Heteronuclear double resonance: the sign of the 29Si–1H coupling constant

Abstract

The signs of the directly bonded spin–spin couplings J(¹³C–¹H) and J(²⁹Si–¹H) are shown to be opposite in methyldichlorosilane and it is concluded that the reduced coupling constant between directly bound Si and H is always positive. The signs and magnitudes of all six coupling constants in ¹³CH₃²⁹SiHCl₂ are determined by tickling procedures.