Cibalackrot-type compounds : stable singlet fission materials with aromatic ground state and excited state

AbstractSinglet fission is a multiexciton generation process, where one singlet exciton is absorbed and two triplet excitons are produced. The potential of more efficient photovoltaic devices utilizing singlet fission materials has attracted wide interests for tuneable, stable organic chromophores with suitable excited‐state ordering. The strict energetic requirements hinder the exploration of novel organic materials, and most well‐known singlet fission materials, linear acenes, are considered to be unstable in their excited states. To solve the stability issue, excited‐state aromaticity provides a feasible research option, from which a few chromophores have been designed and studied. This review describes indolonaphthyridine (IND) derivative chromophores and discusses their ability to undergo singlet fission with superior ambient stability. Deepened theoretical analysis taking into account the excited‐state Hückel‐aromatic and diradical characters rationalizes the special properties of these chromophores. Moreover, the improved understanding of the aromatic character enables us to outline a feasible design strategy suitable for other scaffolds undergo singlet fission and excited‐state aromaticity. Hopefully, this review can light a fire on the way toward various novel singlet fission chromophores designed based on the excited‐state aromatic view.</jats:p

Cibalackrot-type compounds: Stable singlet fission materials with aromatic ground state and excited state

Abstract: Singlet fission is a multiexciton generation process, where one singlet exciton is absorbed and two triplet excitons are produced. The potential of more efficient photovoltaic devices utilizing singlet fission materials has attracted wide interests for tuneable, stable organic chromophores with suitable excited‐state ordering. The strict energetic requirements hinder the exploration of novel organic materials, and most well‐known singlet fission materials, linear acenes, are considered to be unstable in their excited states. To solve the stability issue, excited‐state aromaticity provides a feasible research option, from which a few chromophores have been designed and studied. This review describes indolonaphthyridine (IND) derivative chromophores and discusses their ability to undergo singlet fission with superior ambient stability. Deepened theoretical analysis taking into account the excited‐state Hückel‐aromatic and diradical characters rationalizes the special properties of these chromophores. Moreover, the improved understanding of the aromatic character enables us to outline a feasible design strategy suitable for other scaffolds undergo singlet fission and excited‐state aromaticity. Hopefully, this review can light a fire on the way toward various novel singlet fission chromophores designed based on the excited‐state aromatic view

House dust and forage mite allergens and their role in human and canine atopic dermatitis

This article reviews the literature regarding the role of house dust and forage mite allergens in canine atopic dermatitis. The presence of immunoglobulin E (IgE) to these mites, especially to Dermatophagoides farinae, is common in both normal and atopic dogs. Exposure of dogs to the different mites is described both in the direct environment and in the coat of animals for house dust mites and in the food for forage mites. Allergens causing allergic disease in dogs seem to be different from those in humans. Dogs seem to react to high molecular weight allergens, compared to the low molecular weight group 1 and group 2 proteases that are commonly implicated in humans with atopic diseases. Despite numerous published studies dealing with this subject, a number of questions still need to be addressed to better understand the exact role of these mites in the pathogenesis of canine atopic dermatitis and to improve the quality of the allergens used in practice.T. J. Nuttall, Peter B. Hill, E. Bensignor, T. Willemse and the members of the International Task Force on Canine Atopic Dermatiti