NH STRETCHING BANDS OF SOME HYDRAZINE DERIVATIVES AS EVIDENCE FOR A LONE PAIR-BOND INTERACTION

Monomeric N,N-dialkylhydrazines show two abnormally spaced NH stretching bands (~180 cm-1) the lower frequency one being much more intense. In half-deuterated analogs the two bands persist with only slightly smaller spacing. With phenyls replacing alkyls the spacing and the intensity difference are less pronounced. Symmetrical (1,2 -substituted) hydrazines show similar phenomena. The interaction between the nitrogen lone pair and the next N-H bond is discussed as the most probable cause of these features. © 1969.