Performance of exchange-correlation functionals on describing ground state geometries and excitations of Alizarin Red S : Effect of complexation and degree of deprotonation

Ground state optimizations and excited state calculations were performed to analyze the possible anionic forms of Alizarin Red S(ulphonated) and its ML2 type metal complexes formed with palladium(II). Six functionals have been tested (B3LYP, M06-2X, M06, BH&HLYP, PBE0, LC-wPBE, and CAM-B3LYP) with two basis sets (6-311+g(d,p) and TZVP). The relative errors of these functionals in reproducing the experimental UV-Vis absorption wavelengths are reported for the energetically lowest lying isomers. It was found that the degree of deprotonation affects several functionals in a systematic way. M06 and CAM-B3LYP xc-functionals gave the best estimates according to the average relative errors. These two functionals were then used to explore the coordination mode (hydroxy-keto or catechol) of the palladium(II) complexes and the effect of (de)protonation. © 2014 Elsevier B.V

Palládium-szalán komplexek flexibilitásának modellezése: Modeling the flexibility of palladium-salan complexes

A novel simple topological description of metal-salen-type complexes is presented through the palladium-(sulfo)salan model compound. The selected coordinates with which we define the spatial position of the spine and arms are suitable for systematic conformational analysis, which also makes it possible to find less favorable conformers by quantum chemical methods. Comparison of different compounds and isomers becomes easy using these coordinates.Palladium-salan complexes are also used in hydrogenation reactions, the catalytically active form of which, the monohydride complex, can be formed in several possible ways. In the first step of the process, the substitution of the phenolate arm and the hydrogen molecule takes place directly or via an aqua-complex intermediate, indirectly. Direct proton transfer from the coordinated hydrogen molecule to the oxygen of the phenolate arm is preferred, which in most cases is the rate-determining step. We also examined the emerging hydrogen bridge types, among which we found characteristic patterns. Kivonat A palládium-(szulfo)szalán modellvegyületen keresztül mutatjuk be a fém-szalén típusú komplexek egy új és egyszerű topológiai leírását. A kiválasztott koordináták, melyekkel a gerinc és a karok térállását definiáljuk, alkalmasak a szisztematikus konformáció-analízisre, ami a kevésbé kedvező konformerek megtalálását is lehetővé teszi kvantumkémiai módszerrel. A különböző vegyületek és izomerek összehasonlítása egyszerűvé válik ezen koordináták alkalmazásával.A palládium-szalán komplexeket hidrogénezési reakcióban is alkalmazzák, melyek katalitikusan aktív formája, a monohidrido-komplex több lehetséges úton is kialakulhat. A folyamat első lépésében a fenolát kar és a hidrogénmolekula szubsztitúciója valósul meg direkt, vagy egy akvakomplex intermedieren keresztül, indirekt módon. A koordinált hidrogénmolekuláról a fenolát kar oxigénjére történő közvetlen protontranszfer preferált, ami a legtöbb esetben a sebességmeghatározó lépés. Továbbá megvizsgáltuk a kialakuló hidrogén-híd típusokat, melyek közt jellegzetes mintázatokat találtunk

An acrylated isocyanonaphthalene based solvatochromic click reagent: Optical and biolabeling properties and quantum chemical modeling

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Effect of the Substitution Position on the Electronic and Solvatochromic Properties of Isocyanoaminonaphthalene (ICAN) Fluorophores

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New blue light-emitting isocyanobiphenyl based fluorophores: Their solvatochromic and biolabeling properties

The preparation and optical study of 4-amino-4′-isocyanobiphenyl (ICAB) and its mono-and dialkylated derivatives (monoMICAB and diMICAB) are reported. They were found to be effective blue light emitters with a solvatochromic range of Δλmax = 104 nm, 92 nm and 90 nm, respectively. All three compounds turned out to be promising candidates in protein-labeling, yielding ∼70-190× increase in their fluorescence intensity when mixed with 10× molar excess of bovine serum albumin (BSA). The binding constants for the BSA-fluorophore complexes were found to be KICAB-BSA = 3.8 × 104 ± 5.7 × 103 M-1, KmonoMICAB-BSA = 6.0 × 104 ± 3.9 × 103 M-1 and KdiMICAB-BSA = 2.3 × 104 ± 3.2 × 103 M-1. Time resolved fluorescence measurements revealed a nearly uniform ∼2 ns lifetime for all three BSA-complexed ICAB derivatives. © 2015 Elsevier B.V. All rights reserved

Synthesis of Hydrofluoroolefin‐based Iodonium Reagent via Dyotropic Rearrangement and Its Utilization in Fluoroalkylation

[1,2]‐shift of atoms in alkyl fragments belongs to the class of dyotropic rearrangements. Various atoms, including halogens can be involved in the migration, however participation of iodine is unprecedented. Herein, we report our experimental and DFT studies on the oxidation triggered dyotropic rearrangement of iodo and chloro functions via butterfly‐type transition state to demonstrate the migrating ability of λ(3)‐iodane centre. With the exploitation of dyotropic rearrangement we designed and synthesized a novel fluoroalkyl iodonium reagent from industrial feedstock gas HFO‐1234yf. We demonstrated that the hypervalent reagent serves as an excellent fluoroalkylation agent for various amines and nitrogen heterocycles