IR Mentor Pro:2.0 appears to be the ultimate reference source for infrared spectroscopy of organic molecules. This on-line database contains more than six hundred IR band assignments arising from over two hundred functional groups. Alcohols, for instance, are subdivided into primary, secondary, tertiary, benzylic, and phenols, while ketones have twenty variations that affect the carbonyl frequency. This large database was compiled from several reference works such as Infrared Characteristics Group Frequencies, 2nd edition, by G. Socrates; The Infrared Spectra of Complex Molecules by L. J. Bellamy, and Introduction to Infrared and Raman Spectroscopy by N. B. Colthrup, L. H. Daly, and S. E. Wiberley. The program runs on both Windows 3.x and Windows 95.

IR Mentor Pro may be used in a number of ways to obtain structural information from an IR spectrum. One can see on a displayed spectrum all the characteristic peaks of a suspected functional group. Also appended to each peak is a short description of the peak's origin within the framework of the functional group. Correlation of peaks from a spectrum results in a table of possible functional groups and a list of frequencies from different functional groups that may overlap. Comparison of an experimental spectrum with the database of IR Mentor Pro can also suggest when a sample is impure. The database contains peaks associated with common (usually solvent) impurities. The presence of weak peaks in a spectrum that correlate with a particular functional group can suggest that a more concentrated sample be run.

It seems doubtful that this system would be useful for beginning undergraduate organic chemistry students. The value of the database is in its encyclopedic register of IR absorption frequencies. However, in breadth there is complexity. To use the system most effectively one must couple the spectrum with the chemistry that created the sample. Nevertheless, the information contained in IR Mentor Pro can be very useful to undergraduate organic research students and to many students in advanced classes. Undoubtedly, graduate laboratories and industrial laboratories would benefit from the availability of this program on-line in their labs.

For those familiar with the previous version of IR Mentor Pro, a few new or enhanced features have been provided in this version. These include the ability to access the Socrates book on CD-ROM. This is an optional purchase. A toolbar is available on the screen as an alternate method to access the common functions.

It is much more convenient to switch between results lists by using tabs for each set of functional groups and now the bonds responsible for each IR frequency are highlighted in the displayed structure.

There are a few minor problems with the database and its operation. The spectral assignments are for condensed phase sample, but solvent effects are not included. Also this reviewer feels that phenols should be a separate functional group rather than a subset of alcohols. Finally, some structures can be improved or corrected. Triple bonds are not well done and the structures of conjugated anhydrides contain no conjugation.

This package is the most comprehensive and concise compendium of IR spectral data available and it is strongly recommended.