Crystal Structure of a Cd(II) Polymeric Complex Obtained from a Proton- Transfer Compound Containing Piperazine and Oxalic Acid

Abstract

The reaction of cadmium(II) nitrate hexahydrate with the proton-transfer compound (pipzH2)(ox) (where pipz=piperazine and oxH2=oxalic acid), in aqueous solution leads to the formation of the title polymeric compound (C2H6CdO7)n. This compound crystallizes in the triclinic system, space group P < /em>ī with two formula in the unit cell. The unit cell parameters are: a = 5.998 (4) Å, b = 6.634 (5) Å, c = 8.482 (6) Å,
α = 74.679 (10)°, β = 74.348 (11)° and γ = 81.112(11)°. The final R value was 0.087 for 1309 measured reflections. The CdII ion is seven-coordinated by five O atoms of oxalate ions as tetradentate bridging ligands and two O atoms of coordinated water molecules with distorted pentagonal bipyramid geometry around the central atom. The asymmetric unit also contains one water molecule. The crystal structure is stabilized by O–H···O hydrogen bonds, linking the molecules into a three-dimensional framework, which results in the formation of a supramolecular structure.

Keywords


[1] Aghabozorg H., Ghadermazi M., Attar Gharamaleki J., “A proton-transfer compound: 1,10-phenanthrolinium–2,4,5-tricarboxybenzoate–2,5-dicarboxybenzene-1,4-dicarboxylate (4/2/1)” Acta Cryst., E62 (2006) o3174-o3176.

[2] Aghabozorg H., Ghasemikhah P., Ghadermazi M., Sheshmani S., “Piperazinediium bis(pyridine-2,6-dicarboxylato)plumbate(II) dihydrate”, Acta Cryst., E62 (2006) m2835-m2837.

[3] Aghabozorg H., Aghajani Z., Sharif M. A., “Bis(2,4,6-triamino-1,3,5-triazin-1-ium) bis(pyridine-2,6-dicarboxylato-ĸ3O,N,O')cadmate(II)” Acta Cryst., E62 (2006) m1930-m1932.

[4] Aghabozorg H., Zabihi F., Ghadermazi M., Attar Gharamaleki J., Sheshmani S.,















“Piperazinediium bis(pyridine- 2,6 -dicarboxylato)

cuprate(II) tetrahydrate“, Acta Cryst., E62 (2006) m2091-m2093.

[5] Soleimannejad J., Aghabozorg H., Hooshmand S., Ghadermazi M., Attar Gharamaleki J., “The monoclinic polymorph of catena-poly [[diaquamanganese (II)] - μ-oxalato-ĸ4 O1, O2 :O1',O2']” Acta Cryst., E63 (2007) m2389-m2390.

[6] Odoko M., Kusano A., Okabe N., “Hexaaquabis ( -pyridine-2,6-dicarboxylato O, N, O':O) dicadmium (II) – pyridine – 2,6-dicarboxylic acid (1/2)”, Acta Cryst., E58, (2002) m25-m27.

[7] Ranjbar, M., Aghabozorg, H., Moghimi, A., “A seven-coordinate pyridine-2,6-dicarboxylate-bridged cadmium(II) complex, at 110 K”, Acta Cryst., E58 (2002) m304-m306.