TY - JOUR
T1 - Supramolecular structures and tautomerism of carboxylate salts of adenine and pharmaceutically relevant N6-substituted adenine
AU - McHugh, Charlene
AU - Erxleben, Andrea
PY - 2011/11/2
Y1 - 2011/11/2
N2 - Co-crystal and salt formation of the kinetin analogue N - benzyladenine with the pharmaceutically acceptable co-crystal and salt formers maleic acid, oxalic acid, glutaric acid, succinic acid, benzoic acid, and fumaric acid has been studied by solid-state and solvent-drop grinding in combination with X-ray powder diffraction. In all cases, salt or co-crystal formation was observed. Single crystals of (bzadeH+)(mal-) (1) and (bzadeH +)2(ox2-) (2) were obtained by solution crystallization, and their X-ray structures are reported along with that of (adeH+)2(mal-)2.ade·2H 2O (3) (bzadeH+ = N6-benzyladeninium, adeH += adeninium, ade = adenine, mal- = hydrogen maleate, ox2 = oxalate. The hydrogen-bonding motifs in - 3 are discussed. The salts contain a robust bzade H-carboxylate or ade-carboxylate R2 (9) heterosynthon involving the protonated Hoogsteen sites (N6 - H, N7 - H) of bzadeH and ade. Molecular recognition between the protonated Hoogsteen site and the carboxylate group stabilizes the unusual 7H,9H tautomer of bzadeH + in 2 and the noncanonical 7H-adenine tautomer in 3.
AB - Co-crystal and salt formation of the kinetin analogue N - benzyladenine with the pharmaceutically acceptable co-crystal and salt formers maleic acid, oxalic acid, glutaric acid, succinic acid, benzoic acid, and fumaric acid has been studied by solid-state and solvent-drop grinding in combination with X-ray powder diffraction. In all cases, salt or co-crystal formation was observed. Single crystals of (bzadeH+)(mal-) (1) and (bzadeH +)2(ox2-) (2) were obtained by solution crystallization, and their X-ray structures are reported along with that of (adeH+)2(mal-)2.ade·2H 2O (3) (bzadeH+ = N6-benzyladeninium, adeH += adeninium, ade = adenine, mal- = hydrogen maleate, ox2 = oxalate. The hydrogen-bonding motifs in - 3 are discussed. The salts contain a robust bzade H-carboxylate or ade-carboxylate R2 (9) heterosynthon involving the protonated Hoogsteen sites (N6 - H, N7 - H) of bzadeH and ade. Molecular recognition between the protonated Hoogsteen site and the carboxylate group stabilizes the unusual 7H,9H tautomer of bzadeH + in 2 and the noncanonical 7H-adenine tautomer in 3.
UR - http://www.scopus.com/inward/record.url?scp=82955171700&partnerID=8YFLogxK
U2 - 10.1021/cg201007m
DO - 10.1021/cg201007m
M3 - Article
AN - SCOPUS:82955171700
SN - 1528-7483
VL - 11
SP - 5096
EP - 5104
JO - Crystal Growth and Design
JF - Crystal Growth and Design
IS - 11
ER -