Diaqua­bis(malato-κ²O¹,O²)copper(II)

In the title compound, [Cu(C₆H₅O₅)₂(H₂O)₂], the Cu^II atom, located on an inversion center, is coordinated by four O atoms from two malate ligands forming the equatorial plane and two water mol­ecules in axial positions, resulting in an elongated octa­hedral geometry. The structure of this compound has been reported previously [Polyanskaya et al. (1982). Zh. Strukt. Khim. 23, 117–118], but the quality of the refinement has been improved. The packing is governed by inter­molecular O—H...O hydrogen bonds, forming an intricate three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.022
• wR factor = 0.060
• Data-to-parameter ratio = 12.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.99
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Cu1    -   O1W     ..       7.60 su

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

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

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXTL (Bruker, 1998).

Diaquabis(malato-κ²O¹,O²)copper(II)

Crystal data

[Cu(C6H5O5)2(H2O)2]	F(000) = 374
Mr = 365.73	Dx = 1.915 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3281 reflections
a = 8.4762 (5) Å	θ = 2.5–26.0°
b = 7.4377 (4) Å	µ = 1.79 mm^−1
c = 10.3117 (6) Å	T = 293 K
β = 102.680 (1)°	Block, blue
V = 634.23 (6) Å^3	0.25 × 0.18 × 0.15 mm
Z = 2

Data collection

Bruker SMART CCD area-detector diffractometer	1243 independent reflections
Radiation source: fine-focus sealed tube	1075 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.016
φ and ω scans	θmax = 26.0°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→5
Tmin = 0.663, Tmax = 0.775	k = −8→9
3281 measured reflections	l = −12→12

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)] = 0.022	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.060	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0352P)^2 + 0.179P] where P = (Fo^2 + 2Fc^2)/3
1243 reflections	(Δ/σ)max < 0.001
98 parameters	Δρmax = 0.27 e Å^−3
4 restraints	Δρmin = −0.21 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.

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
C1	0.6316 (2)	0.8161 (2)	0.44474 (17)	0.0257 (4)
C2	0.7027 (2)	0.8000 (2)	0.59459 (17)	0.0262 (4)
H2	0.6549	0.8916	0.6425	0.031*
C3	0.8843 (2)	0.8233 (3)	0.62315 (18)	0.0318 (4)
H3A	0.9315	0.7210	0.5872	0.038*
H3B	0.9096	0.9300	0.5776	0.038*
C4	0.9608 (2)	0.8400 (2)	0.76907 (18)	0.0286 (4)
Cu1	0.5000	0.5000	0.5000	0.02659 (12)
O1	0.66150 (16)	0.62419 (17)	0.63397 (11)	0.0282 (3)
H1	0.6599	0.6115	0.7140	0.042*
O2	0.67008 (19)	0.94835 (18)	0.38459 (13)	0.0369 (3)
O3	0.53759 (15)	0.69405 (17)	0.38880 (11)	0.0297 (3)
O4	0.89459 (17)	0.9002 (2)	0.85141 (13)	0.0402 (4)
O5	1.11194 (17)	0.7845 (2)	0.79593 (14)	0.0456 (4)
H5	1.1505	0.7959	0.8757	0.068*
O1W	0.27165 (16)	0.68362 (18)	0.55055 (13)	0.0346 (3)
H1W	0.2896	0.7859	0.5833	0.052*
H2W	0.2236	0.6168	0.5939	0.052*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0291 (9)	0.0281 (9)	0.0201 (8)	0.0018 (8)	0.0057 (7)	0.0012 (7)
C2	0.0321 (10)	0.0262 (9)	0.0196 (8)	−0.0025 (8)	0.0044 (7)	0.0002 (7)
C3	0.0328 (10)	0.0397 (11)	0.0230 (9)	−0.0049 (9)	0.0064 (8)	−0.0013 (8)
C4	0.0323 (10)	0.0268 (10)	0.0261 (9)	−0.0065 (8)	0.0051 (8)	0.0002 (7)
Cu1	0.03044 (19)	0.03069 (19)	0.01640 (17)	−0.00926 (13)	0.00025 (12)	0.00258 (12)
O1	0.0381 (7)	0.0298 (6)	0.0148 (6)	−0.0090 (6)	0.0020 (5)	0.0021 (5)
O2	0.0588 (9)	0.0287 (7)	0.0214 (7)	−0.0084 (7)	0.0046 (6)	0.0036 (5)
O3	0.0343 (7)	0.0350 (7)	0.0170 (6)	−0.0083 (6)	−0.0003 (5)	0.0031 (5)
O4	0.0390 (8)	0.0545 (10)	0.0274 (7)	0.0056 (7)	0.0081 (6)	−0.0012 (6)
O5	0.0354 (8)	0.0630 (10)	0.0348 (8)	0.0048 (7)	−0.0002 (6)	−0.0141 (8)
O1W	0.0368 (8)	0.0337 (7)	0.0349 (7)	−0.0043 (6)	0.0109 (6)	−0.0041 (6)

Geometric parameters (Å, º)

C1—O2	1.244 (2)	C4—O5	1.316 (2)
C1—O3	1.261 (2)	Cu1—O3^i	1.9130 (12)
C1—C2	1.535 (2)	Cu1—O3	1.9130 (12)
C2—O1	1.435 (2)	Cu1—O1	1.9507 (12)
C2—C3	1.512 (3)	Cu1—O1^i	1.9507 (12)
C2—H2	0.9800	Cu1—O1W	2.5152 (13)
C3—C4	1.507 (3)	O1—H1	0.8334
C3—H3A	0.9700	O5—H5	0.8200
C3—H3B	0.9700	O1W—H1W	0.8330
C4—O4	1.203 (2)	O1W—H2W	0.8325
O2—C1—O3	123.35 (16)	O4—C4—O5	123.51 (18)
O2—C1—C2	118.40 (16)	O4—C4—C3	124.77 (18)
O3—C1—C2	118.25 (15)	O5—C4—C3	111.70 (16)
O1—C2—C3	110.49 (15)	O3^i—Cu1—O3	180.0
O1—C2—C1	106.85 (14)	O3^i—Cu1—O1	96.66 (5)
C3—C2—C1	110.20 (14)	O3—Cu1—O1	83.34 (5)
O1—C2—H2	109.8	O3^i—Cu1—O1^i	83.34 (5)
C3—C2—H2	109.8	O3—Cu1—O1^i	96.66 (5)
C1—C2—H2	109.8	O1—Cu1—O1^i	180.0
C4—C3—C2	113.61 (15)	C2—O1—Cu1	114.06 (10)
C4—C3—H3A	108.8	C2—O1—H1	116.2
C2—C3—H3A	108.8	Cu1—O1—H1	119.1
C4—C3—H3B	108.8	C1—O3—Cu1	116.14 (11)
C2—C3—H3B	108.8	C4—O5—H5	109.5
H3A—C3—H3B	107.7	H1W—O1W—H2W	113.3

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2^ii	0.83	1.80	2.6254 (17)	171
O5—H5···O1W^iii	0.82	1.88	2.6874 (19)	171
O1W—H1W···O2^iv	0.83	2.02	2.8353 (19)	166
O1W—H2W···O4^v	0.83	2.04	2.842 (2)	161

Symmetry codes: (ii) x, −y+3/2, z+1/2; (iii) x+1, −y+3/2, z+1/2; (iv) −x+1, −y+2, −z+1; (v) −x+1, y−1/2, −z+3/2.