metal-organic compounds
Bis{N-[(diethylamino)dimethylsilyl]anilinido-κ2N,N′}nickel(II)
aDepartment of Chemistry, Taiyuan Teachers College, Taiyuan 030031, People's Republic of China, and bCollege of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, 030006, People's Republic of China
*Correspondence e-mail: sdbai@sxu.edu.cn
The mononuclear NiII amide, [Ni(C12H21N2Si)2], has the NiII atom N,N′-chelated by the N-silylated anilinide ligands. The ligands are arranged cis to each other and obey the C2-symmetry operation. The two ends of the N—Si—N chelating unit exhibit different affinities for the metal atom: the Ni—Nanilinide bond length is 1.913 (3) Å and Ni—Namine is 2.187 (3) Å. The four-coordinate NiII ion demonstrates a distorted tetrahedral geometry.
Related literature
For related reviews of metal et al. (1996); Kempe (2000). For the catalytic applications of related N-silylated anilinide group 4 metal compounds towards olefin polymerization, see: Gibson et al. (1998); Hill & Hitchcock (2002); Yuan et al. (2010); Zai et al. (2010). For related organometallic compounds with analogous anilinide ligands, see: Schumann et al. (2000); Chen (2008, 2009).
see: HolmExperimental
Crystal data
|
Data collection: SMART (Bruker, 2000); cell SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.
Supporting information
10.1107/S1600536812008550/rk2340sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812008550/rk2340Isup2.hkl
A solution of LiBun (1.6 M, 1.9 ml, 3.0 mmol) in hexane was slowly added into a solution of N–[(diethylamino)dimethylsilyl]aniline (0.67 g, 3.0 mmol) in THF (20 ml) at 273 K by syringe. The mixture was stirred at room temperature for two hours and then added to a stirring suspension of NiCl2 (0.20 g, 1.5 mmol) in THF (20 ml) at 273 K. The resulting mixture was stirred at room temperature for 8 h. Then all the volatiles were removed under vacuum. The residue was extracted with toluene (25 ml). The filtrate was concentrated to give the title compound as red crystals (yield 0.39 g, 52%). M.p.: 451–452 K. MS (EI, 70 eV): m/z 502 [M]+. Anal. Calc. for C24H42Ni2N4Si2: C, 57.48; H, 8.44; N, 11.17%. Found: C, 56.99; H, 8.13; N, 10.93%.
The methyl H atoms were constrained to an ideal geometry, with C—H distances of 0.96Å and Uiso(H) = 1.5Ueq(C), but each group was allowed to rotate freely about its C–C and C–Si bonds. The methylene H atoms were constrained with C—H distances of 0.97Å and Uiso(H) = 1.2Ueq(C). The phenyl H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C—H distances in the range 0.93Å and Uiso(H) = 1.2Ueq(C).
Metal
were important substitutes for cyclopentadienyl derivatives and were found to have valuable applications in various industrial and biological processes (Holm et al., 1996; Kempe, 2000). Group 4 metal with the N-silylated anilinide ligands were active catalysts for olefin polymerization (Gibson et al., 1998; Hill & Hitchcock, 2002). Our research interest focused on N-silylated anilinide ligands bearing a pendant amino group. Analogous compounds with different metals including Zn (Schumann et al., 2000), Zr (Chen, 2009) and Fe (Chen, 2008) have been synthesized and the zirconium compounds were reported showing good performance in ethylene polymerization (Yuan et al., 2010). Recently, a kind of bidentate N–donor ligand supported nickel complex activated by MAO was used as a catalyst conducting longstanding living ethylene polymerization (Zai et al., 2010). In view of the importance of these compounds, the synthesis and of a new nickel(II) anilinide complex is reported.The title compound was prepared by one–pot reaction of LiBun, N–[(diethylamino)dimethylsilyl]aniline and NiCl2. It is monomeric and the ligand has an N—Si—N chelating group. It is presumed that the empty d–orbitals on silicon would interact with the lone–pair electrons on the p–orbital of nitrogen center through a d···pπ interaction, resulting in a "quasi" conjugated N—Si—N motif. Compared with rigid N—C—N chelating unit in the amidinate ligand, the N1—Si1—N2 chelating group is much flexible. The Ni center is fixed by two ligands. Each ligand bites the center with an N1—Ni1—N2 angle of 77.82 (11)°. As biting the metal center, the angle of N1—Si1—N2 is constrained to be 95.28 (13)°. The two ends of the N—Si—N chelating unit exhibit different affinities for the metal center. Ni—Nanilinide bond is 1.913 (3) Å and Ni—Namino bond is 2.187 (3)Å. The coordinate geometry of Nanilinide atom is trigonal planar (sum of three angles around it being 359°). Both distances of Si1—N1 (1.699 (3)Å) and N1—C1 (1.375 (4)Å) are short. It suggests a certain degree delocalization of the lone–pair electron density from the p–orbital of N1 to the π–orbital of the phenylsubstituent. The two ligands around the Ni atom are arranged cis to each other and obey the C2 The four-coordinate Ni atom demonstrates a distorted tetrahedral geometry.
For related reviews of meatal
see: Holm et al. (1996); Kempe (2000). For the catalytic applications of related N-silylated analido group 4 metal compounds towards olefin polymerization, see: Gibson et al. (1998); Hill & Hitchcock (2002); Yuan et al. (2010); Zai et al. (2010). For related organometallic compounds with analogous analido ligands, see: Schumann et al. (2000); Chen (2008, 2009).Data collection: SMART (Bruker, 2000); cell
SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).[Ni(C12H21N2Si)2] | Dx = 1.210 Mg m−3 |
Mr = 501.49 | Melting point = 451–452 K |
Orthorhombic, Fdd2 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: F 2 -2d | Cell parameters from 2035 reflections |
a = 21.2631 (11) Å | θ = 2.1–26.4° |
b = 30.0347 (16) Å | µ = 0.81 mm−1 |
c = 8.6228 (5) Å | T = 295 K |
V = 5506.8 (5) Å3 | Block, red |
Z = 8 | 0.25 × 0.20 × 0.20 mm |
F(000) = 2160 |
Bruker SMART CCD diffractometer | 2414 independent reflections |
Radiation source: fine-focus sealed tube | 2145 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.029 |
φ and ω scan | θmax = 25.5°, θmin = 2.4° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −25→22 |
Tmin = 0.823, Tmax = 0.855 | k = −36→34 |
6217 measured reflections | l = −10→10 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.040 | H-atom parameters constrained |
wR(F2) = 0.104 | w = 1/[σ2(Fo2) + (0.0724P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.04 | (Δ/σ)max < 0.001 |
2414 reflections | Δρmax = 0.48 e Å−3 |
141 parameters | Δρmin = −0.20 e Å−3 |
1 restraint | Absolute structure: Flack (1983), 1038 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.012 (17) |
[Ni(C12H21N2Si)2] | V = 5506.8 (5) Å3 |
Mr = 501.49 | Z = 8 |
Orthorhombic, Fdd2 | Mo Kα radiation |
a = 21.2631 (11) Å | µ = 0.81 mm−1 |
b = 30.0347 (16) Å | T = 295 K |
c = 8.6228 (5) Å | 0.25 × 0.20 × 0.20 mm |
Bruker SMART CCD diffractometer | 2414 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2145 reflections with I > 2σ(I) |
Tmin = 0.823, Tmax = 0.855 | Rint = 0.029 |
6217 measured reflections |
R[F2 > 2σ(F2)] = 0.040 | H-atom parameters constrained |
wR(F2) = 0.104 | Δρmax = 0.48 e Å−3 |
S = 1.04 | Δρmin = −0.20 e Å−3 |
2414 reflections | Absolute structure: Flack (1983), 1038 Friedel pairs |
141 parameters | Absolute structure parameter: 0.012 (17) |
1 restraint |
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cells.u.'s is used for estimating s.u.'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 | ||
Ni1 | 0.7500 | 0.2500 | 0.59583 (5) | 0.03740 (17) | |
Si1 | 0.62152 (4) | 0.24725 (3) | 0.62421 (11) | 0.0448 (3) | |
N1 | 0.67563 (11) | 0.23000 (10) | 0.4923 (4) | 0.0430 (6) | |
N2 | 0.67555 (11) | 0.28051 (8) | 0.7349 (4) | 0.0426 (6) | |
C1 | 0.67006 (15) | 0.20291 (10) | 0.3645 (4) | 0.0431 (7) | |
C2 | 0.72350 (19) | 0.18285 (13) | 0.2987 (4) | 0.0564 (9) | |
H2A | 0.7629 | 0.1889 | 0.3405 | 0.068* | |
C3 | 0.7188 (2) | 0.15423 (13) | 0.1727 (4) | 0.0622 (10) | |
H3A | 0.7550 | 0.1413 | 0.1318 | 0.075* | |
C4 | 0.6615 (2) | 0.14486 (13) | 0.1082 (5) | 0.0700 (11) | |
H4A | 0.6585 | 0.1255 | 0.0244 | 0.084* | |
C5 | 0.6092 (2) | 0.16427 (14) | 0.1681 (5) | 0.0663 (11) | |
H5A | 0.5702 | 0.1585 | 0.1233 | 0.080* | |
C6 | 0.61285 (17) | 0.19221 (13) | 0.2936 (4) | 0.0567 (9) | |
H6A | 0.5760 | 0.2045 | 0.3330 | 0.068* | |
C7 | 0.58850 (18) | 0.20036 (14) | 0.7411 (5) | 0.0668 (11) | |
H7A | 0.5435 | 0.2026 | 0.7434 | 0.100* | |
H7B | 0.6046 | 0.2019 | 0.8449 | 0.100* | |
H7C | 0.6005 | 0.1725 | 0.6949 | 0.100* | |
C8 | 0.55404 (18) | 0.28164 (14) | 0.5536 (7) | 0.0819 (15) | |
H8A | 0.5153 | 0.2690 | 0.5902 | 0.123* | |
H8B | 0.5540 | 0.2821 | 0.4423 | 0.123* | |
H8C | 0.5582 | 0.3115 | 0.5921 | 0.123* | |
C9 | 0.6760 (2) | 0.27464 (13) | 0.9052 (5) | 0.0579 (9) | |
H9A | 0.7149 | 0.2870 | 0.9452 | 0.069* | |
H9B | 0.6764 | 0.2430 | 0.9274 | 0.069* | |
C10 | 0.6211 (2) | 0.29574 (18) | 0.9940 (7) | 0.0892 (15) | |
H10A | 0.6261 | 0.2903 | 1.1030 | 0.134* | |
H10B | 0.5822 | 0.2829 | 0.9592 | 0.134* | |
H10C | 0.6205 | 0.3273 | 0.9754 | 0.134* | |
C11 | 0.67674 (16) | 0.32842 (11) | 0.6879 (5) | 0.0531 (9) | |
H11A | 0.6419 | 0.3436 | 0.7375 | 0.064* | |
H11B | 0.6704 | 0.3303 | 0.5766 | 0.064* | |
C12 | 0.73718 (17) | 0.35238 (12) | 0.7289 (6) | 0.0634 (10) | |
H12A | 0.7347 | 0.3828 | 0.6948 | 0.095* | |
H12B | 0.7719 | 0.3379 | 0.6787 | 0.095* | |
H12C | 0.7432 | 0.3516 | 0.8392 | 0.095* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ni1 | 0.0262 (3) | 0.0458 (3) | 0.0402 (3) | −0.0003 (2) | 0.000 | 0.000 |
Si1 | 0.0273 (4) | 0.0509 (5) | 0.0561 (8) | 0.0002 (3) | 0.0019 (4) | −0.0001 (4) |
N1 | 0.0295 (13) | 0.0548 (16) | 0.0446 (15) | −0.0033 (11) | −0.0011 (12) | 0.0014 (13) |
N2 | 0.0320 (13) | 0.0449 (15) | 0.0510 (16) | 0.0044 (10) | 0.0024 (13) | 0.0001 (13) |
C1 | 0.0439 (17) | 0.0488 (17) | 0.0365 (18) | −0.0049 (13) | −0.0020 (14) | 0.0065 (14) |
C2 | 0.0478 (19) | 0.075 (2) | 0.046 (2) | −0.0021 (17) | −0.0036 (16) | −0.0034 (17) |
C3 | 0.073 (3) | 0.070 (2) | 0.0439 (19) | 0.008 (2) | 0.004 (2) | −0.0073 (18) |
C4 | 0.106 (3) | 0.063 (2) | 0.0407 (19) | −0.013 (2) | −0.009 (2) | −0.0014 (18) |
C5 | 0.073 (3) | 0.075 (3) | 0.052 (2) | −0.018 (2) | −0.012 (2) | 0.0021 (19) |
C6 | 0.048 (2) | 0.066 (2) | 0.056 (2) | −0.0136 (16) | −0.0102 (18) | 0.0067 (17) |
C7 | 0.062 (2) | 0.070 (2) | 0.068 (3) | −0.0159 (19) | 0.021 (2) | 0.001 (2) |
C8 | 0.0393 (19) | 0.080 (3) | 0.126 (5) | 0.0105 (18) | −0.028 (2) | 0.004 (3) |
C9 | 0.063 (2) | 0.059 (2) | 0.052 (2) | 0.0005 (17) | 0.0074 (18) | −0.0018 (18) |
C10 | 0.089 (3) | 0.102 (3) | 0.077 (3) | 0.010 (2) | 0.027 (3) | −0.012 (3) |
C11 | 0.0448 (18) | 0.0486 (19) | 0.066 (2) | 0.0059 (14) | 0.0031 (16) | −0.0046 (16) |
C12 | 0.061 (2) | 0.047 (2) | 0.082 (3) | −0.0021 (16) | −0.010 (2) | −0.0029 (19) |
Ni1—N1 | 1.913 (3) | C5—C6 | 1.372 (6) |
Ni1—N1i | 1.913 (3) | C5—H5A | 0.9300 |
Ni1—N2i | 2.187 (3) | C6—H6A | 0.9300 |
Ni1—N2 | 2.187 (3) | C7—H7A | 0.9600 |
Ni1—Si1i | 2.7441 (8) | C7—H7B | 0.9600 |
Ni1—Si1 | 2.7441 (8) | C7—H7C | 0.9600 |
Si1—N1 | 1.699 (3) | C8—H8A | 0.9600 |
Si1—N2 | 1.797 (3) | C8—H8B | 0.9600 |
Si1—C7 | 1.869 (4) | C8—H8C | 0.9600 |
Si1—C8 | 1.870 (4) | C9—C10 | 1.534 (6) |
N1—C1 | 1.375 (4) | C9—H9A | 0.9700 |
N2—C9 | 1.479 (5) | C9—H9B | 0.9700 |
N2—C11 | 1.495 (4) | C10—H10A | 0.9600 |
C1—C6 | 1.399 (5) | C10—H10B | 0.9600 |
C1—C2 | 1.406 (5) | C10—H10C | 0.9600 |
C2—C3 | 1.389 (5) | C11—C12 | 1.515 (5) |
C2—H2A | 0.9300 | C11—H11A | 0.9700 |
C3—C4 | 1.369 (6) | C11—H11B | 0.9700 |
C3—H3A | 0.9300 | C12—H12A | 0.9600 |
C4—C5 | 1.359 (6) | C12—H12B | 0.9600 |
C4—H4A | 0.9300 | C12—H12C | 0.9600 |
N1—Ni1—N1i | 124.35 (18) | C3—C4—H4A | 120.4 |
N1—Ni1—N2i | 136.28 (10) | C4—C5—C6 | 121.0 (4) |
N1i—Ni1—N2i | 77.82 (11) | C4—C5—H5A | 119.5 |
N1—Ni1—N2 | 77.82 (11) | C6—C5—H5A | 119.5 |
N1i—Ni1—N2 | 136.28 (10) | C5—C6—C1 | 122.3 (4) |
N2i—Ni1—N2 | 113.51 (15) | C5—C6—H6A | 118.8 |
N1—Ni1—Si1i | 150.95 (9) | C1—C6—H6A | 118.8 |
N1i—Ni1—Si1i | 37.73 (9) | Si1—C7—H7A | 109.5 |
N2i—Ni1—Si1i | 40.81 (7) | Si1—C7—H7B | 109.5 |
N2—Ni1—Si1i | 131.23 (8) | H7A—C7—H7B | 109.5 |
N1—Ni1—Si1 | 37.73 (9) | Si1—C7—H7C | 109.5 |
N1i—Ni1—Si1 | 150.95 (9) | H7A—C7—H7C | 109.5 |
N2i—Ni1—Si1 | 131.23 (8) | H7B—C7—H7C | 109.5 |
N2—Ni1—Si1 | 40.81 (7) | Si1—C8—H8A | 109.5 |
Si1i—Ni1—Si1 | 169.77 (4) | Si1—C8—H8B | 109.5 |
N1—Si1—N2 | 95.28 (13) | H8A—C8—H8B | 109.5 |
N1—Si1—C7 | 112.69 (18) | Si1—C8—H8C | 109.5 |
N2—Si1—C7 | 111.89 (18) | H8A—C8—H8C | 109.5 |
N1—Si1—C8 | 118.0 (2) | H8B—C8—H8C | 109.5 |
N2—Si1—C8 | 110.88 (17) | N2—C9—C10 | 116.2 (4) |
C7—Si1—C8 | 107.7 (2) | N2—C9—H9A | 108.2 |
C7—Si1—Ni1 | 116.41 (13) | C10—C9—H9A | 108.2 |
C8—Si1—Ni1 | 135.91 (16) | N2—C9—H9B | 108.2 |
C1—N1—Si1 | 131.2 (2) | C10—C9—H9B | 108.2 |
C1—N1—Ni1 | 129.1 (2) | H9A—C9—H9B | 107.4 |
Si1—N1—Ni1 | 98.73 (15) | C9—C10—H10A | 109.5 |
C9—N2—C11 | 112.6 (3) | C9—C10—H10B | 109.5 |
C9—N2—Si1 | 117.7 (2) | H10A—C10—H10B | 109.5 |
C11—N2—Si1 | 113.7 (2) | C9—C10—H10C | 109.5 |
C9—N2—Ni1 | 119.3 (2) | H10A—C10—H10C | 109.5 |
C11—N2—Ni1 | 104.02 (19) | H10B—C10—H10C | 109.5 |
Si1—N2—Ni1 | 86.48 (12) | N2—C11—C12 | 114.1 (3) |
N1—C1—C6 | 124.1 (3) | N2—C11—H11A | 108.7 |
N1—C1—C2 | 120.5 (3) | C12—C11—H11A | 108.7 |
C6—C1—C2 | 115.4 (3) | N2—C11—H11B | 108.7 |
C3—C2—C1 | 121.5 (4) | C12—C11—H11B | 108.7 |
C3—C2—H2A | 119.2 | H11A—C11—H11B | 107.6 |
C1—C2—H2A | 119.2 | C11—C12—H12A | 109.5 |
C4—C3—C2 | 120.6 (4) | C11—C12—H12B | 109.5 |
C4—C3—H3A | 119.7 | H12A—C12—H12B | 109.5 |
C2—C3—H3A | 119.7 | C11—C12—H12C | 109.5 |
C5—C4—C3 | 119.1 (4) | H12A—C12—H12C | 109.5 |
C5—C4—H4A | 120.4 | H12B—C12—H12C | 109.5 |
Symmetry code: (i) −x+3/2, −y+1/2, z. |
Experimental details
Crystal data | |
Chemical formula | [Ni(C12H21N2Si)2] |
Mr | 501.49 |
Crystal system, space group | Orthorhombic, Fdd2 |
Temperature (K) | 295 |
a, b, c (Å) | 21.2631 (11), 30.0347 (16), 8.6228 (5) |
V (Å3) | 5506.8 (5) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.81 |
Crystal size (mm) | 0.25 × 0.20 × 0.20 |
Data collection | |
Diffractometer | Bruker SMART CCD |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.823, 0.855 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6217, 2414, 2145 |
Rint | 0.029 |
(sin θ/λ)max (Å−1) | 0.606 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.104, 1.04 |
No. of reflections | 2414 |
No. of parameters | 141 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.48, −0.20 |
Absolute structure | Flack (1983), 1038 Friedel pairs |
Absolute structure parameter | 0.012 (17) |
Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
Acknowledgements
This work was performed under the sponsorship of the Natural Science Foundation of China (20702029) and the Natural Science Foundation of Shanxi Province (2008011024).
References
Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chen, J. (2008). Acta Cryst. E64, m938. Web of Science CSD CrossRef IUCr Journals Google Scholar
Chen, J. (2009). Acta Cryst. E65, m1307. Web of Science CSD CrossRef IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Gibson, V. C., Kimberley, B. S., White, A. J. P., Williams, D. J. & Howard, P. (1998). Chem. Commun. pp. 313–314. Web of Science CSD CrossRef Google Scholar
Hill, M. S. & Hitchcock, P. B. (2002). Organometallics, 21, 3258–3262. Web of Science CSD CrossRef CAS Google Scholar
Holm, R. H., Kenneppohl, P. & Solomon, E. I. (1996). Chem. Rev. 96, 2239–2314. CrossRef PubMed CAS Web of Science Google Scholar
Kempe, R. (2000). Angew. Chem. Int. Ed. 39, 468–493. CrossRef CAS Google Scholar
Schumann, H., Gottfriedsen, J., Dechert, S. & Girgsdies, F. (2000). Z. Anorg. Allg. Chem. 626, 747–758. CrossRef CAS Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Yuan, S. F., Wei, X. H., Tong, H. B., Zhang, L. P., Liu, D. S. & Sun, W. H. (2010). Organometallics, 29, 2085–2092. Web of Science CSD CrossRef CAS Google Scholar
Zai, S. B., Liu, F. S., Gao, H. Y., Li, C., Zhou, G. Y., Cheng, S., Guo, L. H., Zhang, L., Zhu, F. M. & Wu, Q. (2010). Chem. Commun. 46, 4321–4323. Web of Science CSD CrossRef CAS Google Scholar
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Metal amides were important substitutes for cyclopentadienyl derivatives and were found to have valuable applications in various industrial and biological processes (Holm et al., 1996; Kempe, 2000). Group 4 metal amides with the N-silylated anilinide ligands were active catalysts for olefin polymerization (Gibson et al., 1998; Hill & Hitchcock, 2002). Our research interest focused on N-silylated anilinide ligands bearing a pendant amino group. Analogous compounds with different metals including Zn (Schumann et al., 2000), Zr (Chen, 2009) and Fe (Chen, 2008) have been synthesized and the zirconium compounds were reported showing good performance in ethylene polymerization (Yuan et al., 2010). Recently, a kind of bidentate N–donor ligand supported nickel complex activated by MAO was used as a catalyst conducting longstanding living ethylene polymerization (Zai et al., 2010). In view of the importance of these compounds, the synthesis and crystal structure of a new nickel(II) anilinide complex is reported.
The title compound was prepared by one–pot reaction of LiBun, N–[(diethylamino)dimethylsilyl]aniline and NiCl2. It is monomeric and the ligand has an N—Si—N chelating group. It is presumed that the empty d–orbitals on silicon would interact with the lone–pair electrons on the p–orbital of nitrogen center through a d···pπ interaction, resulting in a "quasi" conjugated N—Si—N motif. Compared with rigid N—C—N chelating unit in the amidinate ligand, the N1—Si1—N2 chelating group is much flexible. The Ni center is fixed by two ligands. Each ligand bites the center with an N1—Ni1—N2 angle of 77.82 (11)°. As biting the metal center, the angle of N1—Si1—N2 is constrained to be 95.28 (13)°. The two ends of the N—Si—N chelating unit exhibit different affinities for the metal center. Ni—Nanilinide bond is 1.913 (3) Å and Ni—Namino bond is 2.187 (3)Å. The coordinate geometry of Nanilinide atom is trigonal planar (sum of three angles around it being 359°). Both distances of Si1—N1 (1.699 (3)Å) and N1—C1 (1.375 (4)Å) are short. It suggests a certain degree delocalization of the lone–pair electron density from the p–orbital of N1 to the π–orbital of the phenylsubstituent. The two ligands around the Ni atom are arranged cis to each other and obey the C2 symmetry operation. The four-coordinate Ni atom demonstrates a distorted tetrahedral geometry.