Core Excitation Spectroscopy of Stable Cyclic Diamino Carbenes, Silylenes and Germylenes

John F. Lehmann^a , Stephen G. Urquhart^b , Laura Ennis^a , Adam P. Hitchcock^a++ , Ken Hatano^c ,
Shilpi Gupta^c and Michael K. Denk ^c

a. Department of Chemistry, McMaster University, Hamilton, ON, Canada, L8S 4M1
b. Department of Physics, North Carolina State University, Raleigh, NC, USA, 27696-7518
c. Department of Chemistry, University of Toronto, Mississauga, ON, Canada, L5L 1C6

Abstract

Inner shell electron energy loss spectra, supported by ab initio calculations, are used to explore the origin and relative stability of a series of cyclic, saturated and unsaturated divalent diaminocarbenes, diaminosilylenes and diaminogermylenes. The dominant stabilization comes from delocalization over the N-E(II)-N fragment in all three species, combined with steric stabilization by t-butyl substituents.