BOOK REVIEWS
April 5, 1962
exhibits two very broad bands centered a t about 5400 and 6700 if. I n water the compound is rapidly oxidized to rhodizonate ion, Cf,06-’. The magnetic properties of C6Oa-* are of especial interest in connection with its electronic structure. Simple LCAO molecular orbital calculations3 predict a biradical nature for C6O6-*. However, measurements by the Gouy method show that K&06 is diamagnetic. The compound may be one in which electron correlation effects, neglected in the simple M O approach, operate to prevent the degeneracy. Similar arguments have been used to predict a non-degenerate ground state for X complete treatment of CcO6-*, cy~lobutadiene.~ including configuration interaction, would present a formidable theoretical problem. Pure K4C608gives no electron spin resonance signal, but the compound is rapidly oxidized upon T h e rhodizonate anion in the crystalline salts XagCsOa and KpCeOa appears also t o have a non-planar or otherwise distorted geometrical form. (3) L). L . Powell, M. I t o and K. West, unpublished work. (4) D. P. Craig, Proc. Roy. SOL.( L o n d o n ) , 8 2 0 2 , 40s (1950); cj. A. U. Liehr, Z . p h y s i k . C h e m . , N.P.. 9, 338 (103G).
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exposure to air, with the development of a strong esr signal. Incomplete oxidation of K G O 6 under ether also converts i t to a strongly paramagnetic solid, green in color, with a single electron spin resonance near g = 2.003. A similar green salt may be obtained instead of lC4c\6O6 in the preparation described above if a small amount of oxygen is present. Further oxidation converts the green salt to potassium rhodizonate, but samples stored in the absence of oxygen maintain their radical nature almost undiminished for several months. It has not yet proved feasible to prepare this radical substance in pure form, but observations so far are consistent with the hypothesis that the green salt may contain the tripotassium salt of the aromatic radical-trianion, C606-3. Acknowledgments.-The authors are indebted to Dr. Mitsuo Ito and hlr. David Powell for many helpful discussions, and to The Kational Science Foundation for support of this investigation. DEPARTMENT OF CHEMISTRY UNIVERSITY OF WISCOXSIN ROBERT ~L‘EST MADISON6, WISCONSIN IISIENYINGXIU RECEIVED JANUARY 2 2 , 1962
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BOOK REVIEWS L
Some Recent Developments in the Chemistry of Phosphate the reduced double layer free energy F are calculated from Esters of Biological Interest. By H. GOBINDKHORANA, the previously calculated dependence of reduced potential Institute for Enzyme Research, University of Wisconsin. on reduced reciprocal distance. Tabular results are John % y el and Sons, Inc., 440 Fourth Avenue, New York given for 1-1, 2-1, 3-1, 1-2 and 1-3 electrolytes; data for 16, N. Y. 1961. ix 141 pp. 15.5 X 23.5 cm. Price, other symmetric electrolytes (2-2, 3-3 etc.) can be cal$5.25. culated readily from results for 1-1 electrolytes. Part I of the book (pp. 1-42) describes the ~nelliotlof This volume derives from a series of lectures given a t the integration, including transformations of variables to Rockefeller Institute in 1959, but is up-dated with many dimensionless groups, an outline of the numerical integrareferences into 1961. I t naturally emphasizes the author’s tion method selected for IBM-704 computer prograrnniing, interests but is an essential for those interested in nucleotide and polynucleotide syntheses. The first twelve-page chap- and an outline of methods for transforming tabular results ter is a survey of phosphate compounds of importance in (all in dimensionless groups) into quantities of physical biological reactions and is certainly worthy of attention by interest. Results of the present calculation are comparcd with those of the Debye-Huckel approximate treatment and any graduate student. the flat plate double layer. Empirical analytical fornis SLOAX-KETTERING DIVISIOHOF representing data for I and F to within 26y0 and 2070, COKNELL UNIVERSITY MEDICALCOLLEGE respectively, are also given. Part I contains 28 tables. XEWYORK21, X.Y. GEORGEBOSWORTH BROWN Part I1 (pp. 46-372) presents the dependence of y , I + , I - , and F on x with yo and qo as parameters in t d h d u ‘ form for 1-1, 2-1, 3-1, 1-2 and 1-3 electrolytes. CoinThe Electrical Double Layer Around a Spherical Colloid putations for 1-1 electrolytes are particularly extensive Particle. Computation of the Potential, Charge Density, (pp. 46-208); results for q o = 0.1, for example, are presented and Free Energy of the Electrical Double Layer Around a for the range 0.3 S x 5 10.0 in units of 0.1 for 1 5 yo 5 16 Spherical Colloid Particle. By A. L. LOEB,Associate with increments of 1 from 1-10, 2 from 10 to 16; this is Professor of Electrical Engineering, Massachusetts repeated with reduced ranges of x for qo = 0.2, 0.5, 1.0, 2.0, Professor Institute of Technology, J. TH. G. OVERBEEK, 5.0, 10 and 20. For values of x smaller than those tabulated of Physical Chemistry, University of Utrecht, and the Debye-Huckel approximation is adequate. The authors P. 13. ~VIERSEMA, vnn’t Hoff Laboratory, University of state that numerical interpolation between tabulated reUtrecht. The RI.1.T. Press, Massachusetts Institute of sults will generate results accurate to O.lycif carefully done; Technology, Cambridge, Massachusetts. 1961. 375 pp. linear interpolation between values of x for fixed 90 and yo 18 5 X 26 cm. Price, $10.00. appears generally possible to within 170, but interpolation between different values of qo and yo will require more refined This book reports the numerical integration of the PoissonBoltzmann equation for spherical colloidal particles in interpolation involving, for example, ratios of tabulated quantities to approximate or empirical analytical represenelectrolytic solution. Results are presented in terms of tations of them. reduced ( L e . , dimensionless) quantities. First, y (reduced electrostatic potential) is calculated a s a function of 1: (reThis is a specialist’s book concerned principally with duced reciprocal distance from center of particle) with yo numerical results. These results appear to be carefully and q o = l/xo ( X O and yo are values of x and y a t particle obtained, and t o reflect solutions of the Poisson-Boltzmann surface, outer Helmholtz plane, or slipping plane dependequation of adequate precision and detail covering a wide ing on application) as parameters. I+ and I- (x2/4 times range of parameters. The authors point out that the excess charge due to cation and anion outside of a sphere DebyeHuckel approximation t o the Poisson-Boltzmann of rediced radius l / x centered on the particle center) and equation is only valid if Ze&/kT
