Polymeric crystal structure of trisaquo(my-pyrazine-2,3-dicarboxylato)strontium(II)

Trisaquo(my-pyrazine-2,3-dicarboxylato)strontium(II), SrC6H8N2O7 crystals have been studied by X-ray diffraction. The strontium ion is coordinated by a heteroring nitrogen, Sr-N of 2.793 A, and one oxygen atom belonging to a monodentate carboxylic group, Sr-O of 2.583 A, situated close to this nitrogen atom. Two oxygen atoms of carboxylic groups belonging to adjacent complex molecules, Sr-O=2.647 A and 2.914 A, bridge them into ribbons. Each oxygen atom of the above group is also linked to the Sr ions belonging to adjacent ribbons, Sr-O=2.576 A and 2.620 A, forming molecular sheets, which are parallel to the (010) plane. Each Sr ion coordinates also three oxygen atoms of water molecules (the average distance is 2.669 A. Hydrogen bonds of 2.66(1)-2.84(1) A link the sheets into a 3-dimensional framework.