Synthesis, Photophysical Properties And Singlet Oxygen Quantum Yield Of Functional Groups Substituted Phthalocyanine

In this paper, two kinds of alkynyl substituted functionlized silicon phthalocyanines were synthesized, which were two-3,5-dipropyl alkynyloxy substituted benzene methoxy axial silicon(IV) phthalocyanine and 3,5-dipropyl alkynyloxy substituted benzene methoxy axial silicon(IV) phthalocyanine. They were using dichloro silicon (IV) phthalocyanine as a starting material, and 3,5-dipropyl-substituted alkynyl group of benzyl alcohol was synthesized by the axial direction.The strctures of phthalocyanine were characterized by IR,'H NMR and MALDI-TOF-MS. The photophysical properties of alkynyl substituted phthalocyanine were studied by UV/Vis, steady-state and time-resolved fluorescence spectroscopic analyses. The effect of the number of substituents on the photophysical properties and singlet oxygen quantum yield of phthalocyanine were compared. The results show that the axial alkynyl functional group substituted silicon phthalocyanine in solution exists mainly in monomeric form, is not prone to aggregation, the maximum emission wavelength is 680 nm. In the axial position introduced single or double alkyne of propargyl axially substituted silicon (IV) phthalocyanine did not affect the Q band absorption peak position. The absorption peak intensity of mono substituted alkyne substituted phthalocyanine silicon was higher than disubstituted phthalocyanine. Compared to the double substituted phthalocyanine, the fluorescence intensity of the single substituted phthalocyanine is increased and the quantum yield increases, and the two singlet oxygen quantum yield is very similar.Synthesis of gold nanoclusters by reduction chloroauric acid according to NaBH4, and then by way of ligand exchange will functional alkynyl group substituted silicon phthalocyanine complexes with PVP stabled gold nanoclusters interact, prepared with alkyne phthalocyanine@gold nanoclusters composite system. The morphology and particle size of gold nanoclusters were characterized by transmission electron microscopy. PVP stabled gold nanoclusters were spherical, good dispersion, the average particle size diameter were 1.5nm. The results showed that UV absorption spectra of gold nanoclusters did not have a surface plasmon resonance absorption peak, B band absorption peak of alkyne phthalocyanine at 350 nm, Q absorption peak at 690 nm; alkyne phthalocyanine@ nano gold clusters in the composite system had a Q-band absorption peak in the 700nm, with respect to free phthalocyanine had slight red shift.The electrochemical behavior of different silicon (IV) phthalocyanine were studied by cyclic voltammetry(CV) method and the singlet oxygen quantum yield were studied by chemical capture assay. By cyclic voltammetry (CV) and square wave voltammetry (SWV) investigated the electrochemical behavior of six silicon phthalocyanines. Anodic peak current and cathodic peak currents are proportional to the square root of the cyclic voltammetry and square wave voltammetry graph can be seen with the scan rate. These complexes had a quasi-reversible one-electron oxidation and three quasi-reversible one-electron reduction process. The band gap between them was small, prone to electron transfer. The first and the first oxidation reduction potential of substituents on functional properties of silicon phthalocyanine (HOMO-LUMO gap) effect. SiPc-1, SiPc-2, SiPc-4, SiPc-6 phthalocyanine and substituted by electron withdrawing ester group is connected, SiPc-3 and SiPc-5 phthalocyanine and substituted by the electronic ether group is connected to. Electron-withdrawing groups make the redox potential difference increases, the electron-enable the redox potential difference decreases. Replace silicon (IV) from axially different functional groups of the redox potential difference phthalocyanine found that oxidation-reduction phthalocyanine complexes potential difference smaller bandgap smaller molecules excited by the energy consumed on the electronic transition the smaller, thus the stronger emission spectra. Phthalocyanine potential difference between the second and third objects (ie, HOMO-LUMO energy gap variation) is consistent with the fluorescence intensity variation complexes.The singlet oxygen quantum yield of phthalocyanine was determined by chemical trapping method, and the ability to measure the generation of singlet oxygen was determined by measuring the change of absorbance at 412 nm at DPBF. This was mainly due to the difference between the electron donating ability and electron withdrawing ability, the fluorescence quantum yield of silicon phthalocyanine is different, and the generation ability of singlet oxygen is influenced. SiPc-1, SiPc-2, SiPc-4, SiPc-6 by electron withdrawing groups and the phthalocyanine ring connected, with substituents in the ceiling electronic ability strong, make the silicon phthalocyanine fluorescence quantum yield increases, then causes three line state phthalocyanine and ground state oxygen effect generated 1O2 will reduce the capacity and thus generated 1O2 singlet oxygen quantum yield higher; conversely, SiPc-3 and SiPc-5 were linked by ether bond with the phthalocyanine rings, the substituent to electronic ability strong, so the generated 1O2 singlet oxygen quantum yield is low.By using the chemical capture method,1,3-diphenyl isobenzofuran (DPBF) as singlet oxygen trapping agent, the absorbance at 412 nm DPBF change in intensity was measured in the ability to generate singlet oxygen, comparative study various metal ions on the nature of singlet oxygen quantum yield pyrrolidone phthalocyanine complexes The same substituent, the introduction of different metal phthalocyanine pyrrolidone center, will make the quantum yield of singlet oxygen produced by different. Identical substituents, when the central metal is Zn phthalocyanine pyrrolidone singlet oxygen quantum yield of (Ni, Co and Cu) phthalocyanine pyrrolidone higher than the center metal. The ability of the nature of the central metal ion phthalocyanine complexes generate singlet oxygen has important implications.