Exploring the structural landscape of 2-(thiophen-2-yl)-1,3-benzothiazole: high-Z' packing polymorphism and cocrystallization with calix[4]tube.
We report here for the first time a cocrystal of the so-called neutral calix[4]tube, which is two tail-to-tail-arranged and partially deprotonated tetrakis(carboxymethoxy)calix[4]arenes, including three sodium ions, with 2-(thiophen-2-yl)-1,3-benzothiazole, namely trisodium bis(carboxymethoxy)bis(carboxylatomethoxy)calix[4]arene tris(carboxymethoxy)(carboxylatomethoxy)calix[4]arene-2-(thiophen-2-yl)-1,3-benzothiazole-dimethyl sulfoxide-water (1/1/2/2), 3Na+·C36H30O122-·C36H31O12-·C11H7NS2·2C2H6OS·2H2O, which provides a new approach into the host-guest chemistry of inclusion complexes. Three packing polymorphs of the same benzothiazole with high Z' (one with Z' = 8 and two with Z' = 4) were also discovered in the course of our desired cocrystallization. The inspection of these polymorphs and a previously known polymorph with Z' = 2 revealed that Z' increases as the strength of intermolecular contacts decreases. Also, these results expand the frontier of invoking calixarenes as a host for nonsolvent small molecules, besides providing knowledge on the rare formation of high-Z' packing polymorphs of simple molecules, such as the target benzothiazole.
['Alvarenga|Meiry E|ME|', 'Valdo|Ana Karoline S M|AKSM|', 'Ribeiro|Leandro|L|', 'Do Nascimento Neto|José Antonio|JA|', 'De Araujo|Debora P|DP|', 'Da Silva|Cleiton Moreira|CM|0000-0001-9913-8971', 'De Fátima|Ângelo|Â|', 'Martins|Felipe T|FT|']
packing polymorphism calix[4]tube cocrystal benzothiazole high Z calixarene crystal structure