| abstract |
Various non-limiting embodiments disclosed herein relate generally to photochromic compounds, which may be thermally reversible or non-thermally reversible, and articles made therefrom. Other non-limiting embodiments relate to photochromic-dichroic compounds, which may be thermally reversible or non-thermally reversible, and articles made therefrom. For example, one non-limiting embodiment provides a thermally reversible, photochromic compound adapted to have at least a first state and a second state, wherein the thermally reversible, photochromic compound has an average absorption ratio greater than 2.3 in at least one state as determined according to CELL METHOD. Another non-limiting embodiment provides a photochromic compound comprising: (a) at least one photochromic group chosen from a pyran, an oxazine, and a fulgide; and (b) at least one lengthening agent L attached to the at least one photochromic group and represented by the formula -[S1]c -[Q1-[S2]d ]d’-[Q2 -[S3]e’]e’ -[Q3 - [S4]f ]f -S5-P, which is described herein. |