A Photochromic, Electrochromic, Thermochromic Ru Complexed Benzannulene:  an Organometallic Example of the Dimethyldihydropyrene−Metacyclophanediene Valence Isomerization

Abstract

The preparation of the first photochromic, organometallic derivative of the diarylethene class, the CpRu-complexed benzodimethyldihydropyrene 3, in which the organometallic is directly attached to the photochromic core, is described. The negative dark purple photochrome 3 readily bleaches to form the almost colorless cyclophanediene 3' on irradiation with visible light. The latter switches back to 3 either photochromically with UV light, electrochromically on reduction, or thermochromically on heating. Essentially quantitative conversion between the two states is possible. The open complex 3' thermally closes 2.6 times faster than the uncomplexed parent 2', but the closed form 3 opens with visible light at about 30% of the rate of uncomplexed 2. Both open forms, complexed 3' and uncomplexed 2' close equally fast with UV light.

Charge-Transfer Interactions in Organic Functional Materials

“…Recently, bichromophoric and multichromophoric cyclophanes have been studied for organic solids [113,114,115], biosensors [116,117], eletrocyclic reactions [118,119,120,121], two-photon absorptions [122,123,124], mixed-valence systems [125,126], and nonlinear optical materials [16,17,18]. Particularly, Bazan et al have exploited the advantage of well-defined three-dimensional structures in cyclophanes that contains [2.2]paracyclophane core and found their potential applications in designing organic nonlinear optical materials [16,17].…”

Bidirectional Ring‐Opening and Ring‐Closing of Cationic 1,2‐Dithienylcyclopentene Molecular Switches Triggered with Light or Electricity

“…The full operation of these systems, therefore, requires a combination of optical and electrical inputs. The fulgides [12] and dihydropyrenes [13] undergo ring-closing when electrochemically reduced. The dithienylethenes (DTEs) have more diverse electrochemical responses and can be either ring-closed when oxidized [14] or reduced, [15] or ring-opened when oxidized.…”

“…Cyclic voltammetry (CV) has commonly been employed to measure changes in the redox properties of DTE derivatives as a function of photochemical stimulation as well as for characterizing electrocatalytic isomerization reactions. [9,[12][13][14][15][16] As illustrated in Figure 6, cyclic voltammograms of all three ringopened isomers show peaks for irreversible reductions between -0.8 and -1.0 V that correspond to electrochemical-chemicalelectrochemical (ECE)-type reactions typical of reductive DTE ring-closing. [15] The corresponding electrochemical oxidations of all three ring-opened derivatives occur at the potential limits of the experiment and overlap with the background oxidation of solvent and electrolyte (greater than 2 V).…”

Oxidative Electrochemical Switching in Dithienylcyclopentenes, Part 1: Effect of Electronic Perturbation on the Efficiency and Direction of Molecular Switching

“…Recently, we demonstrated one-way optoelectronic switching of dithienylethenes on gold using breakjunction techniques. [9] The use of redox-active groups covalently attached to the dithienylethenes has been examined in an effort to marry the electronic and redox properties in multicomponent systems, [10,11] but only in a few examples have the electrochemical properties been explored. [12] Only recently, the redox chemistry of dithienylethenes has received attention in reports of electrochemical ring opening and closing.…”