Abstract
Ab initio calculations with full geometry optimization at the 4-21G level show that methyl cyanoacetate, NCCH 2COOCH 3, can exist as the cis (τ=0°) or as the gauche (τ= 145°) conformer, where τ measures the (N)CC(H 2)CO dihedral angle. The cis is calculated to be 3.92 kJ mol −1 more stable than the gauche. Mid infrared spectra of the vapor and solid (77 K) phases and of solutions in liquid argon (80 K) along with Raman spectra of the liquid phase of the undeuterated molecule and of NCCH 2COOCD 3 are reported and assigned. Asymmetric top contour simulations show that in the vapor phase the gauche form is the more stable of the two conformers observed. Low temperature Raman spectra of the liquid phase show that the enthalpy difference between the conformers is 2.46±0.2 kJ mol −1, favoring the cis conformer.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call