Microwave Spectrum, Conformation, Dipole Moment, and Barrier to Internal Rotation in Methyl Vinyl Ether

Abstract

Articles you may be interested inThe microwave spectrum, dipole moment, and barrier to internal rotation of 3methyl2butenenitrile J. Chem. Phys. 77, 5885 (1982); 10.1063/1.443862Microwave spectrum, molecular structure, barrier to internal rotation, and dipole moment of methyl monofluorogermaneThe microwave spectrum of methyl vinyl ether, CHaOCH=CH2, has been studied in the frequency region 8 to 40 Gc/sec. Absorption lines have been assigned to a planar cis isomer, with a barrier to internal rotation of the methyl group of 3830±100 cal/mole. The components of the dipole moment along the principal axes of inertia were measured and found to be 1-'.=0.294 D, 1-'.=0.915 D (I-' total =0.96 D). Spectra were observed of the excited methyl torsional state and of two additional excited vibrational states, corresponding, respectively, to vibrations at about 240, 205, and 327 cm-l . These findings are confirmed by far-infrared and Raman spectra.

Mécanisme de la décomposition photosensibilisée au mercure du méthylvinyléther à 2537 Å

“…4) (c) La dCcomposition dans les deux cas s'effectue presqu'exclusivement par la rupture P, et le radical de type alkyle ainsi crtt est stabilise par rtsonnance (9,15 I1 est concevable que ces resemblances trouvent leur origine dans la similaritt de structure de l'ttat fondamental: cis-planaire (19,20). M&me la barri2re de rotation du groupe vinyle a la meme hauteur chez l'un et chez l'autre (21).…”

Déplacement chimique du proton en résonance magnétique nucléaire. I. Calcul du terme diamagnétique en vue de son utilisation à l'étude de la structure des molécules. Application aux éthers vinyliques

“…Les composts 3, 4 et 5 prtsenteraient donc une gtomttrie prtftrentiellement plane s cis (a), alors que le compost 6 serait en majoritk s trans ou non plan, la seconde alternative ktant ttayte par la comparaison des tnergies totales. En ce qui concerne le dtrivt 3, ces conclusions sont en accord avec les rtsultats relatifs a l'tther de vinyle et de mkthyle (27,28). Des informations suppltmentaires sont recherchtes par spectroscopies ultraviolette et infrarouge.…”

Unexpected signs of five-bond and six-bond proton spin–spin coupling constants in some acyclic conjugated systems. Through-space couplings.

“…The stable form is 20 in which the methyl group is staggered a b c~i t tlhe 8-C bond (301, having 8 = 60": 180', and 300"; C#I = 0". 5J,"5C"3 is calculated as -0.23 Hz by averaging over tlie three values of 8, a reasonable procedure in that the barrier to rotation about the 0-CH3 bond is 3.8 kcal ~n o l (30). j~, " '~" s is calculated as 0.03 Hz for this col~fornlation (Table 4).…”