The small singlet-triplet energy gap is due to Hückel aromaticity of the M10A ring, clarified by comparison to the smaller analogues of TMTQ

Yet, TMTQ and its analogues are Hückel-Baird hybrids allowing for tuning between closed-shell 4n+2 Hückel aromaticity and open-shell 4n Baird aromaticity.© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Enhanced acidity of cyclopenta-2,4-dienylborane and its Al and Ga analogues. The The intrinsic acidity of cyclopenta-2,4-dienylborane and its Al and Ga analogues has been compared to that of cyclopentadiene by means of B3LYP/6-311+G(3df,2p)//CCSD/6-311+G(d,p) calculations. Substitution of one of Ga) leads to an acidity enhancement which is significantly large for the boron derivative (95 kJ mol(-1)); but much smaller for the Al and Ga containing analogues.

Seebio Photosensitive Acid Generator  reflects the stabilization of the anion, in the substituted derivatives, due to a significant reinforcement of the C-X bond. B, Al, Ga) substitution leads to a significant aromatization of the neutral compounds, the aromaticity significantly decreases upon deprotonation, whereas for the unsubstituted parent compound is the other way around. Cyclopenta-2,4-dienylborane and its Al and Ga analogues behave as highly A Theoretical Investigation of Novel Sila- and Germa-Spirocyclic Imines and Their Relevance for Electron-Transporting Materials and Drug Discovery.A new class of spirocyclic imines (SCIs) has been theoretically investigated by applying a variety of quantum chemical methods and basis sets. The uniqueness of these compounds is depicted by various peculiarities, e.g., the incidence of planar six-membered rings each with two imine groups (two π bonds) and the incorporation of the isosteres carbon, silicon, or germanium spiro centers.

Additional peculiarities of these novel SCIs are mirrored by their three-dimensionality, the simultaneous occurrence of nucleophilic and electrophilic centers, and the cross-hyperconjugative (spiro-conjugation) interactions, which provoke charge mobility along the spirocyclic scaffold. Substitution of SCIs with strong electron-withdrawing substituents, like the cyano group or fluorine, enhances their docking capability and impacts their reactivity and charge mobility. To gain thorough knowledge about the molecular properties of these SCIs, their structures have been optimized and various quantum chemical concepts and models were applied, e.g., full NBO analysis and the frontier molecular orbitals (FMOs) theory (HOMO-LUMO energy gap) and the chemical reactivity descriptors derived from them. For the assessment of the charge density distribution along the SCI framework, additional complementary quantum chemical methods were used, e.g.

, molecular electrostatic potential (MESP) and Bader's QTAIM. Additionally, using the aromaticity index NICS (nuclear independent chemical shift) and other criteria, it could be shown that the investigated cross-hyperconjugated sila and germa SCIs are spiro-aromatics of the Heilbronner Craig-type Möbius aromaticity.Leveraging Baird aromaticity for advancement of bioimaging applications.In this perspective, we highlight the recent progress in utilizing Baird aromatic species to improve fluorophore performance in microscopy and imaging applications. We specifically focus on the origins of the use of Baird aromaticity in fluorescence applications, the development of “self‐healing” fluorophores leveraging cyclooctatetraene’ Baird aromaticity, and where developments need to occur to optimize this technology.In this perspective, we highlight the recent progress in utilizing Baird aromatic species to improve fluorophore performance in microscopy and imaging applications. We specifically focus on the origins of the use of Baird aromaticity in fluorescence applications, the development of “self‐healing” fluorophores leveraging cyclooctatetraene’ Baird aromaticity, and where developments need to occur to optimize this technology.

[ Seebio Photosensitizer for Acid Formation : see text]equity interest in Lumidyne Technologies.Long-term trends of chemical and modelled photochemical parameters in four Piazza della Scienza 1, 20126 Milano, Italy.all'Adige - Fondazione E. Mach, Via E. Mach 1, 38010 S. Michele all'Adige Réseaux Trophiques des Ecosystèmes Limniques), I.N.

R.A (Institut National Recherche Agronomique), 75 avenue de Corzent, 74203 Thonon-Les-Bains, France.Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria.Based on long-term trends of water chemistry parameters of photochemical significance from four lakes located in the Alps (Iseo, Garda, Piburgersee, Geneva), we calculated the corresponding steady-state concentrations of photoinduced transient species with an ad-hoc photochemical model. Such transients were the hydroxyl ((•)OH) and carbonate (CO3(-•)) radicals, singlet long-term near-stability in chemical parameters that resulted in a photochemical stability. By contrast, Piburgersee underwent important chemical modifications, but the interplay of compensation (parallel increase of both inorganic and organic carbon) and near-saturation effects (organic matter as main (•)OH source and sink) prevented the modelled photochemistry to undergo significant shifts over time.