Search results for "donor–acceptor"
showing 6 items of 6 documents
First donor stabilized-phosphenium rhodium complexes
2008
Abstract The coordination properties of a donor stabilized-phosphenium adduct have been examined in rhodium chemistry. The preparation as well as the characterization of the first examples of donor stabilized-phosphenium rhodium(I) complexes is reported in this paper. Indeed, mono- and di-cationic rhodium complexes were obtained in quantitative yield by the direct addition of this imidazolium P(III)-ligand to [RhCl(1,5-COD)] 2 in CH 2 Cl 2 solution with a 1:1 P/Rh ratio under argon and 2:1 P/Rh ratio under CO atmosphere, respectively. Crystal structure of the bis-cationic donor stabilized-phosphenium rhodium(I) complex has been obtained from an acetone/pentane mixture. Its molecular structu…
Charge-transfer interactions between fullerenes and a mesoporous tetrathiafulvalene-based metal–organic framework
2019
The design of metal–organic frameworks (MOFs) incorporating electroactive guest molecules in the pores has become a subject of great interest in order to obtain additional electrical functionalities within the framework while maintaining porosity. Understanding the charge-transfer (CT) process between the framework and the guest molecules is a crucial step towards the design of new electroactive MOFs. Herein, we present the encapsulation of fullerenes (C60) in a mesoporous tetrathiafulvalene (TTF)-based MOF. The CT process between the electron-acceptor C60 guest and the electron-donor TTF ligand is studied in detail by means of different spectroscopic techniques and density functional theor…
Tetrathiafulvalene-Based Mixed-Valence Acceptor-Donor-Acceptor Triads: A Joint Theoretical and Experimental Approach
2013
This work presents a joint theoretical and experimental characterisation of the structural and electronic properties of two tetrathiafulvalene (TTF)-based acceptor-donor-acceptor triads (BQ-TTF-BQ and BTCNQ-TTF - BTCNQ; BQ is naphthoquinone and BTCNQ is benzotetracyano-p-quinodimethane) in their neutral and reduced states. The study is performed with the use of electrochemical, electron paramagnetic resonance (EPR), and UV/Vis/NIR spectroelectrochemical techniques guided by quantum-chemical calculations. Emphasis is placed on the mixed-valence properties of both triads in their radical anion states. The electrochemical and EPR results reveal that both BQ-TTF-BQ and BTCNQ-TTF-BTCNQ triads in…
Tetrathiafulvalene-Polychlorotriphenylmethyl Dyads: Influence of Bridge and Open-Shell Characteristics on Linear and Nonlinear Optical Properties
2017
Three conjugated donor-π-acceptor radical systems (1 a–1 c) were prepared by bridging a tetrathiafulvalene (TTF) electron-donor unit to a polychlorotriphenylmethyl (PTM) electron-acceptor radical through vinylene units of different lengths. The dependence of the intramolecular charge transfer on the length of the conjugated bridge has been analyzed by different electrochemical and spectroscopic techniques. Linear optical properties and the second-order nonlinear optical (NLO) response of these derivatives have been computed by comparing systems 1 a–1 c with the non-radical analogues (2 a–2 c). Interestingly, an enhanced NLO response is predicted for dyads 1 a–1 c with PTM in the radical for…
DLPNO-CCSD(T) scaled methods for the accurate treatment of large supramolecular complexes
2017
In this work, we present scaled variants of the DLPNO-CCSD(T) method, dubbed as (LS)DLPNO-CCSD(T) and (NS)DLPNO-CCSD(T), to obtain accurate interaction energies in supramolecular complexes governed by noncovalent interactions. The novel scaled schemes are based on the linear combination of the DLPNO-CCSD(T) correlation energies calculated with the standard (LoosePNO and NormalPNO) and modified (Loose2PNO and Normal2PNO) DLPNO-CCSD(T) accuracy levels. The scaled DLPNO-CCSD(T) variants provide nearly TightPNO accuracy, which is essential for the quantification of weak noncovalent interactions, with a noticeable saving in computational cost. Importantly, the accuracy of the proposed schemes is…
Controlling Spin-Correlated Radical Pairs with Donor-Acceptor Dyads: A New Concept to Generate Reduced Metal Complexes for More Efficient Photocataly…
2021
Abstract One‐electron reduced metal complexes derived from photoactive ruthenium or iridium complexes are important intermediates for substrate activation steps in photoredox catalysis and for the photocatalytic generation of solar fuels. However, owing to the heavy atom effect, direct photochemical pathways to these key intermediates suffer from intrinsic efficiency problems resulting from rapid geminate recombination of radical pairs within the so‐called solvent cage. In this study, we prepared and investigated molecular dyads capable of producing reduced metal complexes via an indirect pathway relying on a sequence of energy and electron transfer processes between a Ru complex and a cova…