Electrochemistry of Multisulfur Heterocycles: Trithiocarbonates and Trithiocarbenium Ions

Abstract

The electrochemistry of trithiocarbonates and trithiocarbenium ions has been studied in nonaqueous solvents, mainly in acetonitrile. Trithiocarbonates are reduced to the corresponding radical anions which undergo further chemical reactions. Anodic oxidation of trithiocarbonates leads to coupling products, but does not provide synthetic entry into the tetrathioethylenes. The latter class of compounds is available by a procedure which involves reductive coupling of trithiocarbenium cations, followed by pyrolysis of the resulting orthothiooxalates. The mechanism of the dimerization reaction appears to involve a simple radical‐radical coupling (DIMI mechanism). Details of the synthetic procedure are given along with voltammetric data for six trithiocarbonates and eighteen trithiocarbenium ions.

Coenzyme-Catalyzed Electro-RAFT Polymerization

“…The reduction potential of the NAD + /NADH pair was E = −0.54 V (vs Ag + /Ag), close to the reported result, 21 while the redox potential of CPAD (E = −0.4 V vs Ag + /Ag) was higher than that of NAD + (Figure S1). 22 This allows NADH to reduce CPAD with a concomitant electron transfer to form a radical. To convert deactivated NAD + to activated NADH species, we provided a −0.65 V of reducing potential.…”

Electro‐Controlled Living Cationic Polymerization

“…and DDQ −. /DDQ 2− previously reported and much higher than that of CTA 1 ( E =+0.51 V vs. Ag + /Ag; Supporting Information, Figure S1) . This allows DDQ to rapidly oxidize 1 with a concomitant electron transfer to yield carbocation species.…”

PET-RAFT Polymerization: Mechanistic Perspectives for Future Materials

“…This mechanism was in part proposed based on the redox potentials of Ir IV /Ir III* and thiocarbonyl compounds. The redox potential of Ir IV /Ir III* was previously found to be −1.72 V (potential vs saturated calomel electrode (SCE) in acetonitrile). , The redox potentials of thiocarbonyl containing compounds are typically higher, ranging from −0.4 to −0.9 V (potential vs SCE). ,, This would mean that the excited state Ir III could reduce the thiocarbonyl compound and itself become oxidized to Ir IV via an electron-transfer process. While in the ground state, the system would return to the ground state Ir III complex through reduction.…”

“…66,67 The redox potentials of thiocarbonyl containing compounds are typically higher, ranging from −0.4 to −0.9 V (potential vs SCE). 68,69,40 This would mean that the excited state Ir III could reduce the thiocarbonyl compound and itself become oxidized to Ir IV via an electron-transfer process. While in the ground state, the system would return to the ground state Ir III complex through reduction.…”