Mechanochemical Preparation of Dipyridyl-Naphthalenediimide Cocrystals: Relative Role of Halogen-Bond and π-π Interactions

Cryst Growth Des. 2021 Oct 6;21(10):5687-5696. doi: 10.1021/acs.cgd.1c00531. Epub 2021 Sep 1.

Abstract

Naphthalenediimide derivates are a class of π-conjugated molecules largely investigated in the literature and used as building blocks for metal-organic frameworks or coformers for hydrogen-bond-based cocrystals. However, their tendency to establish halogen-bond interactions remains unexplored. By using a crystalline engineering approach, we report here four new cocrystals with N,N'-di(4-pyrydyl)-naphthalene-1,4,5,8-tetracarboxidiimide and diiodo-substituted coformers, easily obtained via a mechanochemical protocol. Cocrystals were characterized via NMR, electron ionization mass spectrometry, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction. Crystallographic structures were then finely examined and correlated with energy framework calculations to understand the relative contribution of halogen-bond and π-π interactions toward framework stabilization.