
Supporting information
![]() | Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270106035359/gz3031sup1.cif |
![]() | Structure factor file (CIF format) https://doi.org/10.1107/S0108270106035359/gz3031Isup2.hkl |
CCDC reference: 625680
An ethanol–dimethylformamide (2:1 v/v) solution (40 ml) of the ligand HL (0.5 mmol, 0.15 g) and an aqueous solution (10 ml) of Zn(NO3)2·4H2O (0.25 mmol, 0.26 g) were mixed together, and then five drops of pyridine were added. Red single crystals of (I) suitable for X-ray structure analysis were obtained after two months by slow evaporation of the solvents at room temperature.
H atoms attached to C atoms were included in calculated positions and treated as riding atoms, with C—H = 0.93 Å and Uiso(H) = 1.2Ueq(C). Water H atoms were found in a difference map, relocated in idealized positions with O—H = 0.85 Å, and refined as riding atoms with Uiso(H) = 1.2Ueq(O).
Data collection: SMART (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); 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, 2004); software used to prepare material for publication: SHELXTL.
[Zn(C17H10N5O)2(H2O)2]·4H2O | Z = 1 |
Mr = 774.09 | F(000) = 400 |
Triclinic, P1 | Dx = 1.513 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.9310 (16) Å | Cell parameters from 96 reflections |
b = 10.340 (2) Å | θ = 1.8–26.1° |
c = 11.734 (2) Å | µ = 0.79 mm−1 |
α = 74.87 (3)° | T = 291 K |
β = 75.64 (3)° | Block, red |
γ = 68.06 (3)° | 0.30 × 0.20 × 0.20 mm |
V = 849.4 (3) Å3 |
Bruker SMART APEXII CCD area-detector diffractometer | 3915 independent reflections |
Radiation source: fine-focus sealed tube | 2724 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.002 |
ϕ and ω scans | θmax = 27.5°, θmin = 1.8° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) | h = −10→9 |
Tmin = 0.797, Tmax = 0.858 | k = −13→0 |
5042 measured reflections | l = −15→14 |
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)] = 0.058 | H-atom parameters constrained |
wR(F2) = 0.118 | w = 1/[σ2(Fo2) + (0.1019P)2 + 0.1755P] where P = (Fo2 + 2Fc2)/3 |
S = 1.11 | (Δ/σ)max < 0.001 |
3915 reflections | Δρmax = 0.41 e Å−3 |
242 parameters | Δρmin = −0.60 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0010 (2) |
[Zn(C17H10N5O)2(H2O)2]·4H2O | γ = 68.06 (3)° |
Mr = 774.09 | V = 849.4 (3) Å3 |
Triclinic, P1 | Z = 1 |
a = 7.9310 (16) Å | Mo Kα radiation |
b = 10.340 (2) Å | µ = 0.79 mm−1 |
c = 11.734 (2) Å | T = 291 K |
α = 74.87 (3)° | 0.30 × 0.20 × 0.20 mm |
β = 75.64 (3)° |
Bruker SMART APEXII CCD area-detector diffractometer | 3915 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) | 2724 reflections with I > 2σ(I) |
Tmin = 0.797, Tmax = 0.858 | Rint = 0.002 |
5042 measured reflections |
R[F2 > 2σ(F2)] = 0.058 | 0 restraints |
wR(F2) = 0.118 | H-atom parameters constrained |
S = 1.11 | Δρmax = 0.41 e Å−3 |
3915 reflections | Δρmin = −0.60 e Å−3 |
242 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 | 0.5000 | 0.5000 | 0.0372 (2) | |
O1 | 0.2707 (3) | 0.4975 (2) | 0.6304 (2) | 0.0387 (6) | |
O2 | 0.3429 (3) | 0.5050 (3) | 0.3673 (2) | 0.0455 (6) | |
H2A | 0.2976 | 0.4389 | 0.3803 | 0.055* | |
H2B | 0.3982 | 0.5254 | 0.2966 | 0.055* | |
O3 | 0.0394 (4) | 0.7629 (4) | 0.3528 (3) | 0.0693 (9) | |
H3A | −0.0553 | 0.7616 | 0.3321 | 0.083* | |
H3B | 0.1059 | 0.6760 | 0.3590 | 0.083* | |
O4 | 0.1380 (4) | 0.3246 (3) | 0.4015 (3) | 0.0641 (8) | |
H4A | 0.0702 | 0.3900 | 0.3553 | 0.077* | |
H4B | 0.0670 | 0.3113 | 0.4676 | 0.077* | |
N1 | 0.5550 (4) | 0.2816 (3) | 0.5565 (3) | 0.0378 (6) | |
N2 | 0.1483 (4) | 0.3428 (3) | 0.7768 (2) | 0.0396 (7) | |
N3 | 0.0075 (4) | 0.4630 (3) | 0.8093 (2) | 0.0399 (7) | |
N4 | −0.2687 (5) | 0.2649 (4) | 1.2041 (3) | 0.0548 (9) | |
N5 | −0.4829 (4) | 0.5811 (4) | 1.1370 (3) | 0.0485 (8) | |
C1 | 0.6964 (5) | 0.1768 (4) | 0.5121 (3) | 0.0458 (9) | |
H1 | 0.7876 | 0.2003 | 0.4524 | 0.055* | |
C2 | 0.7117 (6) | 0.0360 (4) | 0.5514 (4) | 0.0523 (10) | |
H2 | 0.8110 | −0.0346 | 0.5189 | 0.063* | |
C3 | 0.5751 (6) | 0.0019 (4) | 0.6407 (4) | 0.0546 (10) | |
H3 | 0.5802 | −0.0922 | 0.6680 | 0.066* | |
C4 | 0.4313 (6) | 0.1092 (4) | 0.6889 (3) | 0.0479 (9) | |
H4 | 0.3412 | 0.0877 | 0.7508 | 0.057* | |
C5 | 0.4227 (5) | 0.2490 (4) | 0.6439 (3) | 0.0379 (7) | |
C6 | 0.2696 (5) | 0.3756 (4) | 0.6852 (3) | 0.0352 (7) | |
C7 | −0.0952 (5) | 0.4421 (4) | 0.9124 (3) | 0.0383 (8) | |
C8 | −0.0860 (5) | 0.3147 (4) | 1.0069 (3) | 0.0408 (8) | |
C9 | 0.0310 (6) | 0.1759 (4) | 1.0179 (4) | 0.0510 (9) | |
H9 | 0.1288 | 0.1455 | 0.9574 | 0.061* | |
C10 | −0.0040 (7) | 0.0838 (5) | 1.1234 (4) | 0.0620 (12) | |
H10 | 0.0714 | −0.0107 | 1.1348 | 0.074* | |
C11 | −0.1505 (7) | 0.1321 (5) | 1.2115 (4) | 0.0620 (12) | |
H11 | −0.1684 | 0.0673 | 1.2812 | 0.074* | |
C12 | −0.2328 (5) | 0.3534 (4) | 1.1016 (3) | 0.0412 (8) | |
C13 | −0.3357 (5) | 0.5038 (4) | 1.0705 (3) | 0.0414 (8) | |
C14 | −0.5497 (6) | 0.7197 (5) | 1.0893 (4) | 0.0558 (10) | |
H14 | −0.6512 | 0.7771 | 1.1334 | 0.067* | |
C15 | −0.4761 (6) | 0.7814 (5) | 0.9786 (4) | 0.0563 (10) | |
H15 | −0.5283 | 0.8781 | 0.9505 | 0.068* | |
C16 | −0.3254 (5) | 0.7009 (4) | 0.9092 (4) | 0.0504 (9) | |
H16 | −0.2751 | 0.7406 | 0.8340 | 0.060* | |
C17 | −0.2531 (5) | 0.5582 (4) | 0.9572 (3) | 0.0402 (8) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Zn | 0.0359 (3) | 0.0319 (3) | 0.0383 (3) | −0.0123 (2) | 0.0049 (2) | −0.0062 (2) |
O1 | 0.0395 (12) | 0.0332 (12) | 0.0348 (12) | −0.0131 (10) | 0.0084 (10) | −0.0046 (10) |
O2 | 0.0461 (14) | 0.0568 (16) | 0.0353 (13) | −0.0235 (13) | 0.0015 (10) | −0.0097 (11) |
O3 | 0.0572 (18) | 0.062 (2) | 0.095 (2) | −0.0136 (16) | −0.0209 (17) | −0.0265 (18) |
O4 | 0.0625 (19) | 0.0493 (17) | 0.074 (2) | −0.0125 (15) | −0.0166 (16) | −0.0039 (15) |
N1 | 0.0396 (15) | 0.0345 (14) | 0.0365 (14) | −0.0131 (12) | 0.0028 (12) | −0.0096 (12) |
N2 | 0.0398 (15) | 0.0399 (15) | 0.0344 (14) | −0.0166 (13) | 0.0058 (12) | −0.0054 (12) |
N3 | 0.0372 (15) | 0.0453 (16) | 0.0360 (15) | −0.0150 (13) | 0.0017 (12) | −0.0108 (13) |
N4 | 0.073 (2) | 0.059 (2) | 0.0395 (17) | −0.035 (2) | 0.0041 (16) | −0.0123 (15) |
N5 | 0.0402 (16) | 0.067 (2) | 0.0393 (16) | −0.0172 (16) | 0.0011 (13) | −0.0192 (15) |
C1 | 0.045 (2) | 0.0396 (19) | 0.045 (2) | −0.0092 (16) | 0.0029 (16) | −0.0129 (16) |
C2 | 0.053 (2) | 0.0384 (19) | 0.053 (2) | −0.0029 (17) | −0.0034 (18) | −0.0107 (17) |
C3 | 0.071 (3) | 0.0317 (18) | 0.054 (2) | −0.0129 (19) | −0.009 (2) | −0.0026 (16) |
C4 | 0.056 (2) | 0.0378 (19) | 0.043 (2) | −0.0161 (18) | −0.0007 (17) | −0.0015 (16) |
C5 | 0.0407 (18) | 0.0357 (17) | 0.0379 (18) | −0.0149 (15) | −0.0041 (14) | −0.0067 (14) |
C6 | 0.0391 (17) | 0.0359 (17) | 0.0290 (15) | −0.0137 (15) | −0.0035 (13) | −0.0038 (13) |
C7 | 0.0355 (17) | 0.050 (2) | 0.0326 (17) | −0.0199 (16) | 0.0006 (13) | −0.0106 (15) |
C8 | 0.0437 (19) | 0.047 (2) | 0.0361 (18) | −0.0225 (17) | 0.0011 (14) | −0.0119 (15) |
C9 | 0.058 (2) | 0.045 (2) | 0.048 (2) | −0.0180 (19) | 0.0021 (18) | −0.0138 (17) |
C10 | 0.090 (3) | 0.043 (2) | 0.051 (2) | −0.027 (2) | −0.004 (2) | −0.0048 (18) |
C11 | 0.090 (3) | 0.056 (3) | 0.045 (2) | −0.040 (3) | 0.002 (2) | −0.0081 (19) |
C12 | 0.050 (2) | 0.048 (2) | 0.0316 (17) | −0.0260 (18) | 0.0000 (15) | −0.0098 (14) |
C13 | 0.0371 (18) | 0.060 (2) | 0.0333 (17) | −0.0221 (17) | 0.0011 (14) | −0.0168 (16) |
C14 | 0.046 (2) | 0.069 (3) | 0.049 (2) | −0.008 (2) | −0.0055 (18) | −0.024 (2) |
C15 | 0.051 (2) | 0.060 (3) | 0.050 (2) | −0.009 (2) | −0.0084 (18) | −0.0117 (19) |
C16 | 0.046 (2) | 0.056 (2) | 0.044 (2) | −0.0127 (19) | −0.0074 (17) | −0.0070 (18) |
C17 | 0.0370 (18) | 0.053 (2) | 0.0333 (17) | −0.0172 (16) | −0.0012 (14) | −0.0144 (16) |
Zn—O1 | 2.069 (2) | C3—C4 | 1.383 (5) |
Zn—N1 | 2.087 (3) | C3—H3 | 0.9300 |
Zn—O2 | 2.202 (3) | C4—C5 | 1.385 (5) |
O1—C6 | 1.259 (4) | C4—H4 | 0.9300 |
O2—H2A | 0.8500 | C5—C6 | 1.508 (5) |
O2—H2B | 0.8500 | C7—C17 | 1.472 (5) |
O3—H3A | 0.8500 | C7—C8 | 1.475 (5) |
O3—H3B | 0.8500 | C8—C9 | 1.380 (5) |
O4—H4A | 0.8500 | C8—C12 | 1.412 (5) |
O4—H4B | 0.8500 | C9—C10 | 1.389 (6) |
N1—C1 | 1.341 (5) | C9—H9 | 0.9300 |
N1—C5 | 1.348 (4) | C10—C11 | 1.381 (6) |
N2—C6 | 1.318 (4) | C10—H10 | 0.9300 |
N2—N3 | 1.391 (4) | C11—H11 | 0.9300 |
N3—C7 | 1.296 (4) | C12—C13 | 1.456 (5) |
N4—C11 | 1.337 (6) | C13—C17 | 1.401 (5) |
N4—C12 | 1.347 (5) | C14—C15 | 1.380 (6) |
N5—C13 | 1.337 (5) | C14—H14 | 0.9300 |
N5—C14 | 1.345 (6) | C15—C16 | 1.384 (6) |
C1—C2 | 1.376 (5) | C15—H15 | 0.9300 |
C1—H1 | 0.9300 | C16—C17 | 1.385 (5) |
C2—C3 | 1.388 (6) | C16—H16 | 0.9300 |
C2—H2 | 0.9300 | ||
O1—Zn—O1i | 180.0 | O1—C6—C5 | 118.1 (3) |
O1—Zn—N1i | 100.25 (11) | N2—C6—C5 | 114.2 (3) |
O1—Zn—N1 | 79.75 (11) | N3—C7—C17 | 121.6 (3) |
N1i—Zn—N1 | 180.00 (17) | N3—C7—C8 | 132.1 (3) |
N1—Zn—O2i | 89.01 (11) | C17—C7—C8 | 106.3 (3) |
O1—Zn—O2 | 88.51 (10) | C9—C8—C12 | 118.6 (3) |
O1i—Zn—O2 | 91.49 (10) | C9—C8—C7 | 133.6 (3) |
N1—Zn—O2 | 90.99 (11) | C12—C8—C7 | 107.8 (3) |
O2i—Zn—O2 | 180.0 | C8—C9—C10 | 116.9 (4) |
C6—O1—Zn | 114.7 (2) | C8—C9—H9 | 121.5 |
H2A—O2—H2B | 116.4 | C10—C9—H9 | 121.5 |
H3A—O3—H3B | 101.2 | C11—C10—C9 | 120.2 (4) |
H4A—O4—H4B | 105.8 | C11—C10—H10 | 119.9 |
C1—N1—C5 | 119.3 (3) | C9—C10—H10 | 119.9 |
C1—N1—Zn | 127.8 (2) | N4—C11—C10 | 124.9 (4) |
C5—N1—Zn | 112.8 (2) | N4—C11—H11 | 117.5 |
C6—N2—N3 | 111.9 (3) | C10—C11—H11 | 117.5 |
C7—N3—N2 | 115.4 (3) | N4—C12—C8 | 125.0 (4) |
C11—N4—C12 | 114.3 (4) | N4—C12—C13 | 126.2 (3) |
C13—N5—C14 | 115.7 (3) | C8—C12—C13 | 108.8 (3) |
N1—C1—C2 | 122.6 (4) | N5—C13—C17 | 124.2 (4) |
N1—C1—H1 | 118.7 | N5—C13—C12 | 127.2 (3) |
C2—C1—H1 | 118.7 | C17—C13—C12 | 108.6 (3) |
C1—C2—C3 | 118.3 (4) | N5—C14—C15 | 123.7 (4) |
C1—C2—H2 | 120.9 | N5—C14—H14 | 118.2 |
C3—C2—H2 | 120.9 | C15—C14—H14 | 118.2 |
C4—C3—C2 | 119.4 (4) | C14—C15—C16 | 120.6 (4) |
C4—C3—H3 | 120.3 | C14—C15—H15 | 119.7 |
C2—C3—H3 | 120.3 | C16—C15—H15 | 119.7 |
C3—C4—C5 | 119.3 (3) | C15—C16—C17 | 116.6 (4) |
C3—C4—H4 | 120.3 | C15—C16—H16 | 121.7 |
C5—C4—H4 | 120.3 | C17—C16—H16 | 121.7 |
N1—C5—C4 | 121.0 (3) | C16—C17—C13 | 119.2 (3) |
N1—C5—C6 | 114.5 (3) | C16—C17—C7 | 132.3 (3) |
C4—C5—C6 | 124.5 (3) | C13—C17—C7 | 108.5 (3) |
O1—C6—N2 | 127.7 (3) | ||
N1i—Zn—O1—C6 | −177.3 (2) | N3—C7—C8—C9 | −1.0 (7) |
N1—Zn—O1—C6 | 2.7 (2) | C17—C7—C8—C9 | −179.3 (4) |
O2i—Zn—O1—C6 | −86.0 (2) | N3—C7—C8—C12 | 179.2 (4) |
O2—Zn—O1—C6 | 94.0 (2) | C17—C7—C8—C12 | 0.9 (4) |
O1—Zn—N1—C1 | 176.4 (3) | C12—C8—C9—C10 | −0.7 (6) |
O1i—Zn—N1—C1 | −3.6 (3) | C7—C8—C9—C10 | 179.6 (4) |
O2i—Zn—N1—C1 | −91.9 (3) | C8—C9—C10—C11 | 0.2 (7) |
O2—Zn—N1—C1 | 88.1 (3) | C12—N4—C11—C10 | −1.0 (7) |
O1—Zn—N1—C5 | 0.1 (2) | C9—C10—C11—N4 | 0.8 (8) |
O1i—Zn—N1—C5 | −179.9 (2) | C11—N4—C12—C8 | 0.5 (6) |
O2i—Zn—N1—C5 | 91.8 (2) | C11—N4—C12—C13 | −178.7 (4) |
O2—Zn—N1—C5 | −88.2 (2) | C9—C8—C12—N4 | 0.4 (6) |
C6—N2—N3—C7 | −166.4 (3) | C7—C8—C12—N4 | −179.8 (3) |
C5—N1—C1—C2 | 0.7 (6) | C9—C8—C12—C13 | 179.6 (3) |
Zn—N1—C1—C2 | −175.4 (3) | C7—C8—C12—C13 | −0.5 (4) |
N1—C1—C2—C3 | −0.2 (6) | C14—N5—C13—C17 | −1.0 (5) |
C1—C2—C3—C4 | −1.4 (6) | C14—N5—C13—C12 | 178.0 (4) |
C2—C3—C4—C5 | 2.4 (6) | N4—C12—C13—N5 | 0.1 (6) |
C1—N1—C5—C4 | 0.4 (5) | C8—C12—C13—N5 | −179.2 (3) |
Zn—N1—C5—C4 | 177.0 (3) | N4—C12—C13—C17 | 179.2 (4) |
C1—N1—C5—C6 | −179.1 (3) | C8—C12—C13—C17 | −0.1 (4) |
Zn—N1—C5—C6 | −2.5 (4) | C13—N5—C14—C15 | 0.8 (6) |
C3—C4—C5—N1 | −1.9 (6) | N5—C14—C15—C16 | 0.1 (7) |
C3—C4—C5—C6 | 177.5 (4) | C14—C15—C16—C17 | −0.9 (6) |
Zn—O1—C6—N2 | 175.2 (3) | C15—C16—C17—C13 | 0.6 (6) |
Zn—O1—C6—C5 | −4.9 (4) | C15—C16—C17—C7 | −178.7 (4) |
N3—N2—C6—O1 | 1.5 (5) | N5—C13—C17—C16 | 0.3 (6) |
N3—N2—C6—C5 | −178.4 (3) | C12—C13—C17—C16 | −178.8 (3) |
N1—C5—C6—O1 | 5.1 (5) | N5—C13—C17—C7 | 179.8 (3) |
C4—C5—C6—O1 | −174.4 (3) | C12—C13—C17—C7 | 0.7 (4) |
N1—C5—C6—N2 | −175.0 (3) | N3—C7—C17—C16 | 0.0 (6) |
C4—C5—C6—N2 | 5.5 (5) | C8—C7—C17—C16 | 178.4 (4) |
N2—N3—C7—C17 | −178.1 (3) | N3—C7—C17—C13 | −179.4 (3) |
N2—N3—C7—C8 | 3.9 (6) | C8—C7—C17—C13 | −1.0 (4) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2A···O4 | 0.85 | 1.97 | 2.799 (4) | 166 |
O2—H2B···N5ii | 0.85 | 1.92 | 2.771 (4) | 177 |
O3—H3A···N2iii | 0.85 | 2.26 | 2.988 (5) | 143 |
O3—H3B···O2 | 0.85 | 2.05 | 2.847 (5) | 157 |
O4—H4A···N3iii | 0.85 | 2.19 | 2.993 (4) | 159 |
O4—H4B···O3iii | 0.85 | 2.12 | 2.947 (5) | 164 |
Symmetry codes: (ii) x+1, y, z−1; (iii) −x, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | [Zn(C17H10N5O)2(H2O)2]·4H2O |
Mr | 774.09 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 291 |
a, b, c (Å) | 7.9310 (16), 10.340 (2), 11.734 (2) |
α, β, γ (°) | 74.87 (3), 75.64 (3), 68.06 (3) |
V (Å3) | 849.4 (3) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 0.79 |
Crystal size (mm) | 0.30 × 0.20 × 0.20 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2003) |
Tmin, Tmax | 0.797, 0.858 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5042, 3915, 2724 |
Rint | 0.002 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.058, 0.118, 1.11 |
No. of reflections | 3915 |
No. of parameters | 242 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.41, −0.60 |
Computer programs: SMART (Bruker, 2004), SAINT (Bruker, 2004), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 2004), SHELXTL.
Zn—O1 | 2.069 (2) | N2—C6 | 1.318 (4) |
Zn—N1 | 2.087 (3) | N2—N3 | 1.391 (4) |
Zn—O2 | 2.202 (3) | N3—C7 | 1.296 (4) |
N3—N2—C6—O1 | 1.5 (5) | N2—N3—C7—C17 | −178.1 (3) |
N3—N2—C6—C5 | −178.4 (3) | N2—N3—C7—C8 | 3.9 (6) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2A···O4 | 0.85 | 1.97 | 2.799 (4) | 166 |
O2—H2B···N5i | 0.85 | 1.92 | 2.771 (4) | 177 |
O3—H3A···N2ii | 0.85 | 2.26 | 2.988 (5) | 143 |
O3—H3B···O2 | 0.85 | 2.05 | 2.847 (5) | 157 |
O4—H4A···N3ii | 0.85 | 2.19 | 2.993 (4) | 159 |
O4—H4B···O3ii | 0.85 | 2.12 | 2.947 (5) | 164 |
Symmetry codes: (i) x+1, y, z−1; (ii) −x, −y+1, −z+1. |
Over recent decades, considerable attention has been paid to theoretical (Xantheas, 1994; Kim et al., 1999) and experimental (Neogi et al., 2004) studies of small water clusters, because of their importance in understanding the structures and characteristics of liquid water and ice (Ma et al., 2004). So far, small water clusters, (H2O)n (n = 2–8, 10, 12, 14, 16, 18, 45), have been obtained in organic or metal–organic crystal hosts (Li et al., 2006). Of all water clusters, the water hexamer is particularly interesting as it is the building block of ice Ih and appears to be relevant to liquid water as well (Speedy et al., 1987). Theoretical calculations have found that several different isomers for the water hexamer, such as ring, block, bag, cage and prism topologies, are almost isoenergetic (Kim & Kim, 1998). To date, chair (Zhao et al., 2004), boat (Park et al., 1993) and planar (Moorthy et al., 2002) cyclic hexamers trapped by hydrogen bonding in host lattices have been reported. Here, we report the title metal–water chain complex, [Zn(L)2(H2O)2]·4H2O (L = 4,5-diazafluoren-9-ylidene)picolinohydrazonato), (I), containing the cyclic water hexamer, in which the water cluster is trapped not only by hydrogen bonds but also by coordination interactions.
As shown in Fig. 1, the structure of complex (I) consists of one [Zn(L)2(H2O)2] complex molecule and four solvent water molecules. The ZnII ion resides on a centre of symmetry and is coordinated by two O atoms and two N atoms from two L ligands arranged trans to each other in the equatorial plane, and two aqua ligands occupying the apical coordination sites to furnish an octahedral geometry. The ligand L coordinates to the ZnII ion as a mono-deprotonated bidentate ligand via the enolic O atom of the amide group and the N atom of the pyridyl group. Within the hydrazine component, both N atoms (N2 and N3) have effectively planar coordination and the N—N bond distance (Table 1) is typical of the value in hydrazine for both N atoms having planar coordination [mean value 1.401 (3) Å; Allen et al., 1987]. The dihedral angle between the diazafluorene plane and the pyridyl plane is small [22.1 (2) °]. This is due to the small N3—N2—C6—O1 torsion angle [1.5 (5) °] and the sp2 hybridization of the C6 (amide) and C7 (diazafluorene) atoms.
The [Zn(L)2(H2O)2] complex molecules are linked into one-dimensional chains along the [101] direction via O2—H2B···N5i hydrogen-bond interactions [symmetry code: (i) 1 + x, y, z − 1]. Within these chains, the separation between two diazafluorene rings is 3.351 (5) Å, indicating significant π–π stacking interactions. Along the [100] direction, the one-dimensional chains are stacked via π–π interactions between two diazafluorene rings of adjacent chains to generate two-dimensional layers parallel to the ac plane [mean interplanar distance = 3.428 (5) Å] (Fig. 2). The layers are stabilized by five independent hydrogen bonds, of O—H···N and O—H···O types (Table 2).
Interestingly, a cyclic centrosymmetric water hexamer [R66(12); Bernstein et al., 1995] that adopts a chair conformation (Fig. 3) is observed in the solid state. The hydrogen-bonding parameters are reported in Table 2. The average O···O distance is 2.864 (4) Å, which is nearly identical to the value of 2.854 (6) Å observed in liquid water (Speedy et al., 1987). However, it is longer than the corresponding values in ice Ih [2.759 (3) Å; Benson & Siebert, 1992], and in water trapped in the organic compound DMNY·2.5H2O [2.783 (3) Å; DMNY is 2,4-dimethyl-5-aminobenzo[b]-1,8-naphthyridine; Custelcean et al., 2000] and the metal–organic framework of [Pr(pbc)(Hpbc)(H2O)2]·4H2O [2.783 (3) Å; H2pbc is pyridine-2,6-dicarboxylic acid; Ghosh & Bharadwaj, 2003], as well as the calculated value of 2.718 (9) Å for the cyclic water hexamer (Stephens & Vagg, 1982). The average of the widely different O···O···O angles is 102 (12) °, which is smaller than that observed in DMNY·2.5H2O [116.5 (2)°] and larger than that in [Pr(pbc)(Hpbc)(H2O)2]·4H2O [98.36 (5)°]. The coordinated water molecule (O2) has a tetrahedral geometry, with two O—H···O hydrogen bonds, one O—H···N hydrogen bond and one water–metal coordination bond. Meanwhile, each of the other water molecules (O3 and O4) involves three hydrogen bonds, with two water–water hydrogen bonds and one water–hydrazine hydrogen bond. Therefore, each water molecule acts as both hydrogen donor and acceptor to form a cyclic water hexamer. Two water molecules in the cyclic hexamers bind to the ZnII ions, resulting in an infinite metal–water chain along the a axis (Fig. 4). To the best of our knowledge, such cyclic water clusters containing metal–water chains are very rare (Ghosh & Bharadwaj, 2003; Turner et al., 2004).