Aqua­(di-2-pyridylamine)oxalato­copper(II) monohydrate

In the structure of the title complex, [Cu(C₂O₄)(C₁₀H₉N₃)(H₂O)]·H₂O, the Cu^II atom displays a square-pyramidal geometry, being coordinated by two N atoms from the di-2-pyridylamine ligand, two O atoms from the oxalate group and one O atom of a water mol­ecule. The complex mol­ecules are linked to form a three-dimensional supra­molecular array by hydrogen-bonding inter­actions between coordinated/uncoordinated water mol­ecules and the uncoordinated oxalate O atoms of neighboring mol­ecules.

S1. Comment

There has been considerable interest in the design and syntheses of transition metal complexes with the oxalate ligand in coordination chemistry, owing to the fact that this type of complex has potential application in molecular-based magnets. Furthermore, such complexes could have potential application as precursors for the synthesis of, for instance, copper-containing superconducting ceramics (Bouayad et al., 1995). Self-assembly of metal compounds by hydrogen bonds into one-, two-, and three-dimensional supramolecular architectures connects with biological chemistry, material chemistry (such as organic film and magnetic material) and supramolecular chemistry (Chen et al., 2001). Hydrogen bonds play vital roles in highly efficient and specific biological reactions and are essential for molecular recognition and self-organization of molecules in supramolecular chemistry. We report here the crystal structure of one such complex, aqua(di-2-pyridylamine)oxalatocopper(II) hydrate, (I). The ligand dpyam has been selected primarily because of the fact that it also has a N— H, H -bond donor function that might consider into one-, two-, or three-dimensional supramolecular architectures. The molecular structure of (I), shown in Fig. 1, consists of discrete monomers. The Cu atom in (I) involves a five-coordinate CuN₂O₂O' environment, with a distorted square-pyramidal structure (τ = 0.10). The structure index is defined as τ = (β - α)/60, where b and a are the largest coordination angles (Addison et al., 1984). The dpyam and oxalate anion are both symmetrically coordinated to the Cu atom in the plane of the square pyramid, with a water molecule occupying the fifth coordinated position (Table 1). The dihedral angle between the planes of the pyridine rings is 16.8 (1)° and that between the CuO₂ and CuN₂ planes is 18.3 (1)°. The Cu atom lies 0.2197 Å above the basal plane, towards the coordinated water molecule. Other related examples of the oxalate compounds are [Cu(bipy)(C₂O₄)(H₂O)]·2H₂O, (II), [Cu(nphen)(C₂O₄)(H₂O)]·2H₂O, (III) (nphen is 5-nitro-1,10-phenanthroline), and [Cu(phen)(C₂O₄)(H₂O)]·H₂O, (IV) (Chen et al., 2001). The Cu^II atoms in these compounds also exhibit distorted square-pyramidal geometry, with τ values of 0.21 for (II), 0.01 for (III) and 0.02 for (IV). The Cu—O(oxalate) bond distances are 1.958 (2) and 1.938 (2) Å for (II), 1.936 (6) and 1.935 (7) Å for (III), and 1.937 (1) and 1.944 (2) Å for (IV); the difference between these and the corresponding distances in (I) (Table 1) is probably due to the effect of the chelating coordination in (I). The Cu—O(water) distance is comparable to those of 2.175 (4) Å in (II), 2.175 (4) Å in (III) and 2.175 (4) Å in (IV) (Chen et al., 2001). The Cu—N bond lengths are somewhat longer than those in [Cu(dpyam)(H₂O)(CO₃)]·2H₂O [1.970 (3) and 1.972 (3) Å; dpyam is di-2-pyridylamine; Akhter et al., 1991].

In (I), hydrogen bonds are observed between atom O5 and the uncoordinated water molecule, and between O5 and O4ⁱⁱ of the oxalate group in the adjacent [Cu(dpyam)(C₂O₄)(H₂O)] unit (Table 2). These hydrogen bonds form a one-dimensional chain structure. Additional hydrogen bonds between the uncoordinated water molecule and atoms O3 and O4 of the oxalate group in an adjacent chain link the molecules into a three-dimensional array (Fig. 2 and Table 2).

S2. Experimental

The title compound was obtained as blue blocks by slow evaporation of a concentrated aqueous ethanol solution (1:2) containing stoichiometric amounts of K₂[Cu(C₂O₄)₂]·2H₂O and di-2-pyridylamine. Crystals of (I) suitable for single-crystal X-ray diffraction were selected directly from the sample as prepared.

S3. Refinement

All H-atom parameters were refined freely. The resulting C—H distances are in the range 0.926 (19)–1.01 (2) Å.

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2000b); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2001).

Figures

	Fig. 1. The molecular structure of (I), showing displacement ellipsoids at the 50% probability level.
	Fig. 2. The molecular packing of (I), showing the three-dimensional structure along the c axis.

Aqua(di-2-pyridylamine)oxalatocopper(II) monohydrate

Crystal data

[Cu(C2O4)(C10H9N3)(H2O)]·H2O	F(000) = 732
Mr = 358.79	Dx = 1.729 Mg m^−3 Dm = 1.732 Mg m^−3 Dm measured by not measured
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3924 reflections
a = 9.3814 (1) Å	θ = 2.3–30.5°
b = 9.7427 (1) Å	µ = 1.62 mm^−1
c = 15.510 (1) Å	T = 293 K
β = 103.487 (1)°	Block, blue
V = 1378.49 (2) Å^3	0.63 × 0.48 × 0.40 mm
Z = 4

Data collection

Siemens SMART CCD area-detector diffractometer	3924 independent reflections
Radiation source: fine-focus sealed tube	3456 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.014
ω scans	θmax = 30.5°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000a)	h = −12→12
Tmin = 0.817, Tmax = 1.000	k = −13→13
9853 measured reflections	l = −17→21

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)] = 0.024	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.069	All H-atom parameters refined
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0444P)^2 + 0.1326P] where P = (Fo^2 + 2Fc^2)/3
3924 reflections	(Δ/σ)max < 0.001
251 parameters	Δρmax = 0.38 e Å^−3
0 restraints	Δρmin = −0.46 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
Cu1	0.194259 (17)	0.032745 (14)	0.129823 (10)	0.02740 (6)
N1	0.20965 (12)	0.20204 (11)	0.06121 (7)	0.0278 (2)
N2	0.29485 (11)	−0.07771 (11)	0.05411 (7)	0.0268 (2)
N3	0.26091 (13)	0.08545 (11)	−0.06236 (7)	0.0302 (2)
O1	0.06190 (12)	0.12540 (10)	0.19213 (8)	0.0422 (2)
O2	0.12187 (11)	−0.13385 (10)	0.17672 (7)	0.0347 (2)
O3	−0.10734 (12)	0.07746 (12)	0.26705 (7)	0.0400 (2)
O4	−0.03132 (12)	−0.19683 (10)	0.25958 (7)	0.0375 (2)
O5	0.39935 (13)	0.04477 (13)	0.24357 (8)	0.0399 (2)
O6	0.65095 (13)	0.87295 (13)	0.23696 (9)	0.0446 (3)
C1	0.18551 (16)	0.32420 (13)	0.09846 (9)	0.0332 (3)
C10	0.34990 (15)	−0.20145 (13)	0.08694 (8)	0.0305 (2)
C11	−0.01152 (14)	0.04384 (13)	0.22884 (9)	0.0293 (2)
C12	0.02792 (13)	−0.10953 (13)	0.22211 (8)	0.0273 (2)
C2	0.17410 (17)	0.44664 (14)	0.05440 (10)	0.0376 (3)
C3	0.18625 (18)	0.44630 (15)	−0.03384 (10)	0.0381 (3)
C4	0.21395 (15)	0.32565 (14)	−0.07210 (9)	0.0332 (3)
C5	0.22767 (13)	0.20361 (12)	−0.02217 (8)	0.0266 (2)
C6	0.30806 (13)	−0.04201 (12)	−0.02706 (8)	0.0255 (2)
C7	0.36902 (14)	−0.13151 (14)	−0.07995 (8)	0.0312 (2)
C8	0.42201 (15)	−0.25649 (14)	−0.04599 (9)	0.0330 (3)
C9	0.41475 (15)	−0.29159 (14)	0.04001 (9)	0.0318 (2)
H1	0.174 (2)	0.317 (2)	0.1612 (13)	0.049 (5)*
H10	0.3428 (17)	−0.2235 (17)	0.1456 (11)	0.031 (4)*
H11	0.634 (3)	0.798 (3)	0.2523 (17)	0.077 (8)*
H12	0.729 (3)	0.893 (3)	0.2635 (17)	0.073 (8)*
H13	0.430 (2)	0.120 (3)	0.2494 (14)	0.057 (6)*
H14	0.469 (3)	−0.005 (3)	0.2431 (18)	0.074 (8)*
H2	0.158 (2)	0.5277 (18)	0.0832 (13)	0.039 (5)*
H3	0.169 (2)	0.526 (2)	−0.0688 (15)	0.054 (6)*
H4	0.221 (2)	0.3199 (19)	−0.1308 (13)	0.044 (5)*
H5	0.276 (2)	0.098 (2)	−0.1111 (13)	0.039 (4)*
H7	0.3686 (18)	−0.1037 (18)	−0.1384 (11)	0.032 (4)*
H8	0.468 (2)	−0.314 (2)	−0.0800 (13)	0.049 (5)*
H9	0.4549 (19)	−0.3741 (19)	0.0637 (11)	0.037 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O6	0.0365 (6)	0.0421 (6)	0.0550 (7)	−0.0024 (5)	0.0101 (5)	0.0084 (5)
Cu1	0.03459 (9)	0.02420 (9)	0.02867 (9)	−0.00029 (5)	0.01801 (6)	0.00075 (5)
O3	0.0403 (5)	0.0422 (5)	0.0450 (6)	−0.0031 (4)	0.0255 (4)	−0.0099 (4)
O4	0.0435 (5)	0.0355 (5)	0.0395 (5)	−0.0033 (4)	0.0217 (4)	0.0070 (4)
O5	0.0417 (6)	0.0371 (6)	0.0403 (6)	−0.0046 (5)	0.0083 (4)	−0.0027 (4)
N2	0.0314 (5)	0.0273 (5)	0.0250 (5)	0.0007 (4)	0.0133 (4)	0.0002 (4)
O2	0.0412 (5)	0.0267 (4)	0.0440 (5)	0.0009 (4)	0.0258 (4)	0.0034 (4)
N3	0.0402 (6)	0.0300 (5)	0.0226 (5)	0.0008 (4)	0.0119 (4)	0.0022 (4)
C6	0.0261 (5)	0.0281 (5)	0.0231 (5)	−0.0029 (4)	0.0076 (4)	−0.0010 (4)
O1	0.0537 (6)	0.0275 (5)	0.0576 (6)	0.0002 (4)	0.0377 (5)	−0.0013 (4)
C8	0.0344 (6)	0.0352 (6)	0.0320 (6)	0.0016 (5)	0.0131 (5)	−0.0071 (5)
N1	0.0333 (5)	0.0257 (5)	0.0267 (5)	−0.0017 (4)	0.0116 (4)	0.0004 (4)
C11	0.0308 (6)	0.0312 (6)	0.0282 (5)	−0.0020 (5)	0.0116 (5)	−0.0046 (4)
C5	0.0269 (5)	0.0279 (5)	0.0254 (5)	−0.0027 (4)	0.0070 (4)	0.0012 (4)
C12	0.0280 (5)	0.0310 (6)	0.0244 (5)	−0.0016 (4)	0.0091 (4)	0.0005 (4)
C9	0.0340 (6)	0.0296 (6)	0.0338 (6)	0.0027 (5)	0.0116 (5)	−0.0002 (5)
C4	0.0377 (6)	0.0329 (6)	0.0289 (6)	−0.0022 (5)	0.0079 (5)	0.0060 (5)
C7	0.0351 (6)	0.0363 (6)	0.0247 (5)	−0.0007 (5)	0.0122 (5)	−0.0027 (5)
C3	0.0444 (7)	0.0287 (6)	0.0407 (7)	−0.0021 (5)	0.0089 (6)	0.0075 (5)
C1	0.0412 (7)	0.0289 (6)	0.0327 (6)	−0.0027 (5)	0.0150 (5)	−0.0026 (5)
C10	0.0362 (6)	0.0301 (6)	0.0277 (5)	0.0014 (5)	0.0127 (5)	0.0024 (4)
C2	0.0454 (7)	0.0268 (6)	0.0431 (7)	−0.0009 (5)	0.0155 (6)	−0.0012 (5)

Geometric parameters (Å, º)

O6—H11	0.80 (3)	C8—C7	1.373 (2)
O6—H12	0.78 (3)	C8—C9	1.3939 (19)
Cu1—O1	1.9623 (10)	C8—H8	0.94 (2)
Cu1—O2	1.9634 (9)	N1—C5	1.3427 (15)
Cu1—N2	1.9861 (10)	N1—C1	1.3647 (16)
Cu1—N1	1.9863 (10)	C11—C12	1.5487 (18)
Cu1—O5	2.2901 (12)	C5—C4	1.4083 (17)
O3—C11	1.2309 (16)	C9—C10	1.3703 (18)
O4—C12	1.2331 (15)	C9—H9	0.926 (19)
O5—H14	0.82 (3)	C4—C3	1.369 (2)
O5—H13	0.79 (3)	C4—H4	0.931 (19)
N2—C6	1.3393 (15)	C7—H7	0.945 (17)
N2—C10	1.3626 (16)	C3—C2	1.400 (2)
O2—C12	1.2721 (15)	C3—H3	0.94 (2)
N3—C5	1.3791 (16)	C1—C2	1.3665 (19)
N3—C6	1.3873 (16)	C1—H1	1.01 (2)
N3—H5	0.812 (19)	C10—H10	0.952 (16)
C6—C7	1.4068 (17)	C2—H2	0.936 (18)
O1—C11	1.2700 (16)
H11—O6—H12	108 (3)	O3—C11—O1	125.63 (13)
O1—Cu1—O2	83.37 (4)	O3—C11—C12	120.13 (12)
O1—Cu1—N2	169.41 (5)	O1—C11—C12	114.24 (11)
O2—Cu1—N2	91.39 (4)	N1—C5—N3	121.22 (11)
O1—Cu1—N1	90.87 (4)	N1—C5—C4	121.55 (12)
O2—Cu1—N1	163.65 (4)	N3—C5—C4	117.22 (11)
N2—Cu1—N1	91.67 (4)	O4—C12—O2	125.38 (12)
O1—Cu1—O5	96.40 (5)	O4—C12—C11	119.52 (11)
O2—Cu1—O5	93.32 (4)	O2—C12—C11	115.10 (10)
N2—Cu1—O5	93.07 (4)	C10—C9—C8	118.54 (12)
N1—Cu1—O5	102.55 (4)	C10—C9—H9	122.4 (11)
Cu1—O5—H14	120 (2)	C8—C9—H9	119.1 (11)
Cu1—O5—H13	110.6 (16)	C3—C4—C5	119.27 (12)
H14—O5—H13	107 (2)	C3—C4—H4	122.8 (12)
C6—N2—C10	118.09 (10)	C5—C4—H4	117.9 (12)
C6—N2—Cu1	125.16 (9)	C8—C7—C6	119.08 (12)
C10—N2—Cu1	116.70 (8)	C8—C7—H7	122.9 (11)
C12—O2—Cu1	113.28 (8)	C6—C7—H7	118.0 (11)
C5—N3—C6	130.82 (11)	C4—C3—C2	119.54 (13)
C5—N3—H5	113.6 (14)	C4—C3—H3	119.1 (14)
C6—N3—H5	113.4 (14)	C2—C3—H3	121.2 (14)
N2—C6—N3	120.83 (11)	N1—C1—C2	123.44 (13)
N2—C6—C7	121.76 (11)	N1—C1—H1	114.3 (11)
N3—C6—C7	117.40 (11)	C2—C1—H1	122.2 (11)
C11—O1—Cu1	113.86 (8)	N2—C10—C9	123.03 (12)
C7—C8—C9	119.38 (12)	N2—C10—H10	116.9 (10)
C7—C8—H8	119.1 (12)	C9—C10—H10	120.1 (10)
C9—C8—H8	121.4 (12)	C1—C2—C3	118.17 (13)
C5—N1—C1	117.92 (11)	C1—C2—H2	120.0 (12)
C5—N1—Cu1	124.51 (9)	C3—C2—H2	121.8 (12)
C1—N1—Cu1	117.22 (8)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H5···O6^i	0.81 (2)	2.23 (2)	3.037 (1)	172 (2)
O5—H13···O4^ii	0.78 (3)	2.04 (3)	2.811 (1)	166 (2)
O5—H14···O6^iii	0.82 (2)	2.10 (3)	2.915 (1)	177 (2)
O6—H12···O3^iv	0.78 (2)	2.36 (3)	2.973 (1)	137 (2)
O6—H12···O4^iv	0.78 (2)	2.43 (3)	2.997 (1)	131 (2)

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