5-(2, 6-Bis((E)-4-(dimethylamino)styryl)-1-ethylpyridin-4(1H)-ylidene)-2, 2-dimethyl-1, 3-dioxane-4, 6-dione: aggregation-induced emission, polymorphism, mechanochromism, and thermochromism. Issue 36 (21st August 2017)