Tetramethylammonium hydroxide

Above about 50°C tetramethylammonium hydroxide is formed as a by-product it is the sole product above 100°C (214). 

Monobasic acids are determined by gas chromatographic analysis of the free acids dibasic acids usually are derivatized by one of several methods prior to chromatographing (176,177). Methyl esters are prepared by treatment of the sample with BF.—methanol, H2SO4—methanol, or tetramethylammonium hydroxide. Gas chromatographic analysis of silylation products also has been used extensively. Liquid chromatographic analysis of free acids or of derivatives also has been used (178). More sophisticated hplc methods have been developed recentiy to meet the needs for trace analyses ia the environment, ia biological fluids, and other sources (179,180). Mass spectral identification of both dibasic and monobasic acids usually is done on gas chromatographicaHy resolved derivatives. 

Modern analytical pyrolysis has conventionally been canied out only by thermal energy to break some covalent bonds in the sample molecules at elevated temperatures to produce smaller and/or volatile fragments (pyrolyzates). On the other hand, the reactive pyrolysis in the presence of organic alkaline, such as tetramethylammonium hydroxide [(CH / NOH] (TMAH) has recently received much attention especially in the field of chai acterizing condensation polymers. 

Tetramethylammonium hydroxide (5H2O) [10424-65-4 (5H2O), 75-59-2 (aq soln) ] M 181.2, m 63°, 65-68°. Freed from chloride ions by passage through an ion-exchange column (Amberlite IRA-400, prepared in its OH" form by passing 2M NaOH until the effluent was free from chloride ions, then washed with distilled H2O until neutral). A modification, to obtain carbonate-free hydroxide, uses the method of Davies and Nancollas [Nature 165 237 1950]. 

Electrolyte methanol containing tetramethylammonium chloride and tetramethylammonium hydroxide current density 22mA/cm2 reference system Ag/AgCl/KCl sat. (after Reference 16). 

Table 6. Characteristics of aminopropyl terminated poly-dimethylsiloxane oligomers synthesized in bulk, at 80 °C with 0.01 weight % tetramethylammonium hydroxide catalyst157-1641...

The alkyl halide (ethyl bromide in the above equation) can react further with the primary amine produced to give a secondary amine and with that to form a tertiary amine and finally a quaternary ammonium salt. Quaternary ammonium hydroxides are very strong bases like sodium hydroxide. Tetramethylammonium hydroxide is a very important chemical used in the manufacture of semiconductors and other electronic industry products. 

The use of a PTC, tetramethylammonium hydroxide, to carry out the coupling under aeration of nitrobenzene and aniline to give nitroso diphenylamine (which on catalytic reduction with H2 gives 4-aminodiphenylamine, required in the rubber industry) may be cited as a green chemistry route compared to the established process based on p-nitrochlorobenzene and aniline where Cl is wasted (Bashkin et al. 1999). 

In the case of an acid HX titrated with a quarternary ammonium base R4NOH there are a few complications as a consequence of some additional equilibrium constants and of a certain degree of instability of the titrant tetramethylammonium hydroxide (TMAOH) in pyridine for this reason the titrant solution was standardized against benzoic acid and used only on the day of preparation. Now, in addition to KHX and ifHX > we had to deal with... 

The sampling port is controlled by the operation software and can be set to continuously monitor a single one of the three inlets, or multiplexed between two (or all three although it is unlikely that a mission scenario will incorporate all three) of the modes (e.g., BWA in air and CWA in air). Also contained in the SIM is the pyrolyzer assembly, including the tetramethylammonium hydroxide (TMAH) solution delivery subsystem. 

Dining the preparation by solid phase interaction of tetramethylammonium hydroxide and potassium superoxide [1] by tumbling for several days in a rotary evaporator flask, a violent explosion occurred [2], This may have been caused by ingress of grease or other organic material leading to contact with potassium superoxide, a powerful oxidant. 

Me4N+0 Preparative hazard See Ozone Tetramethylammonium hydroxide See other QUATERNARY OXIDANTS c4h12no3... 

X. Zang, J.C. Brown, J.D.H. van Heemst, A. Palumbo, P.G. Hatcher, Characterization of Amino Acids and Proteinaceous Materials using Online Tetramethylammonium Hydroxide (TMAH) Thermochemolysis and Gas Chromatography Mass Spectrometry Technique, Journal of Analytical and Applied Pyrolysis, 61, 181 193 (2001). 

Pyrolysis in the presence of tetramethylammonium hydroxide (THM)-GC/MS allowed the identification of high- and low-molecular weight components in manila Copal and sandarac fresh and artificially aged samples. The pyrograms showed signals due to the polymer fraction and to free diterpenoids [43]. THM-GC/MS has also been used to determine the molecular composition of Pinaceae resins, allowing the study of fresh, naturally and artificially aged samples [16, 44 46]. 

A. Joll, T. Huynh and A. Heitz, Off line tetramethylammonium hydroxide thermochemolysis of model compound aliphatic and aromatic carboxylic acids decarboxylation of some ortho and/ or para substituted aromatic carboxylic acids, J. Anal. Appl. Pyrol., 70, 151 167 (2003). 

J.D.J. van den Berg and J.J. Boon, Unwanted alkylation during direct methylation of fatty (di)acids using tetramethylammonium hydroxide reagent in a Curie point pyrolysis unit, J. Anal. Appl. Pyrol., 61, 45 63 (2001). 

D. Fabbri and R. Helleur, Characterization of the tetramethylammonium hydroxide thermo chemolysis products of carbohydrates J. Anal. Appl. Pyrol., 49, 277 293 (1999). 

Characteristic markers of Venice turpentine are larixol and larixyl acetate, but in many cases they may remain undetected, as larixyl acetate hydrolyses and the methylation of hydroxyl groups is not as effective as for carboxylic acids. On-line derivatization with tetramethylammonium hydroxide (TMAH) is, for instance, scarcely effective on hydroxyl groups and involves a number of secondary reactions (isomerization, dehydration and cleavage of hydrolysable bonds) due to the strong alkalinity of the TMAH solution. When the experimental conditions are such that THM of labdanes occurs larixol and larixyl acetate are detected as a single peak since in the derivatization process larixyl acetate is hydrolysed to larixol [29]. 

Y. Ishida, H. Othani and S. Tsuge, Effects of solvents and inorganic salts on the reactive pyrolysis of aromatic polyester in the presence of tetramethylammonium hydroxide studied hy pyrolysis gas chromatography/mass spectrometry, J. Anal. Appl. Pyrol., 33, 167 180 (1995). 

McKinney D, Bortiatynski J, Carson D, Clifford D, deLeeuw J, Hatcher P (1996) Tetramethylammonium hydroxide (TMAH) thermochemolysis of the aliphatic biopolymer cutan insights into the chemical structure. Org Geochem 24 641-650... 

Tetramethylammonium hydroxide, TMAH, (Fluka Chemicals) was diluted with distilled water from a 25 wt % aqueous solution. In all cases the diazonaphthoquinone dissolution inhibitor used was Fairmont Positive Sensitizer 1009 (Fairmont Chemical Company). The syntheses of the PDMSX oligomers and novolac-PDMSX block copolymers have already been reported (11). The dimethylamine terminated poly(dimethyl siloxane), =510 g/mole (Petrarch), was used as the PDMSX component or to prepare higher molecular weight analogs. 

CEL dye. A CEL solution was obtained by dissolving poly(N-vinylpyrrolidone) (PVP) (7 g) and Dl (5.8 g) in 50 wt% aqueous acetic acid. (87.2 g). The CEL layer was spin-coated onto a photoresist, RI-7000P (Hitachi Chemical Co.), and baked at 80T for 20 minutes. Exposure was performed with an in-house i-line reduction projection aligner. The resist was developed in a 2. 38 wt% tetramethylammonium hydroxide aqueous solution. The film thickness was measured with an Alpha-step 200 (Tencor)... 

In another application, the diazonium salt (D1 or D2) (2.5 wt%) was dissolved in a mixture of cyclohexanone and acetic acid containing 12.5 wt% poly(4-hydroxystyrene) and 2. 5 wt% Methylone resin (GE 75108). The resist was exposed with a 600-W Xe-Hg lamp through a 313-nm interference filter. After exposure the resist was baked at 80V for 3 minutes and developed in a 1 wt% tetramethylammonium hydroxide aqueous solution. 

The exact p R+ value for 20+ could also not be determined by the earlier method. Therefore, dimethyl sulfoxide (DMSO)-water-tetramethylammonium hydroxide (0.011 M) system was used for the measurement. The H scale (Hammett acidity scale) for the system ranges from 12 in water up to 26.2 in... 

One of SACHEM s products is tetramethylammonium hydroxide (TMAH), which is sold to semiconductor industries. Suspended particles in TMAH solutions could cause severe mechanical damage to the electronic devices manufactured by their customers. The determination of the particle content in such solutions is therefore critical. It is performed with a laser-equipped particle counter, which provides 70% detection efficiency. The counting must take place in a clean room because tiny airborne particles can land in the solutions and give them a false high reading. A class 1000 environment is required in this case, which means that the count of particles in the air that are greater than or equal to 0.5 jrm in diameter must be less than 1000 per cubic foot. Typically, a customer s specification for TMAH solutions is less than 100 particles per milliliter for particles greater than or equal to 0.5 fim in diameter. 

---