Syntheses and crystal structures of 4-(4-methoxy-phenyl)piperazin-1-ium 4-methylbenzoate monohydrate and bis[4-(4-methoxyphenyl)piperazin-1-ium] benzene-1,2-dicarboxylate

Co-crystallization of N-(4-methoxyphenyl)piperazine with 4-methylbenzoic acid and with benzene-1,2-dicarboxylic acid yields the salts 4-(4-methoxyphenyl)piperazin-1-ium 4-methylbenzoate monohydrate, C11H17N2O+ center dot C8H7O2-center dot H2O (I), and bis[4-(4-methoxyphenyl)piperazin-1-ium] benzene-1,2-dicarboxylate, 2C(11)H(17)N(2)O(+)center dot C8H4O42- (II). These salts both crystallize with Z' = 2, in space groups P (1) over bar and Pna2(1), respectively. In compound (I), a combination of four O-H center dot center dot center dot O, four N-H center dot center dot center dot O, one C-H center dot center dot center dot O and one C-H center dot center dot center dot pi(arene) hydrogen bonds link the six independent components into complex sheets, within which the two piperazine rings, the two anions, and the two water molecules are related by an approximate, non-crystallographic translation along the b-axis direction. In compound (II), sheets containing R-4(4)(18) and R-12(10)(38) rings are formed by the combined action of eight independent N-H center dot center dot center dot O hydrogen bonds. Comparisons are made with the structures of some related compounds.

Automated summary

This article presents the crystal structures of two salts formed by co-crystallization of N-(4-methoxyphenyl)piperazine with two different compounds. Compound (I) forms a complex sheet structure, while compound (II) forms sheets with specific rings.