Noncentrosymmetric Packings Influenced by Electronic Properties of Products of Click Reactions

Though 1,4-disubstituted
1,2,3-triazole rings have been utilized
as electronic bridges in the solution phase, the use of a triazole
ring to serve as an electronic bridge of small molecules in the crystalline
state has been underdeveloped. Here two compounds with a central 1,4-disubstituted
1,2,3-triazole ring are synthesized to investigate the electronic
bridging between terminal stilbazole and pyridine groups in the crystalline
phase. The electronic properties of the molecules are characterized
through solution phase UV–vis spectroscopy, single crystal
X-ray diffractions, and density-of-state and gas-phase DFT calculations.
We show that the electronic bridging behavior of a 1,4-disubstituted
1,2,3-triazole ring derived from a click reaction is maintained in
the solid state by rare head-to-head (hh) packing in noncentrosymmetric
crystal environments.