Rationalizing Photo‐Triggered Hydrogen Evolution Using Polypyridine Cobalt Complexes: Substituent Effects on Hexadentate Chelating Ligands

نویسندگان

چکیده

Four novel polypyridine cobalt(II) complexes were developed based on a hexadentate ligand scaffold bearing either electron-withdrawing (−CF3) or electron-donating (−OCH3) groups in different positions of the ligand. Experiments and theoretical calculations combined to perform systematic investigation effect modification hydrogen evolution reaction. The results indicated that position, rather than type substituent, was dominating factor promoting catalysis. best performances observed upon introduction substituents pyridine moiety ligand, which promoted formation Co(II)H intermediate via intramolecular proton transfer reactions with low activation energy. Quantum yields 11.3 10.1 %, maximum turnover frequencies 86.1 76.6 min−1, numbers 5520 4043 obtained, respectively, −OCH3 −CF3 substituent.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Electrocatalytic hydrogen evolution by cobalt difluoroboryl-diglyoximate complexes.

In the presence of moderately strong acids in CH3CN, cobalt complexes with BF2-bridged diglyoxime ligands are active catalysts for the reduction of protons to H2 at potentials as positive as -0.28 V vs. SCE.

متن کامل

DNA Interactions with Ruthenium(ll) Polypyridine Complexes Containing Asymmetric Ligands

In an attempt to probe nucleic acid structures, numerous Ru(II) complexes with different ligands have been synthesized and investigated. In this contribution we focus on the DNA-binding properties of ruthenium(II) complexes containing asymmetric ligands that have attracted little attention in the past decades. The influences of the shape and size of the ligand on the binding modes, affinity, en...

متن کامل

Substituent effects in hydrogen bonding: DFT and QTAIM studies on acids and carboxylates complexes with formamide

Four series of hydrogen bonded complexes of formamide and substituted benzoic acids and benzoates were studied in the light of substituent effect on intermolecular interactions. The analysis based on energy of interaction, geometry, QTAIM-derived properties of hydrogen bond critical point and energy of hydrogen bonds were made and discussed. The opposite effect of the substituent on hydrogen bo...

متن کامل

Switching on oxygen activation by cobalt complexes of pentadentate ligands.

The monoanionic N(4)O ligand N-methyl-N,N'-bis(2-pyridylmethyl)ethylenediamine-N'-acetate (mebpena(-)) undergoes oxidative C-N bond cleavage in the presence of Co(II) and O(2). The two resultant fragments are coordinated to the metal ion in the product [Co(III)(2-pyridylformate)(mepena)]ClO(4) (mepena(-) = N-methyl-N'-(2-pyridylmethyl)ethylenediamine-N'-acetato). Bond cleavage does not occur in...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Chemsuschem

سال: 2021

ISSN: ['1864-5631', '1864-564X']

DOI: https://doi.org/10.1002/cssc.202100161