Poly­[[copper(II)-di-μ-5-amino­isophthalato(1–)-κ⁴N:O] monohydrate]

The title compound, {[Cu(C₈H₆NO₄)₂]·H₂O}_n, was prepared by the hydro­thermal assembly of 5-amino­isophthalic acid with copper nitrate. Single-crystal X-ray analysis shows that it has a two-dimensional layer coordination framework, in which the unique Cu atom lies on an inversion centre and adopts a square-planar geometry, coordinated to two N and two O atoms from symmetry-related ligands. The water molecule lies on a twofold axis and there are hydrogen-bonding interactions between the layers.

S1. Comment

Through coordination bonds and non-covalent interactions, such as hydrogen bonds and/or π–π stacking interactions, the self-assembly method has proved to be a powerful tool for the construction of supramolecular structures (Batten & Robson, 1998; Moulton & Zaworotko, 2001; Kepert & Rosseinsky, 1999; Biradha & Fujita, 2000). Multi-dimensional frameworks containing large channels of various shapes and sizes (Yaghi et al., 1996, 1997; Subramanian & Zaworotko, 1995; Harrison & Hannooman, 1997) and intercalating arrays (Vaccari, 1999) have recently been reported. Coordination of transition metals to multidentate ligands is one of the main design principles.

As a rigid multidentate ligand, 5-aminoisophthalic acid (AIP) has received considerable attention, owing to its variety of possible bridging modes (Wu Lu Yang et al., 2002; Wu Lu Zhuang et al., 2002; Xu et al., 2002; Tao et al., 2003; Yang et al., 2003; Yang & Zheng, 2003). It can engage in three types of intermolecular interactions, namely M—L bonding, hydrogen bonding and π–π stacking interactions. In order to understand its interesting chemistry, we recently studied the assembly reaction of AIP with various metal ions in solution or under hydrothermal conditions. Here, we report the synthesis and crystal structure of the title compound, (I), which has a two-dimensional layer network. \sch

Compound (I) crystallizes in the monoclinic space group C2/c. As illustrated in Fig. 1, the Cu^II atom, situated in the centre of a square plane, is coordinated by two O atoms and two N atoms from four different AIP ligands. The ligand uses its amino group and one of its two carboxyl groups to coordinate two Cu^II moieties [Cu—N 2.026 (4) Å and Cu—O 1.969 (3) Å]; the other carboxyl group is left free. This coordination pattern of AIP is similar to that in the complex [Co(C₈NH₆O₄)₂(H₂O)]_n (Wu Lu Zhuang et al. 2002), where the central Co^II ion adopts an octahedral geometry.

The coordination around the Cu^II ion in (I) leads to a two-dimensional layer network and Fig. 2 shows the packing of the complex along the a axis. There is intramolecular hydrogen bonding within these two-dimensional layers [O2—O4(x, 1 − y, z − 1/2) 2.554 (6) Å].

Fig. 3 shows the unit-cell packing diagram viewed from the b direction. Interestingly, the two-dimensional networks are packed into a three-dimensional framework via interlayer hydrogen-bonding interactions [N1—O1 2.944 (6) Å]. There are also isolated water molecules between the layers, which form hydrogen bonds with the two-dimensional layers, with N1···OW 2.923 (6) and OW1···O4 3.294 (6) Å. The N1—H1B···OW angle is 127.0° and the OW1—HW1A···O4 angle is 157 (7)°.

S2. Experimental

A mixture of Cu(NO₃)₂·3H₂O (2 mmol) and 5-aminoisophthalic acid (1 mmol) in water (15 ml) was sealed in a 25 ml Teflon-lined stainless steel reactor and heated to 413 K for 6 d under autogenous pressure. After slow cooling of the reaction solution to room temperature, black prism crystals of (I) suitable for X-ray analysis were obtained. Elemental analyses were performed on an EL III CHNOS Elemental Analyzer. Analysis, found: C 43.87, H 2.48, N 6.24%; calculated: C 43.50, H 3.19, N 6.34%.

S3. Refinement

Hydroxy and water H atoms were located from difference maps and refined freely. H atoms bonded to C or N atoms were placed in calculated positions and refined with isotropic displacement parameters using a riding model, with C—H = 0.93 Å and N—H = 0.86 Å, and with U_iso(H) = 1.2U_eq(C,N). Please check amended text.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SMART and SAINT (Siemens, 1994); data reduction: XPREP in SHELXTL (Siemens, 1994); program(s) used to solve structure: SHELXTL; program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. A view of (I), with the atomic labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms and isolated water molecules have been omitted for clarity.
	Fig. 2. The extended two-dimensional lamellar structure of (I), viewed along the a direction. Displacement ellipsoids are drawn at the 50% probability level and H atoms have been omitted for clarity.
	Fig. 3. Unit-cell packing diagram of (I), viewed along the b direction, showing the interlayer hydrogen bonding connecting the two-dimensional layers into a three-dimensional framework. Displacement ellipsoids are drawn at the 50% probability level and hydrogen bonds are depicted by dashed lines.

Poly[[copper(II)-di-µ-5-aminoisophthalato(1-)-κ⁴N:O] monohydrate]

Crystal data

[Cu(C8H6NO4)2]·H2O	F(000) = 900
Mr = 441.83	Dx = 1.868 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1257 reflections
a = 13.2692 (11) Å	θ = 2.7–25.0°
b = 9.1898 (8) Å	µ = 1.45 mm^−1
c = 13.5155 (11) Å	T = 293 K
β = 107.542 (2)°	Prism, black
V = 1571.5 (2) Å^3	0.36 × 0.20 × 0.20 mm
Z = 4

Data collection

Siemens SMART CCD area-detector diffractometer	1359 independent reflections
Radiation source: fine-focus sealed tube	1117 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
ϕ and ω scans	θmax = 25.0°, θmin = 2.7°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −15→12
Tmin = 0.723, Tmax = 0.748	k = −10→8
2289 measured reflections	l = −16→13

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)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.136	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0601P)^2 + 12.8787P] where P = (Fo^2 + 2Fc^2)/3
1359 reflections	(Δ/σ)max = 0.002
137 parameters	Δρmax = 0.68 e Å^−3
0 restraints	Δρmin = −0.83 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	0.2500	0.2500	0.5000	0.0217 (3)
O4	0.3735 (3)	0.3673 (4)	0.3580 (3)	0.0381 (10)
O3	0.2972 (3)	0.1614 (4)	0.3888 (3)	0.0323 (9)
O2	0.3733 (3)	0.4606 (4)	0.0064 (3)	0.0332 (9)
H2B	0.374 (4)	0.510 (6)	−0.044 (4)	0.028 (15)*
O1	0.4182 (3)	0.2832 (4)	−0.0857 (3)	0.0344 (10)
OW1	0.0000	0.0963 (6)	0.2500	0.0391 (14)
HW1A	−0.017 (7)	0.036 (9)	0.296 (6)	0.09 (3)*
N1	0.3816 (3)	−0.1774 (4)	0.1109 (3)	0.0239 (9)
H1A	0.3915	−0.2063	0.0541	0.029*
H1B	0.3741	−0.2400	0.1555	0.029*
C1	0.3775 (4)	−0.0240 (5)	0.1316 (3)	0.0190 (10)
C2	0.3900 (4)	0.0737 (5)	0.0575 (4)	0.0212 (10)
H2A	0.4039	0.0396	−0.0018	0.025*
C3	0.3817 (4)	0.2221 (5)	0.0724 (4)	0.0203 (11)
C4	0.3648 (4)	0.2742 (5)	0.1628 (4)	0.0203 (10)
H4A	0.3600	0.3738	0.1728	0.024*
C5	0.3550 (4)	0.1769 (5)	0.2379 (4)	0.0207 (10)
C6	0.3591 (4)	0.0266 (5)	0.2222 (3)	0.0197 (10)
H6A	0.3497	−0.0386	0.2713	0.024*
C7	0.3931 (4)	0.3237 (6)	−0.0107 (4)	0.0234 (11)
C8	0.3412 (4)	0.2400 (5)	0.3357 (4)	0.0219 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0340 (5)	0.0175 (5)	0.0184 (4)	0.0047 (4)	0.0148 (3)	0.0037 (4)
O1	0.047 (2)	0.038 (2)	0.0279 (19)	0.0065 (18)	0.0259 (18)	0.0053 (16)
O2	0.054 (3)	0.022 (2)	0.031 (2)	0.0060 (17)	0.0234 (19)	0.0102 (17)
O3	0.053 (2)	0.029 (2)	0.0208 (17)	0.0079 (18)	0.0212 (17)	0.0043 (15)
O4	0.058 (3)	0.029 (2)	0.031 (2)	−0.0002 (19)	0.0198 (19)	−0.0115 (17)
OW1	0.057 (4)	0.031 (3)	0.032 (3)	0.000	0.017 (3)	0.000
N1	0.036 (2)	0.016 (2)	0.023 (2)	−0.0013 (18)	0.0145 (19)	−0.0018 (17)
C1	0.019 (2)	0.020 (3)	0.016 (2)	−0.0032 (19)	0.0038 (18)	−0.0013 (19)
C2	0.022 (2)	0.025 (3)	0.020 (2)	0.001 (2)	0.0109 (19)	−0.002 (2)
C3	0.022 (2)	0.023 (3)	0.017 (2)	−0.0008 (19)	0.0072 (19)	0.0035 (19)
C4	0.024 (2)	0.017 (3)	0.021 (2)	−0.0025 (19)	0.0070 (19)	−0.0007 (18)
C5	0.019 (2)	0.021 (3)	0.021 (2)	0.001 (2)	0.006 (2)	0.001 (2)
C6	0.024 (2)	0.018 (2)	0.016 (2)	−0.0048 (19)	0.0048 (19)	0.0001 (18)
C7	0.023 (2)	0.022 (3)	0.026 (3)	−0.002 (2)	0.009 (2)	0.005 (2)
C8	0.024 (2)	0.023 (3)	0.019 (2)	0.009 (2)	0.0072 (19)	0.001 (2)

Geometric parameters (Å, º)

Cu1—O3	1.970 (3)	C4—H4A	0.9300
Cu1—O3^i	1.970 (3)	C1—C2	1.391 (7)
Cu1—N1^ii	2.041 (4)	C1—N1	1.442 (6)
Cu1—N1^iii	2.041 (4)	C3—C2	1.388 (7)
O4—C8	1.251 (6)	C3—C7	1.503 (6)
O3—C8	1.276 (6)	N1—Cu1^iv	2.041 (4)
C8—C5	1.505 (6)	N1—H1A	0.8600
OW1—HW1A	0.91 (8)	N1—H1B	0.8600
C5—C4	1.388 (7)	C2—H2A	0.9300
C5—C6	1.401 (7)	C7—O1	1.217 (6)
C6—C1	1.398 (6)	C7—O2	1.320 (7)
C6—H6A	0.9300	O2—H2B	0.82 (6)
C4—C3	1.391 (7)
O3—Cu1—O3^i	180	C2—C1—C6	120.4 (4)
O3—Cu1—N1^ii	91.53 (16)	C2—C1—N1	118.2 (4)
O3^i—Cu1—N1^ii	88.47 (16)	C6—C1—N1	121.4 (4)
O3—Cu1—N1^iii	88.47 (16)	C2—C3—C4	120.4 (4)
O3^i—Cu1—N1^iii	91.53 (16)	C2—C3—C7	118.1 (4)
N1^ii—Cu1—N1^iii	180	C4—C3—C7	121.4 (4)
C8—O3—Cu1	120.0 (3)	C1—N1—Cu1^iv	112.9 (3)
O4—C8—O3	125.1 (4)	C1—N1—H1A	120.0
O4—C8—C5	116.6 (4)	Cu1^iv—N1—H1A	64.5
O3—C8—C5	118.3 (4)	C1—N1—H1B	120.0
C4—C5—C6	120.5 (4)	Cu1^iv—N1—H1B	92.4
C4—C5—C8	117.2 (4)	H1A—N1—H1B	120.0
C6—C5—C8	122.3 (4)	C3—C2—C1	119.8 (4)
C1—C6—C5	119.0 (4)	C3—C2—H2A	120.1
C1—C6—H6A	120.5	C1—C2—H2A	120.1
C5—C6—H6A	120.5	O1—C7—O2	123.8 (5)
C5—C4—C3	119.7 (4)	O1—C7—C3	123.2 (5)
C5—C4—H4A	120.1	O2—C7—C3	113.1 (4)
C3—C4—H4A	120.1	C7—O2—H2B	110 (4)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O3^v	0.86	2.24	2.874 (5)	130
N1—H1A···O1^vi	0.86	2.53	2.944 (6)	110
N1—H1B···OW1^vii	0.86	2.32	2.923 (6)	127
N1—H1B···O3^iv	0.86	2.35	2.798 (6)	113
OW1—HW1A···O4^viii	0.91 (8)	2.44 (8)	3.294 (6)	157 (7)
O2—H2B···O4^ix	0.82 (6)	1.74 (6)	2.554 (5)	174 (6)

Symmetry codes: (iv) −x+1/2, y−1/2, −z+1/2; (v) x, −y, z−1/2; (vi) −x+1, −y, −z; (vii) x+1/2, y−1/2, z; (viii) x−1/2, y−1/2, z; (ix) x, −y+1, z−1/2.