Galuashvili, Zh. S. published the artcileEnergy of triphenylboron pπ-conjugation, Product Details of C23H20BN, the publication is Doklady Akademii Nauk SSSR (1972), 207(1), 99-101 [Chem], database is CAplus.
Heats of formation of complexes of Ph3B with pyridine (I) and 4-methylpyridine and of Et3B with I, and their dipole moments in C6H6 and dioxane were determined and used to evaluate pπ-resonance in Ph3B. The low value of pπ-resonance in Ph3B is about an order of magnitude smaller than that of π-bonding, calling for care in the use of quantum-mechanics calculations in estimation of rearrangement energies in electron acceptor mols. The degree of charge transfer in these complexes was 0.45 for those of Ph3B and 0.34 for Et3B-I.
Doklady Akademii Nauk SSSR published new progress about 971-66-4. 971-66-4 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene, name is Triphenyl(pyridin-1-ium-1-yl)borate, and the molecular formula is C23H20BN, Product Details of C23H20BN.
Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem