Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807040123/gg2033sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807040123/gg2033Isup2.hkl |
CCDC reference: 660143
Key indicators
- Single-crystal X-ray study
- T = 298 K
- Mean (C-C) = 0.004 Å
- R factor = 0.040
- wR factor = 0.105
- Data-to-parameter ratio = 15.0
checkCIF/PLATON results
No syntax errors found
Alert level B ABSTM02_ALERT_3_B The ratio of expected to reported Tmax/Tmin(RR') is < 0.75 Tmin and Tmax reported: 0.524 1.000 Tmin(prime) and Tmax expected: 0.727 0.916 RR(prime) = 0.660 Please check that your absorption correction is appropriate. PLAT061_ALERT_3_B Tmax/Tmin Range Test RR' too Large ............. 0.66
Alert level C PLAT062_ALERT_4_C Rescale T(min) & T(max) by ..................... 0.92 PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd. # 1 C54 H38 F4 N4 Zn
Alert level G ABSTM02_ALERT_3_G When printed, the submitted absorption T values will be replaced by the scaled T values. Since the ratio of scaled T's is identical to the ratio of reported T values, the scaling does not imply a change to the absorption corrections used in the study. Ratio of Tmax expected/reported 0.916 Tmax scaled 0.916 Tmin scaled 0.480 PLAT794_ALERT_5_G Check Predicted Bond Valency for Zn (2) 1.92
0 ALERT level A = In general: serious problem 2 ALERT level B = Potentially serious problem 2 ALERT level C = Check and explain 2 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 3 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 1 ALERT type 5 Informative message, check
For related literature, see: Chamberlain et al. (1999, 2001); Chen et al. (2005); Chisholm et al. (2003); Duda et al. (1990); Endo et al. (1987); Ko & Lin (2001); Rieth et al. (2002); Sawhney et al. (1993); Shueh et al. (2004); Simic et al. (1997); Stevels et al. (1996); Wu et al. (2006).
For related literature, see: Ni & Yu (1997 or??? 1998).
The title compound was prepared by the reaction of N-((1Z,3Z)-1,3-bis(4-fluorophenyl)-3-(phenylimino)prop-1- enyl)benzenamine (0.82 g, 2.0 mmol) with ZnEt2 (1.1 ml, 1.0 M in hexane, 1.1 mmol) in hexane (20 ml). The mixture was stirred at 25°C for 6 h and was then evaporated to dryness under vacuum. The residue was extracted with hot hexane (30 ml), and the resulting hexane solution was then concentrated to ca 15 ml. Yellow crystals were obtained at room temperature after 16 h. Yield: 0.61 g (69%).
All H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with C—H distances of 0.93 Å and Uiso(H) = 1.2Ueq(C).
Biodegradable polymers have been attracting considerable attention recently due to their potential applications in the environmental protection as well as in the medical field. Among biodegradable polymers, the aliphatic polyesters, such as poly(ε-caprolactone) (PCL), (Endo et al., 1987) poly(lactide) (PLA) (Chamberlain et al., 1999), and their copolymers are especially interested for their applications in the medical field as biodegradable surgical sutures or as a delivery medium for controlled release of drugs (Ni & Yu, 1997). Therefore, there has been increasing interest in the development of efficient catalytic systems for the preparation of PLA and PCL (Wu et al., 2006). The major polymerization method used to synthesize these polymers has been the ring-opening polymerization (ROP) of lactones/lactides and functionally related compounds. For examples, aluminium alkoxides (Duda et al., 1990), stannous (Sawhney et al., 1993), yttrium (Stevels et al., 1996) as well as trivalent lanthanide derivatives (Simic et al., 1997), lithium (Ko & Lin, 2001), magnesium (Shueh et al., 2004; Chamberlain et al., 2001), calcium (Chisholm et al., 2003) and zinc (Chamberlain et al., 2001; Rieth et al., 2002) have been reported to be effective initiators that initiate ROP of lactones/lactides, yielding polymers with both high molecular weights and high yields. Among them, zinc diketiminato-based catalytic systems are especially attracted and well suited as initiators for the ROP of lactones and lactides due to their high Lewis acidity. Recently, we have reported that Zn complexes of diketiminato-based ligands are very active catalysts for ROP of lactide (Chen et al., 2005). Herein, we report the crystal structure of a potentially useful Zn complex with bulky diketiminato ligands.
In the title mononuclear ZnII compound, the Zn atom is tetracoordinated with four N atoms from two diketiminato ligands (Fig. 1). The Zn atom lies on a C2 rotation symmetry. By comparison with the Zn complexes reported in the literature, we notice that the Zn—N coordinated bond distances (1.989 (2) and 1.994 (2) Å)(Table 1) of the title compound are consistent with that reported for [(BDI-2)Zn(µ–OiPr)]2 (1.990 (8) and 2.021 (7) Å) (Chamberlain et al., 2001).
For related literature, see: Chamberlain et al. (1999, 2001); Chen et al. (2005); Chisholm et al. (2003); Duda et al. (1990); Endo et al. (1987); Ko & Lin (2001); Rieth et al. (2002); Sawhney et al. (1993); Shueh et al. (2004); Simic et al. (1997); Stevels et al. (1996); Wu et al. (2006).
For related literature, see: Ni & Yu (1997 or??? 1998).
Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1999); software used to prepare material for publication: SHELXTL (Bruker, 1999).
Fig. 1. A view of the molecular structure of (I) with displacement ellipsoids shown at the 20% probability level. All the H atoms are omitted for clarity. |
[Zn(C27H19F2N2)2] | F(000) = 1824 |
Mr = 884.26 | Dx = 1.358 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 3748 reflections |
a = 21.967 (2) Å | θ = 2.5–25.5° |
b = 10.6232 (10) Å | µ = 0.63 mm−1 |
c = 19.2852 (19) Å | T = 298 K |
β = 106.102 (2)° | Parallelpiped, yellow |
V = 4323.8 (7) Å3 | 0.50 × 0.25 × 0.14 mm |
Z = 4 |
Bruker SMART 1000 CCD diffractometer | 4272 independent reflections |
Radiation source: fine-focus sealed tube | 3043 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.048 |
φ and ω scans | θmax = 26.1°, θmin = 1.9° |
Absorption correction: multi-scan (SADABS, Sheldrick, 1996) | h = −27→24 |
Tmin = 0.524, Tmax = 1.000 | k = −13→11 |
12028 measured reflections | l = −23→23 |
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) = 0.105 | H-atom parameters constrained |
S = 0.95 | w = 1/[σ2(Fo2) + (0.059P)2] where P = (Fo2 + 2Fc2)/3 |
4272 reflections | (Δ/σ)max = 0.001 |
285 parameters | Δρmax = 0.36 e Å−3 |
0 restraints | Δρmin = −0.30 e Å−3 |
[Zn(C27H19F2N2)2] | V = 4323.8 (7) Å3 |
Mr = 884.26 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 21.967 (2) Å | µ = 0.63 mm−1 |
b = 10.6232 (10) Å | T = 298 K |
c = 19.2852 (19) Å | 0.50 × 0.25 × 0.14 mm |
β = 106.102 (2)° |
Bruker SMART 1000 CCD diffractometer | 4272 independent reflections |
Absorption correction: multi-scan (SADABS, Sheldrick, 1996) | 3043 reflections with I > 2σ(I) |
Tmin = 0.524, Tmax = 1.000 | Rint = 0.048 |
12028 measured reflections |
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.105 | H-atom parameters constrained |
S = 0.95 | Δρmax = 0.36 e Å−3 |
4272 reflections | Δρmin = −0.30 e Å−3 |
285 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 | ||
Zn | 0.5000 | 0.15528 (4) | 1.2500 | 0.03975 (14) | |
F1 | 0.72953 (9) | 0.0113 (2) | 0.97921 (11) | 0.0977 (7) | |
F2 | 0.33272 (10) | 0.65322 (18) | 0.92235 (10) | 0.0936 (6) | |
N1 | 0.54684 (9) | 0.06780 (18) | 1.18950 (9) | 0.0403 (5) | |
N2 | 0.44306 (9) | 0.25386 (19) | 1.16987 (9) | 0.0424 (5) | |
C1 | 0.55117 (11) | 0.1220 (2) | 1.12847 (11) | 0.0391 (5) | |
C2 | 0.51558 (11) | 0.2276 (2) | 1.09706 (11) | 0.0428 (6) | |
H2A | 0.5292 | 0.2669 | 1.0609 | 0.051* | |
C3 | 0.46282 (11) | 0.2823 (2) | 1.11195 (11) | 0.0412 (5) | |
C4 | 0.57425 (12) | −0.0522 (2) | 1.21246 (12) | 0.0429 (6) | |
C5 | 0.62314 (13) | −0.0624 (3) | 1.27565 (13) | 0.0550 (7) | |
H5A | 0.6406 | 0.0097 | 1.3008 | 0.066* | |
C6 | 0.64604 (16) | −0.1804 (3) | 1.30144 (15) | 0.0682 (9) | |
H6A | 0.6791 | −0.1869 | 1.3436 | 0.082* | |
C7 | 0.62031 (17) | −0.2870 (3) | 1.26521 (18) | 0.0714 (9) | |
H7A | 0.6355 | −0.3658 | 1.2828 | 0.086* | |
C8 | 0.57228 (17) | −0.2772 (3) | 1.20321 (18) | 0.0709 (9) | |
H8A | 0.5551 | −0.3497 | 1.1784 | 0.085* | |
C9 | 0.54883 (15) | −0.1610 (3) | 1.17676 (15) | 0.0587 (7) | |
H9A | 0.5157 | −0.1559 | 1.1346 | 0.070* | |
C10 | 0.59870 (11) | 0.0783 (2) | 1.09063 (12) | 0.0401 (5) | |
C11 | 0.66212 (12) | 0.0696 (2) | 1.12655 (13) | 0.0495 (6) | |
H11A | 0.6753 | 0.0790 | 1.1764 | 0.059* | |
C12 | 0.70666 (13) | 0.0471 (3) | 1.08923 (16) | 0.0581 (7) | |
H12A | 0.7495 | 0.0419 | 1.1135 | 0.070* | |
C13 | 0.68610 (14) | 0.0326 (3) | 1.01600 (16) | 0.0596 (7) | |
C14 | 0.62417 (15) | 0.0373 (3) | 0.97884 (14) | 0.0583 (7) | |
H14A | 0.6115 | 0.0241 | 0.9292 | 0.070* | |
C15 | 0.57990 (12) | 0.0620 (3) | 1.01597 (12) | 0.0486 (6) | |
H15A | 0.5372 | 0.0678 | 0.9909 | 0.058* | |
C16 | 0.42858 (11) | 0.3809 (2) | 1.06036 (12) | 0.0411 (6) | |
C17 | 0.41609 (13) | 0.4975 (2) | 1.08620 (14) | 0.0534 (7) | |
H17A | 0.4291 | 0.5132 | 1.1356 | 0.064* | |
C18 | 0.38494 (15) | 0.5900 (3) | 1.04009 (16) | 0.0625 (8) | |
H18A | 0.3771 | 0.6682 | 1.0576 | 0.075* | |
C19 | 0.36572 (14) | 0.5641 (3) | 0.96792 (16) | 0.0629 (8) | |
C20 | 0.37753 (14) | 0.4522 (3) | 0.93986 (14) | 0.0633 (8) | |
H20A | 0.3641 | 0.4377 | 0.8904 | 0.076* | |
C21 | 0.40987 (13) | 0.3606 (3) | 0.98648 (13) | 0.0540 (7) | |
H21A | 0.4192 | 0.2844 | 0.9681 | 0.065* | |
C22 | 0.37975 (12) | 0.2775 (2) | 1.17125 (12) | 0.0434 (6) | |
C23 | 0.36800 (14) | 0.3224 (3) | 1.23379 (14) | 0.0563 (7) | |
H23A | 0.4014 | 0.3478 | 1.2725 | 0.068* | |
C24 | 0.30590 (17) | 0.3294 (3) | 1.23820 (17) | 0.0731 (10) | |
H24A | 0.2982 | 0.3601 | 1.2801 | 0.088* | |
C25 | 0.25627 (16) | 0.2920 (3) | 1.1824 (2) | 0.0775 (10) | |
H25A | 0.2151 | 0.2958 | 1.1866 | 0.093* | |
C26 | 0.26751 (14) | 0.2485 (3) | 1.11993 (17) | 0.0688 (8) | |
H26A | 0.2338 | 0.2239 | 1.0813 | 0.083* | |
C27 | 0.32846 (12) | 0.2416 (2) | 1.11452 (14) | 0.0513 (6) | |
H27A | 0.3355 | 0.2123 | 1.0720 | 0.062* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Zn | 0.0429 (2) | 0.0499 (3) | 0.0307 (2) | 0.000 | 0.01727 (16) | 0.000 |
F1 | 0.0807 (14) | 0.1299 (18) | 0.1090 (14) | 0.0018 (12) | 0.0703 (12) | −0.0228 (13) |
F2 | 0.1059 (16) | 0.0791 (13) | 0.0928 (13) | 0.0291 (11) | 0.0227 (12) | 0.0447 (11) |
N1 | 0.0457 (12) | 0.0467 (11) | 0.0319 (9) | 0.0068 (9) | 0.0167 (8) | 0.0036 (9) |
N2 | 0.0427 (12) | 0.0517 (12) | 0.0372 (10) | 0.0062 (9) | 0.0182 (9) | 0.0043 (9) |
C1 | 0.0383 (13) | 0.0491 (14) | 0.0323 (11) | 0.0012 (10) | 0.0138 (10) | 0.0006 (10) |
C2 | 0.0458 (15) | 0.0536 (15) | 0.0345 (11) | 0.0054 (11) | 0.0202 (10) | 0.0083 (11) |
C3 | 0.0437 (14) | 0.0472 (14) | 0.0349 (11) | 0.0016 (11) | 0.0144 (10) | 0.0003 (11) |
C4 | 0.0498 (15) | 0.0502 (15) | 0.0354 (11) | 0.0061 (12) | 0.0231 (11) | 0.0050 (11) |
C5 | 0.0649 (19) | 0.0583 (17) | 0.0425 (13) | 0.0105 (14) | 0.0163 (13) | 0.0038 (12) |
C6 | 0.082 (2) | 0.074 (2) | 0.0500 (16) | 0.0247 (17) | 0.0200 (15) | 0.0170 (15) |
C7 | 0.097 (3) | 0.0561 (19) | 0.074 (2) | 0.0246 (18) | 0.0461 (19) | 0.0225 (17) |
C8 | 0.094 (3) | 0.0479 (18) | 0.081 (2) | −0.0023 (16) | 0.041 (2) | −0.0005 (16) |
C9 | 0.0685 (19) | 0.0552 (17) | 0.0527 (15) | −0.0006 (15) | 0.0174 (13) | −0.0014 (14) |
C10 | 0.0419 (14) | 0.0427 (13) | 0.0406 (12) | 0.0028 (10) | 0.0196 (11) | 0.0040 (10) |
C11 | 0.0504 (17) | 0.0556 (16) | 0.0461 (13) | 0.0068 (12) | 0.0195 (12) | 0.0024 (12) |
C12 | 0.0415 (16) | 0.0621 (18) | 0.0756 (18) | 0.0077 (13) | 0.0247 (14) | 0.0039 (15) |
C13 | 0.0573 (19) | 0.0666 (19) | 0.0701 (18) | 0.0022 (14) | 0.0431 (15) | −0.0042 (15) |
C14 | 0.071 (2) | 0.0680 (18) | 0.0461 (14) | −0.0005 (15) | 0.0338 (14) | −0.0049 (13) |
C15 | 0.0453 (15) | 0.0631 (17) | 0.0417 (12) | −0.0008 (12) | 0.0190 (11) | −0.0033 (12) |
C16 | 0.0411 (14) | 0.0450 (14) | 0.0416 (12) | 0.0035 (10) | 0.0186 (11) | 0.0039 (10) |
C17 | 0.0628 (18) | 0.0510 (17) | 0.0505 (14) | 0.0008 (13) | 0.0226 (13) | 0.0026 (12) |
C18 | 0.077 (2) | 0.0423 (16) | 0.0741 (19) | 0.0078 (14) | 0.0312 (16) | 0.0065 (15) |
C19 | 0.0630 (19) | 0.0569 (18) | 0.0716 (19) | 0.0122 (14) | 0.0232 (15) | 0.0256 (15) |
C20 | 0.070 (2) | 0.075 (2) | 0.0444 (14) | 0.0102 (16) | 0.0153 (13) | 0.0124 (14) |
C21 | 0.0635 (18) | 0.0565 (16) | 0.0446 (13) | 0.0094 (13) | 0.0191 (12) | 0.0041 (12) |
C22 | 0.0463 (15) | 0.0452 (14) | 0.0443 (13) | 0.0088 (11) | 0.0219 (11) | 0.0082 (11) |
C23 | 0.0637 (18) | 0.0658 (19) | 0.0468 (14) | 0.0173 (14) | 0.0274 (13) | 0.0049 (13) |
C24 | 0.084 (2) | 0.087 (2) | 0.0666 (19) | 0.0328 (19) | 0.0501 (18) | 0.0177 (17) |
C25 | 0.059 (2) | 0.092 (2) | 0.096 (2) | 0.0266 (18) | 0.047 (2) | 0.029 (2) |
C26 | 0.0512 (19) | 0.075 (2) | 0.081 (2) | 0.0045 (15) | 0.0209 (16) | 0.0123 (17) |
C27 | 0.0484 (16) | 0.0565 (16) | 0.0531 (15) | 0.0051 (13) | 0.0207 (13) | 0.0034 (13) |
Zn—N1i | 1.9875 (18) | C11—H11A | 0.9300 |
Zn—N1 | 1.9875 (18) | C12—C13 | 1.367 (4) |
Zn—N2i | 1.9942 (19) | C12—H12A | 0.9300 |
Zn—N2 | 1.9942 (19) | C13—C14 | 1.351 (4) |
F1—C13 | 1.356 (3) | C14—C15 | 1.383 (3) |
F2—C19 | 1.356 (3) | C14—H14A | 0.9300 |
N1—C1 | 1.337 (3) | C15—H15A | 0.9300 |
N1—C4 | 1.427 (3) | C16—C21 | 1.386 (3) |
N2—C3 | 1.340 (3) | C16—C17 | 1.391 (3) |
N2—C22 | 1.421 (3) | C17—C18 | 1.374 (4) |
C1—C2 | 1.405 (3) | C17—H17A | 0.9300 |
C1—C10 | 1.503 (3) | C18—C19 | 1.366 (4) |
C2—C3 | 1.396 (3) | C18—H18A | 0.9300 |
C2—H2A | 0.9300 | C19—C20 | 1.361 (4) |
C3—C16 | 1.496 (3) | C20—C21 | 1.380 (4) |
C4—C9 | 1.382 (4) | C20—H20A | 0.9300 |
C4—C5 | 1.387 (3) | C21—H21A | 0.9300 |
C5—C6 | 1.390 (4) | C22—C27 | 1.389 (4) |
C5—H5A | 0.9300 | C22—C23 | 1.386 (3) |
C6—C7 | 1.368 (4) | C23—C24 | 1.392 (4) |
C6—H6A | 0.9300 | C23—H23A | 0.9300 |
C7—C8 | 1.362 (4) | C24—C25 | 1.361 (5) |
C7—H7A | 0.9300 | C24—H24A | 0.9300 |
C8—C9 | 1.379 (4) | C25—C26 | 1.376 (4) |
C8—H8A | 0.9300 | C25—H25A | 0.9300 |
C9—H9A | 0.9300 | C26—C27 | 1.374 (4) |
C10—C11 | 1.376 (3) | C26—H26A | 0.9300 |
C10—C15 | 1.394 (3) | C27—H27A | 0.9300 |
C11—C12 | 1.387 (3) | ||
N1i—Zn—N1 | 124.24 (11) | C11—C12—H12A | 120.7 |
N1i—Zn—N2i | 96.10 (7) | C14—C13—F1 | 118.6 (3) |
N1—Zn—N2i | 112.64 (8) | C14—C13—C12 | 122.6 (2) |
N1i—Zn—N2 | 112.64 (8) | F1—C13—C12 | 118.7 (3) |
N1—Zn—N2 | 96.10 (7) | C13—C14—C15 | 118.8 (2) |
N2i—Zn—N2 | 116.65 (12) | C13—C14—H14A | 120.6 |
C1—N1—C4 | 122.07 (19) | C15—C14—H14A | 120.6 |
C1—N1—Zn | 119.36 (16) | C14—C15—C10 | 120.6 (2) |
C4—N1—Zn | 118.57 (13) | C14—C15—H15A | 119.7 |
C3—N2—C22 | 121.39 (19) | C10—C15—H15A | 119.7 |
C3—N2—Zn | 119.06 (16) | C21—C16—C17 | 118.4 (2) |
C22—N2—Zn | 119.01 (14) | C21—C16—C3 | 121.7 (2) |
N1—C1—C2 | 123.8 (2) | C17—C16—C3 | 119.9 (2) |
N1—C1—C10 | 121.5 (2) | C18—C17—C16 | 121.2 (2) |
C2—C1—C10 | 114.56 (19) | C18—C17—H17A | 119.4 |
C3—C2—C1 | 129.7 (2) | C16—C17—H17A | 119.4 |
C3—C2—H2A | 115.2 | C19—C18—C17 | 118.3 (3) |
C1—C2—H2A | 115.2 | C19—C18—H18A | 120.9 |
N2—C3—C2 | 123.8 (2) | C17—C18—H18A | 120.9 |
N2—C3—C16 | 119.5 (2) | F2—C19—C20 | 118.6 (3) |
C2—C3—C16 | 116.61 (19) | F2—C19—C18 | 118.6 (3) |
C9—C4—C5 | 118.7 (2) | C20—C19—C18 | 122.8 (3) |
C9—C4—N1 | 121.0 (2) | C19—C20—C21 | 118.5 (3) |
C5—C4—N1 | 120.0 (2) | C19—C20—H20A | 120.7 |
C4—C5—C6 | 120.0 (3) | C21—C20—H20A | 120.7 |
C4—C5—H5A | 120.0 | C20—C21—C16 | 120.8 (3) |
C6—C5—H5A | 120.0 | C20—C21—H21A | 119.6 |
C7—C6—C5 | 120.4 (3) | C16—C21—H21A | 119.6 |
C7—C6—H6A | 119.8 | C27—C22—C23 | 118.3 (2) |
C5—C6—H6A | 119.8 | C27—C22—N2 | 121.4 (2) |
C8—C7—C6 | 119.6 (3) | C23—C22—N2 | 119.8 (2) |
C8—C7—H7A | 120.2 | C22—C23—C24 | 119.6 (3) |
C6—C7—H7A | 120.2 | C22—C23—H23A | 120.2 |
C7—C8—C9 | 120.8 (3) | C24—C23—H23A | 120.2 |
C7—C8—H8A | 119.6 | C25—C24—C23 | 121.4 (3) |
C9—C8—H8A | 119.6 | C25—C24—H24A | 119.3 |
C8—C9—C4 | 120.4 (3) | C23—C24—H24A | 119.3 |
C8—C9—H9A | 119.8 | C24—C25—C26 | 119.4 (3) |
C4—C9—H9A | 119.8 | C24—C25—H25A | 120.3 |
C11—C10—C15 | 118.7 (2) | C26—C25—H25A | 120.3 |
C11—C10—C1 | 121.2 (2) | C27—C26—C25 | 120.0 (3) |
C15—C10—C1 | 119.5 (2) | C27—C26—H26A | 120.0 |
C10—C11—C12 | 120.8 (2) | C25—C26—H26A | 120.0 |
C10—C11—H11A | 119.6 | C26—C27—C22 | 121.4 (3) |
C12—C11—H11A | 119.6 | C26—C27—H27A | 119.3 |
C13—C12—C11 | 118.5 (3) | C22—C27—H27A | 119.3 |
C13—C12—H12A | 120.7 |
Symmetry code: (i) −x+1, y, −z+5/2. |
Experimental details
Crystal data | |
Chemical formula | [Zn(C27H19F2N2)2] |
Mr | 884.26 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 298 |
a, b, c (Å) | 21.967 (2), 10.6232 (10), 19.2852 (19) |
β (°) | 106.102 (2) |
V (Å3) | 4323.8 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.63 |
Crystal size (mm) | 0.50 × 0.25 × 0.14 |
Data collection | |
Diffractometer | Bruker SMART 1000 CCD |
Absorption correction | Multi-scan (SADABS, Sheldrick, 1996) |
Tmin, Tmax | 0.524, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12028, 4272, 3043 |
Rint | 0.048 |
(sin θ/λ)max (Å−1) | 0.619 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.105, 0.95 |
No. of reflections | 4272 |
No. of parameters | 285 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.36, −0.30 |
Computer programs: SMART (Bruker, 1999), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1999).
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Biodegradable polymers have been attracting considerable attention recently due to their potential applications in the environmental protection as well as in the medical field. Among biodegradable polymers, the aliphatic polyesters, such as poly(ε-caprolactone) (PCL), (Endo et al., 1987) poly(lactide) (PLA) (Chamberlain et al., 1999), and their copolymers are especially interested for their applications in the medical field as biodegradable surgical sutures or as a delivery medium for controlled release of drugs (Ni & Yu, 1997). Therefore, there has been increasing interest in the development of efficient catalytic systems for the preparation of PLA and PCL (Wu et al., 2006). The major polymerization method used to synthesize these polymers has been the ring-opening polymerization (ROP) of lactones/lactides and functionally related compounds. For examples, aluminium alkoxides (Duda et al., 1990), stannous (Sawhney et al., 1993), yttrium (Stevels et al., 1996) as well as trivalent lanthanide derivatives (Simic et al., 1997), lithium (Ko & Lin, 2001), magnesium (Shueh et al., 2004; Chamberlain et al., 2001), calcium (Chisholm et al., 2003) and zinc (Chamberlain et al., 2001; Rieth et al., 2002) have been reported to be effective initiators that initiate ROP of lactones/lactides, yielding polymers with both high molecular weights and high yields. Among them, zinc diketiminato-based catalytic systems are especially attracted and well suited as initiators for the ROP of lactones and lactides due to their high Lewis acidity. Recently, we have reported that Zn complexes of diketiminato-based ligands are very active catalysts for ROP of lactide (Chen et al., 2005). Herein, we report the crystal structure of a potentially useful Zn complex with bulky diketiminato ligands.
In the title mononuclear ZnII compound, the Zn atom is tetracoordinated with four N atoms from two diketiminato ligands (Fig. 1). The Zn atom lies on a C2 rotation symmetry. By comparison with the Zn complexes reported in the literature, we notice that the Zn—N coordinated bond distances (1.989 (2) and 1.994 (2) Å)(Table 1) of the title compound are consistent with that reported for [(BDI-2)Zn(µ–OiPr)]2 (1.990 (8) and 2.021 (7) Å) (Chamberlain et al., 2001).