N-Diaziridyl anion (1), the conjugate base of a simple hydrazine, has been generated in a Fourier transform mass spectrometer (FTMS) by reduction of the nitrogen-nitrogen double bond in diazirine. The acidity of its conjugate acid (390 ± 3 kcal mol-1) and the electron affinity of its corresponding radical (0.50 ± 0.10 eV) were measured. These data are combined in a thermodynamic cycle to afford the N-H bond strength in trans-diaziridine (2, 88 ± 4 kcal mol-1). This value represents one of the few such bond energies reported for a hydrazine. High-level ab initio complete basis set-quadratic configuration interaction/atomic pair natural orbital (CBS-QCI/APNO) calculations on 1 and the parent hydrazyl anion (NH2NH-) are presented. These results provide strong confirming evidence for Berkowitz's recent determination of the N-H bond strength in hydrazine.
Bibliographical noteFunding Information:
Support from the National Science Foundation, the donors of the Petroleum Research Foundation as administered by the American Chemical Society, the Minnesota Supercomputer Institute, and the University of Minnesota—IBM Shared Research Project are gratefully acknowledged.
© 1999 Elsevier Science B.V.
- Ion cyclotron resonance (ICR)