Synthesis and photochemical properties of a bis(n-Hexanoyl)silicon tribenzonaphthoporphyrazate.
OBJECTIVE
The aim of the present work is to describe the synthesis and photochemical studies of a silicon tribenzonaphthoporphyrazate (Si-tri-PcNc) derivative to be used in photomedicine.


BACKGROUND
Properties of the photosensitizer localization in tumor tissue and photochemical generation of reactive oxygen species are combined with precise delivery of laser-generated light to induce a procedure offering effective local tumoricidal activity. This technique is called photodynamic therapy (PDT).


METHODS
This new phthalocyanine (Pc) compound obtained from 2,3-dicyanonaphthalene and phthalonitrile is analyzed and chemically characterized by (1)H-NMR, elemental analyses, infrared (IR), ultraviolet and visibile absorption spectroscopy (UV-Vis) and fluorescence spectra.


RESULTS
The spectroscopic analysis of this compound in EtOH showed an electronic spectrum with characteristic bands in the Soret and Q region. Steady-state and time-resolved spectral analyses revealed a fluorescence quantum yield of phi(f) = 0.24, in agreement with other Pc compounds. This compound also shows a triplet excited lifetime of 0.40 microsec in air-saturated solution and a transient with the maximum absorption located at 610 nm, 120 nm shifted to the red if compared to the excited triplet state observed with other Pc compounds.


CONCLUSIONS
Based on our results, we can assume that Si-tri-PcNc induces a higher singlet oxygen production under photoactivation, which is in agreement with the expected photobiological behavior. This result could lead to the testing and eventual use of this new generation of dyes in PDT.
Pelisson
Marcelo M M
MM
Research Group of Organic Chemistry, Instituto de Pesquisa & Desenvolvimento (IP&D), Universidade do Vale do Paraíba, São José dos Campos, Brazil.
Delega
Alessandra D P
AD
Beltrame
Milton
M
Simioni
Andreza R
AR
Tedesco
Antonio C
AC
D006801:Humans; D007211:Indoles / Q000138:chemical synthesis*; D054833:Isoindoles; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000138:chemical synthesis*; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000138:chemical synthesis*; D013057:Spectrum Analysis
D007211:Indoles; D054833:Isoindoles; D017646:Organosilicon Compounds; D017319:Photosensitizing Agents; C517915:silicon tribenzonaphthoporphyrazate; C013647:phthalocyanine