Molecular wheel to monocyclic ring transition in boron–carbon mixed clusters C2B6− and C3B5−

Abstract

In this joint experimental and theoretical work we present a novel type of structural transition occurring in the series of C_xB_8−x⁻ (x = 1–8) mixed clusters upon increase of the carbon content from x = 2 to x = 3. The wheel to ring transition is surprising because it is rather planar-to-linear type of transition to be expected in the series since B₈, B₈⁻, B₈²⁻ and CB₇⁻ are known to possess wheel-type global minimum structures while C₈ is linear.