Best way to raise pH without alkali metal? [closed]

I have a process that requires pH~14-14.5 to work. I’ve been achieving this with concentrated NaOH solutions, but the Na cations are later causing side reactions which are detrimental. Is there any organic base/non-alkali base that has the solubility in water and pKa to reach these pH values?

• Do you mean non-alkali metal, i.e. non Group I metal? All "bases" are alkalis. – DrMoishe Pippik Mar 15 '18 at 23:01
• There's a whole lot of them, so better edit your question quickly, 'cause right now you could get either simple yes as an answer or you might find a whole book somewhere. – Mithoron Mar 16 '18 at 0:16
• Did you try KOH? LiOH? – Oscar Lanzi Mar 16 '18 at 1:26
• K and Li are Alkali metals... – TungstenBronze Mar 16 '18 at 2:38
• Mithoron - I'd take a book. You got one? – TungstenBronze Mar 16 '18 at 2:41

Tetramethylammonium hydroxide

This is a strong base like NaOH.

See Behavior of Polyethylene Oxide Based Nonionic Surfactants in Silicon Processing Using Alkaline Solutions J. Electrochem. Soc. 1995 volume 142, 621-627:

alkaline cleaning solutions based on quarternary ammonium hydroxides such as choline ($pK_b = 0.1$) and tetramethyl ammonium hydroxide ($pK_b = 0$)

and Ceramic Nanomaterials and Nanotechnology II which says:

In this research, tetramethylammonium hydroxide (TMAH) was used, instead of KOH, to adjust pH of the precursor solution to 14.0

Also, TETRAMETHYLAMMONIUM HYDROXIDE Journal of the Chemical Society (1905):

An estimation of the strength of the base by means of the velocity of saponification of methyl acetate in N/80 solution showed that it was somewhat weaker than sodium hydroxide. The velocity constants obtained at 25 [degrees] were 0.0106 and 0.0115 respectively, so that if the strength of sodium hydroxide is represented as 100, that of tetramethylammonium hydroxide, under the above conditions, will be represented by 92.

• @OscarLanzi this thesis says pKb is zero digital.library.unt.edu/ark:/67531/metadc822794/m2/1/high_res_d/… – DavePhD Mar 16 '18 at 23:47
• Now we're good. – Oscar Lanzi Mar 17 '18 at 0:06
• @OscarLanzi I think Wikipedia is wrong. Another reference says "In this research, tetramethylammonium hydroxide (TMAH) was used, instead of KOH, to adjust pH of the precursor solution to 14.0". books.google.com/… – DavePhD Mar 17 '18 at 1:43
• @OscarLanzi I added better references to the answer. – DavePhD Mar 17 '18 at 18:33

Water solutions of amines can get to pH+ 12 or so. Piperidine, $\ce{(CH2)5NH}$, is about pH 11.

To get much higher pH+ requires somewhat exotic fluorinated organic chemicals, such as $\ce{9-COO-Me-fluorene}$, $\ce{(4-Me-C6F4)2CHCN}$ or $\ce{(4-Me-C6F4)(C6F5)CHCN}$. See Paenurk et al, A unified view to Brønsted acidity scales: do we need solvated protons? and download the PDF for an interesting explanation.

• You shouldn't make a "sentence link" especially with what looks like acids; you mean their salts or what? – Mithoron Mar 16 '18 at 0:20