96500-56-0Relevant academic research and scientific papers
Peripheral Substitution of Tetraphenyl Porphyrins: Fine-Tuning Self-Assembly for Enhanced Electroluminescence
Charisiadis, Asterios,Bagaki, Anthi,Fresta, Elisa,Weber, Katharina T.,Charalambidis, Georgios,Stangel, Christina,Hatzidimitriou, Antonios G.,Angaridis, Panagiotis A.,Coutsolelos, Athanassios G.,Costa, Rubén D.
, p. 254 - 265 (2018)
This study reports the synthesis of two novel zinc porphyrin families bearing four or eight alkoxy chains at their peripheral phenyl rings, with the length of the alkoxy chains ranging from 2, to 6, and to 12 carbon atoms. All zinc porphyrin derivatives were fully characterized with respect to their photophysical and electrochemical features. The zinc porphyrins could be processed into thin films which, depending on the length of the alkoxy chains on the aryl substituents, were found to be either of an ordered or a disordered nature, as it is revealed by spectroscopic and microscopic techniques. The films containing ordered self-assemblies displayed significantly enhanced electrical conductivity compared to the disordered films. This led to remarkable differences regarding their electroluminescence response that occurs at lower bias. Furthermore, their luminous efficiency was of almost one order of magnitude higher than that of disordered films.
The lowest excited states of copper porphyrins
Asano, Motoko,Kaizu, Youkoh,Kobayashi, Hiroshi
, p. 6567 - 6576 (2007/10/02)
Relaxation processes of excited copper porphyrins were studied with relevance to the structure of the substates of the lowest excited states.Lifetimes of luminescence at room temperature were determined as 17, 29, 69, and 105 ns for T(EtO)PPCu , TPPCu(TPP: 5,10,15,20-tetraphenylporphin), TFPPCu, and OEPCu(OEP: 2, 3, 7, 8,12,13,17,18 octaethylporphin ) in toluene, respectively.Emission intensities and lifetimes of OEPCu and TFPPCu measured as a function of temperature show a variation ascribed to a Boltzmann distribution between the lowest trip-doublet and -quartet with an energy gap of 300-00 cm -1 The anomalous temperature dependence for TPPCu and T( EtO) PPCu is explained by a larger energy gap and larger vibronic distortions in the excited state.The difference in behavior is attributed to the orbital nature of the triplet: a 1 e)>> for OEPCu and TFPPCu but a 2 e)>> for TPPCu and T(EtO)PPCu.The assumption of a low energy charge tl'ansfer state is not necessary for our analysis.
