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From Table 111 it is reasonably certain that the major, if not the entire change is accounted for by the difference, &AH, which may be set equal to the zero point energy difference. This conclusion is the same as was reached from the temperature dependence of k~/ k~ for the solvolysis of l-butyl chloride but differs from initial indications obtained for the mono-and dimethylamines.I5bThe agreement of the values of ACp for the protium and deuterium analogs confirms the absence of significant solvation differences accompanying the secondary deuterium isotope effect in this system (ref 1, p 158).Total effective hydration numbers have been determined for a number of alkali metal salts and alkaline earth metal salts by studying the temperature-dependent proton chemical shifts of their aqueous solutions. The hydration numbers obtained for the alkali metal halides were rationalized by assuming that the cation was coordinated to four waters whereas the anions contributed little if any to the hydration number obtained. The hydration numbers for the alkaline earth metal halides were found to include both primary and secondary waters which was attributed to their larger charge-size ratio. Also studied was the effect of several anions (Cl-, Br-, C104-, and p-toluenesulfonate-) on the effective hydration number of their sodium salts. Both NaC104 and Na p-toluenesulfonate gave hydration numbers lower than NaCl and NlaBr. The decrease in the effective hydration number was explained in terms of ion pairing, which was further supported by 23Na relaxation times. taoduction I n the past decade nuclear magnetic resonance (nmr) has proved to be valuable in studying electrolyte solutions; an excellent review has been given by Hinton and Amis.' Proton chemical shifts of electrolyte solutions have revealed information about solvent structuring and hydrogen bonding in these solutions.Of recent interest, however, have been the studies of solvation numbers by nmr. For ions which form rather strong coordination with water such 8s Ala+, ]Be2+, and Ciaa+, the exchange of solvation water with bulk water is sufficiently slow so that separate resonances for both types of water may be observed using either "0 re~onance~-~ or, a t low temperature, using proton r e s o n a n~e .~~~ By the addition of acetone to aqueous solutions of Mg (Clod) and Mg ( NO3) 2, Matwiyoff and Taube? were able to decrease the exchange rate of solvation waters, thus distinguishing the proton signals of Mg (H2O) 2' + ion from those of the bulk water st temperatures below -70°.The exchange of solvation water for bulk waters is much faster in the case of alkali metals, and their study by the above direct methods is not feasible. However, Malinowski, et al., have shown $ha$ the temperature effects on the proton shifts of aqueous electrolyte solutions are related to the degree of "effective" hydration.8J' Their method is based on the assumption that the hydration number and the chemical shift for the hydration waters do not change with temperature; hence, the observed chemica...

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Microbial transformation of the tetrazolinone herbicide F5231 was accomplished with the ifiamentous fungus Absidia pseudocylindrospora Hesseltine et Ellis (ATCC 24169). The fungus converted the herbicide to six metabolites which were identified spectrally by mass, infrared, and nuclear magnetic resonance spectroscopy. Microbial transformations of pesticides have provided an alternative route for synthesis of pesticide intermediates (4, 6) as well as a means of comparing metabolites produced microbially with those produced in higher organisms (7). F5231 {1-[4-chloro-2-fluoro-5-(ethylsulfonylamino)phenyl]-1, 4-dihydro-4-(3-fluoropropyl)-SH-tetrazol-5-one} is a new herbicide under consideration by the Agricultural Chemical Group of FMC Corp. Its structure is given in Fig. 1. Its synthesis and properties are described in the patent application (G. Theodoridis,