trans-Bis(2-amino­anilinium-κN²)­bis­(oxalato-κ²O,O′)copper(II)

The title compound, [Cu(C₂O₄)₂(C₆H₉N₂)₂], crystallizes in the space group P2₁/c, with the Cu atom located at a centre of symmetry. It is a neutral coordination complex in which the metal exhibits a tetragonally elongated octahedral trans-CuO₄N₂ coordination environment. Extensive intermolecular hydrogen bonding between the oxalate anions and the ammonium cations determines the molecular packing in the crystal.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.035
• wR factor = 0.091
• Data-to-parameter ratio = 14.2

checkCIF/PLATON results

No syntax errors found



Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.605     0.880
            Tmin' and Tmax expected:      0.771     0.880
            RR' =      0.785
            Please check that your absorption correction is appropriate.
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.99
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.78
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT230_ALERT_2_C Hirshfeld Test Diff for    O3     -   C2       =       5.05 su
PLAT369_ALERT_2_C Long   C(sp2)-C(sp2) Bond  C1     -   C2       =       1.56 Ang.

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

   0 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
   3 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: DENZO (Otwinowski and Minor, 1997); cell refinement: DENZO and COLLECT (Hooft, 1998); data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997) in WinGX (Farrugia, 1999); program(s) used to refine structure: SHELXS97 (Sheldrick, 1997) in WinGX; molecular graphics: DIAMOND (Brandenburg, 1999).

(I)

Crystal data

[Cu(C2O4)2(C6H9N2)2]	Dx = 1.709 Mg m^−3
Mr = 457.89	Melting point: N/A K
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 11.5768 (4) Å	Cell parameters from 4249 reflections
b = 10.6642 (3) Å	θ = 2.9–27.5°
c = 7.5782 (2) Å	µ = 1.28 mm^−1
β = 108.013 (1)°	T = 120 K
V = 889.73 (5) Å^3	Block, pale green
Z = 2	0.2 × 0.1 × 0.1 mm
F(000) = 470

Data collection

Nonius KappaCCD area-detector diffractometer	1765 reflections with I > 2σ(I)
φ and ω scans to fill Ewald sphere	Rint = 0.086
Absorption correction: multi-scan (SORTAV; Blessing, 1997)	θmax = 27.5°, θmin = 2.9°
Tmin = 0.605, Tmax = 0.880	h = −15→15
8409 measured reflections	k = −13→13
2023 independent reflections	l = −9→9

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.035	w = 1/[σ^2(Fo^2) + (0.0263P)^2 + 0.8605P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.091	(Δ/σ)max < 0.001
S = 1.06	Δρmax = 0.47 e Å^−3
2023 reflections	Δρmin = −0.56 e Å^−3
142 parameters

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.

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. Amine H atoms were freely refined. Ammonium H atoms were fixed in calculated positions and refined in riding mode with the group allowed to rotate freely along the N2—C4 bond. Aryl H atoms were fixed in calculated positions and refined in riding mode

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
H1B	0.139 (2)	0.118 (3)	0.348 (4)	0.025 (7)*
H1A	0.148 (2)	0.197 (3)	0.188 (4)	0.021 (7)*
Cu1	0	0	0	0.01258 (13)
O1	−0.24205 (13)	0.13669 (14)	0.2149 (2)	0.0157 (3)
O4	−0.03181 (13)	−0.09760 (14)	0.2004 (2)	0.0139 (3)
O2	−0.12189 (12)	0.11570 (14)	0.0367 (2)	0.0136 (3)
O3	−0.15409 (14)	−0.09020 (15)	0.3788 (2)	0.0183 (3)
N2	0.22712 (15)	−0.11713 (17)	0.4045 (3)	0.0137 (4)
H2A	0.2389	−0.1985	0.3901	0.021*
H2B	0.1503	−0.0975	0.3441	0.021*
H2C	0.2428	−0.1002	0.5246	0.021*
N1	0.15697 (16)	0.12297 (18)	0.2376 (3)	0.0152 (4)
C5	0.4172 (2)	−0.0972 (2)	0.3323 (3)	0.0188 (5)
H5	0.4392	−0.1753	0.3872	0.023*
C1	−0.16504 (18)	0.07888 (19)	0.1619 (3)	0.0123 (4)
C8	0.3508 (2)	0.1354 (2)	0.1705 (3)	0.0183 (5)
H8	0.3295	0.2136	0.1158	0.022*
C4	0.30838 (19)	−0.0435 (2)	0.3299 (3)	0.0145 (4)
C2	−0.11398 (18)	−0.0473 (2)	0.2586 (3)	0.0135 (4)
C6	0.4940 (2)	−0.0348 (2)	0.2527 (4)	0.0224 (5)
H6	0.5676	−0.0704	0.2543	0.027*
C3	0.27242 (18)	0.0743 (2)	0.2512 (3)	0.0140 (4)
C7	0.4598 (2)	0.0807 (2)	0.1711 (4)	0.0226 (5)
H7	0.5103	0.1224	0.116	0.027*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0129 (2)	0.0124 (2)	0.0140 (2)	0.00294 (12)	0.00640 (16)	0.00287 (13)
O1	0.0149 (7)	0.0144 (8)	0.0196 (8)	0.0023 (6)	0.0080 (6)	0.0000 (6)
O4	0.0157 (7)	0.0122 (8)	0.0153 (8)	0.0022 (6)	0.0071 (6)	0.0021 (6)
O2	0.0142 (7)	0.0122 (7)	0.0156 (8)	0.0013 (6)	0.0063 (6)	0.0021 (6)
O3	0.0235 (8)	0.0167 (8)	0.0192 (8)	0.0027 (6)	0.0130 (7)	0.0038 (6)
N2	0.0137 (8)	0.0116 (9)	0.0154 (9)	0.0004 (7)	0.0039 (7)	0.0005 (7)
N1	0.0173 (9)	0.0117 (9)	0.0171 (10)	0.0022 (7)	0.0060 (8)	0.0026 (7)
C5	0.0175 (10)	0.0151 (11)	0.0231 (12)	0.0025 (8)	0.0053 (9)	−0.0006 (9)
C1	0.0118 (9)	0.0111 (10)	0.0122 (10)	−0.0018 (7)	0.0012 (8)	−0.0002 (8)
C8	0.0219 (11)	0.0120 (11)	0.0215 (12)	−0.0028 (8)	0.0075 (9)	−0.0005 (9)
C4	0.0143 (10)	0.0136 (10)	0.0146 (11)	−0.0039 (8)	0.0029 (8)	−0.0022 (9)
C2	0.0131 (9)	0.0120 (10)	0.0134 (10)	−0.0010 (8)	0.0012 (8)	−0.0027 (8)
C6	0.0139 (10)	0.0241 (12)	0.0309 (14)	0.0007 (9)	0.0093 (10)	−0.0020 (11)
C3	0.0143 (9)	0.0134 (10)	0.0134 (11)	−0.0006 (8)	0.0028 (8)	−0.0034 (8)
C7	0.0214 (11)	0.0214 (12)	0.0283 (13)	−0.0064 (9)	0.0122 (10)	−0.0011 (10)

Geometric parameters (Å, º)

Cu1—O2	1.9579 (14)	N1—H1B	0.92 (3)
Cu1—O2^i	1.9579 (14)	N1—H1A	0.86 (3)
Cu1—O4^i	1.9675 (14)	C5—C4	1.379 (3)
Cu1—O4	1.9675 (14)	C5—C6	1.389 (3)
Cu1—N1	2.4980 (19)	C5—H5	0.9300
O1—C1	1.248 (2)	C1—C2	1.559 (3)
O4—C2	1.283 (2)	C8—C7	1.389 (3)
O2—C1	1.264 (3)	C8—C3	1.402 (3)
O3—C2	1.231 (3)	C8—H8	0.9300
N2—C4	1.466 (3)	C4—C3	1.398 (3)
N2—H2A	0.8900	C6—C7	1.380 (4)
N2—H2B	0.8900	C6—H6	0.9300
N2—H2C	0.8900	C7—H7	0.9300
N1—C3	1.407 (3)
O2—Cu1—O2^i	180.00 (8)	C4—C5—C6	120.0 (2)
O2—Cu1—O4^i	95.24 (6)	C4—C5—H5	120.0
O2^i—Cu1—O4^i	84.76 (6)	C6—C5—H5	120.0
O2—Cu1—O4	84.76 (6)	O1—C1—O2	125.13 (19)
O2^i—Cu1—O4	95.24 (6)	O1—C1—C2	118.71 (18)
O4^i—Cu1—O4	180.00 (11)	O2—C1—C2	116.14 (17)
O2—Cu1—N1	87.85 (6)	C7—C8—C3	120.9 (2)
O2^i—Cu1—N1	92.15 (6)	C7—C8—H8	119.6
O4^i—Cu1—N1	90.60 (6)	C3—C8—H8	119.6
O4—Cu1—N1	89.40 (6)	C5—C4—C3	122.0 (2)
C2—O4—Cu1	112.33 (13)	C5—C4—N2	117.7 (2)
C1—O2—Cu1	112.36 (13)	C3—C4—N2	120.28 (18)
C4—N2—H2A	109.5	O3—C2—O4	126.0 (2)
C4—N2—H2B	109.5	O3—C2—C1	119.57 (18)
H2A—N2—H2B	109.5	O4—C2—C1	114.39 (18)
C4—N2—H2C	109.5	C7—C6—C5	119.3 (2)
H2A—N2—H2C	109.5	C7—C6—H6	120.3
H2B—N2—H2C	109.5	C5—C6—H6	120.3
C3—N1—Cu1	108.78 (13)	C4—C3—C8	117.16 (19)
C3—N1—H1B	112.9 (17)	C4—C3—N1	120.87 (19)
Cu1—N1—H1B	107.8 (17)	C8—C3—N1	121.7 (2)
C3—N1—H1A	110.3 (17)	C6—C7—C8	120.7 (2)
Cu1—N1—H1A	101.9 (18)	C6—C7—H7	119.7
H1B—N1—H1A	114 (2)	C8—C7—H7	119.7

Symmetry code: (i) −x, −y, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O3^ii	0.86 (3)	2.33 (3)	3.181 (2)	167 (2)
N2—H2A···O1^iii	0.89	1.93	2.799 (2)	164
N2—H2A···O2^iii	0.89	2.56	3.184 (2)	128
N2—H2B···O4	0.89	2.05	2.925 (2)	166
N2—H2C···O1^iv	0.89	2.01	2.843 (2)	154
N2—H2C···O3^iv	0.89	2.49	3.026 (2)	120
N1—H1B···O3^iv	0.92 (3)	2.05 (3)	2.938 (3)	162 (2)

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