TITLE:
Morphological Change of Cocrystal Bis(8-Quinolinolato) Copper(II): 7,7,8,8-Tetracyanoquinodimethane Polymorphism
AUTHORS:
Norihito Doki, Minami Nomura, Masaaki Yokota
KEYWORDS:
Crystal Morphology, Crystal Structure, Organic Compounds
JOURNAL NAME:
Advances in Chemical Engineering and Science,
Vol.13 No.1,
December
27,
2022
ABSTRACT: We
studied cocrystal of bis(8-quinolinolato) copper(II) (CuQ2) and
7,7,8,8-tetracyanoquinodimethane (TCNQ), which change dramatically crystal shape
in a moment by adding press on crystal face. Single crystal was prepared by dissolving CuQ2 and TCNQ in chloroform by
evaporation of the solution at ambient conditions. We investigated about crystal structure and morphological change properties. We proclaim that
this phenomenon is solid phase transition to Form I from Form II, it is caused
by pressure on the crystal face (001) of Form II and the crystal expansion
direction is the side face (100). We take note of the common structure between
polymorph and explain that this transition occurs by the structure like
dominoes falling. We obtained a correlation between molecular level structure
change and macroscopic shape changes.