Elucidating π-π interaction-induced extension effect in sandwich phthalocyaninato compounds.

Electrochemical and theoretical investigations over triple-quadruple-, quintuple-, and sextuple-decker sandwich-type compounds {[(Pc*)Sm][(Pc*)Cd n (Pc*) n ][Sm(Pc*)]} ( n = 0-3) elucidate successive π-π interaction-linked extension in the perpendicular direction of the phthalocyanine plane along with increasing the stacked tetrapyrrole number, significantly improving the nonlinear optical properties including effective imaginary third order molecular hyperpolarizability and optical limiting threshold.