Tunable photochromism in air-stable, robust dithienylethene-containing phospholes through modifications at the phosphorus center.

Robust photoswitch: The photophysical and photochromic properties of a series of robust dithienylethene-containing phosphole derivatives can be readily tuned by simple modifications at the phosphorus center. Both the open and closed forms of the phosphole compounds are stable in benzene solution and in PMMA film in the dark.