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Volume 68 
Part 12 
Pages m1478-m1479  
December 2012  

Received 7 November 2012
Accepted 8 November 2012
Online 14 November 2012

Key indicators
Single-crystal X-ray study
T = 293 K
Mean [sigma](C-C) = 0.003 Å
R = 0.033
wR = 0.107
Data-to-parameter ratio = 16.5
Details
Open access

Poly[[hexaaquabis([mu]3-pyrimidine-4,6-dicarboxylato)dicalcium] dihydrate]

aInstitute of Nuclear Chemistry and Technology, ul.Dorodna 16, 03-195 Warszawa, Poland
Correspondence e-mail: j.leciejewicz@ichtj.waw.pl

The polymeric structure of the title compound, {[Ca2(C6H2N2O4)2(H2O)6]·2H2O}n, is built up of molecular layers composed of CaII ions bridged by both ligand N and O atoms with one of the O atoms being bis-monodentate. Two adjacent CaII ions are bridged by these O atoms, forming a centrosymmetric dimer which is the building unit of the structure. The dimers are nodes of a cross-linked molecular layer parallel to (101). The CaII ion is coordinated by two bidentate ligands, one monodentate ligand and three water molecules in the form of a distorted polyhedron with a coordination number of eight. Solvate water molecules located between adjacent layers participate as donors and acceptors in a system of hydrogen bonds in which coordinating water molecules also act as donors and non-coordinating carboxylate O atoms act as acceptors.

Related literature

For the crystal structures of CaII complexes with pyrazine-2,6-dicarboxylate and water ligands, see: Starosta et al. (2003[Starosta, W., Ptasiewicz-Bak, H. & Leciejewicz, J. (2003). J. Coord. Chem. 56, 677-682.], 2004[Starosta, W., Ptasiewicz-Bak, H. & Leciejewicz, J. (2004). J. Coord. Chem. 57, 167-173.]). The crystal structure of pyrimidine-4,6-dicarboxylic acid dihydrate was reported by Beobide et al. (2007[Beobide, G., Castillo, O., Luque, A., Garcia-Couceiro, U., Garcia-Teran, J. P. & Roman, P. (2007). Dalton Trans. pp. 2668-2680.]).

[Scheme 1]

Experimental

Crystal data
  • [Ca2(C6H2N2O4)2(H2O)6]·2H2O

  • Mr = 278.24

  • Monoclinic, P 21 /n

  • a = 7.7053 (15) Å

  • b = 11.432 (2) Å

  • c = 11.916 (2) Å

  • [beta] = 92.16 (3)°

  • V = 1048.9 (4) Å3

  • Z = 4

  • Mo K[alpha] radiation

  • [mu] = 0.64 mm-1

  • T = 293 K

  • 0.10 × 0.04 × 0.03 mm

Data collection
  • Kuma KM-4 four-circle diffractometer

  • Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2008[Oxford Diffraction (2008). CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.]) Tmin = 0.968, Tmax = 0.982

  • 3274 measured reflections

  • 3065 independent reflections

  • 1709 reflections with I > 2[sigma](I)

  • Rint = 0.049

  • 3 standard reflections every 200 reflections intensity decay: 2.9%

Refinement
  • R[F2 > 2[sigma](F2)] = 0.033

  • wR(F2) = 0.107

  • S = 1.01

  • 3065 reflections

  • 186 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • [Delta][rho]max = 0.44 e Å-3

  • [Delta][rho]min = -0.59 e Å-3

Table 1
Selected bond lengths (Å)

Ca1-O5 2.398 (2)
Ca1-O7 2.420 (2)
Ca1-O3i 2.4361 (17)
Ca1-O1ii 2.4823 (16)
Ca1-O6 2.502 (2)
Ca1-O1 2.5061 (17)
Ca1-N1 2.563 (2)
Ca1-N3i 2.6133 (19)
Symmetry codes: (i) [-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]; (ii) -x, -y, -z+1.

Table 2
Hydrogen-bond geometry (Å, °)

D-H...A D-H H...A D...A D-H...A
O7-H72...O2iii 0.80 (6) 2.34 (6) 3.048 (3) 149 (6)
O6-H61...O2ii 0.85 (5) 1.88 (5) 2.698 (3) 163 (5)
O8-H81...O3iv 0.76 (4) 2.04 (4) 2.793 (3) 170 (4)
O8-H82...O6v 0.77 (5) 2.09 (5) 2.818 (3) 157 (5)
O5-H52...O8vi 0.87 (4) 1.94 (4) 2.798 (3) 169 (4)
O6-H62...O4iii 0.77 (4) 1.96 (4) 2.719 (2) 167 (4)
O7-H71...O4vii 0.79 (4) 2.16 (4) 2.902 (3) 158 (3)
O5-H51...O8iv 0.78 (4) 2.04 (4) 2.816 (3) 176 (4)
Symmetry codes: (ii) -x, -y, -z+1; (iii) [x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]; (iv) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]; (v) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]; (vi) [x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]; (vii) -x, -y+1, -z+1.

Data collection: KM-4 Software (Kuma, 1996[Kuma (1996). KM-4 Software. Kuma Diffraction Ltd, Wroclaw, Poland.]); cell refinement: KM-4 Software; data reduction: DATAPROC (Kuma, 2001[Kuma (2001). DATAPROC. Kuma Diffraction Ltd, Wroclaw, Poland.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: QM2088 ).


References

Beobide, G., Castillo, O., Luque, A., Garcia-Couceiro, U., Garcia-Teran, J. P. & Roman, P. (2007). Dalton Trans. pp. 2668-2680.
Kuma (1996). KM-4 Software. Kuma Diffraction Ltd, Wroclaw, Poland.
Kuma (2001). DATAPROC. Kuma Diffraction Ltd, Wroclaw, Poland.
Oxford Diffraction (2008). CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]
Starosta, W., Ptasiewicz-Bak, H. & Leciejewicz, J. (2003). J. Coord. Chem. 56, 677-682.  [ISI] [CSD] [CrossRef] [ChemPort]
Starosta, W., Ptasiewicz-Bak, H. & Leciejewicz, J. (2004). J. Coord. Chem. 57, 167-173.  [ISI] [CrossRef] [ChemPort]


Acta Cryst (2012). E68, m1478-m1479   [ doi:10.1107/S160053681204617X ]

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