Multiple Z′ in carboxylic acid-pyridine trimer synthon and Kagomé lattice in the structure of 5-methylpyrazine-2,3-dicarboxylic acid

Abstract

We show the requirement of Z′ ≥ 2 for assembling an acid-pyridine trimer synthon in small, dissymmetric molecules. 5-Methylpyrazine-2,3- dicarboxylic acid (1) forms the rare O-H⋯N trimer synthon between three symmetry-independent molecules in a Kagomé lattice. The two-dimensional layers organize in a chiral P65 crystal system stabilized by C-H⋯O helices. © 2006 American Chemical Society.