No abstract

and the natural abundance I7O NQR and nuclear magnetic resonance (NMR) solution spectra of a number of selected systems were obtained. The orientations of the principal axes of the '"N electric field gradient tensor (efg) in the NO group were determined using a Townes-Dailey treatment of the NQR results, combined with a -C crosspolarization magic-angle sample-spinning NMR line shape analysis of carbons bonded directly to nitrogen. The major principal axis ( Z ) is coincident with the N-0 bond. The orientation of the principal ( Z ) axis of the I7O efg tensor also lies along the N-0 bond, as determined by Townes-Dailey analysis. The N-0 m-bond orders show considerable sensitivity to the nature of the para-substituent, ranging from 0.17 to 0.31. "0 and -N NMR chemical shifts parallel these changes in m-bond order.

No abstract

Oxidation of tetrathiafulvalene with CuCI,. 2H,O in ethanol produced the mixed valence metallotetrathiaethylene (TTF),(CuCI,), containing both TTF? and TTF2+, which was converted into (TTF), CuCI, on dissolution in hot acetonitrile while the CUCI,~-and BF,salts of TTF2+ were prepared using CuC1,-2II,O and Cu (BF,), in acetonitrile ; resonance Raman spectroscopy was used to probe the oxidation state of TTF in these copper metallotetrathiafulvalenes, and e.s.r. and magnetic susceptibility data indicate the presence of threedimensional magnetic interactions in the TTF" and TTF2+ CuC1,2-salts.