In the title centrosymmetric binuclear complex, [Cu
2(C
14H
11N
2O
3)
2(H
2O)
2](NO
3)
2, the two metal centres are bridged by the phenolate O atoms of the ligand, forming a Cu
2O
2 quadrangle. Each Cu atom has a distorted square-pyramidal geometry, with the basal donor atoms coming from the
O,
N,
O'-tridentate ligand and a symmetry-related phenolate O atom. The more weakly bound apical donor O atom is supplied by a coordinated water molecule. When a further weak Cu
O interaction with the 4-hydroxy O atom of a neighbouring cation is considered, the extended coordination sphere of the Cu atom can be described as distorted octahedral. This interaction leads to two-dimensional layers, which extend parallel to the (100) direction. The two-dimensional polymeric structure contrasts with other reported structures involving salicylaldehyde benzoylhydrazone ligands, which are usually discrete mono- or dinuclear Cu complexes. The nitrate anions are involved in a three-dimensional hydrogen-bonding network, featuring intermolecular N-H
O and O-H
O hydrogen bonds.
Supporting information
CCDC reference: 707194
Cu(NO3)2.3H2O (0.2 mmol, 48.4 mg) was added to an ethanol solution (20 ml)
containing 4-hydroxy-N-(2-hydroxybenzylidene) benzolhydrazide (0.2 mmol, 51.2 mg). The resulting mixture was stirred for 1.5 h and then filtered.
Dark-blue block-shaped crystals were obtained from the solution after two
weeks.
The H atoms H1WA, H1WB, H03A and H2N were located in different Fourier maps,
but were then allowed to ride on O1W, O3 and N2, respectively, with O—H =
0.82 Å and N—H = 0.86 Å. Other H atoms were positioned geometrically and
treated as riding [C—H = 0.93 Å and Uiso(H) = 1.2Ueq(C)].
Data collection: TEXRAY (Molecular Structure Corporation, 1999); cell refinement: TEXRAY (Molecular Structure Corporation, 1999); data reduction: TEXSAN (Molecular Structure Corporation, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEX (McArdle, 1995); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
bis{µ-[(4-hydroxybenzoyl)hydrazonomethyl]phenolato}bis[aquacopper(II)]
dinitrate
top
Crystal data top
[Cu2(C14H11N2O3)2(H2O)2](NO3)2 | F(000) = 1624 |
Mr = 797.62 | Dx = 1.759 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 11074 reflections |
a = 13.815 (8) Å | θ = 3.1–27.6° |
b = 12.109 (4) Å | µ = 1.50 mm−1 |
c = 18.787 (8) Å | T = 293 K |
β = 106.55 (2)° | Block, dark-blue |
V = 3013 (2) Å3 | 0.28 × 0.23 × 0.19 mm |
Z = 4 | |
Data collection top
Rigaku Weissenberg IP diffractometer | 3442 independent reflections |
Radiation source: rotor target | 2803 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.049 |
ω scans | θmax = 27.5°, θmin = 3.1° |
Absorption correction: empirical (using intensity measurements) (TEXRAY; Molecular Structure Corporation, 1999) | h = −17→17 |
Tmin = 0.668, Tmax = 0.753 | k = −15→15 |
14501 measured reflections | l = −24→24 |
Refinement top
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)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.114 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0674P)2 + 0.3437P] where P = (Fo2 + 2Fc2)/3 |
3442 reflections | (Δ/σ)max < 0.001 |
242 parameters | Δρmax = 0.58 e Å−3 |
3 restraints | Δρmin = −0.42 e Å−3 |
Crystal data top
[Cu2(C14H11N2O3)2(H2O)2](NO3)2 | V = 3013 (2) Å3 |
Mr = 797.62 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 13.815 (8) Å | µ = 1.50 mm−1 |
b = 12.109 (4) Å | T = 293 K |
c = 18.787 (8) Å | 0.28 × 0.23 × 0.19 mm |
β = 106.55 (2)° | |
Data collection top
Rigaku Weissenberg IP diffractometer | 3442 independent reflections |
Absorption correction: empirical (using intensity measurements) (TEXRAY; Molecular Structure Corporation, 1999) | 2803 reflections with I > 2σ(I) |
Tmin = 0.668, Tmax = 0.753 | Rint = 0.049 |
14501 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.037 | 3 restraints |
wR(F2) = 0.114 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.09 | Δρmax = 0.58 e Å−3 |
3442 reflections | Δρmin = −0.42 e Å−3 |
242 parameters | |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Cu1 | 0.24004 (2) | 0.14668 (2) | 0.040767 (16) | 0.03000 (13) | |
O1W | 0.06846 (18) | 0.12405 (17) | −0.04197 (12) | 0.0419 (5) | |
H1WA | 0.024 (2) | 0.145 (2) | −0.0266 (18) | 0.043 (10)* | |
H1WB | 0.056 (3) | 0.0588 (17) | −0.0528 (19) | 0.056 (10)* | |
O1 | 0.29799 (14) | 0.19655 (13) | −0.03632 (9) | 0.0301 (4) | |
O2 | 0.20060 (15) | 0.08051 (13) | 0.12361 (10) | 0.0364 (4) | |
O3 | 0.10075 (17) | −0.25932 (17) | 0.34847 (11) | 0.0411 (5) | |
H03A | 0.088 (2) | −0.222 (2) | 0.3757 (16) | 0.031 (8)* | |
O4 | 0.1555 (2) | 0.2114 (2) | 0.40286 (19) | 0.0832 (9) | |
O5 | 0.0913 (2) | 0.2056 (2) | 0.49415 (13) | 0.0604 (6) | |
O6 | 0.0446 (2) | 0.08899 (17) | 0.40550 (15) | 0.0606 (6) | |
N1 | 0.29051 (17) | −0.00079 (15) | 0.03621 (11) | 0.0299 (4) | |
N2 | 0.26857 (19) | −0.06901 (17) | 0.08869 (13) | 0.0357 (5) | |
H2N | 0.287 (3) | −0.1361 (16) | 0.0904 (19) | 0.045 (9)* | |
N3 | 0.0981 (2) | 0.16791 (18) | 0.43336 (16) | 0.0452 (6) | |
C1 | 0.3706 (2) | 0.02355 (19) | −0.05993 (13) | 0.0295 (5) | |
C2 | 0.35083 (19) | 0.13779 (19) | −0.07343 (13) | 0.0278 (5) | |
C3 | 0.3885 (2) | 0.1890 (2) | −0.12605 (15) | 0.0376 (6) | |
H3A | 0.3775 | 0.2641 | −0.1351 | 0.045* | |
C4 | 0.4419 (3) | 0.1304 (2) | −0.16514 (17) | 0.0447 (7) | |
H4A | 0.4658 | 0.1667 | −0.2004 | 0.054* | |
C5 | 0.4608 (2) | 0.0187 (2) | −0.15315 (15) | 0.0425 (7) | |
H5A | 0.4965 | −0.0202 | −0.1802 | 0.051* | |
C6 | 0.4261 (2) | −0.0329 (2) | −0.10090 (15) | 0.0366 (6) | |
H6A | 0.4394 | −0.1077 | −0.0920 | 0.044* | |
C7 | 0.3403 (2) | −0.04021 (19) | −0.00605 (14) | 0.0330 (6) | |
H7A | 0.3576 | −0.1146 | −0.0013 | 0.040* | |
C8 | 0.2195 (2) | −0.02114 (19) | 0.13196 (13) | 0.0294 (5) | |
C9 | 0.1889 (2) | −0.08552 (19) | 0.18764 (13) | 0.0306 (5) | |
C10 | 0.1907 (2) | −0.2004 (2) | 0.18948 (14) | 0.0348 (6) | |
H10A | 0.2129 | −0.2394 | 0.1545 | 0.042* | |
C11 | 0.1597 (2) | −0.2569 (2) | 0.24290 (14) | 0.0363 (6) | |
H11A | 0.1594 | −0.3337 | 0.2429 | 0.044* | |
C12 | 0.1292 (2) | −0.2000 (2) | 0.29615 (13) | 0.0313 (5) | |
C13 | 0.1270 (2) | −0.0851 (2) | 0.29518 (15) | 0.0379 (6) | |
H13A | 0.1058 | −0.0463 | 0.3308 | 0.045* | |
C14 | 0.1565 (2) | −0.0292 (2) | 0.24096 (15) | 0.0370 (6) | |
H14A | 0.1546 | 0.0476 | 0.2401 | 0.044* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cu1 | 0.0423 (2) | 0.02157 (18) | 0.03376 (19) | 0.00365 (11) | 0.02319 (15) | 0.00282 (11) |
O1W | 0.0483 (13) | 0.0378 (10) | 0.0479 (11) | −0.0010 (9) | 0.0268 (10) | −0.0052 (10) |
O1 | 0.0427 (10) | 0.0208 (7) | 0.0356 (9) | 0.0034 (7) | 0.0253 (8) | 0.0015 (7) |
O2 | 0.0548 (13) | 0.0245 (8) | 0.0390 (9) | 0.0052 (8) | 0.0281 (9) | 0.0054 (8) |
O3 | 0.0556 (14) | 0.0360 (10) | 0.0408 (10) | −0.0043 (9) | 0.0281 (10) | 0.0027 (9) |
O4 | 0.094 (2) | 0.0485 (13) | 0.138 (3) | −0.0186 (14) | 0.083 (2) | −0.0077 (16) |
O5 | 0.0736 (18) | 0.0544 (13) | 0.0555 (13) | −0.0172 (12) | 0.0219 (12) | −0.0030 (12) |
O6 | 0.0674 (17) | 0.0334 (10) | 0.0870 (17) | −0.0093 (10) | 0.0319 (14) | −0.0095 (12) |
N1 | 0.0396 (13) | 0.0228 (9) | 0.0328 (10) | 0.0018 (8) | 0.0192 (9) | 0.0025 (8) |
N2 | 0.0508 (15) | 0.0222 (9) | 0.0430 (12) | 0.0042 (9) | 0.0278 (11) | 0.0058 (10) |
N3 | 0.0454 (15) | 0.0265 (10) | 0.0699 (17) | −0.0014 (10) | 0.0265 (13) | 0.0055 (12) |
C1 | 0.0331 (14) | 0.0274 (11) | 0.0310 (11) | 0.0013 (10) | 0.0139 (10) | −0.0020 (10) |
C2 | 0.0297 (13) | 0.0279 (11) | 0.0291 (11) | 0.0005 (9) | 0.0137 (10) | −0.0040 (9) |
C3 | 0.0487 (17) | 0.0303 (12) | 0.0418 (13) | 0.0021 (11) | 0.0260 (12) | 0.0033 (12) |
C4 | 0.057 (2) | 0.0443 (15) | 0.0450 (15) | 0.0005 (13) | 0.0335 (15) | 0.0001 (13) |
C5 | 0.0493 (18) | 0.0452 (15) | 0.0422 (14) | 0.0057 (13) | 0.0280 (13) | −0.0072 (13) |
C6 | 0.0435 (16) | 0.0314 (12) | 0.0391 (13) | 0.0048 (11) | 0.0185 (12) | −0.0042 (11) |
C7 | 0.0432 (16) | 0.0230 (11) | 0.0373 (12) | 0.0035 (10) | 0.0186 (11) | −0.0016 (10) |
C8 | 0.0355 (14) | 0.0259 (11) | 0.0295 (11) | −0.0013 (10) | 0.0137 (10) | −0.0003 (10) |
C9 | 0.0346 (14) | 0.0279 (11) | 0.0326 (12) | −0.0003 (10) | 0.0148 (10) | 0.0047 (10) |
C10 | 0.0455 (16) | 0.0294 (12) | 0.0347 (12) | −0.0019 (11) | 0.0197 (11) | −0.0029 (11) |
C11 | 0.0505 (17) | 0.0261 (11) | 0.0361 (13) | −0.0028 (11) | 0.0187 (12) | 0.0009 (11) |
C12 | 0.0325 (14) | 0.0328 (12) | 0.0304 (12) | −0.0022 (10) | 0.0117 (10) | 0.0031 (11) |
C13 | 0.0493 (17) | 0.0331 (13) | 0.0393 (14) | 0.0042 (12) | 0.0256 (12) | 0.0016 (11) |
C14 | 0.0495 (18) | 0.0256 (11) | 0.0412 (13) | 0.0040 (11) | 0.0216 (13) | 0.0033 (11) |
Geometric parameters (Å, º) top
Cu1—N1 | 1.928 (2) | C1—C7 | 1.427 (3) |
Cu1—O1 | 1.9400 (17) | C2—C3 | 1.388 (3) |
Cu1—O2 | 1.9606 (17) | C3—C4 | 1.377 (4) |
Cu1—O1i | 1.9651 (17) | C3—H3A | 0.9300 |
Cu1—O1W | 2.452 (3) | C4—C5 | 1.384 (4) |
O1W—H1WA | 0.794 (18) | C4—H4A | 0.9300 |
O1W—H1WB | 0.821 (18) | C5—C6 | 1.362 (4) |
O1—C2 | 1.347 (3) | C5—H5A | 0.9300 |
O1—Cu1i | 1.9651 (17) | C6—H6A | 0.9300 |
O2—C8 | 1.259 (3) | C7—H7A | 0.9300 |
O3—C12 | 1.363 (3) | C8—C9 | 1.460 (3) |
O3—H03A | 0.74 (3) | C9—C14 | 1.388 (4) |
O4—N3 | 1.221 (3) | C9—C10 | 1.391 (4) |
O5—N3 | 1.258 (3) | C10—C11 | 1.380 (4) |
O6—N3 | 1.230 (3) | C10—H10A | 0.9300 |
N1—C7 | 1.281 (3) | C11—C12 | 1.376 (4) |
N1—N2 | 1.384 (3) | C11—H11A | 0.9300 |
N2—C8 | 1.331 (3) | C12—C13 | 1.392 (4) |
N2—H2N | 0.851 (17) | C13—C14 | 1.377 (4) |
C1—C6 | 1.408 (3) | C13—H13A | 0.9300 |
C1—C2 | 1.419 (3) | C14—H14A | 0.9300 |
| | | |
N1—Cu1—O1 | 91.36 (8) | C2—C3—H3A | 119.4 |
N1—Cu1—O2 | 80.94 (8) | C3—C4—C5 | 121.4 (3) |
O1—Cu1—O2 | 170.71 (8) | C3—C4—H4A | 119.3 |
N1—Cu1—O1i | 171.36 (8) | C5—C4—H4A | 119.3 |
O1—Cu1—O1i | 80.20 (7) | C6—C5—C4 | 118.5 (2) |
O2—Cu1—O1i | 107.28 (7) | C6—C5—H5A | 120.8 |
N1—Cu1—O1W | 99.49 (9) | C4—C5—H5A | 120.8 |
O1—Cu1—O1W | 95.25 (8) | C5—C6—C1 | 122.0 (2) |
O2—Cu1—O1W | 91.18 (9) | C5—C6—H6A | 119.0 |
O1i—Cu1—O1W | 83.25 (8) | C1—C6—H6A | 119.0 |
Cu1—O1W—H1WA | 116 (3) | N1—C7—C1 | 123.7 (2) |
Cu1—O1W—H1WB | 111 (3) | N1—C7—H7A | 118.1 |
H1WA—O1W—H1WB | 106 (4) | C1—C7—H7A | 118.1 |
C2—O1—Cu1 | 128.43 (14) | O2—C8—N2 | 118.2 (2) |
C2—O1—Cu1i | 131.75 (14) | O2—C8—C9 | 121.3 (2) |
Cu1—O1—Cu1i | 99.80 (7) | N2—C8—C9 | 120.4 (2) |
C8—O2—Cu1 | 113.84 (15) | C14—C9—C10 | 118.7 (2) |
C12—O3—H03A | 111 (2) | C14—C9—C8 | 118.3 (2) |
C7—N1—N2 | 118.93 (19) | C10—C9—C8 | 123.0 (2) |
C7—N1—Cu1 | 129.60 (16) | C11—C10—C9 | 120.5 (2) |
N2—N1—Cu1 | 111.45 (15) | C11—C10—H10A | 119.8 |
C8—N2—N1 | 115.36 (19) | C9—C10—H10A | 119.8 |
C8—N2—H2N | 127 (2) | C12—C11—C10 | 120.2 (2) |
N1—N2—H2N | 118 (2) | C12—C11—H11A | 119.9 |
O4—N3—O6 | 121.8 (3) | C10—C11—H11A | 119.9 |
O4—N3—O5 | 119.8 (3) | O3—C12—C11 | 118.1 (2) |
O6—N3—O5 | 118.4 (3) | O3—C12—C13 | 121.8 (2) |
C6—C1—C2 | 118.8 (2) | C11—C12—C13 | 120.1 (2) |
C6—C1—C7 | 116.1 (2) | C14—C13—C12 | 119.4 (2) |
C2—C1—C7 | 125.0 (2) | C14—C13—H13A | 120.3 |
O1—C2—C3 | 120.1 (2) | C12—C13—H13A | 120.3 |
O1—C2—C1 | 121.8 (2) | C13—C14—C9 | 121.1 (2) |
C3—C2—C1 | 118.1 (2) | C13—C14—H14A | 119.4 |
C4—C3—C2 | 121.1 (2) | C9—C14—H14A | 119.4 |
C4—C3—H3A | 119.4 | | |
| | | |
N1—Cu1—O1—C2 | 0.5 (2) | O1—C2—C3—C4 | −179.4 (3) |
O2—Cu1—O1—C2 | 34.4 (6) | C1—C2—C3—C4 | 1.2 (4) |
O1i—Cu1—O1—C2 | 178.6 (3) | C2—C3—C4—C5 | −0.5 (5) |
O1W—Cu1—O1—C2 | −99.2 (2) | C3—C4—C5—C6 | −0.6 (5) |
N1—Cu1—O1—Cu1i | −178.13 (9) | C4—C5—C6—C1 | 1.0 (5) |
O2—Cu1—O1—Cu1i | −144.2 (4) | C2—C1—C6—C5 | −0.3 (4) |
O1i—Cu1—O1—Cu1i | 0.0 | C7—C1—C6—C5 | −178.9 (3) |
O1W—Cu1—O1—Cu1i | 82.21 (8) | N2—N1—C7—C1 | −177.4 (2) |
N1—Cu1—O2—C8 | −3.79 (19) | Cu1—N1—C7—C1 | 1.3 (4) |
O1—Cu1—O2—C8 | −38.2 (6) | C6—C1—C7—N1 | 179.2 (3) |
O1i—Cu1—O2—C8 | 178.94 (18) | C2—C1—C7—N1 | 0.6 (4) |
O1W—Cu1—O2—C8 | 95.64 (19) | Cu1—O2—C8—N2 | 4.5 (3) |
O1—Cu1—N1—C7 | −1.6 (3) | Cu1—O2—C8—C9 | −175.73 (19) |
O2—Cu1—N1—C7 | −176.3 (3) | N1—N2—C8—O2 | −2.4 (4) |
O1i—Cu1—N1—C7 | −13.9 (7) | N1—N2—C8—C9 | 177.8 (2) |
O1W—Cu1—N1—C7 | 94.0 (3) | O2—C8—C9—C14 | −12.5 (4) |
O1—Cu1—N1—N2 | 177.18 (17) | N2—C8—C9—C14 | 167.3 (3) |
O2—Cu1—N1—N2 | 2.41 (17) | O2—C8—C9—C10 | 167.4 (3) |
O1i—Cu1—N1—N2 | 164.8 (5) | N2—C8—C9—C10 | −12.8 (4) |
O1W—Cu1—N1—N2 | −87.27 (18) | C14—C9—C10—C11 | 0.7 (4) |
C7—N1—N2—C8 | 178.0 (3) | C8—C9—C10—C11 | −179.2 (3) |
Cu1—N1—N2—C8 | −0.9 (3) | C9—C10—C11—C12 | −1.7 (4) |
Cu1—O1—C2—C3 | −178.51 (19) | C10—C11—C12—O3 | −179.0 (3) |
Cu1i—O1—C2—C3 | −0.4 (4) | C10—C11—C12—C13 | 1.7 (4) |
Cu1—O1—C2—C1 | 0.9 (4) | O3—C12—C13—C14 | −179.9 (3) |
Cu1i—O1—C2—C1 | 179.01 (18) | C11—C12—C13—C14 | −0.6 (4) |
C6—C1—C2—O1 | 179.8 (2) | C12—C13—C14—C9 | −0.4 (4) |
C7—C1—C2—O1 | −1.7 (4) | C10—C9—C14—C13 | 0.4 (4) |
C6—C1—C2—C3 | −0.8 (4) | C8—C9—C14—C13 | −179.8 (3) |
C7—C1—C2—C3 | 177.7 (3) | | |
Symmetry code: (i) −x+1/2, −y+1/2, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H03A···O1Wii | 0.74 (3) | 2.03 (3) | 2.764 (3) | 174 (3) |
N2—H2N···O4iii | 0.85 (2) | 2.00 (2) | 2.847 (3) | 175 (3) |
O1W—H1WA···O5iv | 0.79 (2) | 2.00 (2) | 2.789 (4) | 176 (3) |
O1W—H1WB···O6v | 0.82 (2) | 1.94 (2) | 2.748 (3) | 167 (4) |
Symmetry codes: (ii) x, −y, z+1/2; (iii) −x+1/2, y−1/2, −z+1/2; (iv) −x, y, −z+1/2; (v) x, −y, z−1/2. |
Experimental details
Crystal data |
Chemical formula | [Cu2(C14H11N2O3)2(H2O)2](NO3)2 |
Mr | 797.62 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 293 |
a, b, c (Å) | 13.815 (8), 12.109 (4), 18.787 (8) |
β (°) | 106.55 (2) |
V (Å3) | 3013 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.50 |
Crystal size (mm) | 0.28 × 0.23 × 0.19 |
|
Data collection |
Diffractometer | Rigaku Weissenberg IP diffractometer |
Absorption correction | Empirical (using intensity measurements) (TEXRAY; Molecular Structure Corporation, 1999) |
Tmin, Tmax | 0.668, 0.753 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 14501, 3442, 2803 |
Rint | 0.049 |
(sin θ/λ)max (Å−1) | 0.649 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.114, 1.09 |
No. of reflections | 3442 |
No. of parameters | 242 |
No. of restraints | 3 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.58, −0.42 |
Selected geometric parameters (Å, º) topCu1—N1 | 1.928 (2) | Cu1—O1i | 1.9651 (17) |
Cu1—O1 | 1.9400 (17) | Cu1—O1W | 2.452 (3) |
Cu1—O2 | 1.9606 (17) | | |
| | | |
N1—Cu1—O1 | 91.36 (8) | O2—Cu1—O1i | 107.28 (7) |
N1—Cu1—O2 | 80.94 (8) | N1—Cu1—O1W | 99.49 (9) |
O1—Cu1—O2 | 170.71 (8) | O1—Cu1—O1W | 95.25 (8) |
N1—Cu1—O1i | 171.36 (8) | O2—Cu1—O1W | 91.18 (9) |
O1—Cu1—O1i | 80.20 (7) | O1i—Cu1—O1W | 83.25 (8) |
Symmetry code: (i) −x+1/2, −y+1/2, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H03A···O1Wii | 0.74 (3) | 2.03 (3) | 2.764 (3) | 174 (3) |
N2—H2N···O4iii | 0.851 (17) | 1.998 (18) | 2.847 (3) | 175 (3) |
O1W—H1WA···O5iv | 0.794 (18) | 1.997 (19) | 2.789 (4) | 176 (3) |
O1W—H1WB···O6v | 0.821 (18) | 1.94 (2) | 2.748 (3) | 167 (4) |
Symmetry codes: (ii) x, −y, z+1/2; (iii) −x+1/2, y−1/2, −z+1/2; (iv) −x, y, −z+1/2; (v) x, −y, z−1/2. |
N-Salicylideneacylhydrazines, acting either as neutral, mono- or dinegative O,N,O-tridentate Schiff base ligands, have received intense attention owing to their structural and functional diversities (Iskander et al., 2000a,b, 2004; [a or b???] Yin & Liu, 2002; Li & Liu, 2004). A large number of monomeric and dimeric copper(II) complexes have been prepared, characterized and proved to have magnetic properties (Iskander et al., 2000a,b, 2004; Chan et al., 1995; Ainscough et al., 1995; Sangeetha et al., 1999). An area of particular significance is the relation between the molecular magnetic properties and the intermolecular interactions of this type of dimeric copper(II) complex. As a part of our continuing investigations on these types of Schiff base ligands and their copper(II) compounds, we have synthesized and report here a new Schiff base ligand, 4-hydroxy-N'-(2-hydroxybenzylidene)benzolhydrazide (H3L) (Lin et al., 2007). H3L not only is a potentially tetradentate ligand containing both chelating and bridging units, but also can be involved in hydrogen-bond formation with available hydrogen donor sites. In many cases, these hydrogen bonds dictate interesting molecular packing arrangements in the solid state. We report here the title compound, [Cu2(C14H11N2O3)2(H2O)2](NO3)2, (I), with the ligand (H3L) in its monodeprotonated tridentate form.
The molecular structure of complex (I), as shown in Fig. 1, consists of a centrosymmetric dimeric cation, [Cu(L)(H2O)]22 +, accompanied by two nitrate anions, where the ligand is monoanionic and tridentate. Phenolate atom O1 bridges the two Cu atoms with one short and one long Cu—O bond length (Table 1) resulting in a Cu···Cu distance of 2.987 (1) Å. Each CuII atom exists in a slightly distorted square-pyramidal geometry. The basal plane is defined by atoms N1, O1 and O2 from the ligand and the symmetry-related atom O1(-x + 1/2, -y + 1/2, -z), while the axial site is occupied by the water molecule. Owing to the Jahn–Teller effect, the pendant water O atom has weak bonding interactions with the CuII atom [Cu1—O1W = 2.452 (3) Å]. However, this distance is somewhat longer than that in some related Cu compounds (Sangeetha et al., 1999; Chan et al., 1995). The Cu—N and other Cu—O distances (Table 1) are similar to the corresponding values observed in other related copper(II) complexes (Iskander et al., 2000a,b, 2004 [a or b??]). It is worthy of mention that the remaining protonated phenol group has very weak bonding interactions with atom Cu1vi [Cu1vi—O3 = 2.803 (2) Å; symmetry code: (vi) -x + 1/2, y + 1/2, -z + 1/2] of a neighbouring dimeric cation, and at the same time it is involved in intermolecular hydrogen bonding, as shown in Fig. 2. Overall, the geometry of the Cu atom is considered as a distorted octahedron.
The six-membered ring N1/C7/C1/C2/O1/Cu1 and the five-membered chelating ring O2/C8/N2/N1/Cu1 are almost planar, with a dihedral angle of 3.8° between them. The C7═N1 bond distance of 1.281 (3) Å in the title complex confirms its assignment as a double bond; at the same time, the N1—N2 and C8—N2 bond lengths of 1.384 (3) and 1.331 (3) Å indicate that they are single bonds, all of which are in agreement with the corresponding values reported in other monodeprotonated N-salicylideneacylhydrazines complexes (Iskander et al., 2000a,b, 2004 [a or b???]). The uncoordinated nitrate anions are involved in forming a rich and interesting intermolecular hydrogen-bonding network. The dimers interact via N2—H2N···O4iii, O3—H03A···O1Wii and O1W—H1WB···O6v hydrogen bonds [symmetry codes: (ii) x, -y, z + 1/2; (iii) -x + 1/2, y - 1/2, -z + 1/2; (v) x, -y, z - 1/2] and extend to form a layer of dimers parallel to the (100) plane, as shown in Fig. 2. Layers of coordinated water molecules and nitrate anions alternate with the complex molecule layers along the a direction and further join these two-dimensional sheets into a three-dimensional network via the O1W—H1WA···O5iv interaction [symmetry code: (iv) -x, y, -z + 1/2; Fig 3]. Two nitrate anions and two coordinated water molecules form a chair-shaped cycle through intermolecular hydrogen bonding (as shown in Fig. 3).
Although the 4-hydroxy group in the ligand of the title complex does not take part in coordination, it forms a strong intermolecular hydrogen bond and a weak interaction with the Cu ion of a neighbouring molecule. In most of the reported structures, the 2-hydroxy group on the salicyl part of the ligand salicyloylhydrazone also does not coordinate with the metal and only participates in a strong intramolecular hydrogen bond, usually forming a mononuclear complex (Sur et al., 1993; Tai et al., 2007) (as shown in scheme 2), except in the case of one dinuclear uranium complex (Gatto et al., 2004).
The IR spectrum of the free ligand shows a series of bands at ca 3210, 1670, 1602, 1543 and 1343 cm-1 due to υN—H, υC═O, υC═N, δN—H and υC—N, respectively. In (I), these bands appear at ca 3352, 1612, 1600, 1538 and 1326 cm-1, respectively. The presence of υN—H, υC═O and δN—H in (I) indicate that the hydrazone molecule reacts in the ketoamine form. Moreover, the shift in both υC═O and υC═N to lower frequencies relative to the free ligand suggests that the ligand acts as a mononegative O,N,O'-tridentate ligand (Iskander et al., 2000a,b, 2004 [a or b???]). On the other hand, the intense band at ca 1380 cm-1 shows the characteristic of the nitrate anion (Nakamoto,1986). In addition, the existence of υCu—N and υCu—O at ca 630 and 436 cm-1 further confirms the coordination of the metal with the hydroxy O atom and the amine N atom (Nakamoto, 1986).
It is rare that an N-salicylidenebenzoylhydrazine ligand can both chelate and bridge metal ions at the same time to form coordination polymers. In order to synthesise such a chelating and bridging ligand, the 4-OH group was introduced to the benzoyl ring of N-salicylidenebenzoylhydrazine. On the basis of the capacity of the 4-OH group to coordinate with the Cu ion and form strong hydrogen-bonding interactions, we obtained the title two-dimensional Cu polymer with three-dimensional network.