The reaction of 2 hydroxy 3 (4,5 diphenyl 1,3 oxazol 2 yl) 1 naphthaldehyde with 1,2,3,3 tetramethyl 3H indolium perchlorate afforded photochromic spiro[indoline 2,3´ naphthopyran] containing a 4,5 diphenyloxazole group in position 5´ of the naphtho pyran fragment. The merocyanine form of the spiropyran gave complexes with bivalent heavy cations.Photochromic organic molecules (including spiro pyrans and spirooxazines) have been under intense study in the last few years because they can be used in optical systems for recording and displaying information, as well as in sensors, optobio and optoelectronics, transport sys tems, and catalysis. 2-5Photochromic transformations of spironaphthopyrans (Scheme 1) and spirooxazines involve thermally and pho tochemically reversible cleavage of the C spiro -O bond of the cyclic isomer A followed by cis trans isomerization into metastable merocyanine form B. The latter sponta neously or when exposed to visible light changes to the starting spiro form. 2,3In recent years, isomerization of spiropyrans and spirooxazines in the presence of certain chemical species (specific substrates such as, e.g., metal cations 6 ) has at tracted great interest. In this case, spiropyran and spiro oxazine molecules usually contain an ionophore fragment in the ortho position relative to the pyran/oxazine O atom, while the phenoxide O atom of the colored isomer pro vides additionally coordination to the metal cation. Much research is devoted to spirocyclic photochromes contain ing ionophore crown ether fragments, 7-9 the isomeriza tion of which is substantially affected by alkali and alka line earth metal cations. The number of spiro compounds the transformations of which are affected by transition and rare earth ions is much smaller. Among them are spirobenzopyranindolines with methoxy, 10-12 piperidino methyl, 13 and other electron donating substituents 14 in position 8 and quinolinespiropyranindolines. 15-19 Re cently, 5´ benzothiazolylspirooxazines have been synthe sized and found promising for use as photochromic chelat ing reagents. 20 Oxazole derivatives, especially those containing aro matic or heterocyclic substituents in positions 2 and 5, are good fluorophore systems. 21 They are widely used as fluo rescent bleaching agents and can form complexes with transition element ions. 22 The present work was devoted to the synthesis and study of the coordinative power of 5´ (diphenyloxazo lyl)spironaphthopyran (11).
Photochromic substances T 2200Spiropyrans and Spirooxazines. Part 3. Synthesis of Photochromic 5'-(4,5-Diphenyl-1,3-oxazol-2-yl)-spiro[indoline-2,3'-naphtho[2,3-b]pyran]. -The merocyanine form of title compound (XI) forms intensely colored complexes with bivalent heavy metal ions, e.g., Cu 2+ , Mn 2+ , Ni 2+ , Zn 2+ , and Cd 2+ . -(VOLOSHIN, N. A.; CHERNYSHEV, A. V.; METELITSA*, A. V.; RASKITA, I. M.; VOLOSHINA, E. N.; MINKIN, V. I.; Russ. Chem. Bull. 54 (2005) 3, 705-710; Inst. Phys. Org. Chem., Rostov State Univ., Rostov-on-Don 344090, Russia; Eng.) -D. Singer 08-149
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