Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270109029023/sf3109sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270109029023/sf3109Isup2.hkl |
CCDC reference: 749686
The complex was synthesized by the reaction of warm equimolar MeOH solutions of Cu(NO3)2.H2O and the Schiff base PL–AG.HNO3.HCl obtained by condensation of EtOH solutions of AG.HNO3 and PL.HCl. After 24 h, green monocrystals of the complex were vacuum filtered and washed with MeOH and Et2O (yield 0.17 g, 77%, m.p. > 623 K).
Almost all H atoms were visible in a difference Fourier map, but those bonded to C and N atoms were placed at geometrically calculated positions and refined using a riding model. C—H distances were fixed at 0.96 and 0.93 Å for Csp3 and Csp2 atoms, respectively, with Uiso(H) values equal to 1.2 and 1.5 times Ueq of the corresponding parent atoms. N—H distances were fixed to 0.86 Å, with Uiso(H) values equal to 1.2Ueq of the parent N atom. The H atoms bonded to O atoms were both located in the difference map. The refinement of atom H12 yielded an unreasonable O—H distance; therefore it was placed in a geometrically calculated position, with a fixed O—H distance of 0.82 Å and Uiso(H) equal to 1.5Ueq of the parent O atom. Atom H13 was refined isotropically.
Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: WinGX (Farrugia, 1999).
[Cu(C9H13N5O2)(CH4O)](NO3)2 | F(000) = 908 |
Mr = 442.85 | Dx = 1.793 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 11576 reflections |
a = 8.113 (2) Å | θ = 3.0–29.2° |
b = 13.852 (2) Å | µ = 1.40 mm−1 |
c = 14.9846 (3) Å | T = 293 K |
β = 103.013 (2)° | Prism, green |
V = 1640.8 (5) Å3 | 0.32 × 0.18 × 0.15 mm |
Z = 4 |
Oxford Xcalibur S CCD diffractometer | 3586 independent reflections |
Radiation source: fine-focus sealed tube | 2632 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.022 |
Detector resolution: 16.3280 pixels mm-1 | θmax = 27.1°, θmin = 3.0° |
ω–scan | h = −10→10 |
Absorption correction: multi-scan [(CrysAlis RED; Oxford Diffraction, 2008); Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.] | k = 0→17 |
Tmin = 0.622, Tmax = 0.801 | l = 0→19 |
20236 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)] = 0.045 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.141 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0856P)2] where P = (Fo2 + 2Fc2)/3 |
3586 reflections | (Δ/σ)max = 0.001 |
251 parameters | Δρmax = 0.70 e Å−3 |
0 restraints | Δρmin = −0.73 e Å−3 |
[Cu(C9H13N5O2)(CH4O)](NO3)2 | V = 1640.8 (5) Å3 |
Mr = 442.85 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 8.113 (2) Å | µ = 1.40 mm−1 |
b = 13.852 (2) Å | T = 293 K |
c = 14.9846 (3) Å | 0.32 × 0.18 × 0.15 mm |
β = 103.013 (2)° |
Oxford Xcalibur S CCD diffractometer | 3586 independent reflections |
Absorption correction: multi-scan [(CrysAlis RED; Oxford Diffraction, 2008); Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.] | 2632 reflections with I > 2σ(I) |
Tmin = 0.622, Tmax = 0.801 | Rint = 0.022 |
20236 measured reflections |
R[F2 > 2σ(F2)] = 0.045 | 0 restraints |
wR(F2) = 0.141 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 0.70 e Å−3 |
3586 reflections | Δρmin = −0.73 e Å−3 |
251 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 | 0.71122 (6) | 0.28657 (3) | 0.80082 (3) | 0.03249 (17) | |
O1 | 0.6785 (3) | 0.15587 (17) | 0.82723 (16) | 0.0301 (5) | |
O2 | 0.7451 (4) | 0.0195 (2) | 0.50285 (17) | 0.0507 (8) | |
H12 | 0.6864 | −0.0265 | 0.4807 | 0.076* | |
O3 | 0.6043 (4) | 0.3297 (2) | 0.90019 (19) | 0.0420 (7) | |
O4 | 0.6064 (4) | 0.7435 (2) | 0.8468 (2) | 0.0550 (8) | |
O5 | 0.7667 (4) | 0.6790 (2) | 0.7674 (2) | 0.0598 (9) | |
O6 | 0.6448 (4) | 0.5903 (2) | 0.8511 (2) | 0.0531 (8) | |
O7 | 1.0798 (5) | 0.2974 (2) | 0.3970 (2) | 0.0601 (9) | |
O9 | 0.9828 (7) | 0.2327 (3) | 0.4993 (4) | 0.1071 (18) | |
O8 | 1.0150 (4) | 0.3844 (3) | 0.5011 (2) | 0.0669 (10) | |
N1 | 0.7508 (4) | 0.4160 (2) | 0.7621 (2) | 0.0345 (7) | |
H1 | 0.7271 | 0.4668 | 0.7898 | 0.041* | |
N2 | 0.8475 (4) | 0.3324 (2) | 0.6540 (2) | 0.0323 (7) | |
H2 | 0.8913 | 0.3286 | 0.6069 | 0.039* | |
N3 | 0.8051 (3) | 0.2527 (2) | 0.69626 (18) | 0.0251 (6) | |
N4 | 0.8539 (4) | 0.4981 (2) | 0.6503 (2) | 0.0385 (7) | |
H4A | 0.8353 | 0.5539 | 0.6711 | 0.046* | |
H4B | 0.8972 | 0.4935 | 0.6031 | 0.046* | |
N5 | 0.7185 (3) | −0.0897 (2) | 0.7804 (2) | 0.0287 (6) | |
H5 | 0.7000 | −0.1440 | 0.8042 | 0.034* | |
N6 | 0.6759 (4) | 0.6708 (2) | 0.8222 (2) | 0.0355 (7) | |
N7 | 1.0274 (4) | 0.3054 (2) | 0.4661 (2) | 0.0351 (7) | |
C1 | 0.8164 (4) | 0.4198 (3) | 0.6907 (2) | 0.0280 (7) | |
C2 | 0.7167 (4) | 0.0818 (2) | 0.7846 (2) | 0.0246 (7) | |
C3 | 0.6844 (4) | −0.0105 (2) | 0.8215 (2) | 0.0254 (7) | |
C4 | 0.7796 (4) | −0.0922 (3) | 0.7046 (2) | 0.0288 (7) | |
H4 | 0.7996 | −0.1511 | 0.6792 | 0.035* | |
C5 | 0.8124 (4) | −0.0077 (3) | 0.6650 (2) | 0.0261 (7) | |
C6 | 0.7847 (4) | 0.0811 (2) | 0.7053 (2) | 0.0241 (7) | |
C7 | 0.8257 (4) | 0.1695 (3) | 0.6642 (2) | 0.0281 (7) | |
H7 | 0.8691 | 0.1655 | 0.6119 | 0.034* | |
C8 | 0.6146 (5) | −0.0159 (3) | 0.9047 (2) | 0.0365 (8) | |
H8A | 0.6110 | −0.0821 | 0.9232 | 0.055* | |
H8B | 0.5024 | 0.0105 | 0.8917 | 0.055* | |
H8C | 0.6854 | 0.0203 | 0.9532 | 0.055* | |
C9 | 0.8746 (5) | −0.0127 (3) | 0.5780 (2) | 0.0391 (9) | |
H9A | 0.9741 | 0.0276 | 0.5834 | 0.047* | |
H9B | 0.9057 | −0.0786 | 0.5673 | 0.047* | |
C10 | 0.5250 (6) | 0.2684 (3) | 0.9543 (3) | 0.0474 (11) | |
H10A | 0.4308 | 0.2361 | 0.9155 | 0.071* | |
H10B | 0.4857 | 0.3063 | 0.9989 | 0.071* | |
H10C | 0.6050 | 0.2214 | 0.9849 | 0.071* | |
H13 | 0.678 (8) | 0.363 (5) | 0.947 (4) | 0.10 (2)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.0431 (3) | 0.0266 (3) | 0.0314 (3) | 0.00026 (19) | 0.01596 (19) | 0.00007 (19) |
O1 | 0.0462 (14) | 0.0213 (12) | 0.0281 (12) | 0.0020 (10) | 0.0197 (11) | −0.0006 (9) |
O2 | 0.094 (2) | 0.0291 (15) | 0.0259 (14) | 0.0039 (14) | 0.0077 (14) | −0.0006 (11) |
O3 | 0.0621 (18) | 0.0362 (16) | 0.0348 (15) | −0.0051 (14) | 0.0257 (14) | −0.0071 (12) |
O4 | 0.079 (2) | 0.0269 (14) | 0.076 (2) | −0.0026 (15) | 0.0522 (18) | −0.0016 (15) |
O5 | 0.074 (2) | 0.053 (2) | 0.069 (2) | 0.0026 (17) | 0.0507 (18) | −0.0024 (16) |
O6 | 0.088 (2) | 0.0271 (15) | 0.0437 (16) | −0.0012 (15) | 0.0131 (15) | 0.0100 (13) |
O7 | 0.100 (3) | 0.0445 (19) | 0.0506 (19) | 0.0149 (17) | 0.0486 (18) | 0.0072 (14) |
O9 | 0.153 (4) | 0.069 (3) | 0.138 (4) | 0.016 (3) | 0.114 (4) | 0.040 (3) |
O8 | 0.069 (2) | 0.067 (2) | 0.071 (2) | −0.0057 (18) | 0.0299 (18) | −0.0374 (19) |
N1 | 0.0489 (18) | 0.0237 (16) | 0.0339 (17) | −0.0008 (13) | 0.0154 (14) | −0.0008 (13) |
N2 | 0.0449 (17) | 0.0277 (16) | 0.0299 (15) | −0.0065 (14) | 0.0200 (13) | 0.0023 (13) |
N3 | 0.0306 (15) | 0.0229 (13) | 0.0239 (14) | −0.0009 (12) | 0.0102 (11) | 0.0010 (12) |
N4 | 0.0472 (19) | 0.0294 (17) | 0.0367 (17) | −0.0085 (14) | 0.0050 (14) | 0.0091 (14) |
N5 | 0.0348 (15) | 0.0204 (14) | 0.0310 (15) | −0.0025 (12) | 0.0077 (12) | 0.0039 (12) |
N6 | 0.0473 (18) | 0.0258 (17) | 0.0342 (17) | −0.0003 (14) | 0.0109 (14) | 0.0031 (13) |
N7 | 0.0356 (16) | 0.0419 (19) | 0.0317 (16) | 0.0011 (14) | 0.0157 (13) | 0.0028 (14) |
C1 | 0.0282 (17) | 0.0266 (18) | 0.0265 (17) | −0.0033 (14) | 0.0006 (14) | 0.0021 (14) |
C2 | 0.0268 (16) | 0.0236 (17) | 0.0228 (16) | 0.0000 (13) | 0.0043 (13) | 0.0017 (13) |
C3 | 0.0278 (17) | 0.0252 (18) | 0.0233 (16) | −0.0029 (13) | 0.0061 (13) | 0.0020 (13) |
C4 | 0.0335 (18) | 0.0250 (17) | 0.0284 (17) | 0.0005 (14) | 0.0077 (14) | −0.0038 (14) |
C5 | 0.0302 (17) | 0.0260 (18) | 0.0232 (16) | 0.0013 (14) | 0.0080 (13) | −0.0030 (13) |
C6 | 0.0265 (16) | 0.0240 (17) | 0.0226 (16) | −0.0003 (13) | 0.0076 (13) | −0.0017 (13) |
C7 | 0.0354 (18) | 0.0306 (19) | 0.0218 (16) | −0.0020 (15) | 0.0140 (14) | 0.0011 (14) |
C8 | 0.045 (2) | 0.037 (2) | 0.0315 (19) | −0.0048 (17) | 0.0169 (16) | 0.0037 (16) |
C9 | 0.061 (3) | 0.031 (2) | 0.0325 (19) | 0.0018 (18) | 0.0243 (18) | −0.0060 (16) |
C10 | 0.053 (3) | 0.055 (3) | 0.040 (2) | 0.003 (2) | 0.0239 (19) | 0.0025 (19) |
Cu1—O1 | 1.885 (2) | C2—C3 | 1.440 (5) |
Cu1—O3 | 1.977 (3) | C3—C8 | 1.483 (5) |
Cu1—N1 | 1.934 (3) | C4—C5 | 1.366 (5) |
Cu1—N3 | 1.947 (3) | C4—H4 | 0.9300 |
O1—C2 | 1.283 (4) | C5—C6 | 1.411 (5) |
O2—C9 | 1.428 (5) | C5—C9 | 1.501 (4) |
O2—H12 | 0.8200 | C6—C7 | 1.442 (5) |
O3—C10 | 1.424 (5) | C7—H7 | 0.9300 |
O3—H13 | 0.94 (6) | C8—H8A | 0.9600 |
N1—C1 | 1.300 (4) | C8—H8B | 0.9600 |
N1—H1 | 0.8600 | C8—H8C | 0.9600 |
N2—C1 | 1.376 (4) | C9—H9A | 0.9700 |
N2—H2 | 0.8600 | C9—H9B | 0.9700 |
N3—C7 | 1.275 (5) | C10—H10A | 0.9600 |
N4—C1 | 1.310 (4) | C10—H10B | 0.9600 |
N4—H4A | 0.8600 | C10—H10C | 0.9600 |
N4—H4B | 0.8600 | N6—O4 | 1.250 (4) |
N5—C3 | 1.317 (4) | N6—O5 | 1.226 (4) |
N5—C4 | 1.338 (4) | N6—O6 | 1.242 (4) |
N5—H5 | 0.8600 | N7—O7 | 1.209 (4) |
N2—N3 | 1.355 (4) | N7—O9 | 1.213 (5) |
C2—C6 | 1.419 (4) | N7—O8 | 1.228 (4) |
N1—Cu1—N3 | 81.99 (13) | O1—C2—C3 | 115.7 (3) |
N1—Cu1—O3 | 94.37 (12) | C6—C2—C3 | 117.0 (3) |
O1—Cu1—N3 | 92.10 (11) | N5—C3—C2 | 119.0 (3) |
O1—Cu1—O3 | 91.47 (11) | N5—C3—C8 | 120.7 (3) |
O1—Cu1—N1 | 174.03 (11) | C2—C3—C8 | 120.3 (3) |
O3—Cu1—N3 | 175.01 (12) | N5—C4—C5 | 119.5 (3) |
C2—O1—Cu1 | 127.0 (2) | N5—C4—H4 | 120.2 |
C9—O2—H12 | 109.5 | C5—C4—H4 | 120.2 |
C10—O3—Cu1 | 125.4 (3) | C4—C5—C6 | 119.7 (3) |
C10—O3—H13 | 99 (4) | C4—C5—C9 | 118.4 (3) |
Cu1—O3—H13 | 114 (4) | C6—C5—C9 | 121.9 (3) |
C1—N1—Cu1 | 114.3 (3) | C5—C6—C2 | 119.6 (3) |
C1—N1—H1 | 122.9 | C5—C6—C7 | 118.9 (3) |
Cu1—N1—H1 | 122.9 | C2—C6—C7 | 121.5 (3) |
N3—N2—C1 | 116.2 (3) | N3—C7—C6 | 123.0 (3) |
N3—N2—H2 | 121.9 | N3—C7—H7 | 118.5 |
C1—N2—H2 | 121.9 | C6—C7—H7 | 118.5 |
C7—N3—N2 | 119.5 (3) | C3—C8—H8A | 109.5 |
C7—N3—Cu1 | 129.0 (2) | C3—C8—H8B | 109.5 |
N2—N3—Cu1 | 111.5 (2) | H8A—C8—H8B | 109.5 |
C1—N4—H4A | 120.0 | C3—C8—H8C | 109.5 |
C1—N4—H4B | 120.0 | H8A—C8—H8C | 109.5 |
H4A—N4—H4B | 120.0 | H8B—C8—H8C | 109.5 |
C3—N5—C4 | 125.1 (3) | O2—C9—C5 | 109.8 (3) |
C3—N5—H5 | 117.4 | O2—C9—H9A | 109.7 |
C4—N5—H5 | 117.4 | C5—C9—H9A | 109.7 |
O5—N6—O6 | 121.2 (3) | O2—C9—H9B | 109.7 |
O5—N6—O4 | 120.1 (3) | C5—C9—H9B | 109.7 |
O6—N6—O4 | 118.6 (3) | H9A—C9—H9B | 108.2 |
O7—N7—O9 | 118.0 (4) | O3—C10—H10A | 109.5 |
O7—N7—O8 | 121.6 (4) | O3—C10—H10B | 109.5 |
O9—N7—O8 | 120.3 (4) | H10A—C10—H10B | 109.5 |
N1—C1—N4 | 126.5 (4) | O3—C10—H10C | 109.5 |
N1—C1—N2 | 116.1 (3) | H10A—C10—H10C | 109.5 |
N4—C1—N2 | 117.5 (3) | H10B—C10—H10C | 109.5 |
O1—C2—C6 | 127.3 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H12···O6i | 0.82 | 2.09 | 2.705 (4) | 132 |
O3—H13···O2ii | 0.94 (6) | 1.85 (6) | 2.691 (4) | 147 (5) |
N1—H1···O6 | 0.86 | 2.12 | 2.978 (4) | 175 |
N2—H2···O8 | 0.86 | 2.20 | 3.004 (5) | 155 |
N2—H2···O9 | 0.86 | 2.34 | 3.103 (6) | 149 |
N4—H4A···O5 | 0.86 | 2.40 | 3.229 (5) | 162 |
N4—H4A···O7iii | 0.86 | 2.46 | 2.998 (5) | 121 |
N4—H4B···O8 | 0.86 | 2.49 | 3.241 (5) | 147 |
N4—H4B···O8iii | 0.86 | 2.51 | 3.164 (5) | 133 |
N5—H5···O4iv | 0.86 | 1.91 | 2.750 (4) | 167 |
N5—H5···O5iv | 0.86 | 2.59 | 3.239 (4) | 132 |
C4—H4···O7v | 0.93 | 2.62 | 3.534 (5) | 167 |
C7—H7···O9 | 0.93 | 2.29 | 3.149 (7) | 152 |
C8—H8A···O4iv | 0.96 | 2.67 | 3.440 (5) | 138 |
C9—H9B···O9v | 0.97 | 2.60 | 3.546 (6) | 164 |
C10—H10B···O4vi | 0.96 | 2.67 | 3.388 (6) | 131 |
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) x, −y+1/2, z+1/2; (iii) −x+2, −y+1, −z+1; (iv) x, y−1, z; (v) −x+2, −y, −z+1; (vi) −x+1, −y+1, −z+2. |
Experimental details
Crystal data | |
Chemical formula | [Cu(C9H13N5O2)(CH4O)](NO3)2 |
Mr | 442.85 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 8.113 (2), 13.852 (2), 14.9846 (3) |
β (°) | 103.013 (2) |
V (Å3) | 1640.8 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.40 |
Crystal size (mm) | 0.32 × 0.18 × 0.15 |
Data collection | |
Diffractometer | Oxford Xcalibur S CCD diffractometer |
Absorption correction | Multi-scan [(CrysAlis RED; Oxford Diffraction, 2008); Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.] |
Tmin, Tmax | 0.622, 0.801 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 20236, 3586, 2632 |
Rint | 0.022 |
(sin θ/λ)max (Å−1) | 0.640 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.045, 0.141, 1.06 |
No. of reflections | 3586 |
No. of parameters | 251 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.70, −0.73 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2008), CrysAlis RED (Oxford Diffraction, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009), WinGX (Farrugia, 1999).
Cu1—O1 | 1.885 (2) | C2—C6 | 1.419 (4) |
Cu1—O3 | 1.977 (3) | C2—C3 | 1.440 (5) |
Cu1—N1 | 1.934 (3) | C3—C8 | 1.483 (5) |
Cu1—N3 | 1.947 (3) | C4—C5 | 1.366 (5) |
O1—C2 | 1.283 (4) | C5—C6 | 1.411 (5) |
O2—C9 | 1.428 (5) | C5—C9 | 1.501 (4) |
O3—C10 | 1.424 (5) | C6—C7 | 1.442 (5) |
N1—C1 | 1.300 (4) | N6—O4 | 1.250 (4) |
N2—C1 | 1.376 (4) | N6—O5 | 1.226 (4) |
N3—C7 | 1.275 (5) | N6—O6 | 1.242 (4) |
N4—C1 | 1.310 (4) | N7—O7 | 1.209 (4) |
N5—C3 | 1.317 (4) | N7—O9 | 1.213 (5) |
N5—C4 | 1.338 (4) | N7—O8 | 1.228 (4) |
N2—N3 | 1.355 (4) | ||
N1—Cu1—N3 | 81.99 (13) | C7—N3—N2 | 119.5 (3) |
N1—Cu1—O3 | 94.37 (12) | N1—C1—N2 | 116.1 (3) |
O1—Cu1—N3 | 92.10 (11) | O1—C2—C6 | 127.3 (3) |
O1—Cu1—O3 | 91.47 (11) | O1—C2—C3 | 115.7 (3) |
O1—Cu1—N1 | 174.03 (11) | C2—C6—C7 | 121.5 (3) |
O3—Cu1—N3 | 175.01 (12) | N3—C7—C6 | 123.0 (3) |
N3—N2—C1 | 116.2 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H12···O6i | 0.82 | 2.09 | 2.705 (4) | 132 |
O3—H13···O2ii | 0.94 (6) | 1.85 (6) | 2.691 (4) | 147 (5) |
N1—H1···O6 | 0.86 | 2.12 | 2.978 (4) | 175 |
N2—H2···O8 | 0.86 | 2.20 | 3.004 (5) | 155 |
N2—H2···O9 | 0.86 | 2.34 | 3.103 (6) | 149 |
N4—H4A···O5 | 0.86 | 2.40 | 3.229 (5) | 162 |
N4—H4A···O7iii | 0.86 | 2.46 | 2.998 (5) | 121 |
N4—H4B···O8 | 0.86 | 2.49 | 3.241 (5) | 147 |
N4—H4B···O8iii | 0.86 | 2.51 | 3.164 (5) | 133 |
N5—H5···O4iv | 0.86 | 1.91 | 2.750 (4) | 167 |
N5—H5···O5iv | 0.86 | 2.59 | 3.239 (4) | 132 |
C4—H4···O7v | 0.93 | 2.62 | 3.534 (5) | 167 |
C7—H7···O9 | 0.93 | 2.29 | 3.149 (7) | 152 |
C8—H8A···O4iv | 0.96 | 2.67 | 3.440 (5) | 138 |
C9—H9B···O9v | 0.97 | 2.60 | 3.546 (6) | 164 |
C10—H10B···O4vi | 0.96 | 2.67 | 3.388 (6) | 131 |
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) x, −y+1/2, z+1/2; (iii) −x+2, −y+1, −z+1; (iv) x, y−1, z; (v) −x+2, −y, −z+1; (vi) −x+1, −y+1, −z+2. |
Aminoguanidine is a well known inhibitor of the formation of advanced glycation end products and is considered to be promising for the treatment of diabetic complications (Taguchi et al., 1999). The Schiff base of pyridoxal and aminoguanidine (PL–AG) appeared to be more effective than aminoguanidine, a well known antidiabetic complication compound, in preventing nephropathy in diabetic mice, and brief data have been presented indicating the antioxidant activity of the aduct (Chen et al., 2003). In view of the importance of PL–AG and copper(II) as a biometal, it was of interest to determine the structure of their complex. Our previous work (Leovac et al., 2007) was concerned with the crystal and molecular structures of the square-pyramidal complex of formula [Cu(PL–AG)Cl2]. We report here the crystal structure of (I), the complex compound of CuII with the same ligand, which consists of the complex cation [Cu(PL–AG)MeOH]2+ and two nitrate anions.
In (I), CuII is in a square-planar coordination environment formed by the N,N,O-tridentate pyridoxal–aminoguanidine Schiff base adduct and the molecule of methanol. As in the previous cases of various piridoxal Schiff bases (Belicchi Ferrari et al., 1994, 1995; Poleti et al. 2003; Leovac et al., 2007) the ligand takes the form of a zwitterion as the H atom from the phenol O atom shifts to the pyridine N atom. As a result, the Cu1—O1 bond distance, where the oxygen donor from the Schiff base is negatively charged, is considerably shorter than the Cu1—O3 bond with the neutral methanol ligand (Table 1). On the other hand, the bonds with the two nitrogen donors, Cu1—N1 and Cu1—N3, have more similar lengths [1.934 (3) and 1.947 (3) Å, respectively], which was not the case with the corresponding bonds in the previously reported complex [Cu(PL–AG)Cl2] [1.934 (3) and 1.984 (3) Å]. By coordination to the metal atom the tridentate ligand forms six- and five-membered chelate rings. The whole Schiff base displays a high degree of planarity owing to the evident electron delocalization. The r.m.s. deviations of the fitted atoms in the three rings [the pyridoxal ring (A), and the six- (B) and five-membered (C) chelate rings] do not exceed 0.01 Å, while the dihedral angles between the mean planes A–B, A–C and B–C are 1.8, 2.0 and 0.7°, respectively. This is considerably less than in the case of the [Cu(PL–AG)Cl2] complex, where the dihedral angles between the five-membered chelate and A and B rings reached 8.3 and 8.9°, respectively. In addition, the previously observed bending of the O1— Cu1—N1 angle to 165.7 (2)° is less significant in the present compound [174.03 (11)°], probably because the smaller O atom replaces the more voluminous Cl atoms in the CuII coordination environment.
Owing to the presence of two uncoordinated nitrate anions and the considerable hydrogen donor capacity of the tridentate ligand, the crystal structure is stabilized by a very extensive hydrogen-bonding network. The planar complex unit forms hydrogen bonds with both nitrate anions and engages all their oxygen acceptors to assemble into wide ribbons, as shown in Fig. 2. The nitrate unit N7/O7–O9 is located in the middle of the ribbons, forming five N—H···O and three C—H···O hydrogen bonds with three complex units. The other nitrate ion, N6/O4–O6, is positioned on the lateral sides of ribbons, forming seven hydrogen bonds (four N—H···O, two C—H···O and one O—H···O) and interconnecting the four complex cations. The interactions formed by N6/O4–O6 are, however, somewhat stronger than those formed by the other nitrate group, which could be related to the findings that the N—O bond distances in the N6/O4–O6 group are somewhat longer than those in N7/O7–O9 (Table 1). The elongation is particularly pronounced for N6—O4 [1.250 (4) Å], whose O atom serves as the acceptor of a short N5—H5···O4iv hydrogen bond (H5···O4iv = 1.91 Å; symmetry codes as in Table 2), and also for N6—O6 [1.242 (4) Å], where the O atom is simultaneously involved in two interactions with H···O6 less than 2.12 Å. The O atom from the shortest [N7—O7 = 1.209 (4) Å] is, on the other hand, engaged in two weak interactions where H···O7 is greater than 2.46 Å. The ribbons of molecules further interact via a single C10—H10B···O4vi contact, which engages bordering NO3 and methyl groups from the methanol ligands, to form layers (Fig. 2). The layers coincide with the (202) crystallographic plane. Although NO3- as free anions can take any orientation, the extensive hydrogen bonding leads to a coplanar arrangement of cations and anions. The separation between the layers is approximately 3.2 Å. The OH group of the piridoxal unit is the only fragment that significantly deviates from this overall planarity (the dihedral angle between the mean coordination plane and the plane of the piridoxal C9/O2/H12 group is 77.4°). This group is, however, suitably oriented toward the neighboring layer to serve as an acceptor in very strong O3—H13···O2ii hydrogen bond with the methanol hydroxy group and also as a donor in a second, O2—H12···O6i, bond to a nitrate anion. There is no other connection between the planar two-dimensional formations.