Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807037919/rn2023sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807037919/rn2023Isup2.hkl |
CCDC reference: 660068
The chiral ligand, (S)-2-(4-ethyl-4,5-dihydrooxazol-2-yl)phenol was prepared from 2-hydroxybenzonitrile and (S)-2-aminobutan-1-ol as literature reported (Serrano et al., 1995).
A solution of (S)-2-(4-ethyl-4,5-dihydrooxazol-2-yl)phenol (30.56 mg, 0.16 mmol) in methanol (1.60 ml) was added to a stirred solution of CuCl23H2O (34.10 mg, 0.2 mmol) in methanol(2.00 ml). Crystals suitable for diffraction analysis were obtained after a few days.
H atoms were positioned geometrically (aromatic C—H = 0.93 Å, aliphatic C—H = 0.96–0.98 Å) and refined with the riding model approximation, with Uiso(H) = 1.2Ueq(C) [1.5Ueq(C) for methyl H].
Over the last decade, C2-symmetric chiral oxazoline metal complexes have been recognized as an effective class of chiral catalyst in a variety of transition metal catalyzed asymmetric reactions (Ghosh et al., 1998). High catalytic activities and enantiomeric excesses have been obtained using C2-symmetric chiral ligands in conjunction with suitable transition metal ion, for example, the hydrosilylation of ketone (Imai et al., 1996), allylic alkylation (Chelucci 1997), Michael addition (Ji et al., 1999), Diels-Alder cycloaddition, and cyclopropanation. Thus, the design and synthesis of new chiral oxazoline ligands and their complexes have inspired many scientists to work with great efforts (Du et al., 2003; Zhang et al., 2007).
We report here the crystal structure of the title compound, (I), a CuII complex with the chiral (S)-2-(4-ethyl-4,5-dihydrooxazol -2-yl)phenol, as the coordination ligand.
The title compound, contains one centrosymmetric tetra-coordinated copper(II) complex (Fig 1). The copper atom is coordinated by two 2-(4-ethyl- 4,5-dihydrooxazol-2-yl)-phenol anions, which bind to the metal centre via the N atom and the phenolyl O atom. Pairs of equivalent ligands lie trans to each other in a slightly distorted square planar geometry about the copper(II) atom (see Table 1).
The aryl and oxazoline least-squares planes are linked by π-π stacking interactions with Cg-Cgii distances 3.7953 (12) Å (symmetry code ii: 1 - x, 1 - y, 1 - z). The C—H···Cg (aryl ring) interactions are observed with H9Aiii···Cg = 2.94 Å (symmetry code iii: x, 1/2 - y, -1/2 + z) and H9Ai···Cg = 2.89 Å (Fig 2) (Spek, 2003).
For related literature, see Chelucci (1997); Du et al. (2003); Ghosh et al. (1998); Ji et al. (1999); Imai et al. (1996); Zhang et al. (2007). For synthesis, see: Serrano et al. (1995).
Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; 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 and PLATON (Spek, 2003).
[Cu(C11H12NO2)2] | F(000) = 462 |
Mr = 443.97 | Dx = 1.443 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 3198 reflections |
a = 6.6645 (9) Å | θ = 2.4–26.7° |
b = 14.5796 (19) Å | µ = 1.10 mm−1 |
c = 10.5615 (14) Å | T = 291 K |
β = 95.163 (1)° | Block, dark green |
V = 1022.1 (2) Å3 | 0.48 × 0.27 × 0.19 mm |
Z = 2 |
Bruker SMART CCD area-detector diffractometer | 1882 independent reflections |
Radiation source: fine-focus sealed tube | 1652 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.013 |
Detector resolution: 0 pixels mm-1 | θmax = 25.5°, θmin = 2.4° |
φ and ω scans | h = −8→8 |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | k = −17→17 |
Tmin = 0.621, Tmax = 0.821 | l = −12→12 |
6062 measured 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) = 0.077 | H-atom parameters constrained |
S = 1.08 | w = 1/[σ2(Fo2) + (0.0434P)2 + 0.1918P] where P = (Fo2 + 2Fc2)/3 |
1882 reflections | (Δ/σ)max < 0.001 |
134 parameters | Δρmax = 0.19 e Å−3 |
0 restraints | Δρmin = −0.19 e Å−3 |
[Cu(C11H12NO2)2] | V = 1022.1 (2) Å3 |
Mr = 443.97 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 6.6645 (9) Å | µ = 1.10 mm−1 |
b = 14.5796 (19) Å | T = 291 K |
c = 10.5615 (14) Å | 0.48 × 0.27 × 0.19 mm |
β = 95.163 (1)° |
Bruker SMART CCD area-detector diffractometer | 1882 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1652 reflections with I > 2σ(I) |
Tmin = 0.621, Tmax = 0.821 | Rint = 0.013 |
6062 measured reflections |
R[F2 > 2σ(F2)] = 0.026 | 0 restraints |
wR(F2) = 0.077 | H-atom parameters constrained |
S = 1.08 | Δρmax = 0.19 e Å−3 |
1882 reflections | Δρmin = −0.19 e Å−3 |
134 parameters |
x | y | z | Uiso*/Ueq | ||
Cu1 | 0.0000 | 0.5000 | 0.5000 | 0.05203 (14) | |
O1 | 0.0943 (2) | 0.53611 (12) | 0.66862 (13) | 0.0721 (4) | |
O2 | 0.5047 (2) | 0.64456 (9) | 0.42505 (13) | 0.0618 (4) | |
N1 | 0.2068 (2) | 0.57490 (10) | 0.43014 (14) | 0.0491 (3) | |
C1 | 0.2700 (3) | 0.56981 (13) | 0.71016 (18) | 0.0552 (4) | |
C2 | 0.3213 (3) | 0.57523 (15) | 0.84174 (19) | 0.0688 (5) | |
H2 | 0.2271 | 0.5573 | 0.8967 | 0.083* | |
C3 | 0.5071 (4) | 0.60636 (15) | 0.8920 (2) | 0.0726 (6) | |
H3 | 0.5363 | 0.6089 | 0.9797 | 0.087* | |
C4 | 0.6509 (3) | 0.63390 (15) | 0.8124 (2) | 0.0715 (6) | |
H4 | 0.7774 | 0.6534 | 0.8462 | 0.086* | |
C5 | 0.6042 (3) | 0.63190 (14) | 0.6845 (2) | 0.0609 (5) | |
H5 | 0.6998 | 0.6513 | 0.6313 | 0.073* | |
C6 | 0.4154 (3) | 0.60134 (12) | 0.62996 (17) | 0.0490 (4) | |
C7 | 0.3682 (3) | 0.60446 (12) | 0.49455 (17) | 0.0487 (4) | |
C8 | 0.2135 (3) | 0.60125 (12) | 0.29532 (16) | 0.0504 (4) | |
H8 | 0.1946 | 0.5468 | 0.2411 | 0.060* | |
C9 | 0.4282 (3) | 0.63686 (15) | 0.2930 (2) | 0.0632 (5) | |
H9A | 0.5091 | 0.5944 | 0.2485 | 0.076* | |
H9B | 0.4289 | 0.6961 | 0.2512 | 0.076* | |
C10 | 0.0526 (3) | 0.67215 (15) | 0.2555 (2) | 0.0665 (5) | |
H10A | −0.0764 | 0.6510 | 0.2799 | 0.080* | |
H10B | 0.0848 | 0.7293 | 0.2998 | 0.080* | |
C11 | 0.0365 (4) | 0.68926 (19) | 0.1130 (2) | 0.0902 (8) | |
H11A | 0.1656 | 0.7075 | 0.0879 | 0.135* | |
H11B | −0.0600 | 0.7370 | 0.0920 | 0.135* | |
H11C | −0.0062 | 0.6340 | 0.0690 | 0.135* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.0521 (2) | 0.0579 (2) | 0.0478 (2) | −0.01417 (13) | 0.01397 (14) | −0.00670 (13) |
O1 | 0.0673 (9) | 0.0990 (11) | 0.0521 (8) | −0.0319 (8) | 0.0174 (7) | −0.0150 (8) |
O2 | 0.0532 (7) | 0.0665 (9) | 0.0667 (9) | −0.0141 (6) | 0.0114 (6) | 0.0104 (7) |
N1 | 0.0506 (8) | 0.0491 (8) | 0.0487 (8) | −0.0064 (6) | 0.0097 (6) | −0.0020 (6) |
C1 | 0.0607 (11) | 0.0506 (10) | 0.0548 (10) | −0.0062 (8) | 0.0081 (8) | −0.0073 (8) |
C2 | 0.0817 (14) | 0.0709 (13) | 0.0545 (11) | −0.0105 (11) | 0.0097 (10) | −0.0077 (10) |
C3 | 0.0901 (16) | 0.0666 (13) | 0.0580 (12) | −0.0029 (11) | −0.0105 (11) | −0.0065 (10) |
C4 | 0.0680 (13) | 0.0644 (13) | 0.0779 (15) | −0.0036 (10) | −0.0173 (11) | −0.0024 (11) |
C5 | 0.0542 (11) | 0.0533 (11) | 0.0742 (13) | −0.0025 (8) | 0.0007 (9) | 0.0033 (9) |
C6 | 0.0515 (9) | 0.0390 (9) | 0.0564 (10) | 0.0012 (7) | 0.0041 (8) | −0.0013 (7) |
C7 | 0.0489 (9) | 0.0373 (9) | 0.0613 (11) | 0.0005 (7) | 0.0132 (8) | 0.0020 (7) |
C8 | 0.0578 (10) | 0.0462 (9) | 0.0489 (9) | −0.0023 (8) | 0.0141 (8) | −0.0009 (8) |
C9 | 0.0633 (12) | 0.0657 (12) | 0.0623 (12) | −0.0030 (9) | 0.0154 (9) | 0.0145 (10) |
C10 | 0.0670 (13) | 0.0693 (13) | 0.0634 (12) | 0.0140 (10) | 0.0076 (10) | −0.0008 (10) |
C11 | 0.1026 (19) | 0.0967 (19) | 0.0690 (14) | 0.0271 (15) | −0.0048 (13) | 0.0096 (13) |
Cu1—O1i | 1.9083 (14) | C4—H4 | 0.9300 |
Cu1—O1 | 1.9083 (14) | C5—C6 | 1.408 (3) |
Cu1—N1 | 1.9541 (14) | C5—H5 | 0.9300 |
Cu1—N1i | 1.9541 (14) | C6—C7 | 1.437 (3) |
O1—C1 | 1.309 (2) | C8—C10 | 1.521 (3) |
O2—C7 | 1.352 (2) | C8—C9 | 1.524 (3) |
O2—C9 | 1.446 (3) | C8—H8 | 0.9800 |
N1—C7 | 1.294 (2) | C9—H9A | 0.9700 |
N1—C8 | 1.479 (2) | C9—H9B | 0.9700 |
C1—C2 | 1.403 (3) | C10—C11 | 1.520 (3) |
C1—C6 | 1.419 (3) | C10—H10A | 0.9700 |
C2—C3 | 1.379 (3) | C10—H10B | 0.9700 |
C2—H2 | 0.9300 | C11—H11A | 0.9600 |
C3—C4 | 1.390 (3) | C11—H11B | 0.9600 |
C3—H3 | 0.9300 | C11—H11C | 0.9600 |
C4—C5 | 1.359 (3) | ||
O1i—Cu1—O1 | 180 | C1—C6—C7 | 120.29 (16) |
O1i—Cu1—N1 | 89.19 (6) | N1—C7—O2 | 115.27 (16) |
O1—Cu1—N1 | 90.81 (6) | N1—C7—C6 | 127.55 (16) |
O1i—Cu1—N1i | 90.81 (6) | O2—C7—C6 | 117.16 (16) |
O1—Cu1—N1i | 89.19 (6) | N1—C8—C10 | 111.15 (14) |
N1—Cu1—N1i | 180 | N1—C8—C9 | 102.36 (14) |
C1—O1—Cu1 | 128.74 (12) | C10—C8—C9 | 113.79 (17) |
C7—O2—C9 | 107.09 (14) | N1—C8—H8 | 109.8 |
C7—N1—C8 | 108.87 (14) | C10—C8—H8 | 109.8 |
C7—N1—Cu1 | 124.68 (12) | C9—C8—H8 | 109.8 |
C8—N1—Cu1 | 126.31 (11) | O2—C9—C8 | 105.14 (14) |
O1—C1—C2 | 118.93 (18) | O2—C9—H9A | 110.7 |
O1—C1—C6 | 124.03 (17) | C8—C9—H9A | 110.7 |
C2—C1—C6 | 117.03 (18) | O2—C9—H9B | 110.7 |
C3—C2—C1 | 122.0 (2) | C8—C9—H9B | 110.7 |
C3—C2—H2 | 119.0 | H9A—C9—H9B | 108.8 |
C1—C2—H2 | 119.0 | C11—C10—C8 | 111.75 (17) |
C2—C3—C4 | 120.4 (2) | C11—C10—H10A | 109.3 |
C2—C3—H3 | 119.8 | C8—C10—H10A | 109.3 |
C4—C3—H3 | 119.8 | C11—C10—H10B | 109.3 |
C5—C4—C3 | 119.1 (2) | C8—C10—H10B | 109.3 |
C5—C4—H4 | 120.5 | H10A—C10—H10B | 107.9 |
C3—C4—H4 | 120.5 | C10—C11—H11A | 109.5 |
C4—C5—C6 | 122.0 (2) | C10—C11—H11B | 109.5 |
C4—C5—H5 | 119.0 | H11A—C11—H11B | 109.5 |
C6—C5—H5 | 119.0 | C10—C11—H11C | 109.5 |
C5—C6—C1 | 119.43 (18) | H11A—C11—H11C | 109.5 |
C5—C6—C7 | 120.26 (17) | H11B—C11—H11C | 109.5 |
O1i—Cu1—O1—C1 | −70 (4) | C2—C1—C6—C7 | −175.30 (18) |
N1—Cu1—O1—C1 | −20.2 (2) | C8—N1—C7—O2 | −4.4 (2) |
N1i—Cu1—O1—C1 | 159.8 (2) | Cu1—N1—C7—O2 | 171.45 (11) |
O1i—Cu1—N1—C7 | −161.26 (15) | C8—N1—C7—C6 | 173.99 (16) |
O1—Cu1—N1—C7 | 18.74 (15) | Cu1—N1—C7—C6 | −10.1 (3) |
N1i—Cu1—N1—C7 | −143 (7) | C9—O2—C7—N1 | −3.2 (2) |
O1i—Cu1—N1—C8 | 13.88 (15) | C9—O2—C7—C6 | 178.17 (16) |
O1—Cu1—N1—C8 | −166.12 (15) | C5—C6—C7—N1 | 176.24 (18) |
N1i—Cu1—N1—C8 | 32 (7) | C1—C6—C7—N1 | −5.5 (3) |
Cu1—O1—C1—C2 | −167.87 (16) | C5—C6—C7—O2 | −5.4 (3) |
Cu1—O1—C1—C6 | 11.8 (3) | C1—C6—C7—O2 | 172.87 (16) |
O1—C1—C2—C3 | 177.2 (2) | C7—N1—C8—C10 | −112.28 (18) |
C6—C1—C2—C3 | −2.4 (3) | Cu1—N1—C8—C10 | 71.94 (19) |
C1—C2—C3—C4 | 0.2 (4) | C7—N1—C8—C9 | 9.56 (19) |
C2—C3—C4—C5 | 1.6 (3) | Cu1—N1—C8—C9 | −166.22 (12) |
C3—C4—C5—C6 | −1.0 (3) | C7—O2—C9—C8 | 9.1 (2) |
C4—C5—C6—C1 | −1.3 (3) | N1—C8—C9—O2 | −11.01 (19) |
C4—C5—C6—C7 | 176.96 (18) | C10—C8—C9—O2 | 109.00 (18) |
O1—C1—C6—C5 | −176.67 (19) | N1—C8—C10—C11 | −171.40 (18) |
C2—C1—C6—C5 | 3.0 (3) | C9—C8—C10—C11 | 73.7 (2) |
O1—C1—C6—C7 | 5.1 (3) |
Symmetry code: (i) −x, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C9—H9A···Cgii | 0.97 | 2.89 | 3.632 (2) | 134 |
C9—H9A···Cgiii | 0.97 | 2.94 | 3.814 (2) | 151 |
Symmetry codes: (ii) −x+1, −y+1, −z+1; (iii) x, −y+3/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | [Cu(C11H12NO2)2] |
Mr | 443.97 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 291 |
a, b, c (Å) | 6.6645 (9), 14.5796 (19), 10.5615 (14) |
β (°) | 95.163 (1) |
V (Å3) | 1022.1 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 1.10 |
Crystal size (mm) | 0.48 × 0.27 × 0.19 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.621, 0.821 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6062, 1882, 1652 |
Rint | 0.013 |
(sin θ/λ)max (Å−1) | 0.606 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.026, 0.077, 1.08 |
No. of reflections | 1882 |
No. of parameters | 134 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.19, −0.19 |
Computer programs: SMART (Bruker, 2003), SAINT (Bruker, 2003), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1999), SHELXTL and PLATON (Spek, 2003).
Cu1—O1 | 1.9083 (14) | Cu1—N1 | 1.9541 (14) |
O1i—Cu1—O1 | 180 | O1—Cu1—N1i | 89.19 (6) |
O1—Cu1—N1 | 90.81 (6) |
Symmetry code: (i) −x, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C9—H9A···Cgii | 0.97 | 2.89 | 3.632 (2) | 134 |
C9—H9A···Cgiii | 0.97 | 2.94 | 3.814 (2) | 151 |
Symmetry codes: (ii) −x+1, −y+1, −z+1; (iii) x, −y+3/2, z−1/2. |
Over the last decade, C2-symmetric chiral oxazoline metal complexes have been recognized as an effective class of chiral catalyst in a variety of transition metal catalyzed asymmetric reactions (Ghosh et al., 1998). High catalytic activities and enantiomeric excesses have been obtained using C2-symmetric chiral ligands in conjunction with suitable transition metal ion, for example, the hydrosilylation of ketone (Imai et al., 1996), allylic alkylation (Chelucci 1997), Michael addition (Ji et al., 1999), Diels-Alder cycloaddition, and cyclopropanation. Thus, the design and synthesis of new chiral oxazoline ligands and their complexes have inspired many scientists to work with great efforts (Du et al., 2003; Zhang et al., 2007).
We report here the crystal structure of the title compound, (I), a CuII complex with the chiral (S)-2-(4-ethyl-4,5-dihydrooxazol -2-yl)phenol, as the coordination ligand.
The title compound, contains one centrosymmetric tetra-coordinated copper(II) complex (Fig 1). The copper atom is coordinated by two 2-(4-ethyl- 4,5-dihydrooxazol-2-yl)-phenol anions, which bind to the metal centre via the N atom and the phenolyl O atom. Pairs of equivalent ligands lie trans to each other in a slightly distorted square planar geometry about the copper(II) atom (see Table 1).
The aryl and oxazoline least-squares planes are linked by π-π stacking interactions with Cg-Cgii distances 3.7953 (12) Å (symmetry code ii: 1 - x, 1 - y, 1 - z). The C—H···Cg (aryl ring) interactions are observed with H9Aiii···Cg = 2.94 Å (symmetry code iii: x, 1/2 - y, -1/2 + z) and H9Ai···Cg = 2.89 Å (Fig 2) (Spek, 2003).