Shan-Shan Yu

Two in one: switchable ion conductivity and white light emission integrated in an iodoplumbate-based twin chain hybrid crystal

An iodoplumbate-based hybrid, [C7-Apy][PbI3] (1), where C7-Apy(+) = 1-heptyl-4-aminopyridinium, was prepared using a simple solution process. Three sequential phase transitions occur in the range of 402-443 K. In both the lowest and highest temperature phases, hybrid crystal 1 is composed of discrete [Pb2I6]∞ twin chains surrounded by C7-Apy(+) cations. The connectivity between PbI6 octahedra within a [Pb2I6]∞ twin chain and the arrangement of cations are quite difference between the lowest and highest temperature phases. Hybrid crystal 1 shows switchable ion conductivity due to the structural phase transition and white light emission attributed to the broad band semiconductor emission of the twin chain. The former functionality has potential application in ion conductor devices; the single-phase white light emitter is a useful material in low-cost, easily-made, high-efficiency white light-emitting diodes.

Bis[1-(4-cyano­benz­yl)pyrazinium] bis­(1,2-dicyano­ethene-1,2-dithiol­ato)nickelate(II)

The asymmetric unit of the title complex, (C12H10N3)2[Ni(C4N2S2)2], consists of one 1-(4-cyanobenzyl)pyrazinium cation and one half of an [Ni(mnt)2]2− dianion (mnt2− is 1,2-dicyanoethene-1,2-dithiolate). The Ni2+ ion is located on an inversion center and is coordinated by four S atoms from two mnt2− ligands, exhibiting a square-planar coordination geometry. The cation adopts a conformation where both the pyrazine ring and the benzene ring are twisted with respect to the C—C—N reference plane by 16.5 (2) and 69.8 (1)°, respectively.

3,3'-Dimethyl-1,1'-(propane-1,3-di-yl)diimidazol-1-ium bis-(1,2-dicyano-ethene-1,2-dithiol-ato-κS,S')nickelate(II).

In the title compound, (C11H18N4)[Ni(C4N2S2)2], the asymmetric contains one half-complex, with the cation placed on a twofold axis and the anion located on an inversion center. The NiII ion in the anion is coordinated by four S atoms of two maleonitriledithiolate ligands, and exhibits the expected square-planar coordination geometry.