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Suitability of single-reference density functional theory (DFT) methods for the calculation of redox potentials of copper-containing macrocycle complexes was confirmed by the use of T 1 diagnostics along with a verification of negligible spin contamination or wave function instability. When examining the effect of improvement in the cc-pVnZ basis s...
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... a systematic computational protocol for the calculation of reduction potentials of copper complexes is developed and tested on the series of 14-membered quadradentate macrocyclic polyamino polyether ligands ( Figure 2). These molecules represent a series of valid, and experimentally characterized, copper-binding model systems, previously used as a model for blue copper-binding sites. ...
Citations
Dye-sensitized solar cells (DSSCs) present a promising avenue for addressing the escalating need for clean energy
solutions. These innovative cells offer a sustainable approach to meet the rising demands for environmentally
friendly power sources. An assessment was conducted on a copper complex containing a hexadentate ligand,
serving as a redox shuttle, alongside triphenylamine-based organic dyes in the construction of DSSC. This study
thoroughly investigates the electronic structures, FMO, MEP surfaces, and photophysical properties of copper
redox shuttle and triphenylamine dyes employing DFT and TDDFT calculations. The copper system, [Cu
(bpyPY4)]2+/+, analyzed in this study, is anchored by the hexadentate polypyridyl ligand bpyPY4 (6,6′-bis(1,1-di
(pyridine-2-yl)ethyl)-2,2′-bipyridine), scrutinized as a redox shuttle (RS). The assessed redox potential for [Cu
(bpyPY4)]2+/+ is − 4.67 eV. This indicates that the dye can effectively undergo regeneration by transferring
electrons from the reduced form of the redox shuttle to the oxidized form of the dye. The photovoltaic efficiency
has been analyzed with regard to various factors, including the energy gap between the HOMO and LUMO, the
excited-state oxidation potential (Edye*), electron injection ability (ΔGinj), electron regeneration (ΔGreg), light
harvesting efficiency, short-circuit current density (JSC) and the open-circuit voltage (Voc). This study sheds light
on present-day developments and forthcoming prospects in utilizing 3d transition metal-based redox shuttles,
presenting them as compelling candidates for integration with organic dyes in Dye-Sensitized Solar Cells
(DSSCs). This integration holds promise for more efficient solar spectrum absorption and enhanced performance
of solar devices.
Copper-catalysed radical-relay reactions that employ N-fluorobenzenesulfonimide (NFSI) as the oxidant have emerged as highly effective methods for C(sp³)–H functionalization. Herein, computational studies are paired with experimental data to investigate a series of key mechanistic features of these reactions, with a focus on issues related to site-selectivity, enantioselectivity, and C–H substrate scope. (1) The full reaction energetics of enantioselective benzylic C–H cyanation are probed, and an adduct between Cu and the N-sulfonimidyl radical (˙NSI) is implicated as the species that promotes hydrogen-atom transfer (HAT) from the C–H substrate. (2) Benzylic versus 3° C–H site-selectivity is compared with different HAT reagents: Cu/˙NSI, ˙OtBu, and Cl˙, and the data provide insights into the high selectivity for benzylic C–H bonds in Cu/NFSI-catalyzed C–H functionalization reactions. (3) The energetics of three radical functionalization pathways are compared, including radical–polar crossover (RPC) to generate a carbocation intermediate, reductive elimination from a formal CuIII organometallic complex, and radical addition to a Cu-bound ligand. The preferred mechanism is shown to depend on the ligands bound to copper. (4) Finally, the energetics of three different pathways that convert benzylic C–H bonds into benzylic cations are compared, including HAT/ET (ET = electron transfer), relevant to the RPC mechanism with Cu/NFSI; hydride transfer, involved in reactions with high-potential quinones; and sequential ET/PT/ET (PT = proton transfer), involved in catalytic photoredox reactions. Collectively, the results provide mechanistic insights that establish a foundation for further advances in radical-relay C–H functionalization reactions.
The ab-initio calculation shows that nitrogen, boron, and sulfur (NBS) containing heterocyclic molecules, i.e., boron-doped thiazole, can behave as a superhalogen with high electron affinity value. In this study, DFT calculation found that the calculated electron affinity/vertical detachment energy of the synthesized dimer-NBS heterocyclic molecules is close to 2 eV. After ligand manipulation on the dimer, new superhalogens developed. Frontier molecular orbitals (FMOs) study helps to understand the variation of the electron affinity of the designed superhalogens. Topological analyses such as bond critical point (BCP), electron localization function (ELF), and AdNDP analysis support the bonding pattern of such heterocycle molecules.
