1131480-96-0

Basic information

• Product Name: 4,4’-dipyridyl trisulfide
• Synonyms: 4,4’-dipyridyl trisulfide
• CAS NO: 1131480-96-0
• Molecular Weight: 252.385
• Mol File: 1131480-96-0.mol

Chemical Properties

• CAS DataBase Reference: 4,4’-dipyridyl trisulfide(CAS DataBase Reference)
• NIST Chemistry Reference: 4,4’-dipyridyl trisulfide(1131480-96-0)
• EPA Substance Registry System: 4,4’-dipyridyl trisulfide(1131480-96-0)

Safety Data

• Hazardous Substances Data: 1131480-96-0(Hazardous Substances Data)

Upstream product

• 19829-29-9 4-pyridinethione 
• 10544-50-0 sulfur 
• 7440-57-5 gold 
• 583-39-1 2,3-dihydrobenzimidazol-2-thione 
• 4556-23-4 pyridine-4-thiol 

Relevant articles and documents

Pyridinethiol-Assisted Dissolution of Elemental Gold in Organic Solutions

Dissolution of elemental gold in organic solutions is a contemporary approach to lower the environmental burden associated with gold recycling. Herein, we describe fundamental studies on a highly efficient method for the dissolution of elemental Au that is based on DMF solutions containing pyridine-4-thiol (4-PSH) as a reactive ligand and hydrogen peroxide as an oxidant. Dissolution of Au proceeds through several elementary steps: isomerization of 4-PSH to pyridine-4-thione (4-PS), coordination with Au0, and then oxidation of the Au0 thione species to AuI simultaneously with oxidation of free pyridine thione to elemental sulfur and further to sulfuric acid. The final dissolution product is a AuI complex bearing two 4-PS ligands and SO42? as a counterion. The ligand is crucial as it assists the oxidation process and stabilizes and solubilizes the formed Au cations.

Cooperative Ligands in Dissolution of Gold

Development of new, environmentally benign dissolution methods for metallic gold is driven by needs in the circular economy. Gold is widely used in consumer electronics, but sustainable and selective dissolution methods for Au are scarce. Herein, we describe a quantitative dissolution of gold in organic solution under mild conditions by using hydrogen peroxide as an oxidant. In the dissolution reaction, two thiol ligands, pyridine-4-thiol and 2-mercaptobenzimidazole, work in a cooperative manner. The mechanistic investigations suggest that two pyridine-4-thiol molecules form a complex with Au0 that can be oxidized, whereas the role of inexpensive 2-mercaptobenzimidazole is to stabilize the formed AuI species through a ligand exchange process. Under optimized conditions, the reaction proceeds vigorously and gold dissolves quantitatively in two hours. The demonstrated ligand-exchange mechanism with two thiols allows to drastically reduce the thiol consumption and may lead to even more effective gold dissolution methods in the future.