Luminescence-/morphology-modulation of organic microcrystals by a protonation process†
Organic nano/microcrystals with desirable optical/electrical properties and a regular morphology are extensively applied in various optoelectronic devices at the microscale, but the morphology/luminescence-modulation of organic microstructures remains to be a great challenge. Herein, we utilize a protonation/de-protonation process to simultaneously modulate both the luminescence and the morphology of blue-emissive two-dimensional (2D) organic microcrystals, which are self-assembled from 1,4-bis((E)-2-(3-methylpyridin-4-yl)vinyl)benzene (MSP) by a facile solution-exchange method. Impressively, 1D color-tunable MSP·nHCl (n is an integer) organic microwires can be obtained by the protonation process activated by the addition of an acid (such as hydrochloric acid). When n = 2 or n > 2, these obtained MSP·2HCl or MSP·nHCl microcrystals with a 1D wire-morphology emitted yellow light and red light, respectively.