Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536810042704/zl2316sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536810042704/zl2316Isup2.hkl |
CCDC reference: 799491
Key indicators
- Single-crystal X-ray study
- T = 133 K
- Mean (C-C) = 0.004 Å
- Disorder in main residue
- R factor = 0.026
- wR factor = 0.061
- Data-to-parameter ratio = 23.8
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT057_ALERT_3_C Correction for Absorption Required RT(exp) ... 1.17 PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for C8 PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for C11 PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for C15 PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for C19 PLAT413_ALERT_2_C Short Inter XH3 .. XHn H13B .. H17 .. 2.11 Ang. PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) ..... 1 PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L= 0.600 7 PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF .... 2 PLAT048_ALERT_1_C MoietyFormula Not Given ........................ ? PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given ....... ? PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L= 0.600 43
Alert level G PLAT301_ALERT_3_G Note: Main Residue Disorder ................... 12.00 Perc.
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 12 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 5 ALERT type 2 Indicator that the structure model may be wrong or deficient 5 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
Preparation of tris[N,N'-bis(isopropyl)benzamidinato]cerium(III): A 100 ml Schlenk-flask was charged with lithium N,N'-bis(isopropyl)benzamidinate (3.00 g, 14.3 mmol), anhydrous cerium(III) trichloride (1.17 g, 4.8 mmol) and 100 ml of THF, and the mixture was stirred for 3 h at 333 K, causing the development of a bright yellow color. The mixture was evaporated to dryness and the residue was extracted with n-pentane (3 x 15 ml) followed by filtration. The clear filtrate was concentrated in vacuo to a total volume of ca 10 ml. Cooling to 237 K for 24 h afforded 2.42 g (67%) of tris[N,N'-bis(isopropyl)benzamidinato]cerium(III) as golden-yellow, block-like crystals. X-ray quality single crystals were grown from a saturated solution in n-pentane at 278 K. M. p. 486 K. Anal. calcd for C39H57CeN6 (750.03 g/mol): C 62.45, H 7.66, N 11.20; found: C 62.08, H 7.79, N 10.82%. IR (KBr pellet): νmax 3080 (w), 3061 (w), 3022 (w), 2957 (vs, nas CH3), 2916 (st), 2888 (st, nas CH3), 2861 (st), 1636 (m, NCN unit), 1600 (m, CH ring), 1578 (m, CH ring), 1453 (vsbr, das CH3), 1374 (vs, NCN unit), 1359 (vs), 1335 (vs), 1274 (w), 1208 (vs), 1166 (st, CH ring), 1133 (vs), 1122 (st), 1073 (w), 1005 (vs), 946 (w), 910 (w), 778 (st), 733 (m), 700 (vs, CH ring), 469 (w) cm-1. 1H NMR (400 MHz, C6D6, 298 K): δ = 12.85 (d, 3J = 4.7 Hz, 6H, Ar–H), 10.84 (s, 6H, ((CH3)2CHN)2CPh), 9.30 (s, 6H, Ar–H), 8.69 (t, 3J = 7.4 Hz, 3H, Ar–H), -3.29 (s br, 36H, ((CH3)2CHN)2CPh). 13C{1H} NMR (100.6 MHz, C6D6, 298 K): δ = 186.9 ((iPrN)2CPh), 148.52 (Ar-C), 132.8 (Ar-C), 131.6 (Ar-C), 130.3 (Ar-C), 52.8 ((CH3)2CHN)2CPh), 22.7 ((CH3)2CHN)2CPh). EI—MS: m/z 749.7 (40) [M]+, 546.3 (100) [M – (iPrN)2CPh]+, 203.2 (40) [(iPrN)2CPh]+, 104.1 (80) [HNCPh]+.
One of the phenyl rings is disordered over two alternative symmetry equivalent positions around the two fold rotation axis the molecule is located on. The disordered phenyl ring was contrained to resemble an ideal hexagon with C—C distances of 1.39 Å. No restraints for atom positions or ADPs needed to be applied.
The hydrogen atoms were included using a riding model, with aromatic C—H = 0.95 Å, methyn C—H = 1.00 Å [Uiso(H) = 1.2Ueq(C)] and methyl C—H = 0.98 Å [Uiso(H) = 1.5Ueq(C)].
A hot topic in current organolanthanide chemistry is the search for alternative spectator ligands other than cyclopentadienyls which are able to satisfy the coordination requirements of the large lanthanide cations (Edelmann et al., 2002). Among the most successful approaches in this field is the use of amidinate ligands of the general type [RC(NR')2]- (R = H, alkyl, aryl; R' = alkyl, cycloalkyl, aryl, SiMe3) which can be regarded as steric cyclopentadienyl equivalents (Bailey & Pace, 2001). Homoleptic lanthanide(III) tris(amidinates) are among the longest known lanthanide complexes containing these chelating ligands. The first lanthanide(III) amidinate complexes ever reported were homoleptic tris(amidinates) of the type [RC6H4C(NSiMe3)2]3Ln (Wedler et al., 1992). In 2002 it was discovered that homoleptic lanthanide tris(amidinate) complexes display extremely high activity for the ring-opening polymerization of e-caprolactone at room temperature. High catalytic activity of homoleptic lanthanide(III) tris(amidinate) has also been found for the polymerization of other polar monomers such as trimethylene carbonate (TMC), lactide, and methylmethacrylate (MMA) (Edelmann, 2009). Even more surprising was the finding that such complexes may turn out to be valuable precursors in materials science and nanotechnology (Edelmann, 2009). For example, pure metals can be deposited by using volatile homoleptic metal amidinato complexes of the type [{MeC(NR')2}nM]x (R = Me, But; R = Pri, But) and molecular hydrogen gas as the reactants (Lim et al., 2003). Lanthanide amidinate complexes have also been employed in the fabrication of lanthanide-doped inorganic phases by CVD methods (Päiväsaari et al., 2005). We report here the synthesis and structural characterization of a potentially useful homoleptic cerium amidinate, tris[N,N'-bis(isopropyl)benzamidinato]cerium(III). Besides X-ray crystallography, the title compound was also characterized by elemental analysis and spectroscopic methods. Due to the paramagnetic nature of the Ce3+ ion, the 1H NMR signals of the ortho-, meta- and para-phenyl protons appear well separated at δ 12.85, 9.30 and 8.69 p.p.m., respectively, while only broad singlets were observed for the isopropyl protons.
Golden-yellow, highly air-sensitive, block-like single crystals of the title compound were obtained by slow cooling of a saturated solution in n-pentane to 278 K. In the solid state the molecule is located on a C2 rotation axis, and one of the phenyl rings is disordered over two alternative symmetry equivalent positions around this axis. The coordination geometry around the central cerium(3+) ion can be described as distorted octahedral. The average Ce—N distance is 2.487 Å. With 53.95 (5) - 54.11 (7) the N—Ce—N angles are in the range which is typical for homoleptic lanthanide tris(amidinate) complexes (Edelmann, 2009). The dihedral angles between the phenyl rings and the chelating N—C—N units are in the range of 73.3 - 87.9 °, thus preventing conjugation between the two π -systems.
For general backround to lanthanide coordination complexes, see: Bailey & Pace (2001); Edelmann et al. (2002); Edelmann (2009). Wedler et al. (1992) describe complexes related to the title compound. For applications of homoleptic metal amidinato complexes, see: Lim et al. (2003); Päiväsaari et al. (2005).
Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-RED (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
Fig. 1. The molecule of the title compound in the crystal. Thermal ellipsoids represent 50% probability levels. The disorder of the phenyl ring C15 - C16A is omitted for clarity. |
[Ce(C13H19N2)3] | F(000) = 1564 |
Mr = 750.03 | Dx = 1.225 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
a = 14.1225 (4) Å | Cell parameters from 58857 reflections |
b = 18.5957 (6) Å | θ = 2.1–29.6° |
c = 15.6544 (4) Å | µ = 1.15 mm−1 |
β = 98.324 (2)° | T = 133 K |
V = 4067.8 (2) Å3 | Prism, yellow |
Z = 4 | 0.30 × 0.20 × 0.10 mm |
Stoe IPDS 2T diffractometer | 5147 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.048 |
Plane graphite monochromator | θmax = 29.2°, θmin = 2.1° |
Detector resolution: 6.67 pixels mm-1 | h = −19→19 |
rotation method scans | k = −25→25 |
32963 measured reflections | l = −21→20 |
5485 independent reflections |
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)] = 0.026 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.061 | H-atom parameters constrained |
S = 1.11 | w = 1/[σ2(Fo2) + (0.031P)2 + 1.6552P] where P = (Fo2 + 2Fc2)/3 |
5485 reflections | (Δ/σ)max = 0.002 |
230 parameters | Δρmax = 0.64 e Å−3 |
0 restraints | Δρmin = −1.00 e Å−3 |
[Ce(C13H19N2)3] | V = 4067.8 (2) Å3 |
Mr = 750.03 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 14.1225 (4) Å | µ = 1.15 mm−1 |
b = 18.5957 (6) Å | T = 133 K |
c = 15.6544 (4) Å | 0.30 × 0.20 × 0.10 mm |
β = 98.324 (2)° |
Stoe IPDS 2T diffractometer | 5147 reflections with I > 2σ(I) |
32963 measured reflections | Rint = 0.048 |
5485 independent reflections |
R[F2 > 2σ(F2)] = 0.026 | 0 restraints |
wR(F2) = 0.061 | H-atom parameters constrained |
S = 1.11 | Δρmax = 0.64 e Å−3 |
5485 reflections | Δρmin = −1.00 e Å−3 |
230 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. The phenyl ring with two carbon atoms located on the C2 rotation axis lies in two alternative symmetry related positions. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Ce | 0.5000 | 0.699350 (7) | 0.7500 | 0.03398 (5) | |
N1 | 0.56280 (13) | 0.78730 (10) | 0.86347 (14) | 0.0595 (5) | |
N2 | 0.41661 (11) | 0.74104 (9) | 0.87036 (11) | 0.0465 (4) | |
N3 | 0.57059 (11) | 0.57999 (8) | 0.79492 (11) | 0.0471 (4) | |
C1 | 0.48506 (13) | 0.78591 (10) | 0.90212 (13) | 0.0444 (4) | |
C2 | 0.47606 (12) | 0.83394 (10) | 0.97814 (12) | 0.0413 (4) | |
C3 | 0.52818 (15) | 0.82015 (13) | 1.05786 (14) | 0.0526 (4) | |
H3 | 0.5700 | 0.7799 | 1.0648 | 0.063* | |
C4 | 0.52048 (16) | 0.86400 (15) | 1.12785 (15) | 0.0599 (5) | |
H4 | 0.5566 | 0.8536 | 1.1825 | 0.072* | |
C5 | 0.46115 (17) | 0.92218 (13) | 1.11859 (15) | 0.0592 (5) | |
H5 | 0.4554 | 0.9521 | 1.1667 | 0.071* | |
C6 | 0.40972 (18) | 0.93729 (12) | 1.03927 (16) | 0.0606 (5) | |
H6 | 0.3692 | 0.9783 | 1.0325 | 0.073* | |
C7 | 0.41652 (16) | 0.89307 (11) | 0.96895 (14) | 0.0521 (4) | |
H7 | 0.3801 | 0.9036 | 0.9145 | 0.062* | |
C8 | 0.33639 (13) | 0.72355 (12) | 0.91592 (13) | 0.0475 (4) | |
H8 | 0.3350 | 0.7586 | 0.9641 | 0.057* | |
C9 | 0.3499 (2) | 0.64907 (17) | 0.9530 (2) | 0.0829 (9) | |
H9A | 0.3575 | 0.6149 | 0.9068 | 0.124* | |
H9B | 0.2938 | 0.6357 | 0.9798 | 0.124* | |
H9C | 0.4071 | 0.6480 | 0.9966 | 0.124* | |
C10 | 0.24360 (16) | 0.7286 (2) | 0.85526 (17) | 0.0734 (7) | |
H10A | 0.2345 | 0.7780 | 0.8338 | 0.110* | |
H10B | 0.1904 | 0.7153 | 0.8860 | 0.110* | |
H10C | 0.2454 | 0.6958 | 0.8065 | 0.110* | |
C11 | 0.63744 (17) | 0.84142 (15) | 0.88303 (17) | 0.0688 (7) | |
H11 | 0.6314 | 0.8656 | 0.9391 | 0.083* | |
C12 | 0.6317 (3) | 0.89570 (16) | 0.8125 (3) | 0.1140 (15) | |
H12A | 0.6431 | 0.8721 | 0.7589 | 0.171* | |
H12B | 0.6803 | 0.9329 | 0.8280 | 0.171* | |
H12C | 0.5680 | 0.9178 | 0.8040 | 0.171* | |
C13 | 0.7336 (2) | 0.8035 (2) | 0.8890 (3) | 0.1099 (14) | |
H13A | 0.7361 | 0.7641 | 0.9309 | 0.165* | |
H13B | 0.7851 | 0.8378 | 0.9076 | 0.165* | |
H13C | 0.7414 | 0.7840 | 0.8322 | 0.165* | |
C14 | 0.5000 | 0.54307 (13) | 0.7500 | 0.0408 (5) | |
C15 | 0.5009 (10) | 0.46299 (10) | 0.7603 (6) | 0.0382 (13) | 0.50 |
C16 | 0.4568 (8) | 0.4312 (3) | 0.8245 (4) | 0.068 (2) | 0.50 |
H16 | 0.4272 | 0.4603 | 0.8630 | 0.081* | 0.50 |
C17 | 0.4559 (5) | 0.3567 (3) | 0.8326 (3) | 0.088 (2) | 0.50 |
H17 | 0.4258 | 0.3350 | 0.8765 | 0.105* | 0.50 |
C18 | 0.4992 (6) | 0.31412 (11) | 0.7763 (4) | 0.074 (2) | 0.50 |
H18 | 0.4986 | 0.2633 | 0.7818 | 0.089* | 0.50 |
C17A | 0.5434 (4) | 0.3460 (2) | 0.7121 (3) | 0.0754 (19) | 0.50 |
H17A | 0.5729 | 0.3168 | 0.6736 | 0.090* | 0.50 |
C16A | 0.5442 (7) | 0.4204 (2) | 0.7040 (4) | 0.0574 (15) | 0.50 |
H16A | 0.5744 | 0.4421 | 0.6601 | 0.069* | 0.50 |
C19 | 0.64510 (15) | 0.54478 (12) | 0.85451 (16) | 0.0561 (5) | |
H19 | 0.6431 | 0.4920 | 0.8424 | 0.067* | |
C20 | 0.74139 (19) | 0.5732 (2) | 0.8419 (3) | 0.0961 (11) | |
H20A | 0.7531 | 0.5625 | 0.7830 | 0.144* | |
H20B | 0.7909 | 0.5502 | 0.8833 | 0.144* | |
H20C | 0.7432 | 0.6253 | 0.8511 | 0.144* | |
C21 | 0.6265 (3) | 0.5570 (3) | 0.9468 (2) | 0.1027 (12) | |
H21A | 0.6280 | 0.6086 | 0.9593 | 0.154* | |
H21B | 0.6759 | 0.5326 | 0.9869 | 0.154* | |
H21C | 0.5635 | 0.5376 | 0.9536 | 0.154* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ce | 0.03793 (7) | 0.03059 (7) | 0.03552 (7) | 0.000 | 0.01243 (5) | 0.000 |
N1 | 0.0504 (9) | 0.0655 (11) | 0.0698 (12) | −0.0243 (8) | 0.0333 (8) | −0.0329 (9) |
N2 | 0.0442 (7) | 0.0518 (9) | 0.0486 (8) | −0.0133 (7) | 0.0235 (7) | −0.0136 (7) |
N3 | 0.0468 (8) | 0.0351 (7) | 0.0554 (9) | 0.0003 (6) | −0.0058 (7) | 0.0001 (6) |
C1 | 0.0440 (8) | 0.0453 (9) | 0.0476 (9) | −0.0064 (7) | 0.0195 (7) | −0.0107 (7) |
C2 | 0.0411 (8) | 0.0422 (9) | 0.0439 (9) | −0.0063 (7) | 0.0174 (7) | −0.0080 (7) |
C3 | 0.0478 (10) | 0.0607 (11) | 0.0509 (11) | 0.0047 (9) | 0.0124 (8) | −0.0057 (9) |
C4 | 0.0549 (11) | 0.0809 (15) | 0.0447 (10) | −0.0078 (11) | 0.0102 (9) | −0.0118 (10) |
C5 | 0.0656 (12) | 0.0619 (13) | 0.0543 (11) | −0.0135 (10) | 0.0229 (10) | −0.0223 (10) |
C6 | 0.0748 (14) | 0.0459 (10) | 0.0651 (13) | 0.0059 (10) | 0.0232 (11) | −0.0104 (10) |
C7 | 0.0615 (11) | 0.0483 (10) | 0.0481 (10) | 0.0035 (9) | 0.0138 (8) | −0.0037 (8) |
C8 | 0.0432 (9) | 0.0557 (10) | 0.0478 (10) | −0.0125 (8) | 0.0215 (8) | −0.0093 (8) |
C9 | 0.0660 (15) | 0.0777 (18) | 0.112 (2) | −0.0061 (13) | 0.0372 (15) | 0.0276 (17) |
C10 | 0.0447 (11) | 0.117 (2) | 0.0627 (14) | −0.0066 (12) | 0.0206 (10) | −0.0024 (15) |
C11 | 0.0597 (12) | 0.0783 (16) | 0.0766 (15) | −0.0355 (12) | 0.0377 (11) | −0.0441 (13) |
C12 | 0.093 (2) | 0.0517 (15) | 0.193 (4) | −0.0297 (15) | 0.006 (3) | 0.003 (2) |
C13 | 0.0566 (15) | 0.127 (3) | 0.139 (4) | −0.0321 (17) | −0.0075 (19) | 0.001 (3) |
C14 | 0.0412 (11) | 0.0337 (11) | 0.0476 (13) | 0.000 | 0.0075 (10) | 0.000 |
C15 | 0.0347 (11) | 0.0388 (12) | 0.041 (4) | 0.004 (2) | 0.005 (3) | −0.0062 (17) |
C16 | 0.079 (4) | 0.047 (3) | 0.087 (6) | 0.006 (3) | 0.043 (5) | 0.005 (3) |
C17 | 0.097 (5) | 0.056 (3) | 0.120 (7) | 0.005 (3) | 0.053 (5) | 0.017 (4) |
C18 | 0.076 (3) | 0.0347 (19) | 0.113 (7) | −0.001 (2) | 0.021 (5) | 0.004 (2) |
C17A | 0.089 (4) | 0.035 (3) | 0.111 (6) | 0.008 (3) | 0.045 (4) | −0.013 (3) |
C16A | 0.071 (3) | 0.038 (2) | 0.070 (4) | 0.003 (2) | 0.035 (3) | −0.004 (2) |
C19 | 0.0502 (10) | 0.0450 (10) | 0.0678 (13) | 0.0025 (8) | −0.0093 (9) | 0.0033 (9) |
C20 | 0.0523 (13) | 0.106 (2) | 0.124 (3) | −0.0045 (14) | −0.0092 (15) | 0.042 (2) |
C21 | 0.098 (2) | 0.143 (3) | 0.0621 (17) | 0.027 (2) | −0.0057 (16) | 0.018 (2) |
Ce—N1 | 2.4820 (17) | C10—H10B | 0.9800 |
Ce—N1i | 2.4820 (17) | C10—H10C | 0.9800 |
Ce—N2 | 2.4860 (14) | C11—C12 | 1.490 (5) |
Ce—N2i | 2.4860 (14) | C11—C13 | 1.521 (5) |
Ce—N3i | 2.4924 (15) | C11—H11 | 1.0000 |
Ce—N3 | 2.4924 (15) | C12—H12A | 0.9800 |
Ce—C14 | 2.906 (2) | C12—H12B | 0.9800 |
Ce—C1 | 2.9071 (18) | C12—H12C | 0.9800 |
Ce—C1i | 2.9071 (18) | C13—H13A | 0.9800 |
N1—C1 | 1.328 (2) | C13—H13B | 0.9800 |
N1—C11 | 1.458 (2) | C13—H13C | 0.9800 |
N2—C1 | 1.319 (2) | C14—N3i | 1.325 (2) |
N2—C8 | 1.460 (2) | C14—C15i | 1.498 (3) |
N3—C14 | 1.325 (2) | C14—C15 | 1.498 (3) |
N3—C19 | 1.457 (2) | C15—C16 | 1.3900 |
C1—C2 | 1.508 (2) | C15—C16A | 1.3900 |
C2—C3 | 1.378 (3) | C16—C17 | 1.3900 |
C2—C7 | 1.379 (3) | C16—H16 | 0.9500 |
C3—C4 | 1.383 (3) | C17—C18 | 1.3900 |
C3—H3 | 0.9500 | C17—H17 | 0.9500 |
C4—C5 | 1.363 (4) | C18—C17A | 1.3900 |
C4—H4 | 0.9500 | C18—H18 | 0.9500 |
C5—C6 | 1.374 (4) | C17A—C16A | 1.3900 |
C5—H5 | 0.9500 | C17A—H17A | 0.9500 |
C6—C7 | 1.389 (3) | C16A—H16A | 0.9500 |
C6—H6 | 0.9500 | C19—C20 | 1.498 (4) |
C7—H7 | 0.9500 | C19—C21 | 1.522 (4) |
C8—C9 | 1.503 (4) | C19—H19 | 1.0000 |
C8—C10 | 1.506 (3) | C20—H20A | 0.9800 |
C8—H8 | 1.0000 | C20—H20B | 0.9800 |
C9—H9A | 0.9800 | C20—H20C | 0.9800 |
C9—H9B | 0.9800 | C21—H21A | 0.9800 |
C9—H9C | 0.9800 | C21—H21B | 0.9800 |
C10—H10A | 0.9800 | C21—H21C | 0.9800 |
N1—Ce—N1i | 97.57 (11) | C8—C9—H9C | 109.5 |
N1—Ce—N2 | 53.95 (5) | H9A—C9—H9C | 109.5 |
N1i—Ce—N2 | 100.23 (6) | H9B—C9—H9C | 109.5 |
N1—Ce—N2i | 100.23 (6) | C8—C10—H10A | 109.5 |
N1i—Ce—N2i | 53.95 (5) | C8—C10—H10B | 109.5 |
N2—Ce—N2i | 143.66 (8) | H10A—C10—H10B | 109.5 |
N1—Ce—N3i | 151.12 (7) | C8—C10—H10C | 109.5 |
N1i—Ce—N3i | 107.34 (7) | H10A—C10—H10C | 109.5 |
N2—Ce—N3i | 106.11 (6) | H10B—C10—H10C | 109.5 |
N2i—Ce—N3i | 106.13 (6) | N1—C11—C12 | 110.6 (2) |
N1—Ce—N3 | 107.34 (7) | N1—C11—C13 | 107.7 (2) |
N1i—Ce—N3 | 151.12 (7) | C12—C11—C13 | 108.2 (3) |
N2—Ce—N3 | 106.13 (6) | N1—C11—H11 | 110.1 |
N2i—Ce—N3 | 106.11 (6) | C12—C11—H11 | 110.1 |
N3i—Ce—N3 | 54.12 (7) | C13—C11—H11 | 110.1 |
N1—Ce—C14 | 131.22 (6) | C11—C12—H12A | 109.5 |
N1i—Ce—C14 | 131.22 (6) | C11—C12—H12B | 109.5 |
N2—Ce—C14 | 108.17 (4) | H12A—C12—H12B | 109.5 |
N2i—Ce—C14 | 108.17 (4) | C11—C12—H12C | 109.5 |
N1i—Ce—C1 | 99.24 (7) | H12A—C12—H12C | 109.5 |
N2i—Ce—C1 | 123.14 (6) | H12B—C12—H12C | 109.5 |
N3i—Ce—C1 | 130.59 (6) | C11—C13—H13A | 109.5 |
N3—Ce—C1 | 109.60 (6) | C11—C13—H13B | 109.5 |
C14—Ce—C1 | 123.62 (4) | H13A—C13—H13B | 109.5 |
N1—Ce—C1i | 99.24 (7) | C11—C13—H13C | 109.5 |
N2—Ce—C1i | 123.14 (6) | H13A—C13—H13C | 109.5 |
N3i—Ce—C1i | 109.60 (6) | H13B—C13—H13C | 109.5 |
N3—Ce—C1i | 130.59 (6) | N3—C14—N3i | 117.6 (2) |
C14—Ce—C1i | 123.62 (4) | N3—C14—C15i | 124.5 (6) |
C1—Ce—C1i | 112.76 (8) | N3i—C14—C15i | 117.6 (6) |
C1—N1—C11 | 122.56 (17) | N3—C14—C15 | 117.6 (6) |
C1—N1—Ce | 94.58 (12) | N3i—C14—C15 | 124.5 (6) |
C11—N1—Ce | 141.07 (13) | N3—C14—Ce | 58.81 (11) |
C1—N2—C8 | 122.34 (16) | N3i—C14—Ce | 58.81 (11) |
C1—N2—Ce | 94.66 (10) | C15i—C14—Ce | 173.9 (3) |
C8—N2—Ce | 141.91 (12) | C15—C14—Ce | 173.9 (3) |
C14—N3—C19 | 121.67 (16) | C16—C15—C16A | 120.0 |
C14—N3—Ce | 94.14 (12) | C16—C15—C14 | 120.2 (5) |
C19—N3—Ce | 143.45 (13) | C16A—C15—C14 | 119.8 (5) |
N2—C1—N1 | 116.73 (16) | C17—C16—C15 | 120.0 |
N2—C1—C2 | 122.10 (15) | C17—C16—H16 | 120.0 |
N1—C1—C2 | 121.17 (16) | C15—C16—H16 | 120.0 |
N2—C1—Ce | 58.46 (9) | C16—C17—C18 | 120.0 |
N1—C1—Ce | 58.33 (10) | C16—C17—H17 | 120.0 |
C2—C1—Ce | 177.18 (14) | C18—C17—H17 | 120.0 |
C3—C2—C7 | 118.72 (18) | C17A—C18—C17 | 120.0 |
C3—C2—C1 | 120.63 (18) | C17A—C18—H18 | 120.0 |
C7—C2—C1 | 120.65 (18) | C17—C18—H18 | 120.0 |
C2—C3—C4 | 121.0 (2) | C18—C17A—C16A | 120.0 |
C2—C3—H3 | 119.5 | C18—C17A—H17A | 120.0 |
C4—C3—H3 | 119.5 | C16A—C17A—H17A | 120.0 |
C5—C4—C3 | 120.1 (2) | C17A—C16A—C15 | 120.0 |
C5—C4—H4 | 120.0 | C17A—C16A—H16A | 120.0 |
C3—C4—H4 | 120.0 | C15—C16A—H16A | 120.0 |
C4—C5—C6 | 119.7 (2) | N3—C19—C20 | 110.0 (2) |
C4—C5—H5 | 120.2 | N3—C19—C21 | 109.4 (2) |
C6—C5—H5 | 120.2 | C20—C19—C21 | 111.0 (3) |
C5—C6—C7 | 120.5 (2) | N3—C19—H19 | 108.8 |
C5—C6—H6 | 119.8 | C20—C19—H19 | 108.8 |
C7—C6—H6 | 119.8 | C21—C19—H19 | 108.8 |
C2—C7—C6 | 120.0 (2) | C19—C20—H20A | 109.5 |
C2—C7—H7 | 120.0 | C19—C20—H20B | 109.5 |
C6—C7—H7 | 120.0 | H20A—C20—H20B | 109.5 |
N2—C8—C9 | 109.27 (18) | C19—C20—H20C | 109.5 |
N2—C8—C10 | 110.12 (17) | H20A—C20—H20C | 109.5 |
C9—C8—C10 | 110.5 (2) | H20B—C20—H20C | 109.5 |
N2—C8—H8 | 109.0 | C19—C21—H21A | 109.5 |
C9—C8—H8 | 109.0 | C19—C21—H21B | 109.5 |
C10—C8—H8 | 109.0 | H21A—C21—H21B | 109.5 |
C8—C9—H9A | 109.5 | C19—C21—H21C | 109.5 |
C8—C9—H9B | 109.5 | H21A—C21—H21C | 109.5 |
H9A—C9—H9B | 109.5 | H21B—C21—H21C | 109.5 |
N1i—Ce—N1—C1 | 95.52 (15) | C14—Ce—C1—N2 | −61.08 (14) |
N2—Ce—N1—C1 | −1.66 (13) | C1i—Ce—C1—N2 | 118.92 (14) |
N2i—Ce—N1—C1 | 150.12 (14) | N1i—Ce—C1—N1 | −88.55 (18) |
N3i—Ce—N1—C1 | −54.1 (2) | N2—Ce—C1—N1 | 177.0 (2) |
N3—Ce—N1—C1 | −99.29 (15) | N2i—Ce—C1—N1 | −35.84 (17) |
C14—Ce—N1—C1 | −84.48 (15) | N3i—Ce—C1—N1 | 148.96 (14) |
C1i—Ce—N1—C1 | 122.86 (14) | N3—Ce—C1—N1 | 89.91 (15) |
N1i—Ce—N1—C11 | −67.9 (3) | C14—Ce—C1—N1 | 115.96 (14) |
N2—Ce—N1—C11 | −165.1 (3) | C1i—Ce—C1—N1 | −64.04 (14) |
N2i—Ce—N1—C11 | −13.3 (3) | N2—C1—C2—C3 | 107.5 (2) |
N3i—Ce—N1—C11 | 142.4 (3) | N1—C1—C2—C3 | −73.0 (3) |
N3—Ce—N1—C11 | 97.3 (3) | N2—C1—C2—C7 | −73.4 (3) |
C14—Ce—N1—C11 | 112.1 (3) | N1—C1—C2—C7 | 106.2 (2) |
C1—Ce—N1—C11 | −163.4 (4) | C7—C2—C3—C4 | 0.7 (3) |
C1i—Ce—N1—C11 | −40.5 (3) | C1—C2—C3—C4 | 179.88 (19) |
N1—Ce—N2—C1 | 1.67 (13) | C2—C3—C4—C5 | −0.4 (4) |
N1i—Ce—N2—C1 | −90.29 (14) | C3—C4—C5—C6 | −0.5 (4) |
N2i—Ce—N2—C1 | −50.10 (12) | C4—C5—C6—C7 | 1.1 (4) |
N3i—Ce—N2—C1 | 158.16 (12) | C3—C2—C7—C6 | −0.2 (3) |
N3—Ce—N2—C1 | 101.64 (13) | C1—C2—C7—C6 | −179.3 (2) |
C14—Ce—N2—C1 | 129.90 (12) | C5—C6—C7—C2 | −0.8 (4) |
C1i—Ce—N2—C1 | −74.56 (17) | C1—N2—C8—C9 | −105.7 (3) |
N1—Ce—N2—C8 | −165.3 (3) | Ce—N2—C8—C9 | 58.8 (3) |
N1i—Ce—N2—C8 | 102.8 (2) | C1—N2—C8—C10 | 132.7 (2) |
N2i—Ce—N2—C8 | 143.0 (2) | Ce—N2—C8—C10 | −62.8 (3) |
N3i—Ce—N2—C8 | −8.8 (2) | C1—N1—C11—C12 | −104.8 (3) |
N3—Ce—N2—C8 | −65.3 (2) | Ce—N1—C11—C12 | 55.4 (4) |
C14—Ce—N2—C8 | −37.0 (2) | C1—N1—C11—C13 | 137.2 (3) |
C1—Ce—N2—C8 | −166.9 (3) | Ce—N1—C11—C13 | −62.6 (4) |
C1i—Ce—N2—C8 | 118.5 (2) | C19—N3—C14—N3i | 172.3 (2) |
N1—Ce—N3—C14 | 155.00 (8) | C19—N3—C14—C15i | −13.8 (4) |
N1i—Ce—N3—C14 | −56.63 (17) | Ce—N3—C14—C15i | 173.9 (3) |
N2—Ce—N3—C14 | 98.47 (9) | C19—N3—C14—C15 | −2.0 (4) |
N2i—Ce—N3—C14 | −98.51 (9) | Ce—N3—C14—C15 | −174.3 (3) |
C1—Ce—N3—C14 | 126.50 (9) | C19—N3—C14—Ce | 172.3 (2) |
C1i—Ce—N3—C14 | −85.72 (11) | N1—Ce—C14—N3 | −32.43 (11) |
N1—Ce—N3—C19 | −14.0 (3) | N1i—Ce—C14—N3 | 147.57 (11) |
N1i—Ce—N3—C19 | 134.4 (2) | N2—Ce—C14—N3 | −90.02 (10) |
N2—Ce—N3—C19 | −70.5 (3) | N2i—Ce—C14—N3 | 89.98 (10) |
N2i—Ce—N3—C19 | 92.5 (3) | C1—Ce—C14—N3 | −65.41 (11) |
N3i—Ce—N3—C19 | −169.0 (3) | C1i—Ce—C14—N3 | 114.59 (11) |
C14—Ce—N3—C19 | −169.0 (3) | N1—Ce—C14—N3i | 147.57 (11) |
C1—Ce—N3—C19 | −42.5 (3) | N1i—Ce—C14—N3i | −32.43 (11) |
C1i—Ce—N3—C19 | 105.3 (3) | N2—Ce—C14—N3i | 89.98 (10) |
C8—N2—C1—N1 | 167.7 (2) | N2i—Ce—C14—N3i | −90.02 (10) |
Ce—N2—C1—N1 | −2.8 (2) | C1—Ce—C14—N3i | 114.59 (11) |
C8—N2—C1—C2 | −12.8 (3) | C1i—Ce—C14—N3i | −65.41 (11) |
Ce—N2—C1—C2 | 176.75 (17) | N3—C14—C15—C16 | 88.9 (6) |
C8—N2—C1—Ce | 170.5 (2) | N3i—C14—C15—C16 | −85.0 (5) |
C11—N1—C1—N2 | 170.5 (2) | C15i—C14—C15—C16 | −144 (5) |
Ce—N1—C1—N2 | 2.8 (2) | N3—C14—C15—C16A | −92.6 (5) |
C11—N1—C1—C2 | −9.0 (4) | N3i—C14—C15—C16A | 93.5 (6) |
Ce—N1—C1—C2 | −176.75 (17) | C15i—C14—C15—C16A | 34 (4) |
C11—N1—C1—Ce | 167.7 (3) | C14—C15—C16—C17 | 178.5 (11) |
N1—Ce—C1—N2 | −177.0 (2) | C14—C15—C16A—C17A | −178.5 (11) |
N1i—Ce—C1—N2 | 94.41 (13) | C14—N3—C19—C20 | 134.4 (2) |
N2i—Ce—C1—N2 | 147.12 (11) | Ce—N3—C19—C20 | −58.5 (4) |
N3i—Ce—C1—N2 | −28.07 (16) | C14—N3—C19—C21 | −103.4 (3) |
N3—Ce—C1—N2 | −87.12 (13) | Ce—N3—C19—C21 | 63.7 (3) |
Symmetry code: (i) −x+1, y, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | [Ce(C13H19N2)3] |
Mr | 750.03 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 133 |
a, b, c (Å) | 14.1225 (4), 18.5957 (6), 15.6544 (4) |
β (°) | 98.324 (2) |
V (Å3) | 4067.8 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.15 |
Crystal size (mm) | 0.30 × 0.20 × 0.10 |
Data collection | |
Diffractometer | Stoe IPDS 2T |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 32963, 5485, 5147 |
Rint | 0.048 |
(sin θ/λ)max (Å−1) | 0.687 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.026, 0.061, 1.11 |
No. of reflections | 5485 |
No. of parameters | 230 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.64, −1.00 |
Computer programs: X-AREA (Stoe & Cie, 2002), X-RED (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP (Siemens, 1994).
A hot topic in current organolanthanide chemistry is the search for alternative spectator ligands other than cyclopentadienyls which are able to satisfy the coordination requirements of the large lanthanide cations (Edelmann et al., 2002). Among the most successful approaches in this field is the use of amidinate ligands of the general type [RC(NR')2]- (R = H, alkyl, aryl; R' = alkyl, cycloalkyl, aryl, SiMe3) which can be regarded as steric cyclopentadienyl equivalents (Bailey & Pace, 2001). Homoleptic lanthanide(III) tris(amidinates) are among the longest known lanthanide complexes containing these chelating ligands. The first lanthanide(III) amidinate complexes ever reported were homoleptic tris(amidinates) of the type [RC6H4C(NSiMe3)2]3Ln (Wedler et al., 1992). In 2002 it was discovered that homoleptic lanthanide tris(amidinate) complexes display extremely high activity for the ring-opening polymerization of e-caprolactone at room temperature. High catalytic activity of homoleptic lanthanide(III) tris(amidinate) has also been found for the polymerization of other polar monomers such as trimethylene carbonate (TMC), lactide, and methylmethacrylate (MMA) (Edelmann, 2009). Even more surprising was the finding that such complexes may turn out to be valuable precursors in materials science and nanotechnology (Edelmann, 2009). For example, pure metals can be deposited by using volatile homoleptic metal amidinato complexes of the type [{MeC(NR')2}nM]x (R = Me, But; R = Pri, But) and molecular hydrogen gas as the reactants (Lim et al., 2003). Lanthanide amidinate complexes have also been employed in the fabrication of lanthanide-doped inorganic phases by CVD methods (Päiväsaari et al., 2005). We report here the synthesis and structural characterization of a potentially useful homoleptic cerium amidinate, tris[N,N'-bis(isopropyl)benzamidinato]cerium(III). Besides X-ray crystallography, the title compound was also characterized by elemental analysis and spectroscopic methods. Due to the paramagnetic nature of the Ce3+ ion, the 1H NMR signals of the ortho-, meta- and para-phenyl protons appear well separated at δ 12.85, 9.30 and 8.69 p.p.m., respectively, while only broad singlets were observed for the isopropyl protons.
Golden-yellow, highly air-sensitive, block-like single crystals of the title compound were obtained by slow cooling of a saturated solution in n-pentane to 278 K. In the solid state the molecule is located on a C2 rotation axis, and one of the phenyl rings is disordered over two alternative symmetry equivalent positions around this axis. The coordination geometry around the central cerium(3+) ion can be described as distorted octahedral. The average Ce—N distance is 2.487 Å. With 53.95 (5) - 54.11 (7) the N—Ce—N angles are in the range which is typical for homoleptic lanthanide tris(amidinate) complexes (Edelmann, 2009). The dihedral angles between the phenyl rings and the chelating N—C—N units are in the range of 73.3 - 87.9 °, thus preventing conjugation between the two π -systems.