Pyridine Ring Modification of Indane‐1,3‐dione Dimers for Control of their Crystal Structure

Abstract

AbstractFour 2,2′‐dipyridylindane‐1,3‐dione 2,2′‐dimers with various substituents and orientations of the pyridine rings were synthesized. Detailed analyses of their crystal structures revealed how the atomic geometry around the pyridine N‐atom affects the selective formation of a 1D‐channel‐containing open‐type structure, observed as a major packing structure of the previously reported 2,2′‐di(4‐pyridyl) analogue (4PID). DFT‐based QTAIM and noncovalent interaction index‐reduced density gradient analyses afforded qualitative information on the intra‐ and intermolecular interactions in the open‐type structure of 4PID and in a hypothetical open‐type structure of its 2‐pyridyl analogue that was not observed experimentally. They also indicated that interactions between the framework and channel‐incorporated solvents, rather than N‐atom‐related intermolecular interactions, make a significant contribution to stabilization of the open‐type structure.