The Microwave Spectrum, the <i>r</i>s Structure and the Dipole Moment of the <i>TT</i> Isomer of Diethyl Ether

Abstract

Abstract The microwave spectra of six isotopic species of diethyl ether were measured in relation to the molecular form and dipole moment. Transitions of the TT(trans-trans) isomer could be assigned and the rs structure of this isomer was obtained by the substitution method. The structural parameters of the TT isomer of diethyl ether are; r(CO) 1.408 Å, r(CC) 1.516 Å; α(COC) 112°25′, α(OCC) 108°37′ for the skeleton; r(CH) 1.093 Å, α(CCH) 110°11′, α(OCH) 110°10′, α(HCH) 107°29′ for the CH2 group and r(CH) 1.090 Å, α(CCHs) 110°35′, α(CCHa) 110°15′, α(HsCHa) 108°48′, α(HaCHa) 108°4′ for the CH3 group. The dipole moment was determined to be 1.061±0.018 D from the Stark effect measurement for the TT isomer. A discussion was made on the structure and the dipole moment of the TT isomer of diethyl ether in comparison with those of the similar molecules.