Phosphonato-phosphinito peri-substituted naphthalenes

Nap[P(E)(OMe)2][P(H)(O)(OMe)] (Nap = naphthalene-1,8-diyl, E = S, Se) were synthesized and fully characterised including crystal structure analyses. They show repulsive interactions of phosphorus functionalities with hydrogen atom of phosphinite moiety placed in the peri space, the distortion of naphthalene backbone is comparable to that observed in 1,8-bis(phosphonato) naphthalenes. The conformational isomerism resulting from the restriction of the cogwheel rotational motion about the C–P bonds is observable by NMR.