Poly­[[bis­(pyridine-κN)copper(II)]-μ₃-5-hydroxy­isophthalato-κ³O:O′:O′′]

In the title compound, [Cu(C₈H₄O₅)(C₅H₅N)₂]_n or [Cu(OH-BDC)(py)₂]_n (where OH-H₂BDC is 5-hydroxy­isophthalic acid and py is pyridine), the Cu atoms are coordinated by two N atoms from the pyridine ligands and by three O atoms from hydroxy­isophthalate ligands in a highly distorted triangular bipyramidal environment, with Cu—O distances in the range 1.941 (4)–2.225 (5) Å and Cu—N distances of 2.014 (6) and 2.046 (6) Å. The [Cu(OH-BDC)]_n two-dimensional network is built up from interlocking 22-, 15- and eight-membered rings via sharing of Cu atoms and O—H...O hydrogen bonds. Consolidation of the packing structure is achieved by edge- or point-to-face C—H...π interactions and offset or slipped π–π stacking interactions.

S1. Comment

The design and syntheses of supramolecular coordination polymer networks, especially those constructed via hydrogen bonding and π–π stacking interactions, has been a field of rapid growth because of the special physical properties of these compounds and their potential application in functional materials (Atwood et al., 1996; Barton et al., 1999). Coordination polymers containing symmetric multidentate benzenecarboxylate as bridging ligands have attracted increasing attention because of their interesting network structure and potential application in many fields (Li et al., 1999; Yaghi et al., 1995; Chui et al., 1999). Large numbers of coordination polymers have been prepared from metal ions and aromatic carboxylate ligands such as benzenehexacarboxylate (Wu et al., 1996), 1,3-benzenedicarboxylate (Reineke et al., 1999) and 1,3,5-benzenetricarboxylate (Yaghi et al., 1997; Daiguebonne et al., 1996; Gutschke et al., 1996). 5-Hydroxyisophthalic acid, OH—H₂BDC, like benzene-1,3,5-tricarboxylic acid, has two carboxylic acid groups arranged meta to one another, but with a phenol hydroxy group meta to both (Plate et al., 2001). This phenol hydroxy group was intended as a mimic for the third carboxy group, which remains protonated in the reported layered and helical chain polymers (Foreman et al., 1999; Cao et al., 2004), as well as in the title compound. As part of our research interest in new polycarboxylic acid-bridged polymeric complexes, the title complex, (I), was obtained by the hydrothermal reaction of OH—H₂BDC with cupric acetate and pyridine.

As shown in Fig. 1, the Cu atoms in (I) are five-coordinated via two N atoms from the pyridine ligands and three O atoms from hydroxyisophthalate ligands in a highly distorted triangular bipyramidal environment, with Cu—O distances in the range 1.941 (4)–2.225 (5) Å and Cu—N distances of 2.014 (6) and 2.046 (6) Å. These bond distances are similar to those found in {[Cu₂(1,3-bdc)₂(py)₂]₄}_n (1,3-bdc is 1,3-benzenedicarboxylate; Bourne et al., 2001), [Cu₃(TMA)₂(H₂O)₃]_n (TMA is benzene-1,3,5-tricarboxylate; Chui et al., 1999), {[Cu₂(bdc)₂(Q)₂]_n} (Q is quinoline; Moulton et al., 2003) and the closest relative catena-[(µ₃-benzene-1,3-dicarboxylato)bis(pyridine)copper], [Cu(1,3-bdc)(py)₂]_n (Bourne et al., 2001). The dihedral angle between the two py rings that coordinate to the same Cu atom is 75.41°. The asymmetric unit thus consists of one Cu atom, two pyridine ligands and one hydroxyisophthalate ligand. The 5-hydroxyisophthalate group acts as a tridentate ligand in this structure, with one carboxylate group bonding in a monodentate fashion to one Cu atom and the two remaining O atoms bonding in a monodentate fashion to two further Cu atoms. As illustrated in Fig. 2, the interesting feature for polymer (I) is that the OH-BDC ligands link copper centers in different ways to produce two different subrings, which are 36-membered and eight-membered with Cu···Cu distances of 16.935 (5), 9.814 (2) and 4.523 (3) Å, respectively. In other words, the two-dimensional network of [Cu(OH-BDC)]_n moieties can also be envisioned as being built up from the interlocking 36- and eight-membered rings via sharing of Cu atoms. The coordinated pyridine rings point to the layer region alternately above and below the two-dimensional net as terminal ligands. Finally, as illustrated in Fig. 3, the two-dimensional [Cu(OH-BDC)(py)₂]_n layers are assembled into a three-dimensional framework via edge- or point-to-face C—H ···π interactions and offset or slipped π–π stacking interactions, in which the mean C—H ···π and π–π hydrogen-bonding distances are 3.627 (8) and 3.653 (3) Å, respectively (Janiak, 2000). The dihedral angle between two π–π interacting py rings is 22.83 ° and the distances between the centroids of the two py rings is 4.131 (1) Å.

S2. Experimental

A mixture of Cu(CH₃CO₂)₂·H₂O (0.4 mmol), OH—H₂BDC (0.3 mmol), pyridine (0.6 mmol), NaOH (0.5 mmol) and water (15 ml) was sealed in a 25 ml stainless steel reactor with a Teflon liner. The reaction system was heated at 433 K for 60 h, and then cooled slowly to room temperature. A large number of green crystals of the title complex were obtained and collected by filtration, washed with water and dried in air (56.2% yield based on H₃OABDC).

S3. Refinement

All H atoms were placed at calculated positions and refined with isotropic displacement parameters, using a riding model [C—H = 0.93 Å, O—H = 0.82 Å, and U_iso(H) = 1.2U_eq(C) and 1.5U_eq(O)].

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. The structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are plotted at the 30% probability level. Atoms labbelled with the suffixes a and b are the symmetry positions (-x, 2 − y, 1 − z) and (1/2 + x, 3/2 − y, −1/2 + z), respectively.
	Fig. 2. A view of (I), showing how the organization of the two different subrings contributes to the construction of the [Cu(OH-BDC)]n two-dimensional network.
	Fig. 3. A packing diagram of the title compound, showing the complex C—H ··· π and π–π interactions, with hydrogen bonds shown as dashed lines.

Poly[[bis(pyridine-κN)copper(II)]-µ₃-5-hydroxyisophthalato-k³O:O':O'']

Crystal data

[Cu(C8H4O5)(C5H5N)2]	F(000) = 820
Mr = 401.85	Dx = 1.472 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 10.1055 (9) Å	Cell parameters from 2698 reflections
b = 11.6854 (11) Å	θ = 2.7–25.1°
c = 15.7236 (14) Å	µ = 1.24 mm^−1
β = 102.415 (2)°	T = 293 K
V = 1813.3 (3) Å^3	Prism, green
Z = 4	0.40 × 0.30 × 0.20 mm

Data collection

Siemens SMART CCD area-detector diffractometer	3159 independent reflections
Radiation source: fine-focus sealed tube	2455 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.048
ϕ and ω scans	θmax = 25.1°, θmin = 2.7°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −12→7
Tmin = 0.802, Tmax = 1.000	k = −13→12
5825 measured reflections	l = −18→16

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)] = 0.071	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.192	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0665P)^2 + 13.3127P] where P = (Fo^2 + 2Fc^2)/3
3159 reflections	(Δ/σ)max < 0.001
235 parameters	Δρmax = 0.72 e Å^−3
0 restraints	Δρmin = −0.45 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
Cu	0.09424 (8)	0.88890 (7)	0.41120 (5)	0.0275 (3)
O1	−0.0428 (6)	0.9264 (4)	0.5842 (3)	0.0426 (13)
O2	−0.0081 (5)	0.8052 (4)	0.4821 (3)	0.0403 (13)
O3	−0.2848 (6)	0.7777 (4)	0.8109 (3)	0.0491 (15)
O4	−0.2951 (5)	0.5890 (4)	0.8247 (3)	0.0324 (11)
O5	−0.1504 (7)	0.4234 (4)	0.5667 (4)	0.066 (2)
H5A	−0.1689	0.3762	0.6009	0.099*
N1	−0.0665 (6)	0.8727 (5)	0.3077 (4)	0.0384 (14)
N2	0.2626 (6)	0.8984 (5)	0.5066 (4)	0.0392 (14)
C1	0.2775 (9)	0.9739 (8)	0.5710 (5)	0.053 (2)
H1	0.2047	1.0210	0.5746	0.063*
C2	0.3979 (11)	0.9856 (10)	0.6335 (7)	0.078 (3)
H2	0.4045	1.0392	0.6780	0.093*
C3	0.5041 (12)	0.9185 (11)	0.6289 (7)	0.086 (4)
H3	0.5854	0.9262	0.6695	0.103*
C4	0.4919 (10)	0.8392 (13)	0.5643 (7)	0.091 (4)
H4	0.5641	0.7917	0.5601	0.110*
C5	0.3691 (9)	0.8310 (9)	0.5048 (6)	0.062 (2)
H5B	0.3603	0.7757	0.4614	0.074*
C6	−0.1486 (9)	0.7812 (8)	0.2959 (6)	0.057 (2)
H6	−0.1390	0.7263	0.3397	0.068*
C7	−0.2475 (11)	0.7659 (11)	0.2204 (7)	0.079 (3)
H7	−0.3042	0.7024	0.2145	0.095*
C8	−0.2610 (10)	0.8450 (10)	0.1545 (7)	0.071 (3)
H8	−0.3250	0.8347	0.1029	0.086*
C9	−0.1785 (10)	0.9393 (10)	0.1661 (6)	0.070 (3)
H9	−0.1867	0.9951	0.1231	0.084*
C10	−0.0826 (8)	0.9498 (7)	0.2435 (5)	0.051 (2)
H10	−0.0265	1.0137	0.2510	0.061*
C11	−0.2112 (7)	0.6609 (6)	0.7066 (4)	0.0294 (15)
C12	−0.1606 (6)	0.7516 (6)	0.6663 (4)	0.0273 (14)
H12	−0.1605	0.8251	0.6890	0.033*
C13	−0.1101 (7)	0.7328 (6)	0.5920 (4)	0.0292 (14)
C14	−0.1090 (7)	0.6229 (6)	0.5590 (5)	0.0366 (17)
H14	−0.0756	0.6103	0.5091	0.044*
C15	−0.1572 (8)	0.5315 (6)	0.5998 (5)	0.0388 (18)
C16	−0.2099 (7)	0.5519 (6)	0.6728 (5)	0.0359 (16)
H16	−0.2449	0.4913	0.6994	0.043*
C17	−0.2675 (7)	0.6793 (6)	0.7876 (4)	0.0307 (15)
C18	−0.0490 (6)	0.8317 (6)	0.5502 (4)	0.0261 (14)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu	0.0350 (5)	0.0274 (4)	0.0250 (4)	−0.0018 (4)	0.0171 (3)	0.0002 (4)
O1	0.068 (4)	0.026 (3)	0.042 (3)	−0.006 (2)	0.031 (3)	−0.001 (2)
O2	0.064 (3)	0.031 (3)	0.036 (3)	−0.007 (2)	0.035 (3)	0.000 (2)
O3	0.087 (4)	0.025 (3)	0.047 (3)	0.005 (3)	0.041 (3)	−0.001 (2)
O4	0.038 (3)	0.033 (3)	0.033 (2)	0.003 (2)	0.022 (2)	0.005 (2)
O5	0.130 (6)	0.025 (3)	0.063 (4)	−0.016 (3)	0.065 (4)	−0.010 (3)
N1	0.038 (3)	0.038 (3)	0.041 (3)	0.001 (3)	0.013 (3)	−0.002 (3)
N2	0.048 (4)	0.041 (4)	0.033 (3)	0.007 (3)	0.017 (3)	0.001 (3)
C1	0.053 (5)	0.063 (6)	0.040 (4)	0.003 (4)	0.006 (4)	−0.008 (4)
C2	0.076 (7)	0.084 (8)	0.063 (6)	0.010 (6)	−0.005 (5)	−0.029 (6)
C3	0.071 (7)	0.107 (10)	0.065 (7)	0.009 (7)	−0.016 (6)	−0.015 (7)
C4	0.040 (6)	0.153 (12)	0.071 (7)	0.030 (7)	−0.008 (5)	0.004 (8)
C5	0.059 (6)	0.070 (6)	0.053 (5)	0.014 (5)	0.005 (4)	−0.011 (5)
C6	0.064 (6)	0.059 (6)	0.052 (5)	−0.019 (5)	0.020 (4)	−0.010 (4)
C7	0.077 (7)	0.094 (9)	0.068 (7)	−0.035 (6)	0.017 (6)	−0.023 (6)
C8	0.051 (6)	0.098 (8)	0.059 (6)	−0.012 (6)	−0.003 (5)	−0.016 (6)
C9	0.060 (6)	0.090 (8)	0.052 (5)	−0.002 (6)	−0.003 (5)	0.001 (5)
C10	0.050 (5)	0.047 (5)	0.051 (5)	−0.006 (4)	0.001 (4)	0.006 (4)
C11	0.042 (4)	0.027 (3)	0.025 (3)	0.004 (3)	0.021 (3)	0.004 (3)
C12	0.029 (3)	0.030 (3)	0.025 (3)	−0.001 (3)	0.009 (3)	−0.002 (3)
C13	0.033 (4)	0.029 (3)	0.030 (3)	0.000 (3)	0.016 (3)	0.000 (3)
C14	0.052 (4)	0.032 (4)	0.033 (4)	−0.003 (3)	0.025 (3)	0.000 (3)
C15	0.066 (5)	0.021 (3)	0.038 (4)	−0.006 (3)	0.029 (4)	−0.005 (3)
C16	0.047 (4)	0.029 (4)	0.038 (4)	0.001 (3)	0.021 (3)	0.000 (3)
C17	0.038 (4)	0.029 (4)	0.030 (3)	0.004 (3)	0.020 (3)	0.005 (3)
C18	0.028 (3)	0.028 (4)	0.024 (3)	0.000 (3)	0.010 (3)	0.003 (3)

Geometric parameters (Å, º)

Cu—O2	1.941 (4)	C4—C5	1.387 (13)
Cu—O4^i	1.955 (4)	C4—H4	0.9300
Cu—N2	2.014 (6)	C5—H5B	0.9300
Cu—N1	2.046 (6)	C6—C7	1.389 (13)
Cu—O1^ii	2.225 (5)	C6—H6	0.9300
O1—C18	1.225 (8)	C7—C8	1.374 (15)
O1—Cu1^ii	2.225 (5)	C7—H7	0.9300
O2—C18	1.265 (7)	C8—C9	1.371 (15)
O3—C17	1.231 (8)	C8—H8	0.9300
O4—C17	1.266 (8)	C9—C10	1.389 (12)
O4—Cu1^iii	1.955 (4)	C9—H9	0.9300
O5—C15	1.374 (8)	C10—H10	0.9300
O5—H5A	0.8200	C11—C16	1.382 (10)
N1—C10	1.337 (10)	C11—C12	1.388 (9)
N1—C6	1.342 (10)	C11—C17	1.518 (8)
N2—C1	1.328 (10)	C12—C13	1.388 (9)
N2—C5	1.338 (11)	C12—H12	0.9300
C1—C2	1.397 (12)	C13—C14	1.386 (9)
C1—H1	0.9300	C13—C18	1.525 (9)
C2—C3	1.344 (15)	C14—C15	1.387 (9)
C2—H2	0.9300	C14—H14	0.9300
C3—C4	1.360 (16)	C15—C16	1.386 (9)
C3—H3	0.9300	C16—H16	0.9300
O2—Cu—O4^i	157.2 (2)	C7—C6—H6	119.0
O2—Cu—N2	94.0 (2)	C8—C7—C6	119.7 (10)
O4^i—Cu—N2	89.6 (2)	C8—C7—H7	120.2
O2—Cu—N1	88.9 (2)	C6—C7—H7	120.2
O4^i—Cu—N1	86.2 (2)	C9—C8—C7	118.8 (9)
N2—Cu—N1	175.0 (2)	C9—C8—H8	120.6
O2—Cu—O1^ii	108.26 (19)	C7—C8—H8	120.6
O4^i—Cu—O1^ii	93.81 (18)	C8—C9—C10	118.5 (10)
N2—Cu—O1^ii	95.1 (2)	C8—C9—H9	120.7
N1—Cu—O1^ii	88.0 (2)	C10—C9—H9	120.7
C18—O1—Cu1^ii	154.2 (5)	N1—C10—C9	123.5 (9)
C18—O2—Cu1	132.4 (5)	N1—C10—H10	118.3
C17—O4—Cu1^iii	115.2 (4)	C9—C10—H10	118.3
C15—O5—H5A	109.5	C16—C11—C12	119.6 (6)
C10—N1—C6	117.5 (7)	C16—C11—C17	119.3 (6)
C10—N1—Cu1	119.0 (5)	C12—C11—C17	121.1 (6)
C6—N1—Cu1	123.0 (6)	C11—C12—C13	120.1 (6)
C1—N2—C5	116.5 (7)	C11—C12—H12	120.0
C1—N2—Cu1	122.9 (6)	C13—C12—H12	120.0
C5—N2—Cu1	120.5 (6)	C14—C13—C12	119.7 (6)
N2—C1—C2	122.7 (8)	C14—C13—C18	120.3 (5)
N2—C1—H1	118.6	C12—C13—C18	119.9 (6)
C2—C1—H1	118.6	C13—C14—C15	120.5 (6)
C3—C2—C1	119.3 (9)	C13—C14—H14	119.7
C3—C2—H2	120.4	C15—C14—H14	119.7
C1—C2—H2	120.4	O5—C15—C16	122.1 (6)
C2—C3—C4	119.5 (10)	O5—C15—C14	118.8 (6)
C2—C3—H3	120.2	C16—C15—C14	119.2 (6)
C4—C3—H3	120.2	C11—C16—C15	120.9 (6)
C3—C4—C5	118.3 (10)	C11—C16—H16	119.6
C3—C4—H4	120.8	C15—C16—H16	119.6
C5—C4—H4	120.8	O3—C17—O4	125.6 (6)
N2—C5—C4	123.5 (9)	O3—C17—C11	119.1 (6)
N2—C5—H5B	118.2	O4—C17—C11	115.4 (6)
C4—C5—H5B	118.2	O1—C18—O2	126.6 (6)
N1—C6—C7	122.0 (9)	O1—C18—C13	118.9 (5)
N1—C6—H6	119.0	O2—C18—C13	114.5 (6)

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