LAUSR

Abstract Ternary carbodiimides, Ba1-xSrxNCN (x ​= ​0, 0.1, 0.2, 0.5, 0.8, and 1.0) were prepared by an ammonolysis reaction with a (Ba,Sr)CO3 precursor obtained by a polymerized complex method. A new orthorhombic carbodiimide was obtained at x ​= ​0.1. It coexists with SrNCN-type solid solutions between x ​= ​0.2 and 0.5. The crystal structure of Ba0.9Sr0.1NCN was determined using single-crystal X-ray and powder neutron diffraction data, and was found to adopt an orthorhombic Pnnm crystal structure. In this structure, both Ba2+ and Sr2+ cations are situated in an octahedron of N atoms of NCN2− anionic groups, and the (Ba/Sr)N6 octahedra form a distorted rutile-type structure with C atoms bridging the N atoms.