Die Kristallstruktur von Molybdännitridchlorid,MoNCI3

MoNCl₃ crystallises in the triclinic space group PI with 4 formula units per unit cell, the lattice constants being a = 9.14, b = 7.67, c = 8.15 Å; α = 108.8°, β = 99.3° and γ = 108.6°. The crystal structure was solved by means of three-dimensional PATTERSON and FOURIER syntheses and refined by the method of least squares to a reliability index of 5.8%. The structure is built up from two slightly different kinds of MoNCl₃ molecules having Mo? N triple bonds (Mo? N distances 1.64 and 1.67 Å). Each N atom is coordinated to the Mo atom of a neighbouring molecule in such a way that tetramers with the pseudosymmetry 4/m are formed. The tetramers are linked together by bridging Cl atoms so that puckered layers parallel to (010) result.