Synthesis and photophysical properties of N-(5-amino-2-substituted-10-methyl-9H-benzo[a]phenoxazin-9-ylidene)ethanaminium chlorides

Abstract

Fluorescent benzo[a]phenoxazinium chlorides possessing different substituents at position 2, namely propoxyl, 4-ethoxy-4-oxobutoxyl or 3-carboxypropoxyl groups, and at positions 5, 9 and 10 of the tetracyclic system, the amino, ethylamino and methyl groups, respectively, were synthesised in good to excellent yields. Absorption and emission studies carried out in ethanol, water and at simulated physiological conditions revealed that all compounds absorbed in the range 614–628 nm and emitted from 630 to 652 nm.