| abstract |
A naphthopyran compound represented by formula (I); wherein R4, R5, R6, R7, R8, R9, R10 and R11 are each selected from the group consisting essentially of hydrogen, a first stable organic radical, a heterocyclic groug, halogen, a first nitrogen-substituted group, and a first nitrogen-substituted ring compound; A and B are each selected from the group consisting essentially of hydrogen, substituted phenyl, and substituted naphthyl, provided that at least one of A or B is substituted phenyl or substituted naphthyl; and any substituent of any substituted phenyl or substituted naphthyl at A or B is selected from the group consisting essentially of hydrogen, a second stable organic radical, a heterocyclic group, halogen, a second nitrogen-substituted group, and a second nitrogen-substituted ring compound, provided that at least one substituent of any substituted phenyl or substituted naphthyl at either A or B is phenyl, naphthyl, or furyl. |