Subject: Summary of non-aqueous solution pKa

From: YONG HUANG <[email-masked]>
Date: Thu, 6 Feb 1997 22:11:37 -0600 (CST)

---------------------------The Original Question------------------------------
> Does anybody know where I can find pKa of phenol and some carboxylic acids in
> non-aqueous solution such as ammonia? Thanks very much.
> 
> Yong

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From:	SMTP%"[email-masked]"  5-DEC-1996 12:58:19.92

See if you can find any papers by Charles A. Kraus of Brown University.  
He published from before the turn of the century into the 1960's or 
later.  He did a great deal of work in liquid ammonia.  
Pacem in Calcio 
Ciao
Fr. Ascanio, C.H.S.

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From:	SMTP%"[email-masked]"  5-DEC-1996 20:08:02.51

Dear Yon,

Bordwell has done several studies of compounds in DMSO.  I know these studies
included some carboxylic acids.  I don't know if they included any phenols.
His full name is Frederick G. Bordwell. 

Jennifer Radkiewicz
Department of Chemistry
University of California, Los Angeles
email: [email-masked]

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From:	SMTP%"[email-masked]"  9-DEC-1996 16:34:48.12
Subj:	Your message to Dr. Lagowski

Hello Yong!

I am Dr. Lagowski's secretary.  We spoke on the phone when you called last
week.  In the interest of expediency, I am sending you Dr. Lagowski's reply
to your e-mail.
rita
~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dear Yong,

	My apologies for not answering your query sooner, but it came at a VERY BAD
time.  The following references represent the extent of my knowledge about
quantitative descriptions of acid-base equilibria in liquid ammonia.

1.  "Indicator Equilibria in Liquid Ammonia,"  E. C. Fohn, Dissertation, The
University of Texas, 1963.
This source contains:
(a) a good analysis of dissociation and ion-pairing equilibria in liquid
ammonia.
(b) a reasonable overview of extant literature up to the publication date of
this dissertation.
(c) the work described is based on precision optical absorption measurements.

2.  "Acid-Base Equilibria in Liquid Ammonia," J. H. Takemoto, Ph.D.,
Dissertation, The University of Texas, 1968.
This source is concerned with carbon and nitrogen acids and employs the
techniques and analyses described in (1) above.  This source incorporates a
nice review of the literature of semi-qualitative methods to establish a
relative order of acidity.

3.  W. L. Jolley and T. Buchall, J. Am. Chem. Soc., 88, 5439 (1966).
This source uses an nmr method to establish equilibrium constants.

4.  There are a number of papers derived from (1) and (2) in the open
literature which provide the usual summaries of the dissertation work.  The
details, which may be of interest to you, appear in the full dissertations.
You can find the relevant papers under the names of the authors of the
dissertations who, by convention for this laboratory, are listed as the
first authors.

I hope this is sufficient for your purposes.

My regards to Dr. Zingaro.

Best regards,
J. J. Lagowski
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Life is what happens while you're making other plans..."~~Betty Talmadge
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Rita Wilkinson
Administrative Associate for             
J. J. Lagowski, Professor of 
Chemistry & Education
512/471-3288 ofc.
512/471-8696 fax
WEL 4.422

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From:	SMTP%"[email-masked]" 12-DEC-1996 18:01:52.13
Subj:	RE: Your message to Dr. Lagowski

Hi, Yong!
I have a reply from Dr. Lagowski for you!
rita
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
My instinct tells me that benzoic acid is sufficiently acidic in liquid
ammonia that it would be completely ionized, but the ions would not be
completely dissociated because of the low dielectric constant of the
solvent.  The pKa of benzoic acid in water is similar to that of acetic acid
and it's possible to isolate the ammonium salt of acetic acid from liquid
ammonia.  Ammonium acetate is surely ionic in the solid state (but possibly
H-bonded).  I am less certain about phenol.

Regards,
J. J. Lagowski
Professor of Chemistry and Education
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Life is what happens while you're making other plans..."~~Betty Talmadge
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Rita Wilkinson
Administrative Associate for             
J. J. Lagowski, Professor of 
Chemistry & Education
512/471-3288 ofc.
512/471-8696 fax
WEL 4.422

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My comments: Two of Dr. Lagowski's recommendations seem very important: J.H.
Takemoto "Acid-Base Equilibria in Liquid Ammonia" and E. Fohn "Indicator
Equilibria in Liquid Ammonia" but unfortunately they can't be checked out
through inter-library loan. They can only be read at Univ. of Texas @Austin
library.

I found a reference listing pKa of phenol in liquid NH3 = 3.5 (Treatise on
Anal. Chem. Part 1 Vol.2, 2nd ed., Kolthoff and Elving eds., p.335, citing M.
Herlem and A. Thiebault, Bull.Soc.Chim.Fr.,1970,383, in French), with a note
"solutions in 0.10M KI. I believe KI is used to increase the ionic strength of
the solution. But does this make a comparison with a pKa not in KI solution
unfair?

In the same book, p.366, pKa of benzoic acid is 9.8 in pyridine, citing L.M.
Mukherjee et al. J.Phys.Chem., Vol.72, 3410(1968), Table IV. No pKa of benzoic
acid in liquid NH3 is found.

Yong