Electrochemistry and time dependent DFT study of a (vinylenedithio)-TTF derivative in different oxidation states

Abstract

a b s t r a c tThe electrochemical and spectroelectrochemical properties of a bis-pyrid-4-yl functionalised vinylenedithio-TTF derivative, 1, in solution are reported. The compound was immobilised on a Pt electrode and the resulting layers formed were investigated using electrochemical techniques. Two oxidation processes were observed for 1, typical of TTF derivatives. A solvent dependence study revealed that the stabilisation of the radical cation intermediate, 1• + , towards further oxidation is achieved in solvents with a low Gutmann donor number such as dichloromethane. Analysis of 1 2+ in solution under aerobic and anaerobic conditions reveal that its stability is compromised in the presence of oxygen and therefore the stability of monolayers of 1 is greatly enhanced under anaerobic conditions. Time dependent DFT calculations of the compound in several oxidation states are discussed to obtain information on the location of the various redox processes.

Multistep Electron Injection Dynamics and Optical Nonlinearity Investigations of π-Extended Thioalkyl-Substituted Tetrathiafulvalene Sensitizers

“…The spectroelectrochemical studies are carried out to investigate the shift in the absorption spectra of oxidized species of the sensitizers . In this experiment, KCL-saturated calomel electrode (SCE) served as the reference electrode, and all potentials were reported relative to it.…”

“…The spectroelectrochemical studies are carried out to investigate the shift in the absorption spectra of oxidized species of the sensitizers. 48 In this experiment, KCL-saturated calomel electrode (SCE) served as the reference electrode, and all potentials were reported relative to it. During the controlled potential oxidation of G1 at 0.7 V versus the SCE, as shown in Figure 3, the absorption maxima at 374 nm continues to increase, while the absorption maxima at 421 nm continues to decrease with the evolution of a new band at 442 nm.…”

Reviving BVDT-TTF and EVT-TTF salts

“…On the other hand, the structurally related but unsaturated compounds bis-vinylenedithio-tetrathiafulvalene ( BVDT-TTF ) and ethylene-vinylenedithio-tetrathiafulvalene ( EVT-TTF ) have been far less reported in the literature. On the Scifinder database, over 5000 papers are reported for BEDT-TTF , while only 16 and 7 scientific reports do exist for BVDT-TTF 21–31 and EVT-TTF , 27,32–37 respectively. Amongst these, only 2 papers reported the X-ray structures of single-crystals for BVDT-TTF salts (PF 6 − ) 25,27 and two for EVT-TTF salts (PF 6 − , AsF 6 − , and Pt(CN) 4 2− ) 27,36 despite the fact that early reports described conductive salts, though without structures, with the ReO 4 − , ClO 4 − or I 3 − anions, amongst others.…”

“…[16][17][18][19][20] On the other hand, the structurally related but unsaturated compounds bis-vinylenedithio-tetrathiafulvalene (BVDT-TTF) and ethylene-vinylenedithio-tetrathiafulvalene (EVT-TTF) have been far less reported in the literature. On the Scifinder database, over 5000 papers are reported for BEDT-TTF, while only 16 and 7 scientific reports do exist for BVDT-TTF [21][22][23][24][25][26][27][28][29][30][31] and EVT-TTF, 27,[32][33][34][35][36][37] respectively. Amongst these, only 2 papers reported the X-ray structures of single-crystals for BVDT-TTF salts (PF 6 À ) 25,27 and two for EVT-TTF salts (PF 6 À , AsF 6…”