| C6H7N2O+·Cl− | F(000) = 656 | 
| Mr = 158.59 | Dx = 1.496 Mg m−3 | 
| Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å | 
| a = 24.960 (2) Å | Cell parameters from 5016 reflections | 
| b = 5.1055 (4) Å | θ = 3.7–59.1° | 
| c = 12.4664 (9) Å | µ = 0.47 mm−1 | 
| β = 117.545 (5)° | T = 150 K | 
| V = 1408.6 (2) Å3 | Block, colourless | 
| Z = 8 | 0.34 × 0.28 × 0.26 mm |