“…For pyrazine-2,3-dicarboxamide, four Cu II structures (Mondal & Ray, 1977;Klein et al, 1983) with the ligand in an N,O-chelating mode and one Ag I structure (Massoud et al, 2009) with the ligand in an N:N 0 -bridging mode have been reported. In contrast, many compounds of pyrazine-2,3-dicarboxylic acid with alkali (Tombul et al, 2006(Tombul et al, , 2007Tombul, Gü ven & Bü yü kgü ngö r, 2008;Tombul, Gü ven & Svoboda, 2008;Tombul & Guven, 2009) and transition metals (Zou et al, 1998(Zou et al, , 1999Konar et al, 2004;Xu et al, 2008) have been synthesized and structurally characterized.…”