Structural analysis of pyridine-imino boronic esters involving secondary interactions on solid state

Abstract Twelve boronic esters ( 1a - 1l ) synthesized from 4-halo- substituted arylboronic acids (halo = F, Cl, Br, I and CF 3 ) with 2-amino-2- alkyl (H, Me) -1,3-propanediol in presence of (3- or 4)-pyridine carboxaldehyde are described. A solvent mixture toluene/methanol 1:4 ratio was used. All compounds include both donor/acceptor functional groups, which are the necessary elements to self-assembly of the molecular species. Several secondary interactions as I⋯N, Br⋯Br, Br⋯B, F⋯B, C H⋯N, C H⋯O, Br⋯π and C H⋯π support the 1D and 2D polymeric frameworks in solid state. The coordination of the nitrogen atom from the pyridine moiety with the boron atom was not observed in either solution or solid state.