title: The influence of a 1,1-diarylvinyl moiety on the photochromism of naphthopyrans.
abstract: 1,1,3-Triarylpent-4-en-1-yn-3-ols, efficiently obtained in two steps from 1,1,3-triarylprop-2-yn-1-ols by a Meyer-Schuster rearrangement and subsequent addition of lithium trimethylsilylacetylide, react with either a 1- or 2- naphthol to afford photochromic 1,1-diarylvinyl substituted naphtho[1,2-b]- or naphtho[2,1-b]-pyrans respectively. Irradiation of solutions of these naphthopyrans results in reversible electrocyclic ring-opening to afford photomerocyanines which possess an extended conjugated system and show a bathochromically-shifted λ(max) relative to the non-vinyl substituted analogues.
authors: School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
authors: Christopher D
authors: CD
authors: Gabbutt
authors: B Mark
authors: BM
authors: Heron
authors: Colin
authors: C
authors: Kilner
authors: Suresh B
authors: SB
authors: Kolla