Crystal structure and physicochemical properties of a new organic dihydrogenmonoarsenate

A new organic dihydrogenmonoarsenate (C₃H₉N₂O₂)H₂AsO₄ (abbreviate as ECAs) is prepared by reacting H₃AsO₄ with ethyl carbazate. This compound crystallizes in the monoclinic crystal system, space group P2₁/n. Unit cell parameters are a = 4.8370(2) Å, b = 24.6270(2) Å, c = 7.6311(5) Å, β = 92.948(4)°, with, Z = 4 and ρ_m = 1.800 g cm⁻³. The structure is solved, using the direct methods and refined against F² to a reliability R factor of 0.0475. The compound is characterized by infinite [H₂AsO₄]_nⁿ⁻ ribbons, parallel to the a-direction, connected by organic cations and forming layers localized at y = 0 and 1/2. The cohesion of the framework is ensured by hydrogen bonds N(O)-H?O. The thermal properties of the compounds are investigated as well as the IR properties supported by group theoretical analyses.