Bis(2-oxopyridinato N-oxide-κ²O,O′)copper(II)

The title complex, [Cu(C₅H₄NO₂)₂], displays a trans-O₂(N-oxide)O₂ square-planar coordination geometry for the Cu^II centre. In the crystal structure, the mol­ecules assemble into a three-dimensional structure by way of intermolecular π–π interactions and weak intermolecular C—H...O interactions.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.044
• wR factor = 0.113
• Data-to-parameter ratio = 11.8

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT052_ALERT_1_A (Proper) Absorption Correction Method Missing ..          ?

Alert level C
PLAT057_ALERT_3_C Correction for Absorption Required   RT(exp) ...       1.20
PLAT199_ALERT_1_C Check the Reported cell_measurement_temperature         293
PLAT200_ALERT_1_C Check the Reported cell_ambient_temperature ....        293
PLAT480_ALERT_4_C Long H...A H-Bond Reported H5     ..  O2      ..       2.64 Ang.

   1 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: XSCANS (Bruker, 2000); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Bis(2-oxopyridinato N-oxide-κ²O,O')copper(II)

Crystal data

[Cu(C10H8N2O4)2]	F(000) = 572
Mr = 567.45	Dx = 1.829 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 6.873 (5) Å	θ = 3.0–25.0°
b = 9.721 (5) Å	µ = 2.12 mm^−1
c = 15.523 (2) Å	T = 293 K
β = 96.49 (1)°	Block, blue
V = 1030.5 (9) Å^3	0.30 × 0.20 × 0.15 mm
Z = 2

Data collection

Siemens P4 diffractometer	1595 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.029
Graphite monochromator	θmax = 25.0°, θmin = 2.5°
ω/2θ scans	h = −8→8
Absorption correction: ψ scan (XPREP; Bruker, 2000)	k = −11→7
Tmin = 0.612, Tmax = 0.734	l = −15→18
4108 measured reflections	3 standard reflections every 97 reflections
1820 independent reflections	intensity decay: 0.2%

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.113	H-atom parameters constrained
S = 0.99	w = 1/[σ^2(Fo^2) + (0.07P)^2 + 1.66P] where P = (Fo^2 + 2Fc^2)/3
1820 reflections	(Δ/σ)max < 0.001
154 parameters	Δρmax = 0.33 e Å^−3
0 restraints	Δρmin = −0.70 e Å^−3

Special details

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.

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)

-0.1266(0.0055)x + 6.8235(0.0066)y + 11.0140(0.0100) z = 10.7455 (0.0079)

* 0.2085 (0.0010) Cu1 * 0.0927 (0.0031) O1 * -0.0238 (0.0030) O2 * 0.2839 (0.0029) O3 * 0.0928 (0.0033) O4 * 0.0193 (0.0033) N1 * 0.1055 (0.0034) N2 * -0.0498 (0.0032) C1 * -0.1338 (0.0035) C2 * -0.1474 (0.0042) C3 * -0.0253 (0.0036) C4 * 0.0147 (0.0035) C5 * 0.0331 (0.0039) C6 * -0.1362 (0.0044) C7 * -0.1934 (0.0044) C8 * -0.1433 (0.0036) C9 * 0.0025 (0.0032) C10

Rms deviation of fitted atoms = 0.1269

0.1606 (0.0088) x + 7.0762 (0.0097) y + 10.5281 (0.0157) z = 10.9347 (0.0082)

Angle to previous plane (with approximate e.s.d.) = 3.21 (0.14)

* 0.0780 (0.0013) Cu1 * 0.0571 (0.0016) O1 * -0.0963 (0.0016) O2 * 0.0582 (0.0016) O3 * -0.0971 (0.0016) O4

Rms deviation of fitted atoms = 0.0793

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 (Ų)

	x	y	z	Uiso*/Ueq
Cu1	0.13089 (6)	0.91230 (5)	0.43086 (3)	0.0271 (2)
O1	0.3893 (4)	0.9428 (3)	0.40439 (19)	0.0355 (7)
O2	0.0591 (4)	1.0350 (3)	0.33294 (18)	0.0350 (7)
N1	0.3894 (5)	1.0335 (4)	0.3416 (2)	0.0326 (8)
C1	0.2141 (5)	1.0796 (4)	0.3047 (2)	0.0225 (8)
C2	0.2142 (6)	1.1746 (4)	0.2383 (2)	0.0313 (9)
H2	0.0960	1.2086	0.2115	0.038*
C3	0.3822 (7)	1.2177 (5)	0.2122 (3)	0.0405 (10)
H3	0.3786	1.2786	0.1659	0.049*
C4	0.5603 (6)	1.1746 (5)	0.2521 (3)	0.0345 (10)
H4	0.6767	1.2103	0.2362	0.041*
C5	0.5610 (6)	1.0760 (4)	0.3168 (3)	0.0329 (9)
H5	0.6785	1.0397	0.3427	0.039*
O3	−0.1338 (4)	0.8810 (3)	0.4540 (2)	0.0327 (6)
O4	0.1904 (4)	0.7655 (3)	0.5120 (2)	0.0395 (7)
N2	−0.1368 (5)	0.7722 (4)	0.5052 (2)	0.0320 (8)
C6	0.0379 (6)	0.7148 (4)	0.5362 (3)	0.0301 (9)
C7	0.0301 (7)	0.5999 (5)	0.5919 (3)	0.0450 (12)
H7	0.1455	0.5561	0.6139	0.054*
C8	−0.1409 (7)	0.5539 (5)	0.6133 (3)	0.0422 (11)
H8	−0.1431	0.4808	0.6518	0.051*
C9	−0.3190 (6)	0.6150 (4)	0.5780 (3)	0.0340 (10)
H9	−0.4383	0.5811	0.5916	0.041*
C10	−0.3123 (6)	0.7234 (4)	0.5241 (2)	0.0280 (8)
H10	−0.4278	0.7647	0.4999	0.034*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0228 (3)	0.0293 (3)	0.0303 (3)	0.00315 (19)	0.00785 (18)	0.0052 (2)
O1	0.0288 (15)	0.0369 (16)	0.0418 (16)	0.0069 (13)	0.0085 (12)	0.0190 (13)
O2	0.0205 (14)	0.0526 (18)	0.0320 (15)	−0.0034 (12)	0.0030 (11)	0.0138 (14)
N1	0.0343 (19)	0.0353 (19)	0.0283 (17)	0.0020 (15)	0.0034 (14)	−0.0003 (15)
C1	0.0216 (17)	0.0294 (19)	0.0170 (16)	0.0072 (15)	0.0049 (13)	−0.0079 (15)
C2	0.030 (2)	0.033 (2)	0.030 (2)	0.0082 (17)	−0.0009 (16)	0.0008 (17)
C3	0.048 (3)	0.036 (2)	0.040 (2)	−0.003 (2)	0.0129 (19)	0.013 (2)
C4	0.031 (2)	0.036 (2)	0.039 (2)	−0.0130 (18)	0.0161 (17)	−0.0054 (18)
C5	0.039 (2)	0.030 (2)	0.032 (2)	0.0122 (18)	0.0127 (17)	−0.0037 (17)
O3	0.0205 (13)	0.0265 (14)	0.0506 (17)	0.0040 (11)	0.0023 (12)	0.0114 (13)
O4	0.0283 (15)	0.0398 (17)	0.0510 (18)	0.0045 (13)	0.0068 (12)	0.0217 (14)
N2	0.0288 (17)	0.039 (2)	0.0287 (17)	0.0015 (15)	0.0059 (13)	0.0084 (15)
C6	0.024 (2)	0.026 (2)	0.044 (2)	0.0047 (16)	0.0150 (16)	0.0052 (17)
C7	0.046 (3)	0.041 (3)	0.050 (3)	0.016 (2)	0.016 (2)	0.019 (2)
C8	0.049 (3)	0.038 (2)	0.043 (3)	0.000 (2)	0.018 (2)	0.015 (2)
C9	0.036 (2)	0.034 (2)	0.034 (2)	−0.0156 (18)	0.0146 (17)	−0.0026 (18)
C10	0.0240 (18)	0.034 (2)	0.0260 (19)	0.0095 (16)	0.0016 (14)	−0.0081 (16)

Geometric parameters (Å, º)

Cu1—O1	1.891 (3)	C4—H4	0.9300
Cu1—O4	1.916 (3)	C5—H5	0.9300
Cu1—O3	1.918 (3)	O3—N2	1.325 (4)
Cu1—O2	1.951 (3)	O4—C6	1.254 (5)
O1—N1	1.314 (4)	N2—C10	1.358 (5)
O2—C1	1.273 (5)	N2—C6	1.361 (5)
N1—C5	1.346 (6)	C6—C7	1.418 (6)
N1—C1	1.351 (5)	C7—C8	1.334 (7)
C1—C2	1.384 (6)	C7—H7	0.9300
C2—C3	1.333 (6)	C8—C9	1.414 (7)
C2—H2	0.9300	C8—H8	0.9300
C3—C4	1.373 (7)	C9—C10	1.350 (6)
C3—H3	0.9300	C9—H9	0.9300
C4—C5	1.389 (6)	C10—H10	0.9300
O1—Cu1—O4	97.10 (12)	N1—C5—C4	119.2 (4)
O1—Cu1—O3	178.28 (12)	N1—C5—H5	120.4
O4—Cu1—O3	83.99 (12)	C4—C5—H5	120.4
O1—Cu1—O2	84.02 (12)	N2—O3—Cu1	108.6 (2)
O4—Cu1—O2	169.56 (14)	C6—O4—Cu1	111.5 (3)
O3—Cu1—O2	94.67 (12)	O3—N2—C10	118.8 (3)
N1—O1—Cu1	110.2 (2)	O3—N2—C6	117.8 (3)
C1—O2—Cu1	109.2 (2)	C10—N2—C6	123.4 (3)
O1—N1—C5	119.4 (3)	O4—C6—N2	117.8 (4)
O1—N1—C1	117.5 (3)	O4—C6—C7	125.7 (4)
C5—N1—C1	123.1 (4)	N2—C6—C7	116.4 (4)
O2—C1—N1	118.8 (3)	C8—C7—C6	120.7 (4)
O2—C1—C2	123.7 (3)	C8—C7—H7	119.6
N1—C1—C2	117.5 (3)	C6—C7—H7	119.6
C3—C2—C1	120.6 (4)	C7—C8—C9	120.8 (4)
C3—C2—H2	119.7	C7—C8—H8	119.6
C1—C2—H2	119.7	C9—C8—H8	119.6
C2—C3—C4	121.8 (4)	C10—C9—C8	118.7 (4)
C2—C3—H3	119.1	C10—C9—H9	120.7
C4—C3—H3	119.1	C8—C9—H9	120.7
C3—C4—C5	117.8 (4)	C9—C10—N2	119.9 (4)
C3—C4—H4	121.1	C9—C10—H10	120.0
C5—C4—H4	121.1	N2—C10—H10	120.0

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O3^i	0.93	2.57	3.332 (5)	140
C3—H3···O1^ii	0.93	2.58	3.343 (5)	139
C5—H5···O3^iii	0.93	2.55	3.394 (5)	150
C5—H5···O2^iii	0.93	2.64	3.428 (6)	143

Symmetry codes: (i) −x, y+1/2, −z+1/2; (ii) −x+1, y+1/2, −z+1/2; (iii) x+1, y, z.