title: Supramolecular hydrogen-bonding patterns in two cocrystals of the N(7)-H tautomeric form of N(6)-benzoyladenine: N(6)-benzoyladenine-3-hydroxypyridinium-2-carboxylate (1/1) and N(6)-benzoyladenine-DL-tartaric acid (1/1).
abstract: Two novel cocrystals of the N(7)-H tautomeric form of N(6)-benzoyladenine (BA), namely N(6)-benzoyladenine-3-hydroxypyridinium-2-carboxylate (3HPA) (1/1), C12H9N5O·C6H5NO3, (I), and N(6)-benzoyladenine-DL-tartaric acid (TA) (1/1), C12H9N5O·C4H6O6, (II), are reported. In both cocrystals, the N(6)-benzoyladenine molecule exists as the N(7)-H tautomer, and this tautomeric form is stabilized by intramolecular N-H···O hydrogen bonding between the benzoyl C=O group and the N(7)-H hydrogen on the Hoogsteen site of the purine ring, forming an S(7) motif. The dihedral angle between the adenine and phenyl planes is 0.94 (8)° in (I) and 9.77 (8)° in (II). In (I), the Watson-Crick face of BA (N6-H and N1; purine numbering) interacts with the carboxylate and phenol groups of 3HPA through N-H···O and O-H···N hydrogen bonds, generating a ring-motif heterosynthon [graph set R2(2)(6)]. However, in (II), the Hoogsteen face of BA (benzoyl O atom and N7; purine numbering) interacts with TA (hydroxy and carbonyl O atoms) through N-H···O and O-H···O hydrogen bonds, generating a different heterosynthon [graph set R2(2)(4)]. Both crystal structures are further stabilized by π-π stacking interactions.
authors.affiliation: School of Chemistry, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India.
authors.forename: Ammasai
authors.initials: A
authors.lastname: Karthikeyan
authors.affiliation: School of Chemistry, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India.
authors.forename: Robert
authors.initials: R
authors.lastname: Swinton Darious
authors.affiliation: School of Chemistry, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India.
authors.forename: Packianathan
authors.initials: P
authors.lastname: Thomas Muthiah
authors.affiliation: Faculty of Chemistry and Chemical Technology, University of Ljubljana, Vecna pot 113, PO Box 537, SI-1000 Ljubljana, Slovenia.
authors.forename: Franc
authors.initials: F
authors.lastname: Perdih
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000737:chemistry; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D015394:Molecular Structure; D011687:Purines / Q000737:chemistry*; D011726:Pyridinium Compounds / Q000737:chemistry*; D013644:Tartrates / Q000737:chemistry*
chemical_list: C000605361:N(6)-benzoyladenine-3-hydroxypyridinium-2-carboxylate; C000605363:N(6)-benzoyladenine-DL-tartaric acid; D011687:Purines; D011726:Pyridinium Compounds; D013644:Tartrates; D000225:Adenine; C029768:tartaric acid
keywords: 3-hydroxypyridinium-2-carboxylate; N6-benzoyladenine; cocrystal; dl-tartaric acid; intermolecular hydrogen bonding; stacking interactions; supramolecular architectures