Crystal structure of guanidinium fumarate dihydrate, [CN₃H₆]₂· C₄H₂O₄· 2H₂O

Two-dimensional hydrogen-bonded networks in guanidinium hydrogen dicarboxylates

“…The anti-anti geometry of this interaction is very rare and worth attention since the carboxylic proton switches its orientation from syn to anti in order to approach the anti-lone pair of another hydroxyl oxygen. Hydrogen bonds 1, 3, 6 and 1, 5, 7 generate two different inter-ribbon motifs R2,3 (11) and hydrogen bonds 2, 4, 6 and 7 generate another inter-ribbon motif R2,4 (10). It is remarkable that only syn-lone pairs are exploited in the intra-ribbon hydrogen bonds while the anti-lone pairs in the inter-ribbon hydrogen bonds.…”

“…Two water molecules, incorporated in the empty chambers generated between each four chemical units, serve as additional donor and acceptor sites in order to stabilize the structure. 11 On the other hand the availability of separate hydrogen-bond donor and acceptor sites, located on both ends of the monoguanidinium hydrogen dicarboxylate unit GC, favours the ribbon formation via synthon (iv). Only a few structures of monoguanidinium dicarboxylate crystals are reported in the literature, but they all are not adequate to our considerations.…”

Anhydrous guanidinium hydrogen fumarate: a two-dimensional hydrogen-bonded network structure

“…The known structures of guanidinium salts with diprotic aliphatic acids are not common and many are acid salts (Adams, 1978;Andrews et al, 1979;Leban & Rupnik, 1992;Zyss et al, 1993;Krumbe et al, 1989;Krumbe & Haussuehl, 1987;Golic et al, 1985;Froehlich et al, 1985).…”