2'-deoxycytidine-N(3)-cyanoborane monohydrate

The structure of the title compound, [4-amino-1-(2-deoxy-beta-D-ribofuranosyl)-2-oxo-1H-3-pyrimidinio]-(cyano)borate, C10H15BN4O4.H2O, features an interaction of 2.05 (4) Angstrom between an H atom of the -BH2CN group and an H atom of the -NH2 group. The -C=N group does not lie in the cytosine plane, the N atom being 2.24 Angstrom away from the plane. The cytosine rings are stacked with almost complete overlap along the twofold screw axis with an interplanar separation of 4.03 Angstrom. The sugar is in the T-3(4) puckering mode, the C(5')-O(5') bond has the gg conformation and the relative orientation of the sugar and the base is anti.