This paper reports the synthesis and a detailed investigation in solution, through ¹H NMR, optical absorption, fluorescence spectroscopy and second-order nonlinear optical studies, on the structure and photophysical properties of a series of unsymmetrical alkoxy-derivatized Schiff-base Zn^II species bearing on one side an alkyl ammonium bromide as a Lewis base. Overall results suggest that these complexes are present in solution of dichloromethane as dimeric aggregates in which each molecular unit mutually interacts with another unit through intermolecular Zn⋯Br⁻ interactions. This represents an alternative approach to control the supramolecular architecture of Lewis acidic, Schiff-base Zn^II complexes.