charge determination of substituted benzoic acids

[dkeidel397' at \`att.net]

Hello all,
 I am writing to find out if anyone knows of a program
 that is available (free or not) that can determine the
 charge on various benzoates (some para, meta, ortho).  I
 have InsightII and Gaussian.  I have a library of many
 benzoic acids with different substituents at different
 positions around the benzene ring.  I want to see how
 the charge on the ionized carboxylic acid will change
 when different substituents are present at the ortho,
 meta, and para positions.  I can use my intuition, but a
 program would also be very helpful.  Thank you to anyone
 that can help in advance.  Have a great day all.
 Don
 --
 Donald J. Keidel
 University of California, Riverside
 Department of Biochemistry and
 Molecular Biology
 Riverside, CA 92521
 phone:  (909) 787-5493
 fax:  (909) 787-4434
 dkeidel397' at \`att.net