β Scribed by Yordanka Dimitrova; Derek steele
No coin nor oath required. For personal study only.
The concept of bond moments and derivatives in the context of vibrational transition moments has been examined by calculations on methylene fluoride and ethene at the 3-21 G* level and N,Ndimethylformamide at the 3-21 G level. It is shown that transition moments on stretching and bending lie up to 15' off the bond axis and perpendiculars.
Nearest atom non-bonded interactions appear to be responsible for these deviations in that as bonds stretch the moments swing in the direction expected for a reduced spatial interaction.
It is proposed that as more data is accumulated it may be possible to establish the magnitude of these interaction moments in any defined system and hence to improve considerably predictive capabilities for large systems without the expensive procedure of uh inifio calculations.
π SIMILAR VOLUMES
The additivity of the effect of hydrogen bonding has been studied by ab initio calculations for two 1:2 formamide-water complexes, one where the formamide molecule is both a donor and acceptor (DON) and one where the two water molecules are bonded to the carbonyl oxygen (Doe). By comparison with the
The microwave spectrum of the heterodimer EKYbMF is reported, the collinearity of the nuclei establislIed, and ro(N--F) = 2.796 A obtained. From the Stark effect, ~10 (tiCN4iF) = 5.59 r 0.02 D which indicates an enhancement of 0.78 D over the vector sum of the monomer values.