The purine-carboxylate-containing coordination polymer poly[[[mu]₄-1-(2-carboxyl­ato­ethyl)-6-oxo-6,9-di­hydro-1H-purin-9-ido]zinc(II)]

The title compound, [Zn(C₈H₆N₄O₃)]_n or [Zn(L)]_n [H₂L is 3-(6-oxo-6,9-di­hydro-1H-purin-1-yl)propionic acid], crystallized as a nonmerohedral twin. The Zn^II cation is four-coordinated, ligated by two carboxyl­ate O atoms from two L ligands and two N atoms from another two ligands. Each ligand bridges four Zn^II centres, extending the structure into a three-dimensional polymer with a 4-connected (6⁵,4¹) topological structure containing two-dimensional homochiral layers constructed from one-dimensional metal-organic helices. Investigation of the thermal stability of the compound shows that the network has very high thermostability and is stable up to 720 K.

Computing details

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Poly[[µ₄-1-(2-carboxylatoethyl)-6-oxo-9H-purin-9-ido]zinc(II)]

Crystal data

[Zn(C8H6N4O3)]	F(000) = 544
Mr = 271.54	Dx = 1.985 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 10.785 (2) Å	Cell parameters from 892 reflections
b = 10.1308 (19) Å	θ = 3.2–29.0°
c = 8.910 (3) Å	µ = 2.70 mm^−1
β = 111.01 (3)°	T = 291 K
V = 908.8 (4) Å^3	Prism, colourless
Z = 4	0.20 × 0.12 × 0.08 mm

Data collection

Oxford Xcalibur Gemini diffractometer with Eos detector	2941 independent reflections
Radiation source: Enhance (Mo) X-ray Source	2237 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.000
Detector resolution: 16.2312 pixels mm^-1	θmax = 26.4°, θmin = 3.2°
ω scans	h = −13→13
Absorption correction: multi-scan (CrysAlisPro; Agilent, 2012)	k = −12→12
Tmin = 0.614, Tmax = 0.813	l = −11→11
2941 measured reflections

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.111	H-atom parameters constrained
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0672P)^2] where P = (Fo^2 + 2Fc^2)/3
2941 reflections	(Δ/σ)max < 0.001
146 parameters	Δρmax = 0.57 e Å^−3
0 restraints	Δρmin = −0.78 e Å^−3

Special details

Experimental. CrysAlis PRO, Agilent Technologies, Version 1.171.36.20 (release 27–06-2012 CrysAlis171. NET) (compiled Jul 11 2012,15:38:31) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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. Item _reflns_Friedel_fraction is defined as the number of unique Friedel pairs measured divided by the number that would be possible theoretically, ignoring centric projections and systematic absences. These statistics refer to single and composite reflections containing twin component 1 only. Refined as a 2-component twin.

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

	x	y	z	Uiso*/Ueq
Zn1	0.64942 (4)	0.26247 (4)	0.78290 (5)	0.02551 (16)
O1	0.1125 (3)	−0.0691 (3)	0.3944 (4)	0.0463 (9)
O2	−0.3078 (3)	0.2088 (3)	0.0857 (3)	0.0322 (7)
O3	−0.1937 (3)	0.1663 (3)	−0.0675 (3)	0.0294 (6)
N1	0.5004 (3)	0.1375 (3)	0.7029 (4)	0.0280 (8)
N2	0.3858 (3)	−0.0526 (3)	0.6707 (4)	0.0288 (8)
N3	0.3506 (4)	0.2617 (4)	0.4777 (4)	0.0408 (9)
N4	0.1644 (3)	0.1354 (3)	0.3244 (4)	0.0290 (8)
C1	0.4928 (4)	0.0163 (4)	0.7555 (4)	0.0265 (10)
H1	0.5584	−0.0182	0.8462	0.032*
C2	0.3864 (4)	0.1490 (4)	0.5706 (4)	0.0257 (9)
C3	0.3174 (4)	0.0337 (4)	0.5504 (4)	0.0273 (9)
C4	0.1914 (4)	0.0216 (5)	0.4221 (5)	0.0322 (10)
C5	0.2415 (4)	0.2450 (5)	0.3579 (6)	0.0386 (10)
H5	0.2125	0.3153	0.2868	0.046*
C6	0.0441 (4)	0.1323 (5)	0.1776 (5)	0.0394 (12)
H6A	0.0414	0.0497	0.1216	0.047*
H6B	0.0483	0.2036	0.1069	0.047*
C7	−0.0817 (4)	0.1461 (5)	0.2149 (5)	0.0347 (11)
H7A	−0.0960	0.0653	0.2648	0.042*
H7B	−0.0702	0.2172	0.2917	0.042*
C8	−0.2015 (4)	0.1738 (4)	0.0695 (4)	0.0249 (9)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0213 (2)	0.0284 (3)	0.0203 (2)	0.0012 (2)	−0.00048 (19)	0.0004 (2)
O1	0.0315 (17)	0.0347 (19)	0.053 (2)	−0.0031 (15)	−0.0082 (14)	0.0016 (14)
O2	0.0207 (14)	0.0445 (19)	0.0241 (17)	0.0075 (13)	−0.0008 (11)	0.0039 (12)
O3	0.0270 (14)	0.0416 (17)	0.0166 (14)	0.0078 (13)	0.0041 (12)	0.0010 (13)
N1	0.0241 (17)	0.0306 (19)	0.0224 (19)	−0.0017 (14)	0.0000 (15)	0.0022 (14)
N2	0.0256 (17)	0.0296 (18)	0.0215 (18)	−0.0015 (14)	−0.0033 (14)	0.0021 (15)
N3	0.0371 (19)	0.042 (2)	0.036 (2)	−0.008 (2)	0.0045 (19)	0.0101 (16)
N4	0.0224 (19)	0.035 (2)	0.0214 (18)	0.0008 (15)	−0.0023 (15)	0.0042 (14)
C1	0.0193 (18)	0.033 (2)	0.018 (2)	0.0010 (17)	−0.0043 (15)	0.0023 (16)
C2	0.021 (2)	0.032 (2)	0.023 (2)	0.0043 (17)	0.0072 (17)	0.0031 (17)
C3	0.025 (2)	0.036 (2)	0.017 (2)	0.0000 (17)	0.0026 (17)	−0.0004 (16)
C4	0.024 (2)	0.038 (3)	0.030 (3)	0.002 (2)	0.0037 (19)	−0.0023 (19)
C5	0.033 (2)	0.042 (3)	0.034 (2)	0.005 (2)	0.003 (2)	0.016 (2)
C6	0.028 (2)	0.063 (3)	0.019 (2)	0.004 (2)	−0.0025 (18)	0.002 (2)
C7	0.031 (2)	0.046 (3)	0.022 (2)	0.006 (2)	0.0033 (19)	0.0033 (19)
C8	0.024 (2)	0.023 (2)	0.022 (2)	0.0019 (18)	0.0023 (17)	0.0015 (17)

Geometric parameters (Å, º)

Zn1—N1	1.968 (3)	N3—C2	1.381 (5)
Zn1—N2^i	1.984 (3)	N4—C5	1.354 (5)
Zn1—O2^ii	1.992 (3)	N4—C4	1.411 (5)
Zn1—O3^iii	1.993 (3)	N4—C6	1.476 (5)
O1—C4	1.216 (5)	C1—H1	0.9300
O2—C8	1.257 (5)	C2—C3	1.361 (6)
O2—Zn1^iv	1.992 (3)	C3—C4	1.433 (5)
O3—C8	1.256 (4)	C5—H5	0.9300
O3—Zn1^v	1.993 (3)	C6—C7	1.514 (6)
N1—C1	1.327 (5)	C6—H6A	0.9700
N1—C2	1.370 (5)	C6—H6B	0.9700
N2—C1	1.328 (5)	C7—C8	1.492 (5)
N2—C3	1.375 (5)	C7—H7A	0.9700
N2—Zn1^vi	1.984 (3)	C7—H7B	0.9700
N3—C5	1.286 (5)
N1—Zn1—N2^i	119.36 (13)	C2—C3—N2	109.1 (3)
N1—Zn1—O2^ii	101.05 (13)	C2—C3—C4	119.7 (4)
N2^i—Zn1—O2^ii	99.67 (13)	N2—C3—C4	131.1 (4)
N1—Zn1—O3^iii	108.35 (13)	O1—C4—N4	121.2 (3)
N2^i—Zn1—O3^iii	120.17 (12)	O1—C4—C3	128.4 (4)
O2^ii—Zn1—O3^iii	104.60 (12)	N4—C4—C3	110.4 (4)
C8—O2—Zn1^iv	130.6 (3)	N3—C5—N4	126.7 (4)
C8—O3—Zn1^v	106.5 (2)	N3—C5—H5	116.7
C1—N1—C2	103.4 (3)	N4—C5—H5	116.7
C1—N1—Zn1	127.8 (3)	N4—C6—C7	112.1 (3)
C2—N1—Zn1	128.4 (3)	N4—C6—H6A	109.2
C1—N2—C3	102.9 (3)	C7—C6—H6A	109.2
C1—N2—Zn1^vi	124.8 (3)	N4—C6—H6B	109.2
C3—N2—Zn1^vi	132.3 (3)	C7—C6—H6B	109.2
C5—N3—C2	111.4 (4)	H6A—C6—H6B	107.9
C5—N4—C4	124.0 (3)	C8—C7—C6	113.1 (4)
C5—N4—C6	119.2 (4)	C8—C7—H7A	109.0
C4—N4—C6	116.8 (4)	C6—C7—H7A	109.0
N1—C1—N2	115.9 (3)	C8—C7—H7B	109.0
N1—C1—H1	122.1	C6—C7—H7B	109.0
N2—C1—H1	122.1	H7A—C7—H7B	107.8
C3—C2—N1	108.7 (3)	O3—C8—O2	120.7 (3)
C3—C2—N3	127.4 (4)	O3—C8—C7	119.6 (4)
N1—C2—N3	123.9 (4)	O2—C8—C7	119.7 (4)
N2^i—Zn1—N1—C1	−131.8 (3)	C1—N2—C3—C4	−177.5 (4)
O2^ii—Zn1—N1—C1	120.4 (3)	Zn1^vi—N2—C3—C4	4.7 (7)
O3^iii—Zn1—N1—C1	10.8 (4)	C5—N4—C4—O1	173.1 (4)
N2^i—Zn1—N1—C2	55.6 (4)	C6—N4—C4—O1	−6.8 (6)
O2^ii—Zn1—N1—C2	−52.2 (4)	C5—N4—C4—C3	−6.0 (6)
O3^iii—Zn1—N1—C2	−161.8 (3)	C6—N4—C4—C3	174.1 (4)
C2—N1—C1—N2	0.3 (5)	C2—C3—C4—O1	−173.7 (4)
Zn1—N1—C1—N2	−173.8 (3)	N2—C3—C4—O1	3.2 (8)
C3—N2—C1—N1	0.1 (5)	C2—C3—C4—N4	5.3 (5)
Zn1^vi—N2—C1—N1	178.1 (3)	N2—C3—C4—N4	−177.9 (4)
C1—N1—C2—C3	−0.5 (4)	C2—N3—C5—N4	2.6 (7)
Zn1—N1—C2—C3	173.5 (3)	C4—N4—C5—N3	2.1 (8)
C1—N1—C2—N3	178.7 (4)	C6—N4—C5—N3	−178.0 (5)
Zn1—N1—C2—N3	−7.3 (6)	C5—N4—C6—C7	−105.8 (5)
C5—N3—C2—C3	−3.1 (6)	C4—N4—C6—C7	74.1 (5)
C5—N3—C2—N1	177.8 (4)	N4—C6—C7—C8	167.0 (4)
N1—C2—C3—N2	0.6 (5)	Zn1^v—O3—C8—O2	14.9 (4)
N3—C2—C3—N2	−178.6 (4)	Zn1^v—O3—C8—C7	−162.6 (3)
N1—C2—C3—C4	178.1 (4)	Zn1^iv—O2—C8—O3	−177.2 (3)
N3—C2—C3—C4	−1.1 (7)	Zn1^iv—O2—C8—C7	0.3 (6)
C1—N2—C3—C2	−0.4 (5)	C6—C7—C8—O3	9.1 (6)
Zn1^vi—N2—C3—C2	−178.2 (3)	C6—C7—C8—O2	−168.4 (4)

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