The structure of 2,2,4-trimethyl-2,3-dihydro-1,5-benzodiazepin-5-ium hydrogen oxalate was determined by X-ray crystallography. The compound crystallizes in the triclinic space group P1¯ with the following unit-cell parameters: a = 9.2402(6), b = 10.0287(7), c = 17.7145(12)A˚, α = 74.7700(10)°, β = 86.4570(10)°, γ = 70.1760(10)°, Z = 2, V = 1489.36(17)A˚3. The crystal structure was solved by direct methods and refined by full-matrix least-squares on F2 to final values of R1 = 0.0502 and wR2 = 0.1467 for 4517 reflections with I > 2σ(I)....
