Phosphorus(V) porphyrin-azoarene conjugates: Synthesis, spectroscopy, cis-trans isomerization, and photoswitching function

被引:34
作者
Reddy, DR [1 ]
Maiya, BG [1 ]
机构
[1] Univ Hyderabad, Sch Chem, Hyderabad 500046, Andhra Pradesh, India
关键词
D O I
10.1021/jp026991f
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
A series of photochemically active, "axial-bonding" type phosphorus(V) porphyrin-azoarene (P-A) conjugates, viz., [(TTP)Pv(-O-AZM)(2)](+), [(TTP)P-V(-O-AZT)(2)](+), [(TTP)P-V(-O-AZB)(2)](+), and [(TTP)P-V(-O-AZN)(2)](+) (TTP is 5,10,15,20-tetra(4-methylphenyl)porphyrinato dianion and O-AZM, O-AZT, O-AZB, and O-AZN are the axially coordinated 4-methoxy azophenoxo, 4-methyl azophenoxo, azophenoxo, and 4-nitro azophenoxo ligands, respectively) have been synthesized and fully characterized by mass (FAB), infrared, UV-visible, proton nuclear magnetic resonance (1D and H-1-H-1 COSY), and electrochemical methods. The spectroscopic data suggest that the two azoarene subunits in these hexa-coordinated systems exist in their trans isomeric forms and that there is minimal ground-state interaction between the axial ligands and the basal porphyrin pi plane in each case. Continuous irradiation of CH3CN solutions containing these new P-A conjugates at 345 +/- 5 nm results in isomerization of the phosphorus-bound azoarene subunits to produce the respective cis forms, as revealed by the UV-visible spectral data. The reverse, thermal back reactions have also been spectrally monitored, and the trans forms could be recovered quantitatively. Rate measurements and detailed analysis of the kinetic data have been made for both the forward and the reverse reactions. Fluorescence due to the porphyrin components of the "trans forms" of [(TTP)P-V(-O-AZM)(2)](+), [(TTP)P-V(-O-AZT)(2)](+), and [(TTP)P-V(-O-AZB)(2)](+) are quenched in comparison with that due to a porphyrin reference compound ([(TTP)P-V(OH)(2)](+)). Moreover, fluorescence intensities of the respective "cis forms" are less than the corresponding "trans forms" in each case. The photochemical/thermal trans <----> cis isomerization reactions of the axial azoarene subunits and the consequent modulation of the fluorescence intensities have been repeated several times with minimal loss of the material. Based on the results of detailed photochemical studies carried out with these new P-A conjugates, it is argued that distance dependence of the photoinduced electron transfer occurring between the axial azoarene subunit and the singlet porphyrin is responsible for their effective and stable photoswitching function.
引用
收藏
页码:6326 / 6333
页数:8
相关论文
共 54 条
[1]   THE NMR-SPECTRA OF THE PORPHYRINS .16. ZINC(II) MESO-TETRAPHENYLPORPHYRIN (ZN TPP) AS A DIAMAGNETIC SHIFT-REAGENT - A QUANTITATIVE RING CURRENT MODEL [J].
ABRAHAM, RJ ;
BEDFORD, GR ;
MCNEILLIE, D ;
WRIGHT, B .
ORGANIC MAGNETIC RESONANCE, 1980, 14 (05) :418-425
[2]   Ruthenium(II) complexes of 6,7-dicyanodipyridoquinoxaline: Synthesis, luminescence studies, and DNA interaction [J].
Ambroise, A ;
Maiya, BG .
INORGANIC CHEMISTRY, 2000, 39 (19) :4264-4272
[3]   Ruthenium(II) complexes of redox-related, modified dipyridophenazine ligands: Synthesis, characterization, and DNA interaction [J].
Ambroise, A ;
Maiya, BG .
INORGANIC CHEMISTRY, 2000, 39 (19) :4256-4263
[4]  
[Anonymous], 1990, Photochromism: Molecules and Systems. Photochromism
[5]  
Archut A, 1998, CHEM-EUR J, V4, P699, DOI 10.1002/(SICI)1521-3765(19980416)4:4<699::AID-CHEM699>3.0.CO
[6]  
2-9
[7]   INTRAMOLECULAR FLUORESCENCE QUENCHING IN AZOBENZENE-SUBSTITUTED PORPHYRINS [J].
AUTRET, M ;
LEPLOUZENNEC, M ;
MOINET, C ;
SIMONNEAUX, G .
JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, 1994, (10) :1169-1170
[8]  
Balzani V, 2000, ANGEW CHEM INT EDIT, V39, P3348, DOI 10.1002/1521-3773(20001002)39:19<3348::AID-ANIE3348>3.0.CO
[9]  
2-X
[10]   PREPARATION OF GROUP-15 (PHOSPHORUS, ANTIMONY, AND BISMUTH) COMPLEXES OF MESO-TETRA-PARA-TOLYLPORPHYRIN (TTP) AND X-RAY CRYSTAL-STRUCTURE OF [SB(TTP)(OCH(CH3)2)2]CL [J].
BARBOUR, T ;
BELCHER, WJ ;
BROTHERS, PJ ;
RICKARD, CEF ;
WARE, DC .
INORGANIC CHEMISTRY, 1992, 31 (05) :746-755