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·CHO·CHO·CHNS·2CHOS·2HO, 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.

A Blue-Light-Emitting Cadmium Coordination Polymer with 75.4% Photoluminescence Quantum Yield.

We report a novel bright deep-blue-emitting crystal form based on a simple cadmium coordination polymer with an impressive external photoluminescence quantum yield of 75.4(9)%.