The microwave spectra of the CD3species and of seven monosubstituted isotopic species of CH3CHdblbnd;Cdblbnd;O have been examined, and a complete structure of methylketene has been obtained by the substitution method. The structural parameters found are: Cdblbnd;O=1.171, Cdblbnd;C=1.306, Csngbnd;C=1.518, Csngbnd;H (vinyl)=1.083, and Csngbnd;H (methyl)=1.083 or 1.11 Aring; (see text). The ketene group is linear, and the methyl group is staggered, ang;CCC=122.6deg;, ang;C(1)C(2)H(2)=113.7deg;, and ang;HCH=109.9deg; or 108.8deg;.The barrier splittings were used to determine the value of the barrier to hindered rotationandthe angle between the methylhyphen;axis and the principalhyphen;axis system for each of the monosubstituted species;V3=1177plusmn;20 cal/mole. The dipole moment of methylketene was measured on the 21,2rarr;31,3transition, yielding mgr;a=1.755, mgr;b=0.35, mgr;=1.79 D.
展开▼
