Observation of the Magnetic Ground State of the Two Smallest Triangular Nanographenes.

Fusion of three benzene rings in a triangular fashion gives rise to the smallest open-shell graphene fragment, the phenalenyl radical, whose π-extension leads to an entire family of non-Kekulé triangular nanographenes with high-spin ground states. Here, we report the first synthesis of unsubstituted phenalenyl on a Au(111) surface, which is achieved by combining in-solution synthesis of the hydro-precursor and on-surface activation by atomic manipulation, using the tip of a scanning tunneling microscope. Single-molecule structural and electronic characterizations confirm its open-shell S = 1/2 ground state that gives rise to Kondo screening on the Au(111) surface. In addition, we compare the phenalenyl's electronic properties with those of triangulene, the second homologue in the series, whose S = 1 ground state induces an underscreened Kondo effect. Our results set a new lower size limit in the on-surface synthesis of magnetic nanographenes that can serve as building blocks for the realization of new exotic quantum phases of matter

Family Dynamics and First-Time Homeownership

The transition to first-time homeownership is related to household events such as cohabitation and marriage as well as to parents' homeownership. This paper investigates how these relationships have changed during the last few decades, using the first wave of the Netherlands Kinship Panel Study and event history analysis techniques, including interaction effects with the calendar year. The study finds that singles, cohabiters and those who are just starting cohabitation have become more likely to be first-time homeowners than married people without children. The data did not provide evidence for changes in the importance of the intergenerational transmission of homeownership

Observation of the Magnetic Ground State of the Two Smallest Triangular Nanographenes

Fusion of three benzene rings in a triangular fashion gives rise to the smallest open-shell graphene fragment, the phenalenyl radical, whose π-extension leads to an entire family of non-Kekulé triangular nanographenes with high-spin ground states. Here, we report the first synthesis of unsubstituted phenalenyl on a Au(111) surface, which is achieved by combining in-solution synthesis of the hydro-precursor and on-surface activation by atomic manipulation, using the tip of a scanning tunneling microscope. Single-molecule structural and electronic characterizations confirm its open-shell S = 1/2 ground state that gives rise to Kondo screening on the Au(111) surface. In addition, we compare the phenalenyl’s electronic properties with those of triangulene, the second homologue in the series, whose S = 1 ground state induces an underscreened Kondo effect. Our results set a new lower size limit in the on-surface synthesis of magnetic nanographenes that can serve as building blocks for the realization of new exotic quantum phases of matter

Pi Radical Cascade to a Chiral Saddle Shaped Peropyrene

Author Keywords: phenalenyl · biradicals · peropyrene · negative curvature · circularly polarized luminescenceReactions of open-shell molecular graphene fragments are typically thought of as undesired decomposition processes because they lead to the loss of desired features like π-magnetism. Oxidative dimerization of phenalenyl to peropyrene shows, however, that these transformations hold promise as a synthetic tool for making complex structures via formation of multiple bonds and rings in a single step. Here, we explore the feasibility of using this “undesired” reaction of phenalenyl to build up strain and provide access to non-planar polycyclic aromatic hydrocarbons. To this end, we designed and synthesized a biradical system with two phenalenyl units linked via a biphenylene backbone. The design facilitates an intramolecular cascade reaction to a helically twisted saddle-shaped product, where the key transformations—ring-closure and ring-fusion—occur within one reaction. The negative curvature of the final peropyrene product, induced by the formed eightmembered ring, was confirmed by single-crystal X-ray diffraction analysis and the helical twist was validated via resolution of the product’s enantiomers that display circularly polarized luminescence and high configurational stability.H2020 European Research Council. Grant Number: ERC StG 716139 / INSPIRALSchweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung. Grant Numbers: CRSK-2_190365, PP00P2_170534, PP00P2_198900, TMCG-2_213829 / CASCADERUniversität Zürich. Grant Number: FK-21-131Deutsche Forschungsgemeinschaft. Grant Number: 417643975Open Access funding provided by Universität Zürich

π-Radical Cascade to a Chiral Saddle-Shaped Peropyrene

Reactions of open-shell molecular graphene fragments are typically thought of as undesired decomposition processes because they lead to the loss of desired features like π-magnetism. Oxidative dimerization of phenalenyl to peropyrene shows, however, that these transformations hold promise as a synthetic tool for making complex structures via formation of multiple bonds and rings in a single step. Here, we explore the feasibility of using this “undesired” reaction of phenalenyl to build up strain and provide access to non-planar polycyclic aromatic hydrocarbons. To this end, we designed and synthesized a diradical system with two phenalenyl units linked via a biphenylene backbone. The design facilitates an intramolecular cascade reaction to a helically twisted saddle-shaped product, where the key transformations—ring-closure and ring-fusion—occur within one reaction. The negative curvature of the final peropyrene product, resulting from the presence of an eight-membered ring, was confirmed by single-crystal X-ray diffraction analysis and the helical twist was validated via resolution of the product’s enantiomers that display circularly polarized luminescence

The value of circulating biomarkers in bicuspid aortic valve-associated aortopathy

AbstractTraditional risk stratification model of bicuspid aortic valve (BAV) aortopathy is based on measurement of maximal cross-sectional aortic diameter, definition of proximal aortic shape, and aortic stiffness/elasticity parameters. However, conventional imaging-based criteria are unable to provide reliable information regarding the risk stratification in BAV aortopathy, especially considering the heterogeneous nature of BAV disease. Given those limitations of conventional imaging, there is a growing clinical interest to use circulating biomarkers in the screening process for thoracic aortic aneurysms as well as in the risk-assessment algorithms. We aimed to systematically review currently available biomarkers, which may be of value to predict the natural evolution of aortopathy in individuals with BAV.</jats:p

Exchange Interactions and Intermolecular Hybridization in a Spin-1/2 Nanographene Dimer

Phenalenyl is a radical nanographene with a triangular shape hosting an unpaired electron with spin S = 1/2. The open-shell nature of the phenalenyl is expected to be retained in covalently bonded networks. As a first step, we report synthesis of the phenalenyl dimer by combining in-solution synthesis and on-surface activation and its characterization on Au(111) and on a NaCl decoupling layer by means of inelastic electron tunneling spectroscopy (IETS). IETS shows inelastic steps that are identified as singlet–triplet excitation arising from interphenalenyl exchange. Spin excitation energies with and without the NaCl decoupling layer are 48 and 41 meV, respectively, indicating significant renormalization due to exchange with Au(111) electrons. Furthermore, third-neighbor hopping-induced interphenalenyl hybridization is fundamental to explaining the position-dependent bias asymmetry of the inelastic steps and activation of kinetic interphenalenyl exchange. Our results pave the way for bottom-up synthesis of S = 1/2 spin-lattices with large exchange interactions