Dx = 1.596 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 9.5970 (19) Å | Cell parameters from 25 reflections |
b = 10.073 (2) Å | θ = 10–30° |
c = 12.755 (3) Å | µ = 5.70 mm−1 |
α = 95.04 (3)° | T = 210 K |
β = 111.77 (3)° | Block, colorless |
γ = 113.46 (3)° | 0.34 × 0.26 × 0.14 mm |
V = 1009.5 (6) Å3 |
Siemens P3 diffractometer | 3098 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.072 |
Graphite monochromator | θmax = 25.1°, θmin = 1.8° |
ω scans | h = −11→0 |
Absorption correction: psi-scan (North et al., 1968) | k = −11→11 |
Tmin = 0.182, Tmax = 0.450 | l = −15→15 |
4079 measured reflections | 3 standard reflections every 200 reflections |
3528 independent reflections | intensity decay: 1% |
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)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.109 | H-atom parameters constrained |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0639P)2 + 2.1304P] where P = (Fo2 + 2Fc2)/3 |
3528 reflections | (Δ/σ)max = 0.001 |
219 parameters | Δρmax = 1.44 e Å−3 |
22 restraints | Δρmin = −1.36 e Å−3 |
[Ta(C3H7N)(C3H8N)(C3H9N)2Cl2] | γ = 113.46 (3)° |
Mr = 485.27 | V = 1009.5 (6) Å3 |
Triclinic, P1 | Z = 2 |
a = 9.5970 (19) Å | Mo Kα radiation |
b = 10.073 (2) Å | µ = 5.70 mm−1 |
c = 12.755 (3) Å | T = 210 K |
α = 95.04 (3)° | 0.34 × 0.26 × 0.14 mm |
β = 111.77 (3)° |
Siemens P3 diffractometer | 3098 reflections with I > 2σ(I) |
Absorption correction: psi-scan (North et al., 1968) | Rint = 0.072 |
Tmin = 0.182, Tmax = 0.450 | 3 standard reflections every 200 reflections |
4079 measured reflections | intensity decay: 1% |
3528 independent reflections |
R[F2 > 2σ(F2)] = 0.040 | 22 restraints |
wR(F2) = 0.109 | H-atom parameters constrained |
S = 1.09 | Δρmax = 1.44 e Å−3 |
3528 reflections | Δρmin = −1.36 e Å−3 |
219 parameters |
Experimental. NMR Data: 1H, 13C and 15N NMR spectra were recorded with a Bruker AF500 or AF300 NMR spectrometer. Chemical shifts for 1H and 13C are referenced to the residual protio impurity in the deuterated solvent. 15N chemical shifts are referenced to formamide used as an external standard. 14N NMR spectra were recorded by Dr. M. Minelli, Grinnell College, Iowa. They were measured on a Bruker AC 300 MHz NMR spectrometer with a 10 mm broadband probehead (109 A g-31P) with digital tuning. Nitromethane neat was used as external reference (0 p.p.m.). 1H NMR (300.13 MHz, C6D6, 25°C): d 0.83 (d, 6H, 3JHH = 6.00 Hz, NH2CH(CH3)2), 0.86 (d, 6H, 3JHH = 6.00 Hz, NH2CH(CH3)2), 1.10 (d, 6H, 3JHH = 6.00 Hz, NHCH(CH3)2), 1.30 (d, 6H, 3JHH = 6.00 Hz, NCH(CH3)2), 3.38 (br, 6H, NH2CH(CH3)2, NH2CH(CH3)2), 4.52 (sept, 1H, 6.00 Hz, NCH(CH3)2), 4.70 (m, 1H, NHCH(CH3)2), 7.80 (d, 1H, 3JHH = 10.00 Hz, NHCH(CH3)2). 13C {1H} NMR (75.4 MHz, CDCl3, 25°C): d 24.9 (NH2CH(CH3)2, 26.5 (NHCH(CH3)2), 27.8 (NCH(CH3)2), 49.5 (NH2CH(CH3)2, 60.0 (NCH(CH3)2), 60.2 (NHCH(CH3)2). 14N {1H} NMR (21.69 MHz, CH2Cl2, 25°C): d −31 (NCH(CH3)2), −122 (NHCH(CH3)2), −321 (NH2CH(CH3)2), −335 (NH2CH(CH3)2). 15N NMR (50.68 MHz, C6D6, 25°C): d −30.0 (s, NCH(CH3)2), −115 (d, NHCH(CH3)2, JNH=66 Hz), −314 (t, NH2CH(CH3)2, JNH = 66 Hz). |
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 | Occ. (<1) | |
Ta | 0.48688 (4) | 0.75452 (4) | 0.14669 (3) | 0.03003 (14) | |
Cl1 | 0.5564 (3) | 0.7808 (2) | −0.03389 (19) | 0.0383 (5) | |
Cl2 | 0.2364 (3) | 0.5145 (2) | 0.0052 (2) | 0.0447 (5) | |
N1 | 0.4401 (10) | 0.7437 (9) | 0.2678 (7) | 0.0453 (18) | |
N2 | 0.6992 (9) | 0.9446 (8) | 0.2199 (6) | 0.0425 (17) | |
H2 | 0.7431 | 0.9689 | 0.1723 | 0.051* | |
N3 | 0.3155 (9) | 0.8502 (8) | 0.0502 (7) | 0.0371 (16) | |
H3A | 0.3806 | 0.9501 | 0.0679 | 0.045* | |
H3B | 0.2789 | 0.8128 | −0.0271 | 0.045* | |
N4 | 0.6142 (8) | 0.6068 (8) | 0.1716 (6) | 0.0355 (15) | |
H4A | 0.5324 | 0.5106 | 0.1376 | 0.043* | |
H4B | 0.6763 | 0.6268 | 0.1313 | 0.043* | |
C1 | 0.3827 (14) | 0.7259 (12) | 0.3581 (10) | 0.068 (3) | |
H1 | 0.3313 | 0.7926 | 0.3586 | 0.082* | |
C2 | 0.2439 (17) | 0.5659 (13) | 0.3255 (12) | 0.088 (4) | |
H2A | 0.1748 | 0.5313 | 0.2420 | 0.133* | |
H2B | 0.1751 | 0.5637 | 0.3646 | 0.133* | |
H2C | 0.2943 | 0.5014 | 0.3491 | 0.133* | |
C3 | 0.5286 (17) | 0.775 (2) | 0.4788 (11) | 0.119 (7) | |
H3C | 0.5564 | 0.6948 | 0.4914 | 0.178* | |
H3D | 0.4965 | 0.8014 | 0.5373 | 0.178* | |
H3E | 0.6254 | 0.8616 | 0.4841 | 0.178* | |
C4 | 0.802 (2) | 1.056 (2) | 0.3366 (15) | 0.055 (3) | 0.50 |
H4 | 0.7607 | 1.0167 | 0.3925 | 0.066* | 0.50 |
C5 | 0.983 (2) | 1.080 (3) | 0.375 (4) | 0.078 (11) | 0.50 |
H5A | 0.9845 | 0.9855 | 0.3777 | 0.117* | 0.50 |
H5B | 1.0551 | 1.1503 | 0.4514 | 0.117* | 0.50 |
H5C | 1.0227 | 1.1184 | 0.3198 | 0.117* | 0.50 |
C6 | 0.787 (4) | 1.199 (3) | 0.324 (3) | 0.090 (12) | 0.50 |
H6A | 0.6716 | 1.1788 | 0.3004 | 0.135* | 0.50 |
H6B | 0.8209 | 1.2336 | 0.2649 | 0.135* | 0.50 |
H6C | 0.8590 | 1.2758 | 0.3973 | 0.135* | 0.50 |
C4' | 0.802 (3) | 1.057 (3) | 0.3364 (16) | 0.055 (3) | 0.50 |
H4' | 0.8056 | 0.9970 | 0.3930 | 0.066* | 0.50 |
C5' | 0.986 (3) | 1.150 (4) | 0.362 (4) | 0.13 (2) | 0.50 |
H5D | 1.0260 | 1.0860 | 0.3365 | 0.193* | 0.50 |
H5E | 1.0533 | 1.1980 | 0.4444 | 0.193* | 0.50 |
H5F | 0.9943 | 1.2256 | 0.3198 | 0.193* | 0.50 |
C6' | 0.721 (5) | 1.149 (4) | 0.363 (4) | 0.16 (3) | 0.50 |
H6D | 0.6095 | 1.0831 | 0.3522 | 0.244* | 0.50 |
H6E | 0.7143 | 1.2116 | 0.3103 | 0.244* | 0.50 |
H6F | 0.7890 | 1.2114 | 0.4424 | 0.244* | 0.50 |
C7 | 0.1630 (10) | 0.8274 (10) | 0.0684 (8) | 0.050 (3) | |
H7 | 0.1173 | 0.7291 | 0.0836 | 0.060* | |
C8 | 0.2188 (16) | 0.9487 (12) | 0.1763 (9) | 0.072 (4) | |
H8A | 0.3242 | 0.9633 | 0.2365 | 0.108* | |
H8B | 0.1340 | 0.9181 | 0.2045 | 0.108* | |
H8C | 0.2332 | 1.0412 | 0.1560 | 0.108* | |
C9 | 0.0282 (13) | 0.8269 (14) | −0.0418 (10) | 0.072 (4) | |
H9A | 0.0691 | 0.9239 | −0.0561 | 0.109* | |
H9B | −0.0724 | 0.8048 | −0.0319 | 0.109* | |
H9C | 0.0023 | 0.7515 | −0.1074 | 0.109* | |
C10 | 0.726 (2) | 0.616 (3) | 0.2924 (12) | 0.047 (3) | 0.50 |
H10 | 0.7652 | 0.7148 | 0.3437 | 0.057* | 0.50 |
C11 | 0.619 (3) | 0.496 (2) | 0.3330 (19) | 0.057 (6) | 0.50 |
H11A | 0.5276 | 0.5134 | 0.3325 | 0.086* | 0.50 |
H11B | 0.6884 | 0.4994 | 0.4112 | 0.086* | 0.50 |
H11C | 0.5740 | 0.3986 | 0.2811 | 0.086* | 0.50 |
C12 | 0.880 (2) | 0.603 (3) | 0.296 (2) | 0.071 (7) | 0.50 |
H12A | 0.9435 | 0.6834 | 0.2721 | 0.106* | 0.50 |
H12B | 0.8432 | 0.5080 | 0.2445 | 0.106* | 0.50 |
H12C | 0.9494 | 0.6082 | 0.3751 | 0.106* | 0.50 |
C10' | 0.7534 (19) | 0.646 (3) | 0.2899 (13) | 0.047 (3) | 0.50 |
H10' | 0.7347 | 0.7004 | 0.3464 | 0.057* | 0.50 |
C11' | 0.752 (4) | 0.505 (3) | 0.325 (3) | 0.114 (14) | 0.50 |
H11D | 0.6445 | 0.4439 | 0.3233 | 0.172* | 0.50 |
H11E | 0.8408 | 0.5333 | 0.4026 | 0.172* | 0.50 |
H11F | 0.7697 | 0.4491 | 0.2705 | 0.172* | 0.50 |
C12' | 0.921 (2) | 0.751 (3) | 0.292 (2) | 0.072 (7) | 0.50 |
H12D | 0.9135 | 0.8374 | 0.2682 | 0.108* | 0.50 |
H12E | 0.9434 | 0.6996 | 0.2384 | 0.108* | 0.50 |
H12F | 1.0104 | 0.7840 | 0.3697 | 0.108* | 0.50 |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ta | 0.0323 (2) | 0.02502 (19) | 0.0349 (2) | 0.01388 (14) | 0.01641 (15) | 0.00899 (13) |
Cl1 | 0.0457 (12) | 0.0326 (10) | 0.0431 (12) | 0.0177 (9) | 0.0260 (10) | 0.0142 (9) |
Cl2 | 0.0347 (11) | 0.0286 (10) | 0.0613 (14) | 0.0073 (9) | 0.0215 (10) | 0.0058 (10) |
N1 | 0.051 (5) | 0.039 (4) | 0.053 (5) | 0.025 (4) | 0.025 (4) | 0.016 (4) |
N2 | 0.037 (4) | 0.041 (4) | 0.034 (4) | 0.013 (3) | 0.008 (3) | 0.005 (3) |
N3 | 0.041 (4) | 0.036 (4) | 0.045 (4) | 0.023 (3) | 0.022 (4) | 0.016 (3) |
N4 | 0.036 (4) | 0.032 (4) | 0.036 (4) | 0.015 (3) | 0.014 (3) | 0.009 (3) |
C1 | 0.096 (9) | 0.073 (8) | 0.076 (8) | 0.051 (7) | 0.063 (8) | 0.032 (7) |
C2 | 0.101 (11) | 0.088 (10) | 0.087 (10) | 0.030 (9) | 0.063 (9) | 0.042 (9) |
C3 | 0.094 (12) | 0.167 (19) | 0.065 (10) | 0.027 (12) | 0.042 (9) | 0.030 (11) |
C4 | 0.054 (6) | 0.040 (5) | 0.035 (5) | 0.003 (5) | 0.009 (5) | −0.009 (4) |
C5 | 0.060 (19) | 0.044 (17) | 0.07 (2) | 0.011 (15) | −0.011 (15) | −0.003 (17) |
C6 | 0.12 (3) | 0.054 (17) | 0.05 (2) | 0.037 (18) | 0.002 (18) | −0.015 (14) |
C4' | 0.054 (6) | 0.040 (5) | 0.035 (5) | 0.003 (5) | 0.009 (5) | −0.009 (4) |
C5' | 0.08 (2) | 0.10 (3) | 0.07 (3) | −0.05 (2) | 0.03 (2) | −0.07 (3) |
C6' | 0.21 (6) | 0.12 (4) | 0.10 (4) | 0.14 (4) | −0.04 (3) | −0.05 (3) |
C7 | 0.034 (5) | 0.042 (5) | 0.091 (8) | 0.023 (4) | 0.036 (5) | 0.037 (5) |
C8 | 0.112 (11) | 0.079 (8) | 0.093 (10) | 0.072 (8) | 0.077 (9) | 0.049 (7) |
C9 | 0.043 (6) | 0.067 (8) | 0.110 (11) | 0.029 (6) | 0.030 (7) | 0.042 (8) |
C10 | 0.057 (8) | 0.055 (10) | 0.034 (5) | 0.034 (7) | 0.016 (5) | 0.015 (5) |
C11 | 0.102 (19) | 0.050 (12) | 0.044 (12) | 0.045 (13) | 0.041 (13) | 0.027 (10) |
C12 | 0.051 (14) | 0.088 (19) | 0.068 (16) | 0.040 (14) | 0.013 (12) | 0.020 (14) |
C10' | 0.057 (8) | 0.055 (10) | 0.034 (5) | 0.034 (7) | 0.016 (5) | 0.015 (5) |
C11' | 0.16 (4) | 0.09 (2) | 0.048 (17) | 0.06 (3) | 0.00 (2) | 0.024 (16) |
C12' | 0.028 (10) | 0.11 (2) | 0.041 (12) | 0.021 (12) | −0.002 (9) | −0.003 (13) |
Ta—Cl1 | 2.632 (2) | C4'—C5' | 1.52 (4) |
Ta—Cl2 | 2.504 (3) | C4'—H4' | 0.98 |
Ta—N1 | 1.763 (8) | C5'—H5D | 0.96 |
Ta—N2 | 1.964 (7) | C5'—H5E | 0.96 |
Ta—N3 | 2.262 (7) | C5'—H5F | 0.96 |
Ta—N4 | 2.247 (7) | C6'—H6D | 0.96 |
N1—C1 | 1.446 (13) | C6'—H6E | 0.96 |
N2—C4' | 1.478 (10) | C6'—H6F | 0.96 |
N2—C4 | 1.479 (10) | C7—C9 | 1.515 (8) |
N2—H2 | 0.86 | C7—C8 | 1.519 (8) |
N3—C7 | 1.498 (11) | C7—H7 | 0.98 |
N3—H3A | 0.90 | C8—H8A | 0.96 |
N3—H3B | 0.90 | C8—H8B | 0.96 |
N4—C10 | 1.482 (10) | C8—H8C | 0.96 |
N4—C10' | 1.483 (10) | C9—H9A | 0.96 |
N4—H4A | 0.90 | C9—H9B | 0.96 |
N4—H4B | 0.90 | C9—H9C | 0.96 |
C1—C3 | 1.513 (9) | C10—C11 | 1.517 (10) |
C1—C2 | 1.519 (9) | C10—C12 | 1.519 (10) |
C1—H1 | 0.98 | C10—H10 | 0.98 |
C2—H2A | 0.96 | C11—H11A | 0.96 |
C2—H2B | 0.96 | C11—H11B | 0.96 |
C2—H2C | 0.96 | C11—H11C | 0.96 |
C3—H3C | 0.96 | C12—H12A | 0.96 |
C3—H3D | 0.96 | C12—H12B | 0.96 |
C3—H3E | 0.96 | C12—H12C | 0.96 |
C4—C5 | 1.523 (10) | C10'—C11' | 1.517 (10) |
C4—C6 | 1.523 (10) | C10'—C12' | 1.523 (10) |
C4—H4 | 0.98 | C10'—H10' | 0.98 |
C5—H5A | 0.96 | C11'—H11D | 0.96 |
C5—H5B | 0.96 | C11'—H11E | 0.96 |
C5—H5C | 0.96 | C11'—H11F | 0.96 |
C6—H6A | 0.96 | C12'—H12D | 0.96 |
C6—H6B | 0.96 | C12'—H12E | 0.96 |
C6—H6C | 0.96 | C12'—H12F | 0.96 |
C4'—C6' | 1.51 (4) | ||
N1—Ta—Cl1 | 177.8 (2) | H6B—C6—H6C | 109.5 |
N1—Ta—Cl2 | 97.7 (3) | N2—C4'—C6' | 114 (2) |
N1—Ta—N2 | 98.5 (4) | N2—C4'—C5' | 113 (2) |
N1—Ta—N3 | 98.3 (3) | C6'—C4'—C5' | 114 (2) |
N1—Ta—N4 | 98.0 (3) | N2—C4'—H4' | 104.9 |
N2—Ta—Cl1 | 80.4 (2) | C6'—C4'—H4' | 104.9 |
N2—Ta—Cl2 | 163.7 (2) | C5'—C4'—H4' | 104.9 |
N2—Ta—N3 | 97.2 (3) | C4'—C5'—H5D | 109.5 |
N2—Ta—N4 | 95.0 (3) | C4'—C5'—H5E | 109.5 |
N3—Ta—Cl1 | 80.02 (19) | H5D—C5'—H5E | 109.5 |
N3—Ta—Cl2 | 81.1 (2) | C4'—C5'—H5F | 109.5 |
N3—Ta—N4 | 158.0 (3) | C4'—C6'—H6D | 109.5 |
N4—Ta—Cl1 | 84.06 (18) | C4'—C6'—H6E | 109.5 |
N4—Ta—Cl2 | 82.11 (18) | H6D—C6'—H6E | 109.5 |
Cl2—Ta—Cl1 | 83.43 (8) | C4'—C6'—H6F | 109.5 |
Ta—N1—C1 | 173.8 (8) | H6D—C6'—H6F | 109.5 |
Ta—N2—C4 | 135.8 (11) | H6E—C6'—H6F | 109.5 |
Ta—N2—C4' | 135.9 (14) | N3—C7—C9 | 109.8 (8) |
Ta—N3—C7 | 120.9 (5) | N3—C7—C8 | 108.4 (7) |
Ta—N4—C10 | 119.1 (10) | C9—C7—C8 | 113.4 (8) |
Ta—N4—C10' | 116.3 (10) | N3—C7—H7 | 108.4 |
C4'—N2—H2 | 112.0 | C9—C7—H7 | 108.4 |
C4—N2—H2 | 112.1 | C8—C7—H7 | 108.4 |
Ta—N2—H2 | 112.1 | C7—C8—H8A | 109.5 |
C7—N3—H3A | 107.1 | C7—C8—H8B | 109.5 |
Ta—N3—H3A | 107.1 | H8A—C8—H8B | 109.5 |
C7—N3—H3B | 107.1 | C7—C8—H8C | 109.5 |
Ta—N3—H3B | 107.1 | H8A—C8—H8C | 109.5 |
H3A—N3—H3B | 106.8 | H8B—C8—H8C | 109.5 |
C10—N4—H4A | 107.5 | C7—C9—H9A | 109.5 |
C10'—N4—H4A | 119.0 | C7—C9—H9B | 109.5 |
Ta—N4—H4A | 107.5 | H9A—C9—H9B | 109.5 |
C10—N4—H4B | 107.5 | C7—C9—H9C | 109.5 |
C10'—N4—H4B | 98.1 | H9A—C9—H9C | 109.5 |
Ta—N4—H4B | 107.5 | H9B—C9—H9C | 109.5 |
H4A—N4—H4B | 107.0 | N4—C10—C11 | 107.7 (13) |
N1—C1—C3 | 111.8 (10) | N4—C10—C12 | 110.9 (15) |
N1—C1—C2 | 109.5 (9) | C11—C10—C12 | 113.4 (12) |
C3—C1—C2 | 114.0 (9) | N4—C10—H10 | 108.3 |
N1—C1—H1 | 107.1 | C11—C10—H10 | 108.3 |
C3—C1—H1 | 107.1 | C12—C10—H10 | 108.3 |
C2—C1—H1 | 107.1 | C10—C11—H11A | 109.5 |
C1—C2—H2A | 109.5 | C10—C11—H11B | 109.5 |
C1—C2—H2B | 109.5 | H11A—C11—H11B | 109.5 |
H2A—C2—H2B | 109.5 | C10—C11—H11C | 109.5 |
C1—C2—H2C | 109.5 | H11A—C11—H11C | 109.5 |
H2A—C2—H2C | 109.5 | H11B—C11—H11C | 109.5 |
H2B—C2—H2C | 109.5 | C10—C12—H12A | 109.5 |
C1—C3—H3C | 109.5 | C10—C12—H12B | 109.5 |
C1—C3—H3D | 109.5 | H12A—C12—H12B | 109.5 |
H3C—C3—H3D | 109.5 | C10—C12—H12C | 109.5 |
C1—C3—H3E | 109.5 | H12A—C12—H12C | 109.5 |
H3C—C3—H3E | 109.5 | H12B—C12—H12C | 109.5 |
H3D—C3—H3E | 109.5 | N4—C10'—C11' | 111.2 (17) |
N2—C4—C5 | 106.1 (18) | N4—C10'—C12' | 108.8 (13) |
N2—C4—C6 | 108.0 (19) | C11'—C10'—C12' | 113.3 (12) |
C5—C4—C6 | 112.8 (13) | N4—C10'—H10' | 107.8 |
N2—C4—H4 | 110.0 | C11'—C10'—H10' | 107.8 |
C5—C4—H4 | 110.0 | C12'—C10'—H10' | 107.8 |
C6—C4—H4 | 110.0 | C10'—C11'—H11D | 109.5 |
C4—C5—H5A | 109.5 | C10'—C11'—H11E | 109.5 |
C4—C5—H5B | 109.5 | H11D—C11'—H11E | 109.5 |
H5A—C5—H5B | 109.5 | C10'—C11'—H11F | 109.5 |
C4—C5—H5C | 109.5 | H11D—C11'—H11F | 109.5 |
H5A—C5—H5C | 109.5 | H11E—C11'—H11F | 109.5 |
H5B—C5—H5C | 109.5 | C10'—C12'—H12D | 109.5 |
C4—C6—H6A | 109.5 | C10'—C12'—H12E | 109.5 |
C4—C6—H6B | 109.5 | H12D—C12'—H12E | 109.5 |
H6A—C6—H6B | 109.5 | C10'—C12'—H12F | 109.5 |
C4—C6—H6C | 109.5 | H12D—C12'—H12F | 109.5 |
H6A—C6—H6C | 109.5 | H12E—C12'—H12F | 109.5 |
N1—Ta—N2—C4' | −0.9 (19) | Cl2—Ta—N4—C10 | −135.1 (9) |
N4—Ta—N2—C4' | −99.7 (19) | Cl1—Ta—N4—C10 | 140.7 (9) |
N3—Ta—N2—C4' | 98.6 (19) | N1—Ta—N4—C10' | −52.2 (10) |
Cl2—Ta—N2—C4' | −178.5 (17) | N2—Ta—N4—C10' | 47.2 (10) |
Cl1—Ta—N2—C4' | 177.2 (19) | N3—Ta—N4—C10' | 170.6 (10) |
N1—Ta—N2—C4 | −0.5 (13) | Cl2—Ta—N4—C10' | −148.9 (9) |
N4—Ta—N2—C4 | −99.3 (13) | Cl1—Ta—N4—C10' | 126.9 (9) |
N3—Ta—N2—C4 | 99.0 (13) | Ta—N2—C4—C5 | 129.0 (16) |
Cl2—Ta—N2—C4 | −178.1 (11) | Ta—N2—C4—C6 | −109.8 (18) |
Cl1—Ta—N2—C4 | 177.6 (13) | Ta—N2—C4'—C6' | −70 (4) |
N1—Ta—N3—C7 | −24.3 (7) | Ta—N2—C4'—C5' | 158 (3) |
N2—Ta—N3—C7 | −124.1 (7) | Ta—N3—C7—C9 | −151.0 (7) |
N4—Ta—N3—C7 | 112.9 (8) | Ta—N3—C7—C8 | 84.6 (8) |
Cl2—Ta—N3—C7 | 72.3 (6) | Ta—N4—C10—C11 | 93.8 (15) |
Cl1—Ta—N3—C7 | 157.1 (6) | Ta—N4—C10—C12 | −141.6 (13) |
N1—Ta—N4—C10 | −38.4 (10) | Ta—N4—C10'—C11' | 142.6 (16) |
N2—Ta—N4—C10 | 61.0 (10) | Ta—N4—C10'—C12' | −91.9 (17) |
N3—Ta—N4—C10 | −175.6 (10) |
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3A···Cl1i | 0.90 | 2.65 | 3.473 (7) | 153 |
N4—H4A···Cl1ii | 0.90 | 2.75 | 3.547 (7) | 148 |
N4—H4B···Cl2ii | 0.90 | 2.71 | 3.456 (7) | 141 |
Symmetry codes: (i) −x+1, −y+2, −z; (ii) −x+1, −y+1, −z. |
Experimental details
Crystal data | |
Chemical formula | [Ta(C3H7N)(C3H8N)(C3H9N)2Cl2] |
Mr | 485.27 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 210 |
a, b, c (Å) | 9.5970 (19), 10.073 (2), 12.755 (3) |
α, β, γ (°) | 95.04 (3), 111.77 (3), 113.46 (3) |
V (Å3) | 1009.5 (6) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 5.70 |
Crystal size (mm) | 0.34 × 0.26 × 0.14 |
Data collection | |
Diffractometer | Siemens P3 diffractometer |
Absorption correction | Psi-scan (North et al., 1968) |
Tmin, Tmax | 0.182, 0.450 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4079, 3528, 3098 |
Rint | 0.072 |
(sin θ/λ)max (Å−1) | 0.596 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.109, 1.09 |
No. of reflections | 3528 |
No. of parameters | 219 |
No. of restraints | 22 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.44, −1.36 |
Computer programs: Siemens P3/PC (Siemens 1990), SHELXTL (version 5.10) (Sheldrick, 1997a), SHELXS97 (Sheldrick, 1997b), SHELXL97 (Sheldrick, 1997b), PLATON (Spek 2002), SHELXTL (version 5.10) (Sheldrick 1997a).
Ta—Cl1 | 2.632 (2) | Ta—N2 | 1.964 (7) |
Ta—Cl2 | 2.504 (3) | Ta—N3 | 2.262 (7) |
Ta—N1 | 1.763 (8) | Ta—N4 | 2.247 (7) |
N1—Ta—Cl1 | 177.8 (2) | N3—Ta—N4 | 158.0 (3) |
N1—Ta—Cl2 | 97.7 (3) | N4—Ta—Cl1 | 84.06 (18) |
N1—Ta—N2 | 98.5 (4) | N4—Ta—Cl2 | 82.11 (18) |
N1—Ta—N3 | 98.3 (3) | Cl2—Ta—Cl1 | 83.43 (8) |
N1—Ta—N4 | 98.0 (3) | Ta—N1—C1 | 173.8 (8) |
N2—Ta—Cl1 | 80.4 (2) | Ta—N2—C4 | 135.8 (11) |
N2—Ta—Cl2 | 163.7 (2) | Ta—N2—C4' | 135.9 (14) |
N2—Ta—N3 | 97.2 (3) | Ta—N3—C7 | 120.9 (5) |
N2—Ta—N4 | 95.0 (3) | Ta—N4—C10 | 119.1 (10) |
N3—Ta—Cl1 | 80.02 (19) | Ta—N4—C10' | 116.3 (10) |
N3—Ta—Cl2 | 81.1 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3A···Cl1i | 0.90 | 2.65 | 3.473 (7) | 153 |
N4—H4A···Cl1ii | 0.90 | 2.75 | 3.547 (7) | 148 |
N4—H4B···Cl2ii | 0.90 | 2.71 | 3.456 (7) | 141 |
Symmetry codes: (i) −x+1, −y+2, −z; (ii) −x+1, −y+1, −z. |
The synthesis of the title compound Ta(NiPr)(NHiPr)(NH2iPr)2Cl2, (I) was first reported by Bates et al., (1985) and it was originally proposed to be dimeric with the formula [TaCl(µ-Cl)(NiPr)(NHiPr)(NH2iPr)Cl2]2 by analogy with the previously reported structure of the dimeric [TaCl(µ-Cl)(NtBu)(NHtBu)(NH2tBu)Cl2]2 (Jones et al., 1984). Compound (I) was later studied by Jayaratne et al., (1996) who proposed a monomeric formulation based on 1H and 13C NMR spectroscopy data.
Our interest in this compound was sparked by our studies of imine metathesis by metal imido complexes of the general formula CpTa(=NR)Cl2 (Burland et al., 2002). Our mechanistic work had suggested the possible involvement of metal amido complexes in the reaction mechanism. We decided to survey metal amido complexes previous reported in the literature in order to develop the tools necessary to help us identify possible intermediates in our reactions. We were immediately struck by the title compound as it contained all three N-moieties that were of interest to us. A search of the Cambridge Structural Database (Allen, 2002) for metal complexes with imido, amido and amino groups yielded hits for only two complexes, both centrosymmetric dimers; the Ta complex reported by Jones et al., (1984) and mentioned above (CSD Refcode CEDTOU), and the isostructural vanadium complex (CSD Refcode DAJCOG, Preuss et al., 1985).
In the structure of the title imide/amide/amine compound (I) (Fig. 1) the distinction between imide, amide and amine N atoms was clear from the Ta—N dimensions (Table 1) and also by the location of the amide and amine H atoms via difference maps. The imido Ta=N bond length of 1.763 (8) Å, is typical for monomeric tantalum imides (Wigley, 1994), but long compared with the unusually short Ta=N bond length of 1.61 (3) Å reported for the dimeric tBu analog by Jones et al., (1984). The nearly linear C—N—Ta bond angle [173.8 (8)°] is consistent with a high degree of π-bonding with the metal.
The Ta—N(H) bond length [1.964 (8) Å] of the amido moiety has a formal bond order of one and is nearly 0.2 Å longer than the Ta=N bond length. The Ta—N—C bond angle [135.9 (11)°] indicates that, as with the imide, there is some metal–lone pair overlap. In the dimeric tBu analog the Ta—N amide bond is short at 1.86 (3) Å and exhibits an unusually almost linear Ta—N—C bond angle of 160 (2)°.
The Ta—N(H2) bond lengths of the two amine moieties of (I) (Table 1) are similar with a mean value 2.255 (8) Å and a mean Ta—NH2—C bond angle of [118.8 (19)°]. The amine dative interaction is again weaker than the amide as indicated by the approximately 0.3 Å elongation of the Ta—N bond length. The dative amine bond for the dimeric tBu analog is similar with a 2.23 (3) Å Ta—N bond length and 126 (2)° Ta—N—C angle.
In the crystal, molecules of (I) are linked by N—H···Cl hydrogen bonds (Table 2) about inversion centers to generate chains extending in the b direction.
As proposed by Jayaratne et al., (1996) we have shown that the structure of (I) is indeed monomeric and as such is potentially a very useful reference compound for comparison of amino, amido and imido bond lengths and angles. It is analogous to the structure of the alkyl/alkylidene/alkylidyne compound W(CH2CMe3)(CHCMe3)(CCMe3)(dmpe) [dmpe is 1,2-bis(dimethylphosphino)ethane] reported by Churchill & Youngs (1979) [CSD Refcode DMPMPW10] which is often cited for comparisons of metal-carbon bond lengths.
We used two-dimensional heteronuclear multiple bond correlation (HMBC) NMR spectroscopy to fully assign the 1H and 13C NMR spectra of (I). We also report 14N and 15N NMR spectroscopy data for this compound. The 1H NMR spectrum of the (I) depends on concentration. At low concentrations the NH2 protons for the amine moiety appear as a broad singlet in the δ 3.2–3.4 region of the spectrum. At higher concentrations, the amine protons shift upfield and become distinctive multiplets. It seems likely that the title compound is in equilibrium with a dimeric form that is analogous to that reported previously for the tBu derivative.