SYNTHESIS OF PORPHYRIN trans-A2B2 TYPE AND A3B TYPE AND USING 5-PHENYLDIPYRROMETHANE AS PRECURSORS

• Main Author: Septiyana, Maulida
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/38245
• Institution: Institut Teknologi Bandung

Porphyrin is a macrocyclic compound formed by the combination of four pyrrole rings through methine bridges. Porphyrin and its derivatives are widely applied, such as photodynamic therapy agents, catalysts in chemical reactions, catalysts in secondary battery and sensitizing agents in solar cells. Synthesis porphyrin and its derivatives is done by several methods, one of them is the condensation reaction [2 + 2] between dipyrromethane with an aldehyde. This study was conducted by two-stage synthesis, the first was the synthesis of 5-phenyldipyrromethane and the second was synthesis of derivatives tetraphenylporphyrin trans-A2B2 type and A3B type. The first phase synthesis was done by reacting pyrrole with benzaldehyde in water solvent with the aid of hydrochloric acid catalyst. The purification process used recrystallization technique with solvent mixtures of ethanol : water (4: 1) to produce a reaction yield of 23%. 1H-NMR spectrum (500 MHz, CDCl3) showed fourteen proton signals; ? 7.94 ppm (2H, s), 7.21 to 7.33 ppm (5H, m), 6.70 ppm (2H, dd), 6.16 ppm (2H, d), 5.92 ppm ( 2H, s), 5.48 ppm (1H, s). The second phase synthesis was done by reacting 5- phenyldipyrromethane with p-methoxybenzaldehyde. This synthesis route is the route for synthesis porphyrin type trans-A2B2. The formation of porphyrin A3B type was caused by the competitive reaction between the reagent used, it was p- methoxybenzaldehyde with benzaldehyde. Benzaldehyde coming from the residue of the reagents in the first stage of synthesis and benzaldehyde that was formed from acidolysis. The porphyrin synthesis reaction took place at room temperature using TFA as a catalyst and followed by oxidation with p-chloranil. Separation of synthesis result was done using column chromatography with eluent n-hexane : ethyl acetate. Analysis TLC with eluent n-hexane : ethyl acetate (7: 1) showed two purple fractions with Rf respectively of 0.54 and 0.45. First Compound is 5,15-(4-methoxyphenyl)-10,20-diphenylporphyrin (BMeOPDPP) and second compound is 5-(4-methoxyphenyl)-10,15,20-triphenylporphyrin (5-MeOTPP). The results of spectroscopic absorption of UV-Vis characterization for BMeOPDPP showed Soret band absorption at a wavelength of 420 nm and four Q band absorption at a wavelength of 517, 552, 592, and 649 nm. 5-MeOTPP UV- Vis absorption indicated there was Soret band absorption at a wavelength of 418 nm and Q band absorption at a wavelength of 515, 550, 590, and 648 nm. Furthermore, the emission spectrum of BDMeOTPP and 5-MeOTPP produced a peak with maximum intensity at 660 nm and 659 nm. 1H-NMR spectrum of BMeOPDPP compound showed 34 proton signals; ? -2.757 ppm (2H, s), ? 4.100 ppm (6H, s) from 8.836 to 8.875 ppm (8 H, d), ? 7.750 to 7.781 ppm (6H, m), ? 8.214 to 8.227 ppm (6H, d) , 8.124 to 8.140 ppm (2H, d), ? 7.284 to 7.299 ppm (4 H, d). 1H-NMR spectral data of 5-MeOTPP showed 32 proton signals; ? -2.766 ppm (2H, s), ? 4.102 ppm (3H, s), ? 8.835 ppm (6H, s), ? 8.874 to 8.883 ppm (2H, d), ? 7.735 to 7.781 ppm (9H, m), ? 8.208 to 8.223 ppm (6H, d). ? 8.122 to 8.138 ppm (2H, d), ? 7.284 to 7.301 (2H, d).