Photochromism of a Methyl Viologen Bismuth(III) Chloride: Structural Variation Before and After UV Irradiation

Abstract

Color scheme: Reversibly photochromic crystals of (MV)Bi2Cl8 (methyl viologen, MV2+: N,N′‐dimethyl‐4,4′‐bipyridinium) show structural variations before and after UV irradiation. Color reversion is accomplished by heating in air (see picture). ([Bi2Cl8]2−)∞ double‐octahedral chains serve as electron donors to in situ generated MV2+ dications.

ZnCl3(4-methyl-4,4′-bipyridinium) with 4-methyl-4,4′-bipyridinium generated in situ: synthesis, structure and photoluminescence

“…A variety of novel complexes synthesized in situ have been documented [4]. However, viologen (4,4 0 -bipyridinium)-containing in situ reactions are relatively rare [5].Compound 1 was obtained from the reaction of ZnCl 2 , 4,4 0 -bipyridine, concentrated HCl acid and methanol by hydrothermal reaction [6]. X-ray diffraction analysis [7] reveals that the structure of 1 is characterized by an isolated structure, based on the MQ + ligand coordinating to a zinc atom that is further terminally bound by three chlorine atoms, as shown in Fig.…”

Synthesis, structure, photoluminescence and theoretical study of (MQ)(CdBr4) with MQ2+ generated In Situ (MQ2+ = N-Me-4,4′-bipyridinium)

“…This provides a route for the synthesis of viologenbased compounds, and makes the synthesis of viologen comparatively less toxic and more efficient. To our knowledge, this is the first example of the in situ generation of the MQ 2+ dication (MQ 2+ = N-Me-4,4ƍ-bipyridinium), although an unprecedented in situ generation of the MV 2+ dication (MV 2+ = N, was reported before [6]. Obviously, the MQ 2+ dication in 1 (MQ 2+ = N- is different from the MV 2+ dication (MV 2+ = N, reported before.…”

“…A variety of novel compounds synthesized in situ have been documented [ 5 ]. However, viologen-containing in situ reactions are relatively rare [6].…”

Synthesis, Structure, Photoluminescence and Theoretical Study of (N,N′-Dimethyl-4,4′-bipyridinium)[Cd2(μ 2-Cl)4Cl2]n with N,N′-Dimethyl-4,4′-bipyridinium Generated in Situ

“…This paves the way for the synthesis of viologen-based complexes, and makes the synthesis of viologen comparatively less toxic and more efficient. To the best of our knowledge, this is the second example of the in situ generation of the MV 2+ dication and it is the first cadmium-containing complex with the in situ generation of the MV 2+ dication, although an unprecedented in situ generation of the MV 2+ dication in the complex of (MV) Bi 2 Cl 8 was reported before [10].…”