Syntheses,Structures And Photochromic Properties Of Sulfo-substituted Spiropyrans And Their Sulfonyl Azides

The photochromism of spiropyran derivatives has been attracted increasing interest due to their practical applicability in the areas of optical switches,photochromic spectacles,liquid crystalline components,memories and sensors.Most the reported spiropyrans show positive photochromism with a structural changing from the colorless(or light colored)ring-closed spiropyran(SP)form to the deep colored open-ring merocyanine(MC)form under ultraviolet/visible light irradiation.Besides finding positive photochromic compounds with new structure,developing negative photochromic spiropyrans is also desirable for both highly efficient photochromism and excellent fatigue resistance.However,only few examples of the latter have been published so far.Organic azide compound is an important class of organic synthesis intermediates which contain azido-based high-energy active functional groups.They have been widely used in organic synthesis,chemical biology,functional materials and clinical medicine field etc.Basing upon the initial accumulation on the research of spiropyran ligands,we designed and synthesized a series of new reversible negative photochromic sulfo-substituted spiropyrans,in which sulfonic acid group bound directly to the indoline group.Then we synthesized a series of novel sulfonyl azide compounds through azide reaction,and the combination of theoretical calculations and experimental method laid the foundation for the study of fluorescent probe materials.The article includes a review of the literature concerning spiropyran compounds and the following four part:The first part of the thesis demonstrated a detailed summary on negative photochromic compounds,negative photochromic sulfo-substituted spiropyrans,sulfonyl azides,as well as their application,followed by coming up with the research destination and plan.The second part of the thesis exhibited the design and synthesis of a serie s of novel sulfo-substituted spiropyrans,namely 1’,3’,3’-trimethylspiro[chromene-2,2’-indoline]-6’-sulfonic acid(SSP),6-methyl-1’,3’,3’-trimethylspiro[chromene-2,2’-indoline]-6’-sulfonic acid(SSP-CH3),6-nitro-1’,3’,3’-trimethylspiro[chromene-2,2’-indoline]-6’-sulfonic acid(SSP-NO2),6-chloro-1’,3’,3’-trimethylspiro[chromene-2,2’-indoline]-6’_sulfonic acid(SSP-Cl),5-methoxy-1’,3’,3’-trimethylspiro[chromene-2,2’-indoline]-6’-sulfonic acid(f-SSP-OCH3),6-methoxy-1’,3’,3’-trimethylspiro[chro mene-2,2’-indoline],6’-sulfonic acid(p-SSP-OCH3),7-methoxy-1’,3’,3’-trimethylspi ro[chromene-2,2’-indoline]-6’-sulfonic acid(m-SSP-OCH3),8-methoxy-1’,3’,3’-trim ethylspiro[chromene-2,2’-indoline]-6’-sulfonic acid(o-SSP-OCH3),were designed and synthesized.These compounds were all synthesized by the reaction of sulf onate-substituted indolenium with salicylaldehyde,and were successfully charact erized by 1H NMR,IR spectroscopies and 13C NMR.In addition,the C38H46N2 O12S2(H2O)4 was successfully characterized by single-crystal X-ray structural ana lysis.The third part of the thesis presented the design and synthesis of a series of novel sulfonyl azide spiropyrans and its reduction products.Namely 1’,3’,3’-t rimethylspiro[chromene-2,2’-indoline]-6’-sulfonyl azide(SSP-N3),6-methyl-1’,3’,3’-t rimethylspiro[chromene-2,2’-indoline]-6’-sulfonyl azide(SSP-CH3-N3),6-nitro-1’,3’,3’-trimethylspiro[chromene-2,2’-indoline]-6’-sulfonyl azide(SSP-NO2-N3),were des igned and synthesized.They were synthesized by the azide reaction of sodium azide with SSP,SSP-CH3,SSP-NO2,respectively.Then a series of sulfonyl am ide spiropyrans were synthesized by the reduction reaction of Na2S with sulfon yl azide spiropyrans synthesized above,namely 1’,3’,3’-trimethylspiro[chromene-2,2’-indoline]-6’-sulfonyl amide(SSP-NH2),6-methyl-1’,3’,3’-trimethylspiro[chromene-2,2’-indoline]-6’-sulfonyl amide(SSP-CH3-NH2),6-nitro-1’,3’,3’-trimethylspiro[chro mene-2,2’-indoline]-6’-sulfonyl amide(SSP-NO2-NH2).These compounds were suc cessfully characterized by 1H NMR and IR spectroscopies.At the same time,w e optimized geometrical structures of the synthesized compounds and confirmed the IR absorption peak by calculating at the DFT level using a B3LYP/6-31+G(d,p)basis set.For these calculations the package of Gaussion 09 was used.T he results established that the synthesized compounds were consistent with the theory.In order to study the photochromic properties of sulfo-substituted spiropyrans,the fourth part of the thesis described the investigation on UV absorption spectroscopy for their DMF solution.It was shown well reversible negative photochromism in solution,and the process of color change could be recycled and repeated over many times with the stable properties.The resistance to fatigue was also greatly enhanced.In addition,the photochromic properties of the sulfonyl azide spiropyrans were also compared with those of the sulfonic acid spiropyrans by UV absorption spectroscopy.The energy of HOMO and LUMO orbitals of these open-ring/closed-ring compounds were also calculated at the DFT level using a B3LYP/6-31+G(d,p)basis set.