Crossed Molecular Beam Study on the Ground State Reaction of Atomic Boron [B(2Pj)] with Hydrogen Cyanide [HCN(X1Σ+)]

The linear boronisocyanide species, [BNC(X-1 Sigma(+))], represents the simplest triatomic molecule with three distinct, neighboring main group atoms of the second row of the periodic table of the elements: boron, carbon, and nitrogen. This makes boronisocyanide a crucial benchmark system to understand the chemical bonding and the electronic structure of small molecules, in particular when compared to the isoelectronic tricarbon molecule, [CCC(X-1 Sigma(+))]. However, a clean, directed synthesis of boronisocyanide a crucial prerequisite to study the properties of this molecule has remained elusive so far. Here, we combine crossed molecular beam experiments of ground state boron atoms (P-2(j)) with hydrogen cyanide with electronic structure calculations and reveal that the boronisocyanide molecule, [BNC(X-1 Sigma(+))], is formed as the exclusive product under gas phase single collision conditions. We also show that higher energy isomers such as the hitherto unnoticed, ring-strained cyclic BNC(X(3)A') structure, which is isoelectronic to the triplet, cyclic tricarbon molecule, [C-3(X(3)A(2)')], do exist as local minima. Our studies present the first directed synthesis and observation of gas phase boronisocyanide providing a doorway for further fundamental studies on one of the simplest triatomic molecules composed solely of group III-V elements.