Measurement of the sign and magnitude of J(XX′) in AnA′nXX′ nuclear spin systems: examples from organophosphorus chemistry

Abstract
A convenient, sensitive, and accurate nuclear magnetic double resonance technique is described for the determination of J(XX′) in AnA nXX′ spin systems in which J(AA′) is zero and |J(XX′)| is large compared with |J(AX)–J(AX′)|. The method is applied to the determination of the sign and magnitude of J(PP) in trans-{(MeO)(PhO)2P}2Mo(CO)4, trans-{(Me2N)3P}2Hg,PtCl2, {(MeO)2P(O)}2·MePhPeqn;PMePh, and trans-(Et3P)2(Me2N[graphic omitted]H)RhCl3.