A PYRAZINE-BRIDGED CHAIN STRUCTURE OF MAGNESIUM COMPLEX WITH PYRAZINE-2,3-DICARBOXYLIC ACID

Trisaquo(pyrazine-2,3-dicarboxylato) magnesium(II) monohydrate, MgC6H1 4N2O8 crystals are monoclinic, Cc, a = 8.444(2) Angstrom, b = 18.153(4 ) Angstrom, c = 7.416(1) Angstrom, beta = 114.49(3) deg., Z = 4. The s tructure consists of molecular chains propagating in the [101] directi on. Magnesium ions are bridged hy the 2,3-pzdc molecules via the oxyge n atom of the monodentate carboxylic group (Mg-O = 2.037 Angstrom) on one side and a (N, O) moiety on the other side (Mg-N = 2.246 Angstrom, Mg-O = 2.056 Angstrom). Three water molecules (mean Mg-O = 2.062 Angs trom) complete a fairly regular octahedral environment around the magn esium ion. An extensive hydrogen bond system is responsible for the st ability of the crystal.