Cationic Chains of Phosphanyl- and Arsanylboranes

Whilst catena‐phosphorus cations have been intensively studied in the last years, mixed Group 13/15 element cationic chains have not yet been reported. Reaction of the pnictogenboranes H2EBH2⋅NMe3 (E=P, As) with monohalideboranes lead to the cationic chain compounds [Me3N⋅BH2EH2BH2⋅NMe3][X] (E=P, As; X=AlCl4, I) and [Me3N⋅BH2PH2BH2PH2BH2⋅NMe3][X] (X=I, VCl4(thf)2), respectively. All of the compounds have been characterized by X‐ray structure analysis, NMR spectroscopy, IR spectroscopy, and mass spectrometry. DFT calculations elucidate the reaction pathway, the high thermodynamic stability, the charge distribution within the chain and confirm the observed solid‐state structures. Inorganic alkanes: The monomeric Group 13/15 building blocks H2EBH2⋅NMe3 (E=P, As) have been linked to form cationic chains in a straightforward synthesis in good yields. The backbone consists of alternating B and P or As atoms bearing only hydrogen substituents. DFT calculations give insight into the formation, the bonding situation, and also the structural parameters of the cationic inorganic alkanes.