Diaza-15-crown-5 extends the lifetime of M intermediates in BR membranes. Diaza-15-crown-5 is a crown ether compound that alters the surface charge of BR membranes. Diaza-15-crown-5 changes the surface charge of the BR film. and overall membrane stability. Diaza-15-crown-5 allows the M state to be maintained for a longer period of time^[1].