A systematic approach to the AA′BB′, AA′BB′MX and derived systems in nuclear magnetic resonance

The AA′BB′ and AA′BB′MX nuclear magnetic resonance spin systems for I = ½ nuclei have been analysed. Expressions for the transition frequencies and intensities have been obtained which have the maximum accuracy consistent with practicable use. The analyses have been applied respectively to a hypothetical AA′BB′ nuclear spin system and to the two molecules para- fluoro-phenyldichlorophosphine and tris-para-fluorophenylphosphine. Inconsistencies in earlier treatments of the AA′BB′ system have been clarified.