LAUSR

Abstract Novel thiophene monomers containing porphyrin units attached via di(ethylene glycol) and tetra(ethylene glycol) spacers were synthesized: 3-methyl-4- (4- (1- (5-phenyl-10,15,20-triphenylporphyrin)) diethoxy) thiophene (M2PPh) and 3-methyl-4- (4- (1- (5-phenyl-10,15,20-triphenylporphyrin)) tetraethoxy) thiophene (M4PPh). These monomers and other co-monomers with pyrene units 3-methyl-4-(diethoxy) thiophene (M2) and 3-methyl-4-(tetraethoxy) thiophene (M4) previously reported by us, were linked to thiophene and bithiophene via a Suzuki coupling reaction to give the corresponding terthiophenes and quaterthiophenes: [3-diethoxypyrene, 3-diethoxyporphyrin, 4,4‴ dimethyl - 2,2: 5′2”- terthiophene (TT2PY-PPh)], [3-tetraethoxypyrene, 3-tetraethoxyporphyrin, 4, 4‴dimethyl - 2,2:5′2”-terthiophene (TT4PY-PPh)], [3′-diethoxypyrene, 3′-diethoxyporphyrin, 4,4‴methyl-2,2′:5′: 2′′:5″,2‴-quaterthiophene (QT2PY-PPh)], and [3′-tetraethoxypyrene, 3′-tetraethoxyporphyrin,4,4‴methyl −2,2′:5′:2′′:5″,2‴-quaterthiophene (QT4PY-PPh)]. The synthesized compounds were characterized by 1H NMR, 13C NMR and MALDI-TOF mass spectrometry; their optical properties were studied by absorption and fluorescence spectroscopy. The emission spectra of the oligothiophenes bearing pyrene-porphyrin units showed a significant decrease in the pyrene monomer emission and the appearance of a new emission band at 650 nm, arising from the porphyrin, which revealed that a FRET phenomenon is occurring from the excited pyrene to the porphyrin. The obtained FRET efficiencies were between 93 and 98% depending on the oligomer structure.