Self-assembly of self-assembled molecular triangles

Abstract

A rare variety of self-assembled molecular triangle [Pd3(bpy)3(imidazolate)3](NO3)3, 1 is prepared by the combination of Pd(bpy)(NO3)2 with imidazole, at 1:1 ratio, in acetonitrile-water. Deprotonation of imidazole happened during the course of the complexation reaction where upon the metallomacrocycle is formed. The bowl-shaped trinuclear architecture of 1 is crafted with three peripheral bpy units capable of π−π stacking interactions. While the solution state structure of 1can be best described as a trinuclear complex, in the solid-state well-fashioned intermolecular π−π and CH- π interactions are observed. Thus, in the solid-state further self-assembly of already self-assembled molecular triangle is witnessed. The triangular panels are arranged in a linear manner utilizing intermolecular π−π interactions where upon two out of three bpy units of each molecule participated in the chain formation.