Accession Number : AD0696744

Title :   NMR MEASUREMENTS OF PROTON EXCHANGE IN AQUEOUS THIOUREA.

Descriptive Note : Technical rept.,

Corporate Author : CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF CHEMISTRY

Personal Author(s) : Vold,R. L. ; Correa,Adolfo

Report Date : 12 NOV 1969

Pagination or Media Count : 22

Abstract : The semiclassical lineshape expression of Hahn, Maxwell and McConnell for chemical exchange between two unequally populated sites is extended to the case where spin 1/2 nuclei in one site are coupled to a relaxing nucleus of spin I. The lineshape expression is written in closed algebraic form for spin I=1 and I=3/2. Experimental results are reported for acid catalyzed protolysis of aqueous thiourea. Possible exchange reactions are discussed. Water linewidths are used to derive rate parameters. The rate law for acid catalyzed protolysis of aqueous thiourea was found. Protolysis of thiourea N-H protons is concluded to be catalyzed about 60 times more efficiently than N-methyl acetamide N-H protons. (Author)

Descriptors :   (*THIOUREA, *NUCLEAR MAGNETIC RESONANCE), SOLUTIONS(MIXTURES), EXCHANGE REACTIONS

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE