L. Bencivenni et al., THE MOLECULAR-STRUCTURE OF N,N'-DIFORMOHYDRAZIDE FROM AB-INITIO STUDIES (MP2 AND DENSITY-FUNCTIONAL THEORY) AND FTIR MATRIX SPECTROSCOPY, Perkin transactions. 2, (11), 1997, pp. 2445-2451
The FTIR spectrum of N,N'-diformohydrazide isolated in argon and nitro
gen matrices is presented and discussed in terms of normal modes predi
cted by ab initio calculations, MP2/6-31G and BLYP/6-31G* methods are
applied to calculate vibrational frequencies, IR intensities and isot
opic shifts of different structures of the molecule. The number of abs
orption bands and their frequencies for the isolated molecule differ s
ignificantly from those of N,N'-diformohydrazide in the solid state. T
he conformation of the undistorted molecule is different from the plan
ar structure adopted by the molecule in the crystal and such a conform
ation change is proposed as the reason for the spectral differences, A
b initio calculations support this assignment and predict the vapour o
f N,N'-diformohydrazide to be a mixture of conformers.