Tin(ii) oxide carbodiimide and its relationship to SnO

Abstract

The compound Sn₂O(CN₂) was obtained as a brick-red crystalline powder from a solid-state reaction of equimolar amounts of SnCl₂, SnO and Li₂(CN₂). Thermal analysis of the reaction indicates the formation of two intermediate compounds until Sn₂O(CN₂) is formed at 400 °C. The crystal structure of Sn₂O(CN₂) was determined in the space group Pccn (a = 13.3949(7) Å, b = 5.2954(3) Å, c = 5.5369(2) Å, Z = 4) from single-crystal X-ray diffraction data. The structure contains a Sn²⁺ ion with a 5s² lone pair, situated in a fourfold, mixed O-/N-coordination environment. The crystal structure of Sn₂O(CN₂) is analyzed and discussed in relation to that of SnO, namely by electronic-structure calculations and a COHP bonding analysis of Sn₂O(CN₂).