Quantitative investigations of cation complexation of photochromic 8-benzothiazole-substituted benzopyran: towards metal-ion sensors

The photochromic, thermochromic and metallochromic behaviour of a series of three spiro[indoline-8-(benzothiazol-2-yl)-benzopyrans] has been investigated. The thermodynamic and kinetic parameters of their thermal equilibrium between the ring-closed (spiro) and ring-opened (merocyanine) isomeric forms have been determined using UV-Vis absorption and (1)H NMR spectroscopies. By adding Co(ii) and Ni(ii) ions in acetonitrile solution, 1 : 1 and 1 : 2 metal : merocyanine complexes are formed simultaneously. Using appropriate numerical methods, the kinetic analysis of the complexation allowed us to determine accurately key thermodynamic and spectroscopic parameters of the metal complexes. Results showed that the complexation strength is very sensitive to the size of the indoline nitrogen substituent. Complexation can be reversed by shining white light on the coloured complexes which regenerates the inactive spiropyran form, and releases the metallic ion; hence, these systems display fully reversible negative photochromism. The Zn(ii) complexes exhibit intense fluorescence in the 600-800 nm wavelength range. All these behaviours make these spiropyrans bearing benzothiazole heterocycles promising building blocks for the future construction of photodynamic chemosensors for transition metal ions.

[1]  O. Fedorova,et al.  Spironaphtoxazines produced from crown-containing dihydroisoquinolines: Synthesis and spectroscopic study of cation-dependent photochromism , 2007 .

[2]  Yuepeng Cai,et al.  Synthesis and characterization of zinc(II) and cobalt(III) Schiff base complexes , 2009 .

[3]  Olga A. Fedorova,et al.  Photoswitchable molecular receptors , 2003 .

[4]  M. Abdel-Mottaleb,et al.  Effect of complexation with lanthanide metal ions on the photochromism of (1,3,3-trimethyl-5′-hydroxy-6′-formyl- indoline-spiro2,2′-[2h]chromene) in different media , 2006 .

[5]  V. Minkin,et al.  Photo- and ionochromism of 5’-(4,5-diphenyl-1,3-oxazol-2-yl) substituted spiro[indoline-naphthopyrans] , 2006 .

[6]  Daisuke Watanabe,et al.  Colorimetric sensing of metal ions by bis(spiropyran) podands: Towards naked-eye detection of alkaline earth metal ions , 2009 .

[7]  L. S. Atabekyan.  The Kinetics of Photocoloration of Spiropyrans upon Complexation , 2002 .

[8]  R. Martínez‐Máñez,et al.  A regenerative chemodosimeter based on metal-induced dye formation for the highly selective and sensitive optical determination of Hg2+ ions. , 2005, Angewandte Chemie.

[9]  V. Minkin,et al.  Kinetic and Thermodynamic Investigations of the Photochromism and Solvatochromism of Semipermanent Merocyanines , 2001 .

[10]  J. Micheau,et al.  Quantitative analysis of continuous-variation plots with a comparison of several methods: Spectrophotometric study of organic and inorganic 1:1 stoichiometry complexes , 1992 .

[11]  Yunhua Gao,et al.  Photo-switchable molecular devices based on metal-ionic recognition , 2005 .

[12]  K. Kimura,et al.  High stability constants for multivalent metal ion complexes of crown ether derivatives incorporating two spirobenzopyran moieties , 2002 .

[13]  M. Querol,et al.  Synthesis, metal complex formation, and switching properties of spiropyrans linked to chelating sites , 2003 .

[14]  G. Collins,et al.  Selective metals determination with a photoreversible spirobenzopyran. , 1999, Analytical chemistry.

[15]  Jason Locklin,et al.  Reversible colorimetric ion sensors based on surface initiated polymerization of photochromic polymers. , 2008, Chemical communications.

[16]  David Hernández,et al.  Synthesis, photochromic properties, and light-controlled metal complexation of a naphthopyran derivative. , 2008, Organic letters.

[17]  J. Otsuki,et al.  Molecular switches for electron and energy transfer processes based on metal complexes , 2008 .

[18]  H. Nishihara,et al.  Photochrome-coupled metal complexes: molecular processing of photon stimuli. , 2008, Dalton transactions.

[19]  Satish Kumar,et al.  Synthesis and metal complexation properties of bisbenzospiropyran chelators in water. , 2008, Tetrahedron.

[20]  T. Konno,et al.  Synthesis and characterization of luminescent zinc(II) and cadmium(II) complexes with N,S-chelating Schiff base ligands. , 2008, Inorganic chemistry.

[21]  J. Winkler,et al.  Photodynamic Fluorescent Metal Ion Sensors with Parts per Billion Sensitivity , 1998 .

[22]  H. Nishihara,et al.  Metal-based Photoswitches Derived from Photoisomerization , 2006 .

[23]  K. Kimura,et al.  Evaluation of photoinduced changes in stability constants for metal-ion complexes of crowned spirobenzopyran derivatives by electrospray ionization mass spectrometry , 2003, Journal of the American Society for Mass Spectrometry.

[24]  H. Tian,et al.  Thermally Stable Merocyanine Form of Photochromic Spiropyran with Aluminum Ion as a Reversible Photo-driven Sensor in Aqueous Solution , 2007, Sensors.

[25]  Dermot Diamond,et al.  Spiropyran modified micro-fluidic chip channels as photonically controlled self-indicating system for metal ion accumulation and release , 2009 .

[26]  Helmut Görner,et al.  Complexes of spiropyran-derived merocyanines with metal ions Thermally activated and light-induced processes , 1998 .

[27]  T. Deligeorgiev,et al.  Effect of complexation on the photochromism of 5'-(benzothiazol-2-yl)spiroindolinonaphthooxazines in polar solvents , 2005 .

[28]  V. Minkin,et al.  Spectral and kinetic properties of a red–blue pH-sensitive photochromic spirooxazine , 2007 .

[29]  V. Minkin,et al.  Photochromic spiro[indoline-pyridobenzopyrans]: fluorescent metal ion sensors , 2004 .

[30]  L. Popov,et al.  Synthesis, IR, UV/vis-, (1)H NMR and DFT study of chelatophore functionalized 1,3-benzoxazinone spiropyrans. , 2008, Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy.

[31]  G. Collins,et al.  Photoinduced switching of metal complexation by quinolinospiropyranindolines in polar solvents , 1999 .

[32]  Rong-Hua Yang,et al.  Tunable photochromism of spirobenzopyran via selective metal ion coordination: an efficient visual and ratioing fluorescent probe for divalent copper ion. , 2008, Analytical chemistry.

[33]  K. Kamada,et al.  Synthesis and photochromism of spirobenzopyran derivatives bearing an oxymethylcrown ether moiety: metal ion-induced switching between positive and negative photochromisms. , 2001, The Journal of organic chemistry.

[34]  James T. C. Wojtyk,et al.  Modulation of the Spiropyran−Merocyanine Reversion via Metal-Ion Selective Complexation: Trapping of the “Transient” cis-Merocyanine , 2001 .

[35]  Zhibin Zhang,et al.  Positive and negative photochromism of novel spiro[indoline-phenanthrolinoxazines] , 2008 .

[36]  A. Chibisov,et al.  Complexes of spiropyran-derived merocyanines with metal ions: relaxation kinetics, photochemistry and solvent effects , 1998 .

[37]  J. P. Phillips,et al.  Photochromic Chelating Agents , 1965 .

[38]  Dermot Diamond,et al.  Photonic modulation of surface properties: a novel concept in chemical sensing , 2007 .

[39]  Xinqi Song,et al.  Investigation of the chelation of a photochromic spiropyran with Cu(II) , 1995 .

[40]  Dermot Diamond,et al.  Photo-regenerable surface with potential for optical sensing , 2006 .

[41]  S. Hecht,et al.  Photoswitchable catalysts: correlating structure and conformational dynamics with reactivity by a combined experimental and computational approach. , 2009, Journal of the American Chemical Society.

[42]  P. G. Sammes,et al.  Photochromic crowned spirobenzopyrans: Quantitative metal-ion chelation by UV, competitive selective ion-extraction and metal-ion transportation demonstration studies , 2008 .

[43]  T. Deligeorgiev,et al.  Synthesis of photochromic chelating spironaphthoxazines , 2002 .

[44]  V. Minkin,et al.  Photo- and thermochromic cation sensitive spiro[indoline-pyridobenzopyrans] , 2007 .

[45]  James T. C. Wojtyk,et al.  Effects of metal ion complexation on the spiropyran–merocyanine interconversion: development of a thermally stable photo-switch , 1998 .

[46]  P. G. Sammes,et al.  Photoreversible Zn2+ Ion Transportation Across an Interface Using Ion‐Chelating Substituted Photochromic 3,3′‐Indolospirobenzopyrans: Steric and Electronic Controlling Effects , 2008 .

[47]  K. Kimura,et al.  Analytical and Separation Chemistry by Taking Advantage of Organic Photochromism Combined with Macrocyclic Chemistry , 2009, Analytical sciences : the international journal of the Japan Society for Analytical Chemistry.

[48]  K. Kamada,et al.  METAL-ION STABILIZATION OF PHOTOINDUCED OPEN COLORED ISOMER IN CROWNED SPIROBENZOTHIAPYRAN , 1999 .