207Pb Satellite spectra and 207Pb–H long-range coupling constants of the symmetrical isomers of tetrafuryl- and tetrathienyl-lead

Abstract

The ¹H n.m.r. spectra and the ²⁰⁷Pb satellite bands of the two symmetrical isomers of tetrafuryl- and tetrathienyl-lead have been analysed and all the coupling constants and proton chemical shifts derived. The relative signs of long-range J(²⁰⁷Pb–H) coupling constants appear to be alike, as may be seen by comparing experimental and simulated spectra.

Proton chemical shifts can be interpreted in terms of some degree of (d–p)π interactions, while proton–proton coupling constants seem to be only slightly affected by such perturbation.

Long-range J(²⁰⁷Pb–H) coupling constants were found to be mainly determined by the Fermi contact mechanism.