Inclusion of viologen cations leads to switchable metal–organic frameworks

Abstract

The reactions of Zn(NO3)2·6H2O with the polycarboxylic acids 1,3-benzenedicarboxylic acid (H2mbdc), 1,4-benzenedicarboxylic acid (H2bdc), 1,3,5-benzenetricarboxylic acid (H3btc) and 4,4'-biphenyldicarboxylic acid (H2bpdc) in the presence of methyl viologen iodide ([MV]I2) in...

Inverse photochromism in viologen–tetraarylborate ion-pair complexes: optical write/microwave erase switching in polymer matrices

“…The decay time profiles were recorded with a TC900 counting board and software from Edinburgh Instruments. Lifetimes were evaluated using the Deconvolution procedure with a three-exponential decay model, according to eqn (9).…”

“…Heretofore, this photochromic property of viologen has been found mainly in solution and liquid crystals, but few cases are observed in the solid state, in particular in crystalline solids. [4][5][6]8,9 4…”

“…Heretofore, this photochromic property of viologen has been found mainly in solution and liquid crystals, but few cases are observed in the solid state, in particular in crystalline solids. [4][5][6]8,9 In viologen-borate ion pair systems such as shown in Scheme 1, charge separation involves a redox reaction between a photoexcited electron donor (D*) and an electron acceptor (A), resulting in the production of the ion pair (D* + A -D + + A À ). 7 In fact, for such systems, the efficiency of the photoinduced electron-transfer processes is dependent on the rate of the thermal back-electron-transfer reaction (D + + A À -D* + A).…”

The chemical and electrochemical stimuli viologen substituted phthalocyanine with tunable optical features1

“…Among them, the N,N’-disubstituted 4,4-bipyridine, also known as viologen, is widely exploited in numerous materials and compounds where it mostly serves as an electro- and photosensitive active group [ 16 – 18 ]. Viologens are known to undergo chemical or electrochemical one-electron reductions yielding cation radical and neutral state that are stable in the absence of O 2 [ 19 , 20 ].…”