Quaternary ammonium molybdate salts have been used for epoxidation and other oxidations using hydrogen peroxide. US Patent 10,590,364 (17-Mar-2020 assigned to Vanderbilt Chemicals) describes quaternary ammonium molybdate salts that contain sulfur that are useful as additives in lubricants and greases for friction reduction, wear reduction, and/or extreme pressure performance. The composition of these salts is [R4N]2 [Mo2S8O2].
The procedure is laid out in the patent and involves reacting ammonium heptamolybdate, sulfur dissolved in aqueous ammonium sulfide for 16 hours then adding quat bromide dropwise or portionwise plus post-reaction time and workup.
The quat salts prepared, isolated and characterized include tetramethylammonium, tetraethylammonium, tetrabutylammonium, tetraoctyalammonium, hexadecyl trimethyl ammonium, methyl trioctylammonium and ditallow dimethyl ammonium.
If your company needs help to choose a phase-transfer catalysis for the development or optimization of a commercial PTC application, contact Marc Halpern of PTC Organics for highly specialized expertise in industrial phase-transfer catalysis.
About Marc Halpern
Dr. Halpern is founder and president of PTC Organics, Inc., the only company dedicated exclusively to developing low-cost high-performance green chemistry processes for the manufacture of organic chemicals using Phase Transfer Catalysis. Dr. Halpern has innovated PTC breakthroughs for pharmaceuticals, agrochemicals, petrochemicals, monomers, polymers, flavors & fragrances, dyes & pigments and solvents. Dr. Halpern has provided PTC services on-site at more than 260 industrial process R&D departments in 37 countries and has helped chemical companies save > $200 million. Dr. Halpern co-authored five books including the best-selling “Phase-Transfer Catalysis: Fundamentals, Applications and Industrial Perspectives” and has presented the 2-day course “Practical Phase-Transfer Catalysis” at 50 locations in the US, Europe and Asia.
Dr. Halpern founded the journal “Industrial Phase-Transfer Catalysis” and “The PTC Tip of the Month” enjoyed by 2,100 qualified subscribers, now beyond 130 issues. In 2014, Dr. Halpern is celebrating his 30th year in the chemical industry, including serving as a process chemist at Dow Chemical, a supervisor of process chemistry at ICI, Director of R&D at Sybron Chemicals and founder and president of PTC Organics Inc. (15 years) and PTC Communications Inc. (20 years). Dr. Halpern also co-founded PTC Interface Inc. in 1989 and PTC Value Recovery Inc. in 1999. His academic breakthroughs include the PTC pKa Guidelines, the q-value for quat accessibility and he has achieved industrial PTC breakthroughs for a dozen strong base reactions as well as esterifications, transesterifications, epoxidations and chloromethylations plus contributed to more than 100 other industrial PTC process development projects.
Dr. Halpern has dedicated his adult life to his family and to phase-transfer catalysis (in that order!).
