Influence of structural changes on photophysical properties of terpyridine derivates: Experimental studies and theoretical calculations

Abstract

International audienceFour terpyridine ligands containing different aryl substituents 4'-(4-quinolinyl)-3,2':6′,3″-terpyridine (3-qtpy), 4'-(4-quinolinyl)-2,2':6′,2″-terpyridine (2-qtpy), 4'-(3-methyl-2-thienyl)-4,2':6′,4″-terpyridine (4-stpy) and 4'-(3-methyl-2-thienyl)-2,2':6′,2″-terpyridine (2-stpy) were synthesized in a one-pot procedure and characterized by elemental analysis, FT-IR and 1H- and 13C NMR spectroscopy. Additionally, the 2-stpy structure was confirmed by single crystal X-ray diffraction analysis. The influence of the N-position in the tpy and aryl substituents on the photophysical properties was systematically investigated by spectroscopic methods and simulated by density functional theory (DFT and TD-DFT) calculations. Thermal stability was observed until about 280 °C, making these kind of ligands interesting candidates for their use as complex ligands, which are obtained by solvothermal synthesis under temperatures of about 180 °C. The electrochemical behavior was also investigated. All molecules show irreversible anodic and cathodic voltammetric peaks in organic medium

Photoinduced Processes in Rhenium(I) Terpyridine Complexes Bearing Remote Amine Groups: New Insights from Transient Absorption Spectroscopy

“…This approach opens possibilities to modulate the properties of these systems, especially that the introduction of donor-π-acceptor type (D-A, D-π-A) ligands into a heavy metal coordination sphere is an effective way for lowering the energy gap of compounds to realize deep red or NIR light emission and offer additional advantages in optoelectronic properties due to efficient hole-transporting abilities of the bipolar systems [ 13 , 56 , 57 ]. Regarding the convenience of structural modifications of the 2,2′:6′,2″-terpyridine framework [ 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 ], [ReCl(CO) 3 (R-C 6 H 4 -terpy-κ 2 N)] complexes of bidentate-coordinated 4′-(4-substituted-phenyl)-terpyridine-like ligands with strong electron-donating groups were found to be suitable systems for studies of photoinduced ILCT processes, and they were regarded as promising photoluminescence materials [ 55 , 66 ].…”

Copper(II) Complexes with 2,2′:6′,2″-Terpyridine Derivatives Displaying Dimeric Dichloro−μ–Bridged Crystal Structure: Biological Activities from 2D and 3D Tumor Spheroids to In Vivo Models

“…Copper(II) chloride dihydrate and ammonium hexafluorophosphate were purchased from Merck and used without further purification. 4′-Substituted 2,2′:6′,2″-terpyridines (R-terpy) were all previously reported − and were prepared, according to the methods presented earlier, , reacting 2-acetylpyridine and appropriate aldehyde (2:1 molar ratio) in the presence of aqueous ammonia. Detailed experimental conditions and methodology are described in the Supporting Information.…”