"

Cookies ussage consent

I agree.

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

Ft-ir, fluorescence and electronic spectra for monitoring the aggregation process of tetra-pyridylporphyrine entrapped in silica matrices

E. FAGADAR-COSMA1,* , C. ENACHE, D. DASCALU2, GH. FAGADAR-COSMA3, R. GAVRILA4

Affiliation

  1. Institute of Chemistry –Timişoara of Romanian Academy, 24 M. Viteazul Ave, 300223-Timisoara, Romania
  2. West University of Timisoara, 16 Pestalozzi Street, 300115 - Timisoara, Romania
  3. "Politehnica" University, 2 T. Lalescu Street, 300223-Timisoara, Romania
  4. National Institute for R&D in Microtechnologies, 32B Iancu Nicolae Street, R-72296, Bucharest, Romania

Abstract

New inorganic-organic hybrid materials consisting in 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (TPYP), encapsulated in silica matrices were obtained by the sol-gel process. A control of pH influence over accessibility of incorporation of porphyrin into silica was performed, by using two different acids in the first acid catalyzed step of the sol-gel process. As a novelty element, glacial acetic acid was used as catalyst, and the results were compared with those obtained with the commonly used HCl. The compositions were monitored and comparatively characterized by using spectroscopic methods such as FT-IR, UV-vis and luminescence. The major changes in UV-vis spectral shape might be attributed to the dication (H+ 2TPYP) generation, in acid media, and are associated with an increase of the intensity of the last Q band. Atomic force microscopy (AFM) investigations were carried out and discussed. Co-facial porphyrin aggregation with random orientation was noticed.

Keywords

Porphyrin, Tetraethylorthosilicate, Silica matrices, Hybrid nanomaterial, Sol-gel techniques.

Citation

E. FAGADAR-COSMA, C. ENACHE, D. DASCALU, GH. FAGADAR-COSMA, R. GAVRILA, Ft-ir, fluorescence and electronic spectra for monitoring the aggregation process of tetra-pyridylporphyrine entrapped in silica matrices, Optoelectronics and Advanced Materials - Rapid Communications, 2, 7, July 2008, pp.437-441 (2008).

Submitted at: March 22, 2008

Accepted at: July 8, 2008