Premium
2‐ and 2,7‐Substituted para ‐ N ‐Methylpyridinium Pyrenes: Syntheses, Molecular and Electronic Structures, Photophysical, Electrochemical, and Spectroelectrochemical Properties and Binding to Double‐Stranded (ds) DNA
Author(s) -
Kole Goutam Kumar,
Merz Julia,
Amar Anissa,
Fontaine Bruno,
Boucekkine Abdou,
Nitsch Jörn,
Lorenzen Sabine,
Friedrich Alexandra,
Krummenacher Ivo,
Košćak Marta,
Braunschweig Holger,
Piantanida Ivo,
Halet JeanFrançois,
MüllerBuschbaum Klaus,
Marder Todd B.
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202004748
Subject(s) - protonation , intercalation (chemistry) , chemistry , cationic polymerization , density functional theory , electrochemistry , crystallography , pyrene , dna , photochemistry , absorption (acoustics) , medicinal chemistry , stereochemistry , inorganic chemistry , computational chemistry , materials science , organic chemistry , biochemistry , electrode , composite material , ion
Two N ‐methylpyridinium compounds and analogous N ‐protonated salts of 2‐ and 2,7‐substituted 4‐pyridyl‐pyrene compounds were synthesised and their crystal structures, photophysical properties both in solution and in the solid state, electrochemical and spectroelectrochemical properties were studied. Upon methylation or protonation, the emission maxima are significantly bathochromically shifted compared to the neutral compounds, although the absorption maxima remain almost unchanged. As a result, the cationic compounds show very large apparent Stokes shifts of up to 7200 cm −1 . The N ‐methylpyridinium compounds have a single reduction at ca. −1.5 V vs. Fc/Fc + in MeCN. While the reduction process was reversible for the 2,7‐disubstituted compound, it was irreversible for the mono‐substituted one. Experimental findings are complemented by DFT and TD‐DFT calculations. Furthermore, the N ‐methylpyridinium compounds show strong interactions with calf thymus (ct)‐DNA, presumably by intercalation, which paves the way for further applications of these multi‐functional compounds as potential DNA‐bioactive agents.