ChemInform Abstract: Photochromism of Spirooxazines in Homogeneous Solution and Phospholipid Liposomes.

Abstract

organic phosphors, phototropic organic phosphors, phototropic (photochromic) substances T 2200 -185Photochromism of Spirooxazines in Homogeneous Solution and Phospholipid Liposomes. -The photochromic behavior of spirooxazines, e.g. (I)-(III), in several solvents and phosphatidylcholine (PC) liposomes as well as substituent and solvent effects upon reaction dynamics and intramembrane diffusion of their merocyanine (MC) forms are studied. In contrast to PC liposome-bound spirooxazines containing a phenanthrene moiety, e.g. (I), photoexcitation of phenanthroline analogues, e.g. (II) and (III), is accompanied by spectral shifts. This is due to translocation of their MC forms from relatively nonpolar sites within the PC liposome membrane to more polar sites at the aqueous-organic interface, and by a dramatic destabilization equivalent to a dramatic increase in ring-closure rate of the MC form upon coordination to a Ru(bpy) 2+ 2 metal center. -(KHAIRUTDINOV, RAFAIL F.; GIERTZ, KETURAH; HURST, JAMES K.; VOLOSHINA, ELENA N.; VOLOSHIN, NIKOLAI A.; MINKIN, VLADIMIR I.; J.