2,6-Diamino-5-(2,4-diamino-6-oxo-1,6-dihydropyrimidin-5-ylmethyl)-4-oxopyrimidin-1-ium 3,5-dinitrobenzoate

Abstract

Key indicators: single-crystal X-ray study; T = 293 K; mean (C-C) = 0.002 Å; R factor = 0.044; wR factor = 0.129; data-to-parameter ratio = 13.7.In the title compound, C 9 H 13 N 8 O 2 + ÁC 7 H 3 N 2 O 6 À , the aminopyrimidine molecule is protonated at one of the pyrimidine N atoms. The carboxylate group of the 3,5-dinitrobenzoate anion interacts with the protonated N atom and the 2-amino group in a nearly linear fashion through a pair of N-HÁ Á ÁO hydrogen bonds, generating the typical R 2 2 (8) motif. Two inversion-related pyrimidine units are connected through a pair of N-HÁ Á ÁN hydrogen bonds, forming a cyclic hydrogenbonded R 2 2 (8) motif. In addition to the base pairing, one of the carboxylate O atoms bridges the 4 0 -amino and 6 0 -amino groups on both side of the pairing, forming a DADA array. The molecular conformation of the cation is stabilized by two intramolecular N-HÁ Á ÁO hydrogen bonds. ExperimentalCrystal data C 9 H 13 N 8 O 2 + ÁC 7 H 3 N 2 O 6 À M r = 476.39 Monoclinic, P2 1 =n a = 7.365 (2) Å b = 19.788 (3) Å c = 13.658 (2) Å = 92.70 (2) V = 1988.3 (7) Å 3 Z = 4 Mo K radiation = 0.13 mm À1 T = 293 K 0.16 Â 0.13 Â 0.11 mm Data collection Bruker SMART CCD diffractometer Absorption correction: none 14081 measured reflections 4216 independent reflections 3046 reflections with I > 2(I) R int = 0.027