Meta-Bifunctional thiol-carboxylic acid featuring a thiol pKa ≈ 7.4 and carboxyl pKa ≈ 4.0. The –SH group forms strong complexes with soft metal ions (Ag⁺, Hg²⁺, Cu⁺), while the –COOH provides hydrogen bonding or ionic anchoring, making the molecule a versatile platform for:
Metal-organic frameworks (MOFs) and coordination polymers – soft S-donor plus hard O-donor sites allow construction of heterometallic cages used in gas storage (CO₂, CH₄) and catalysis;
Self-assembled monolayers (SAMs) on gold or silver – meta-orientation produces tilted, densely packed films for SERS biosensors and mercury-ion optrodes with detection limits down to 1 ppt;
Pharmaceutical & biotech intermediates – reacts with alkyl/aryl halides to give meta-substituted thio-ethers used in kinase inhibitors and PROTAC linkers;
Agro-chemical synthesis – Cu-catalysed thio-arylation affords meta-(trifluoromethyl)thio-benzoates active as rice-blast fungicides;
High-performance poly(aryl sulfide) resins – chain-transfer agent in RAFT polymerisation, yielding high-refractive-index (nD ≈ 1.68) optical materials for 5G lens and OLED encapsulation films.
Store sealed, dry and under nitrogen; avoid strong oxidants to prevent disulfide formation.
