Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807026967/lh2403sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807026967/lh2403Isup2.hkl |
CCDC reference: 655579
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.005 Å
- R factor = 0.039
- wR factor = 0.088
- Data-to-parameter ratio = 17.4
checkCIF/PLATON results
No syntax errors found
Alert level A DIFF019_ALERT_1_A _diffrn_standards_number is missing Number of standards used in measurement.
Author Response: We used an IP diffractometer to collect the data. Therefore, no standard reflections have been used during the measurement. |
DIFF020_ALERT_1_A _diffrn_standards_interval_count and _diffrn_standards_interval_time are missing. Number of measurements between standards or time (min) between standards.
Author Response: We used an IP diffractometer to collect the data. Therefore, no standard reflections have been used during the measurement. |
Alert level C PLAT241_ALERT_2_C Check High Ueq as Compared to Neighbors for O3 PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for C10 PLAT380_ALERT_4_C Check Incorrectly? Oriented X(sp2)-Methyl Moiety C11
Alert level G PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature . 293 K PLAT794_ALERT_5_G Check Predicted Bond Valency for Cu1 (2) 2.19
2 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 3 ALERT level C = Check and explain 3 ALERT level G = General alerts; check 4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 2 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion 1 ALERT type 5 Informative message, check
Cu2L2Ac2 was synthesized as previously reported with a slight modification (Cristiano et al., 1990). A solution of salicylaldehyde (2.45 g, 20 mmol) was slowly added to a water-ethanol solution (1: 1, v/v) of copper (II) acetate (4.00 g, 20 mmol) of 100 ml. After adding NaOH (0.10 g, 2.5 mmol) and heating for 10 min, we carefully add ethylenediamine (1.25 g, 20 mmol) to the resulting black-green solution, which gradually changed to black-blue. After the addition was completed, the solution was heated for half an hour. After evaporation of the excess solvent and cooling in the refrigerator, a dark blue precipitate was formed and collected by filtration. Yield: 65%.
A small quantity of the precipitate (50 mg, 0.2 mmol) was dissolved in a water-methanol solution (1: 4, v/v) of 15 ml approximately. After slow evaporation for two weeks, single crystals sutiable for X-ray diffraction analysis were obtained as light-blue rhombic slices.
H atoms bound to C and N atoms were placed in caculated positions with C—H = 0.93–0.77Å and N—H = 0.90Å and included in the refinement with Uiso(H) = 1.2Ueq(C,N) or 1.5Ueq(C) for methyl H atoms.
Schiff bases play a significant role in coordination chemistry as a widely used ligand (Green et al., 1973; Dey, 1974). Not only the nitrogen atoms but also other high electronegativity atoms like oxygen and sulfur exist in the molecular structure lead to various chelation modes (Dutta & Das, 1988; Chattopadhyay et al., 2006; Mikuriya et al., 2001; Nakajima et al., 1998). In this contribution, we report the tridentate Schiff base 2-(Salicylideneimino)ethylamine, which is not saturated and then other donors may be accepted in the coordination environment giving the bridged structures. Several mono- and di-nuclear complexes have been reported (Gardner et al., 1968; Saridha et al., 2005; Mandal & Nag, 1984). Carboxylate is another interesting bridging group because it exhibits several coordination modes (Sessler et al., 1991; Boyle et al., 1998; Turner et al., 1992; Rettig et al., 1999; Wang et al., 2004). We focus our interest in the carboxylate and tridentate Schiff base groups and obtain the title acetate-bridged dinuclear copper(II) complex Cu2L2Ac2 (I).
Fig. 1 shows the dimeric structure of (I). The two Cu(II) atoms are inversion-center related and are doubly bridged by two oxygen atoms of two acetate ligands. The Cu(1) atom reveals a CuN2O3 coordination environment with the two nitrogen atoms and one oxygen atom of the L- ligand and one oxygen atom of the acetate occupying the basal plane [Cu(1)—O(1) 1.916 (2) Å, Cu(1)—N(1) 1.946 (2) Å, Cu(1)—N(2) 2.011 (2) Å]. Each acetate group bridges two copper(II) ions through O(2) and O(2 A) oxygen atoms involving axial and equatorial positions in the copper(II) coordination polyhedra, respectively. The axial Cu—O bond distance [Cu(1)—O(2 A) 2.454 (3) Å] is significantly longer than the equatorial one [Cu(1)—O(2) 1.970 (2) Å]. Since many five-coordinate structures with intermediate geometries between regular trigonal bipyramidal (TBP) and square pyramidal (SP), the τ value has been used to evaluate the distortion (Addison et al., 1984). In the present complex, τ values is calculated to be 0.08 which indicates that it is very close to a SP geometry. The Cu(II) centers and bridged oxygen atoms form a rhombic plane with the angles O(2)—Cu(1)—O(2 A) and Cu(1)—O(2)—Cu(1 A) of 85.60 ° and 94.40 °, respectively.
A supramolecular network through weak intermolecular N—H···O hydrogen bonds was displayed in Fig. 2. The intramolecular hydrogen bonds exist through N—H···O (phenol) with a distance of 3.203 Å (N···O), which help to stabilize each of the dinuclear unit. The intermolecular hydrogen bonds exist through N—H···O (acetate) of the adjacent molecules with the N···O distance of 3.009 Å. As a result, the crystal structure can be described as a two-dimensional network.
For related literature, see: Addison et al. (1984); Boyle et al. (1998); Chattopadhyay et al. (2006); Dey (1974); Dutta & Das (1988); Gardner et al. (1968); Green et al. (1973); Mandal & Nag (1984); Mikuriya et al. (2001); Nakajima et al. (1998); Rettig et al. (1999); Saridha et al. (2005); Sessler et al. (1991); Turner et al. (1992); Wang et al. (2004).
For related literature, see: Benelli et al. (1990).
Data collection: CrystalStructure (Rigaku/MSC, 2004); cell refinement: CrystalStructure; data reduction: CrystalStructure; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHEXLTL (Sheldrick, 1998); software used to prepare material for publication: SHELXTL.
[Cu2(C9H11N2O)2(C2H3O2)2] | F(000) = 588 |
Mr = 571.56 | Dx = 1.622 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 2675 reflections |
a = 11.099 (2) Å | θ = 3.2–27.5° |
b = 14.745 (3) Å | µ = 1.86 mm−1 |
c = 7.4660 (15) Å | T = 293 K |
β = 106.68 (3)° | Rhomb, blue |
V = 1170.4 (4) Å3 | 0.28 × 0.20 × 0.12 mm |
Z = 2 |
Rigaku R-AXIS RAPID IP diffractometer | 2675 independent reflections |
Radiation source: fine-focus sealed tube | 2159 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.065 |
Detector resolution: 100x100 microns pixels mm-1 | θmax = 27.5°, θmin = 3.2° |
ω scans | h = −14→14 |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | k = −19→19 |
Tmin = 0.652, Tmax = 0.795 | l = −8→9 |
10843 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)] = 0.039 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.088 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.010P)2 + 1.P] where P = (Fo2 + 2Fc2)/3 |
2675 reflections | (Δ/σ)max = 0.007 |
154 parameters | Δρmax = 0.39 e Å−3 |
0 restraints | Δρmin = −0.40 e Å−3 |
[Cu2(C9H11N2O)2(C2H3O2)2] | V = 1170.4 (4) Å3 |
Mr = 571.56 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 11.099 (2) Å | µ = 1.86 mm−1 |
b = 14.745 (3) Å | T = 293 K |
c = 7.4660 (15) Å | 0.28 × 0.20 × 0.12 mm |
β = 106.68 (3)° |
Rigaku R-AXIS RAPID IP diffractometer | 2675 independent reflections |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | 2159 reflections with I > 2σ(I) |
Tmin = 0.652, Tmax = 0.795 | Rint = 0.065 |
10843 measured reflections |
R[F2 > 2σ(F2)] = 0.039 | 0 restraints |
wR(F2) = 0.088 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.39 e Å−3 |
2675 reflections | Δρmin = −0.40 e Å−3 |
154 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 | ||
Cu1 | 0.42654 (3) | 1.09572 (2) | −0.06380 (4) | 0.03275 (12) | |
O1 | 0.31409 (19) | 1.07381 (13) | 0.0841 (3) | 0.0416 (5) | |
O2 | 0.57032 (18) | 1.06438 (13) | 0.1520 (3) | 0.0380 (4) | |
N1 | 0.2959 (2) | 1.14930 (14) | −0.2682 (3) | 0.0363 (5) | |
N2 | 0.5350 (2) | 1.10879 (15) | −0.2366 (3) | 0.0383 (5) | |
H2B | 0.5828 | 1.1590 | −0.2081 | 0.046* | |
H2C | 0.5860 | 1.0604 | −0.2263 | 0.046* | |
C1 | 0.1953 (3) | 1.09581 (18) | 0.0429 (4) | 0.0373 (6) | |
C7 | 0.1813 (3) | 1.16371 (18) | −0.2704 (4) | 0.0392 (7) | |
H7A | 0.1292 | 1.1917 | −0.3762 | 0.047* | |
C6 | 0.1268 (3) | 1.14059 (18) | −0.1248 (4) | 0.0388 (6) | |
C8 | 0.3441 (3) | 1.17848 (19) | −0.4217 (4) | 0.0439 (7) | |
H8A | 0.3751 | 1.2402 | −0.4010 | 0.053* | |
H8B | 0.2777 | 1.1764 | −0.5390 | 0.053* | |
C3 | 0.0044 (3) | 1.0980 (2) | 0.1428 (5) | 0.0578 (9) | |
H3A | −0.0363 | 1.0827 | 0.2314 | 0.069* | |
C5 | −0.0006 (3) | 1.1638 (2) | −0.1492 (5) | 0.0509 (8) | |
H5A | −0.0447 | 1.1935 | −0.2581 | 0.061* | |
C2 | 0.1283 (3) | 1.0751 (2) | 0.1724 (5) | 0.0492 (8) | |
H2A | 0.1697 | 1.0448 | 0.2820 | 0.059* | |
C4 | −0.0610 (3) | 1.1440 (3) | −0.0189 (6) | 0.0620 (10) | |
H4A | −0.1445 | 1.1608 | −0.0375 | 0.074* | |
C9 | 0.4492 (3) | 1.1152 (2) | −0.4288 (4) | 0.0444 (7) | |
H9A | 0.4159 | 1.0559 | −0.4727 | 0.053* | |
H9B | 0.4938 | 1.1387 | −0.5132 | 0.053* | |
O3 | 0.6197 (3) | 1.20989 (15) | 0.1595 (3) | 0.0636 (7) | |
C10 | 0.6400 (3) | 1.13237 (19) | 0.2222 (4) | 0.0364 (6) | |
C11 | 0.7492 (3) | 1.1133 (3) | 0.3916 (5) | 0.0594 (9) | |
H11A | 0.7948 | 1.1684 | 0.4325 | 0.089* | |
H11B | 0.8039 | 1.0696 | 0.3601 | 0.089* | |
H11C | 0.7185 | 1.0898 | 0.4901 | 0.089* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.0409 (2) | 0.02722 (18) | 0.02902 (19) | 0.00513 (14) | 0.00822 (13) | 0.00394 (12) |
O1 | 0.0430 (12) | 0.0456 (12) | 0.0369 (11) | 0.0091 (9) | 0.0123 (9) | 0.0104 (8) |
O2 | 0.0418 (11) | 0.0312 (10) | 0.0364 (10) | 0.0011 (9) | 0.0040 (8) | 0.0037 (8) |
N1 | 0.0495 (15) | 0.0265 (11) | 0.0302 (12) | 0.0032 (10) | 0.0071 (10) | 0.0011 (8) |
N2 | 0.0458 (14) | 0.0304 (12) | 0.0388 (13) | 0.0013 (10) | 0.0122 (10) | 0.0022 (9) |
C1 | 0.0442 (16) | 0.0276 (13) | 0.0391 (15) | −0.0010 (12) | 0.0104 (12) | −0.0035 (10) |
C7 | 0.0451 (17) | 0.0274 (14) | 0.0354 (15) | 0.0030 (12) | −0.0038 (12) | −0.0002 (10) |
C6 | 0.0402 (16) | 0.0273 (14) | 0.0455 (16) | 0.0009 (12) | 0.0069 (12) | −0.0044 (11) |
C8 | 0.064 (2) | 0.0328 (15) | 0.0321 (15) | 0.0041 (14) | 0.0101 (13) | 0.0082 (11) |
C3 | 0.054 (2) | 0.055 (2) | 0.075 (3) | −0.0083 (17) | 0.0350 (19) | −0.0121 (17) |
C5 | 0.0393 (17) | 0.0391 (17) | 0.067 (2) | −0.0020 (14) | 0.0038 (15) | −0.0044 (14) |
C2 | 0.055 (2) | 0.0421 (17) | 0.0540 (19) | −0.0056 (15) | 0.0211 (15) | −0.0042 (14) |
C4 | 0.0373 (18) | 0.051 (2) | 0.097 (3) | −0.0039 (16) | 0.0182 (19) | −0.0133 (19) |
C9 | 0.064 (2) | 0.0398 (16) | 0.0321 (15) | 0.0013 (15) | 0.0176 (14) | 0.0010 (11) |
O3 | 0.0890 (19) | 0.0327 (12) | 0.0596 (15) | 0.0009 (12) | 0.0063 (13) | −0.0027 (10) |
C10 | 0.0409 (16) | 0.0351 (15) | 0.0350 (14) | 0.0035 (13) | 0.0137 (12) | −0.0014 (11) |
C11 | 0.0465 (19) | 0.071 (2) | 0.054 (2) | −0.0057 (17) | 0.0034 (15) | 0.0008 (16) |
Cu1—O1 | 1.916 (2) | C8—C9 | 1.506 (4) |
Cu1—N1 | 1.946 (2) | C8—H8A | 0.9700 |
Cu1—O2 | 1.970 (2) | C8—H8B | 0.9700 |
Cu1—N2 | 2.011 (2) | C3—C2 | 1.370 (5) |
Cu1—O2i | 2.454 (3) | C3—C4 | 1.393 (5) |
O1—C1 | 1.306 (3) | C3—H3A | 0.9300 |
O2—C10 | 1.283 (3) | C5—C4 | 1.362 (5) |
N1—C7 | 1.285 (4) | C5—H5A | 0.9300 |
N1—C8 | 1.462 (4) | C2—H2A | 0.9300 |
N2—C9 | 1.480 (4) | C4—H4A | 0.9300 |
N2—H2B | 0.9000 | C9—H9A | 0.9700 |
N2—H2C | 0.9000 | C9—H9B | 0.9700 |
C1—C2 | 1.413 (4) | O3—C10 | 1.231 (3) |
C1—C6 | 1.426 (4) | C10—C11 | 1.506 (4) |
C7—C6 | 1.429 (4) | C11—H11A | 0.9600 |
C7—H7A | 0.9300 | C11—H11B | 0.9600 |
C6—C5 | 1.415 (4) | C11—H11C | 0.9600 |
O1—Cu1—N1 | 93.33 (9) | C9—C8—H8A | 110.1 |
O1—Cu1—O2 | 89.89 (8) | N1—C8—H8B | 110.1 |
N1—Cu1—O2 | 169.50 (8) | C9—C8—H8B | 110.1 |
O1—Cu1—N2 | 174.17 (9) | H8A—C8—H8B | 108.4 |
N1—Cu1—N2 | 84.65 (10) | C2—C3—C4 | 120.6 (3) |
O2—Cu1—N2 | 93.06 (9) | C2—C3—H3A | 119.7 |
O2i—Cu1—O1 | 93.10 (8) | C4—C3—H3A | 119.7 |
O2—Cu1—O2i | 85.59 (7) | C4—C5—C6 | 122.3 (3) |
O2i—Cu1—N1 | 104.19 (8) | C4—C5—H5A | 118.8 |
O2i—Cu1—N2 | 82.12 (8) | C6—C5—H5A | 118.8 |
C1—O1—Cu1 | 127.10 (17) | C3—C2—C1 | 122.5 (3) |
C10—O2—Cu1 | 113.76 (17) | C3—C2—H2A | 118.8 |
C7—N1—C8 | 121.7 (2) | C1—C2—H2A | 118.8 |
C7—N1—Cu1 | 126.14 (19) | C5—C4—C3 | 118.8 (3) |
C8—N1—Cu1 | 112.09 (19) | C5—C4—H4A | 120.6 |
C9—N2—Cu1 | 106.92 (18) | C3—C4—H4A | 120.6 |
C9—N2—H2B | 110.3 | N2—C9—C8 | 107.2 (2) |
Cu1—N2—H2B | 110.3 | N2—C9—H9A | 110.3 |
C9—N2—H2C | 110.3 | C8—C9—H9A | 110.3 |
Cu1—N2—H2C | 110.3 | N2—C9—H9B | 110.3 |
H2B—N2—H2C | 108.6 | C8—C9—H9B | 110.3 |
O1—C1—C2 | 118.7 (3) | H9A—C9—H9B | 108.5 |
O1—C1—C6 | 124.7 (3) | O3—C10—O2 | 123.2 (3) |
C2—C1—C6 | 116.6 (3) | O3—C10—C11 | 120.5 (3) |
N1—C7—C6 | 125.7 (2) | O2—C10—C11 | 116.3 (3) |
N1—C7—H7A | 117.1 | C10—C11—H11A | 109.5 |
C6—C7—H7A | 117.1 | C10—C11—H11B | 109.5 |
C5—C6—C1 | 119.1 (3) | H11A—C11—H11B | 109.5 |
C5—C6—C7 | 118.0 (3) | C10—C11—H11C | 109.5 |
C1—C6—C7 | 122.9 (3) | H11A—C11—H11C | 109.5 |
N1—C8—C9 | 107.9 (2) | H11B—C11—H11C | 109.5 |
N1—C8—H8A | 110.1 |
Symmetry code: (i) −x+1, −y+2, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2B···O3ii | 0.90 | 2.26 | 3.009 (6) | 140 |
N2—H2C···O1i | 0.90 | 2.37 | 3.203 (3) | 155 |
Symmetry codes: (i) −x+1, −y+2, −z; (ii) x, −y+5/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | [Cu2(C9H11N2O)2(C2H3O2)2] |
Mr | 571.56 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 11.099 (2), 14.745 (3), 7.4660 (15) |
β (°) | 106.68 (3) |
V (Å3) | 1170.4 (4) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 1.86 |
Crystal size (mm) | 0.28 × 0.20 × 0.12 |
Data collection | |
Diffractometer | Rigaku R-AXIS RAPID IP |
Absorption correction | Multi-scan (ABSCOR; Higashi, 1995) |
Tmin, Tmax | 0.652, 0.795 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10843, 2675, 2159 |
Rint | 0.065 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.039, 0.088, 1.07 |
No. of reflections | 2675 |
No. of parameters | 154 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.39, −0.40 |
Computer programs: CrystalStructure (Rigaku/MSC, 2004), CrystalStructure, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHEXLTL (Sheldrick, 1998), SHELXTL.
Cu1—O1 | 1.916 (2) | Cu1—N2 | 2.011 (2) |
Cu1—N1 | 1.946 (2) | Cu1—O2i | 2.454 (3) |
Cu1—O2 | 1.970 (2) | ||
O1—Cu1—N1 | 93.33 (9) | O2—Cu1—N2 | 93.06 (9) |
O1—Cu1—O2 | 89.89 (8) | O2i—Cu1—O1 | 93.10 (8) |
N1—Cu1—O2 | 169.50 (8) | O2—Cu1—O2i | 85.59 (7) |
O1—Cu1—N2 | 174.17 (9) | O2i—Cu1—N1 | 104.19 (8) |
N1—Cu1—N2 | 84.65 (10) | O2i—Cu1—N2 | 82.12 (8) |
Symmetry code: (i) −x+1, −y+2, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2B···O3ii | 0.90 | 2.261 | 3.009 (6) | 140 |
N2—H2C···O1i | 0.90 | 2.366 | 3.203 (3) | 155 |
Symmetry codes: (i) −x+1, −y+2, −z; (ii) x, −y+5/2, z−1/2. |
Schiff bases play a significant role in coordination chemistry as a widely used ligand (Green et al., 1973; Dey, 1974). Not only the nitrogen atoms but also other high electronegativity atoms like oxygen and sulfur exist in the molecular structure lead to various chelation modes (Dutta & Das, 1988; Chattopadhyay et al., 2006; Mikuriya et al., 2001; Nakajima et al., 1998). In this contribution, we report the tridentate Schiff base 2-(Salicylideneimino)ethylamine, which is not saturated and then other donors may be accepted in the coordination environment giving the bridged structures. Several mono- and di-nuclear complexes have been reported (Gardner et al., 1968; Saridha et al., 2005; Mandal & Nag, 1984). Carboxylate is another interesting bridging group because it exhibits several coordination modes (Sessler et al., 1991; Boyle et al., 1998; Turner et al., 1992; Rettig et al., 1999; Wang et al., 2004). We focus our interest in the carboxylate and tridentate Schiff base groups and obtain the title acetate-bridged dinuclear copper(II) complex Cu2L2Ac2 (I).
Fig. 1 shows the dimeric structure of (I). The two Cu(II) atoms are inversion-center related and are doubly bridged by two oxygen atoms of two acetate ligands. The Cu(1) atom reveals a CuN2O3 coordination environment with the two nitrogen atoms and one oxygen atom of the L- ligand and one oxygen atom of the acetate occupying the basal plane [Cu(1)—O(1) 1.916 (2) Å, Cu(1)—N(1) 1.946 (2) Å, Cu(1)—N(2) 2.011 (2) Å]. Each acetate group bridges two copper(II) ions through O(2) and O(2 A) oxygen atoms involving axial and equatorial positions in the copper(II) coordination polyhedra, respectively. The axial Cu—O bond distance [Cu(1)—O(2 A) 2.454 (3) Å] is significantly longer than the equatorial one [Cu(1)—O(2) 1.970 (2) Å]. Since many five-coordinate structures with intermediate geometries between regular trigonal bipyramidal (TBP) and square pyramidal (SP), the τ value has been used to evaluate the distortion (Addison et al., 1984). In the present complex, τ values is calculated to be 0.08 which indicates that it is very close to a SP geometry. The Cu(II) centers and bridged oxygen atoms form a rhombic plane with the angles O(2)—Cu(1)—O(2 A) and Cu(1)—O(2)—Cu(1 A) of 85.60 ° and 94.40 °, respectively.
A supramolecular network through weak intermolecular N—H···O hydrogen bonds was displayed in Fig. 2. The intramolecular hydrogen bonds exist through N—H···O (phenol) with a distance of 3.203 Å (N···O), which help to stabilize each of the dinuclear unit. The intermolecular hydrogen bonds exist through N—H···O (acetate) of the adjacent molecules with the N···O distance of 3.009 Å. As a result, the crystal structure can be described as a two-dimensional network.