est in the hook and presents facts ahout electromagnetic radiation: the propage tion of electromagnetic waves, quantize I n general the author chooses to summarize tion of energy, Bohr's theory of atomic results or state principles rather than to spectra, types of molecular motion (indevelop them. Reference to Barrow's chiding degrees of freedom), the wrhook could be made to overcome these responding energies of molecules (includlimitations. ing the equipartition principle), end the Instead of presenting the long estahexperimentally observed features of moleclished fields of optical spectroscopy first, ular spectra, in the ultraviolet, visible, and the author begins with the mare recently infrared regions. developed low frequency studies such as In the second chapter the theoretical NMR and EPR. The motive is to preinterpretation of spectra is considered in pare a better background for understandreference to rot,ationd motion in diatomic ing some of the finer details of the high fremolecules. After a. discussion of the quency types of spectroscopy. However, simple rigid rotator model based on classithese introductory chapters are quite cal mechanics, quantized energy levels are abrupt, and a. reader knowing little of specconsidered. Examples are given of the troscopy may find comprehension difficult. calculation of moment of inertia and interSome interesting applications of specnuclear distance from rotation spectral troscopy are mentioned occasionally data. Attention is also given to isotope throughout the hook. For example i t effect in rotation spectra. seems probable that most chemists and The third chapter is a discussion of the some spectroscopists, are not aware t h a t relationship between the infrared spectra for 6LiBr and 'LiBr the lithium isotope of simple diatomic molecules and the ratio obtained from microwave moments &etching and bending types of vibration of inertia does not agree with mass specof which they are capable. The concept tral data unless the mass of one electron is of force constant is developed from clsssitransferred from Li to Br, forming Li+Br-. eal mechanics and the concept of zeroIt is unfortunate that the author refers point energy from the results of wave consistently to magnetic field strengths in mechanical treatment of the system. I t is oersteds rather than gauss. Even though emphasized that the vibrational motion of the distinction is explained in a footnote, the nuclei must give rise to a change in the this choice is a. disservice to the reader since dipole moment of the molecule in order for nearly all reference works and literature the vibration to be infrared active. To articles conventionally use gauss. The illustrate the isotope effect in vibration text is generally free of typographical erspectra, the author calculates the wave rors, although in discussing overtone selecnumber of the fundamental band of H F I a s 2 was tion rules t. 02 appears where 0 and compares it wilh the value far H'CI35. intended. Fundamental band wave numbers for A set of 29 problems with answers is insome other isotopic molecules me presented cluded. The author warns that some of in s. table. the ~ r o b l e m are s difficult. and the reviewer I n the fourth chaeter the nonrigid roagrees with this judgment. tator and snhsrmonic oscillator model A very complete bibliography is given concepts are considered. The energy covering all types of spectroscopy. Only a. levels for the rigid rotator are compared few omissions are significant. with those of the nonrigid rotator. The J. LELANDHOLLENBERQ potential energy curve for the anharmonic oscillator is compared with that for the University of Redlands simple harmonic oscillator. In the fifth Redlands, California chapter the author takes another quantum jump in level of presentation to wnsider simultaneous vibrational and rotationit1 Inlroduetion to Molecular Spectroscopy motion. He does this first on the m m m p tian that there is no interaction hetween Anthony J. Sonnessa, Seton Hall Unithe two motions and then considers the versity, South Orange, New Jersey. more realistic situation of interact,ion heReinhold Publishing Carp., New York, tween vibration and rutation. The sixth 1966. Select,edTopics in Modern Chemchapter is a long one (23 pages) concerned 116 pp. Figs. and istry Series. ix with spectra due to electronic transitions tables. 13 X 19 cm. $1.95. in diatomic molecules. I n t,he last chapter (2 pages) the author The purpose of this little hook is to present the important aspects of molecular reminds the reader that the discussion in spectroscopy on an elementary level. No this hook has been limited to diatomic mathematical preparation beyond algebra. gaseous molecules and that an exact is required for understanding it. The theoretical treatment of the spectra. of book is the eighteenth volume in the many complex molecules would lead into Reinhold paperback series, Selected Topics an almost hupeless mathematical problem. But the reader is assured that the princiin Modern Chemistry, and is intended ples presented in t,his book can be applied primarily for use as supplementary reading to a n empirical interpretat,ion of the by undergraduate chemistry students. spectra of many complex molecules. The The author presents the suhject matter ,
