Photosensitization of asymmetric molecular, and bimolecular aliphatic-μ -bridged-meso-phenyl porphyrin

Abstract

The desired asymmetric metal-free porphyrin derivatives were prepared by condensing freshly prepared the phenyl dipyrraomethane and triphenyl tetrapyrrane building blocks with the different molar ratios of acetaldehyde (CH3CHO), and glutaraldehyde (OHC(CH2)3CHO, Glu). The obtained asymmetric [3+1] (MePh3Por, Ph3Por-μ-(CH2)3Ph3Por) and [2+2] (Me2Ph2Por, (Ph2Por)×-μ-(CH2)3 oligomer) porphyrin derivatives were characterized by UV-Vis, FT-IR, and 1H NMR. Their photoelectric properties were investigated by examining their current density-voltage (J-V) curves in dark, and under artificial sunlight, illumination using standard bulk heterojunction cell arrangements. The Jphoto-V plots show that they display photosensitive semiconducting properties in the range of (σ = 1.7-14.5 μS/cm) with negligible photovoltaic effects. All data were compared to those of symmetric metal-free Ph4Por(σ = 33.8 μS/cm). Density functional theory (DFT) is employed to validate the ground-state molecular geometry.