The First Observation of theE,ZConfiguration Of Ar–X–N=S=N–X–Ar (X = S, Se) Chains in the Crystalline State

Abstract

AbstractNew oligomeric analogues of poly(sulfur nitride), i.e. 3‐ClC6R4–X–N=S=N–X–C6R4Cl‐3 (5–8; R = H, F and X = S, Se), were synthesized and structurally characterized in the solid state by single‐crystal XRD, in solution by variable‐temperature NMR spectroscopy and in the gas phase with DFT/B3LYP calculations. In the crystal, compounds5–7display the well‐knownZ,Zconfiguration, whereas8(R = F, X = Se) is the first compound to display theE,Zconfiguration amongst twelve structurally defined Ar–X–N=S=N–X–Ar (X = S, Se) derivatives in the hydrocarbon and fluorocarbon series. Through a careful analysis of the packing schemes and the intermolecular interactions of the various compounds, an explanation of the abnormal behaviour of8is put forward.