A New Oxynitride Compound of Molybdenum,Na3MoO3N — Synthesis via the Azide Route and Structure

The new oxynitride compound of molybdenum, Na₃MoO₃N was prepared via the azide route. Its crystal structure was solved and refined from X‐ray powder data (orthorhombic, Pmn2₁, a = 724.63(1), b = 624.98(1), c = 563.86(1) pm, R_p: 9.04 %; R_wp: 9.83 %). The structure consists of isolated MoO₃N]^3— tetra‐hedra which are separated by Na⁺ cations, also in a tetrahedral coordination. It is isostructural to Na₃WO₃N which is a lower symmetry derivative of the Cu₃AsS₄ structure. Due to the small difference in the scattering lengths of nitrogen and oxygen, we were unable to distinguish between fully ordered, fully disordered, or partially ordered anions. However, from the positive SHG responses, we can deduce the acentric space group being the correct one and based on the lattice energy calculations, we have been able to identify the position most probably being occupied by nitrogen.