The microwave spectra ofcishyphen;CHDNOH,transhyphen;CHDNOH, C13H2NOH, CH2N15OH, and CH2NO18H were assigned. Together with the results of previous work on the normal species and CH2NOD, the data give the following planar structure for formaldoxime: bond lengths in Aring;; CHcis=1.085, CHtrans=1.086, Cdblbnd;N=1.276, NO=1.408, OH=0.956; bond angles; HcisCN 121deg;46prime;, HtransCN 115deg;33prime;, CNO 110deg;12prime;, NOH 102deg;41prime;.The most significant feature of the structure is the difference betweencishyphen; andtranshyphen;HCN bond angles. This ``tilt'' of the methylene group appears to be too large to be attributed to steric repulsion. The Cdblbnd;N and Nsngbnd;O bond lengths are consistent with the Schomakermdash;Stevenson relation if allowance for resonance is made.
展开▼
