Activation of the strongest triplet bond in molecular nitrogen (N-2) under mild conditions is particularly challenging. Recently, its fixation and reduction were achieved by highly reactive dicoordinated borylene species at ambient conditions, ripping the limits of harsh reaction conditions by metallic species. Less reactive species with a facile preparation could be desirable for next-generation N-2 activation. Now density functional theory calculations reveal that tricoordinated boranes could be a potential candidate of N-2 activation/functionalization. As composites of an intramolecular frustrated Lewis pair (FLP), optimal and realistic boranes are screened out to activate N-2 in a significantly favorable manner (both thermodynamically and kinetically). The significant thermodynamic stabilities of the FLP-N-2 adducts as well as the low activation barriers could be particularly interesting for the development of borane-based FLP chemistry applied in N, activation.