Tetraalkyl ammonium chloride

Extensive work by Yamaki and Tobishima was devoted to the effect of additives on Li cycling efficiency in ethers and alkyl carbonates [265], This included the use of cation complexing compounds (e.g., 12 crown 4, TMEDA), reactive organic compounds (e.g., quinoneimine derivatives), and adsorption compounds (e.g., large tetraalkyl ammonium chloride substituted with aromatic rings) [265],... 

Chloride initiation of chloral polymerization could be readily achieved with tetraalkyl ammonium chlorides, such as tetrabutyl ammonium chloride, or with trialkyl sulphonium chlorides as initiators. Chloral polymerization initiated with R4NCI behaved very similarly to that with tertiary amine initiation. It is likely that the actual initiator of chloral polymerization with tertiary amines was chloride ion, which was presumably formed by chloride abstraction from chloral by the amine. The ease of chloride exchange in chloral reactions was demonstrated by initiation studies with Cl as initiator. 

Cuprous chloride supported on a Y-type zeolite by high-temperature anhydrous reaction gave a DMC productivity as good as the active carbon supported catalyst. Addition of tetraalkyl ammonium chlorides to copper chlorides on zeolites or alumina increased the DMC productivity and the catalyst life. In any case, active carbons are the most preferred supports for this reaction, compared to zeolites or alumina, because of higher DMC productivity when working with copper(II) chlorides. 

Tetrabutylammonium tetrafluoroborate (TBATFB, Bu4NBF4) is another excellent electrolyte for general use. Like other tetrafluoroborate salts, it is somewhat more soluble in both organic compounds and water than TBAHFP, and is more stable than TBAHFP in methylene chloride. House and coworkers have described procedures for the synthesis of TBATFB and other tetraalkyl-ammonium tetrafluoroborates [9]. Thus, a solution of 8.4 g (0.025 mol) of... 

Phase-transfer agents are the most popular catalysts for the Halex reaction with alkaline fluorides. All types of transfer agents have been claimed tetraalkyl-ammonium halides (refs. 34, 48), Aliquat 336 (ref. 49), branched pyridinium halides (eventually supported on a polymer) (refs. 50 to 53), tetraalkylphosphonium chlorides (refs. 42, 54 - 57) or bromides (ref. 12), crown-ethers (refs. 58, 59) eventually associated with Ph4PBr (refs. 43, 60), tris-(dioxa-3,6-heptyl)amine (TDA-1) (ref. 61) or polyethyleneglycols (PEG) (ref. 62). 

Silica-supported catalyst systems comprised of tetra-n-butylammonium chloride and PdCl2 with C0CI2/CUCI2 promotors (melting points ca. 60 °C) have also been used for hydrodechlorination of chloroform with hydrogen at 90-150 °C [60]. As one reason for the observed catalyst deactivation the authors propose the thermal ionic liquid decomposition ([Bu4N]Cl, Td = 170 °C), which seems very likely since tetraalkyl ammonium salts are known to undergo dealkylation under the applied conditions [61,62]. 

Selection of appropriate quaternary ammonium catalysts is limited by their stability in the reaction medium. The cellulose pretreatment requires heating in strong caustic solutions up to 120 most tetraalkyl ammonium salts undergo Hoffman degradation under these conditions. We have found two relatively stable quat salts, tetramethylammonium chloride and N,N-dimethylmorpholinium... 

The reaction can be driven to the tetraalkoxide stage by addition of an amine or ammonia to scavenge the Hberated hydrochloric acid. The amine or ammonium hydrochloride that forms can be filtered from the reaction mass and the tetraalkyl titanate purified by distillation. If the reaction is mn in the starting alcohol as solvent, the chloride salts formed are in a finely divided state and difficult to filter. When the reaction is mn in the presence of an inert hydrocarbon solvent such as heptane or toluene, a much more readily filterable salt is obtained. The solution of cmde tetraalkyl titanate can be distilled to remove solvent and give a pure product (1,2). 

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