Light-Induced Charge Separation in Covalently Linked BODIPY-Quinone-Alkyne Dyads.

Visible light-induced charge separation and directional charge transfer are cornerstones for artificial photosynthesis and the generation of solar fuels. Here, we report synthetic access to a series of noble metal-free donor-acceptor dyads based on bodipy light-absorbers and redox-active quinone/anthraquinone charge storage sites. Peripheral functionalization of the quinone/anthraquinone units with alkynes primes the dyads for integration into a range of light-harvesting systems, e. g., by Cu-catalyzed cycloadditions (CLICK chemistry) or Pd-catalyzed C-C cross-coupling reactions. Initial photophysical, electrochemical and theoretical analyses reveal the principal processes during the light-induced charge separation in the reported dyads.

Supramolecular Aggregation Control in Polyoxometalates Covalently Functionalized with Oligoaromatic Groups.

CLICK-chemistry has become a universal route to covalently link organic molecules functionalized with azides and alkynes, respectively. Here, we report how CLICK-chemistry can be used to attach oligoaromatic organic moieties to Dawson-type polyoxometalates. In step one, the lacunary Dawson anion [α2 -P2 W17 O61 ]6- is functionalized with phosphonate anchors featuring peripheral azide groups. In step two, this organic-inorganic hybrid undergoes microwave-assisted CLICK coupling. We demonstrate the versatility of this route to access a series of Dawson anions covalently functionalized with oligoaromatic groups. The supramolecular chemistry and aggregation of these systems in solution is explored, and we report distinct changes in charge-transfer behavior depending on the size of the oligoaromatic π-system.

Initial Steps of the Acid-Catalyzed Polyoxometalate-Functionalization with Phosphonic Acid Esters.

The organo-functionalization of metal oxides is a key strategy to introduce new functionalities. Often, phosphonates are used to anchor organic moieties to a range of metal oxides. Despite their widespread use, there is a lack of understanding of the parameters which enable selective and efficient formation of organophosphonate-metal oxide hybrids. Here, we report fundamental insights into the mechanism of phosphonate anchoring to a molecular metal oxide model. Specifically, we use in situ 31P NMR spectroscopy to follow the acid-catalyzed deprotection of a model phosphonate and its subsequent condensation to form a phosphonate-functionalized Dawson-polyoxometalate. Our study shows that the nucleophilicity of the acid anion is a key parameter which controls the clean and selective deprotection and polyoxometalate attachment of phosphonates. This insight will allow researchers to expand the scope of phosphonate anchoring to metal oxides by enabling the development of mild and scalable syntheses.

High Proton-Conductivity in Covalently Linked Polyoxometalate-Organoboronic Acid-Polymers.

The controlled bottom-up design of polymers with metal oxide backbones is a grand challenge in materials design, as it could give unique control over the resulting chemical properties. Herein, we report a 1D-organo-functionalized polyoxometalate polymer featuring a purely inorganic backbone. The polymer is self-assembled from two types of monomers, inorganic Wells-Dawson-type polyoxometalates, and aromatic organo-boronates. Their covalent linkage results in 1D polymer strands, which combine an inorganic oxide backbone (based on B-O and Nb-O linkages) with functional organic side-chains. The polymer shows high bulk proton conductivity of up to 1.59×10-1  S cm-1 at 90 °C and 98 % relative humidity. This synthetic approach could lead to a new class of organic-inorganic polymers where function can be designed by controlled tuning of the monomer units.

The blue-eyes stereotype: do eye color, pupil diameter, and scleral color affect attractiveness?

BACKGROUND: Blue eyes have been the embodiment of attractiveness not only for decades but even for centuries. The primary aim of this study was to determine whether iridal color, particularly color blue, can increase the attractiveness of a person's eye area. As a secondary aim, the study examined the impact of pupil diameter and scleral color on the attractiveness of the eye area. METHODS: The stimulus material comprised images of the eye areas of 60 women ages 15-65 years. A total of 80 participants rated the attractiveness of each eye area on a 7-point Likert scale and estimated the age of the person. The color values of the iris and sclera were measured. As an additional subsample, 50% of the participants were asked what features of each eye area they found particularly appealing. RESULTS: Most surprisingly, no correlation was found between iridal color and rated attractiveness. However, the participants mentioned the color blue more often as a positive aspect than other iridal colors. A high inverse correlation was observed between attractiveness of the eye area and age. The larger the pupil diameter and the whiter the scleral color, the lower was the real and perceived age and the higher was the attractiveness. CONCLUSION: The data showed that the "blue-eyes stereotype" does exist. People consider blue eyes attractive, but in reality, blue is rated as attractive as other iridal colors. Bright scleral color and large pupils positively affect attractiveness because both features are significantly correlated with youthfulness.

A photosensitizer-polyoxometalate dyad that enables the decoupling of light and dark reactions for delayed on-demand solar hydrogen production.

Decoupling the production of solar hydrogen from the diurnal cycle is a key challenge in solar energy conversion, the success of which could lead to sustainable energy schemes capable of delivering H2 independent of the time of day. Here, we report a fully integrated photochemical molecular dyad composed of a ruthenium-complex photosensitizer covalently linked to a Dawson polyoxometalate that acts as an electron-storage site and hydrogen-evolving catalyst. Visible-light irradiation of the system in solution leads to charge separation and electron storage on the polyoxometalate, effectively resulting in a liquid fuel. In contrast to related, earlier dyads, this system enables the harvesting, storage and delayed release of solar energy. On-demand hydrogen release is possible by adding a proton donor to the dyad solution. The system is a minimal molecular model for artificial photosynthesis and enables the spatial and temporal separation of light absorption, fuel storage and hydrogen release.

Female eye attractiveness - Where beauty meets science.

INTRODUCTION: While periorbital and -ocular surgery ranks amongst the most frequently performed plastic surgical procedures, only scarce information exists regarding the contributing factors of aging and its systematic anatomic assessment. The presented study, based on measuring distinct physical landmarks, aimed to gather data to provide a foundation of in-depth periorbital analysis in order to more clearly define female eye attractiveness. METHODS: 80 probands (age range: 30-50 years, M = 38.4 ± 6.5 years) were asked to judge 60 standardized high-resolution digital pictures of female eye regions in respect to the perceived age (in years) and attractiveness (7-point Likert scale). All photographs were objectively evaluated and measured utilizing a total of 38 distinct landmarks. The data was analyzed by calculating correlations between relevant measured eye area parameters and mean attractiveness ratings including age estimations. RESULTS: Overall, it was found that several specific eye shape features correlate with attractiveness and perceived age. For instance, large visible height of the iris and large upward and lateral inclination of both eye axis and eyebrows correlated moderately to strongly with attractiveness (p < 0.05). CONCLUSION: Regarding the female eye, there exist distinct periorbital anatomic features and landmarks which contribute to a youthful appearance and attractiveness. Knowledge regarding these facts may serve as an important guideline for pre- and post-operative patient analysis.