On-Surface Synthesis and Characterization of a High-Spin Aza-[5]-Triangulene

Triangulenes are open-shell triangular graphene flakes with total spin increasing with their size. In the last years, on-surface-synthesis strategies have permitted fabricating and engineering triangulenes of various sizes and structures with atomic precision. However, direct proof of the increasing total spin with their size remains elusive. In this work, we report the combined in-solution and on-surface synthesis of a large nitrogen-doped triangulene (aza-[5]-triangulene) and the detection of its high spin ground state on a Au(111) surface. Bond-resolved scanning tunneling microscopy images uncovered radical states distributed along the zigzag edges, which were detected as weak zero-bias resonances in scanning tunneling spectra. These spectral features reveal the partial Kondo screening of a high spin state. Through a combination of several simulation tools, we find that the observed distribution of radical states is explained by a quintet ground state (S = 2), instead of the expected quartet state (S = 3/2), confirming the positively charged state of the molecule on the surface. We further provide a qualitative description of the change of (anti)aromaticity introduced by N-substitution, and its role in the charge stabilization on a surface, resulting in a S = 2 aza-[5]-triangulene on Au(111).Comment: 8 pages with 4 figure

Anales del III Congreso Internacional de Vivienda y Ciudad "Debate en torno a la nueva agenda urbana"

Acta de congresoEl III Congreso Internacional de Vivienda y Ciudad “Debates en torno a la NUEVa Agenda Urbana”, ha sido una apuesta de alto compromiso por acercar los debates centrales y urgentes que tensionan el pleno ejercicio del derecho a la ciudad. Para ello las instituciones organizadoras (INVIHAB –Instituto de Investigación de Vivienda y Hábitat y MGyDH-Maestría en Gestión y Desarrollo Habitacional-1), hemos convidado un espacio que se concretó con potencia en un debate transdisciplinario. Convocó a intelectuales de prestigio internacional, investigadores, académicos y gestores estatales, y en una metodología de innovación articuló las voces académicas con las de las organizaciones sociales y/o barriales en el Foro de las Organizaciones Sociales que tuvo su espacio propio para dar voz a quienes están trabajando en los desafíos para garantizar los derechos a la vivienda y los bienes urbanos en nuestras ciudades del Siglo XXI

Expresiones de la sexualidad y del uso del condón en las relaciones sexuales en jóvenes universitarios de Colombia. Aportes a la clínica psicológica

El objetivo del presente estudio fue comprender y analizardiversos factores socioculturales que se asocian a las prácticassexuales y uso del condón de un grupo de hombres ymujeres, estudiantes universitarios de la ciudad de Cúcuta,Colombia. Se utilizó un estudio exploratorio descriptivo conenfoque cualitativo, mediante la técnica de grupos focalesmixtos, en los cuales participaron mujeres y hombres estudiantesuniversitarios con edades entre 18 y 21años; losresultados dan cuenta que, tanto mujeres como hombresresaltan la importancia de comunicar a su pareja sexual eluso del condón en las relaciones sexuales; y que la habilidadde negociación del uso del condón está regida por los rolesy representaciones sociales del mismo; además, ejercen susexualidad en función de los roles de género

Expressions of sexuality and the use of condoms in sexual relationships among university students in Colombia. Contributions to psychological therapy.

El objetivo del presente estudio fue comprender y analizar diversos factores socioculturales que se asocian a las prácticas sexuales y uso del condón de un grupo de hombres y mujeres, estudiantes universitarios de la ciudad de Cúcuta, Colombia. Se utilizó un estudio exploratorio descriptivo con enfoque cualitativo, mediante la técnica de grupos focales mixtos, en los cuales participaron mujeres y hombres estudiantes universitarios con edades entre 18 y 21años; los resultados dan cuenta que, tanto mujeres como hombres resaltan la importancia de comunicar a su pareja sexual el uso del condón en las relaciones sexuales; y que la habilidad de negociación del uso del condón está regida por los roles y representaciones sociales del mismo; además, ejercen su sexualidad en función de los roles de género.The objective of the present study was to understand and analyze various sociocultural factors that are associated with sexual practices and condom use of a group of men and women, university students from the city of Cúcuta, Colombia. We used a descriptive exploratory study with a qualitative approach, using the technique of mixed focus groups, in which women and men university students aged between 18 and 21 years participated; The results show that both women and men emphasize the importance of communicating to their sexual partners the use of condoms in sexual relationships; and that the negotiation ability of condom use is governed by the roles and social representations of it; In addition, they exercise their sexuality according to gender roles

On‐Surface Synthesis and Characterization of a High‐Spin Aza‐[5]‐Triangulene

Triangulenes are a class of open‐shell triangular graphene flakes with total spin increasing with their size. In the last years, on‐surface‐synthesis strategies have permitted fabricating and engineering triangulenes of various sizes and structures with atomic precision. However, direct proof of the increasing total spin with their size remains elusive. In this work, we report the combined in‐solution and on‐surface synthesis of a large nitrogen‐doped triangulene (aza‐[5]‐triangulene) on a Au(111) surface, and the detection of its high‐spin ground state. Bond‐resolved scanning tunneling microscopy images uncovered radical states distributed along the zigzag edges, which were detected as weak zero‐bias resonances in scanning tunneling spectra. These spectral features reveal the partial Kondo screening of a high‐spin state. Through a combination of several simulation tools, we find that the observed distribution of radical states is explained by a quintet ground state (S=2), instead of the quartet state (S=3/2) expected for the neutral species. This confirms that electron transfer to the metal substrate raises the spin of the ground state. We further provide a qualitative description of the change of (anti)aromaticity introduced by N‐substitution, and its role in the charge stabilization on a surface, resulting in an S=2 aza‐triangulene on Au(111)

On‐Surface Synthesis and Characterization of a High‐Spin Aza‐[5]‐Triangulene

Triangulenes are a class of open‐shell triangular graphene flakes with total spin increasing with their size. In the last years, on‐surface‐synthesis strategies have permitted fabricating and engineering triangulenes of various sizes and structures with atomic precision. However, direct proof of the increasing total spin with their size remains elusive. In this work, we report the combined in‐solution and on‐surface synthesis of a large nitrogen‐doped triangulene (aza‐[5]‐triangulene) on a Au(111) surface, and the detection of its high‐spin ground state. Bond‐resolved scanning tunneling microscopy images uncovered radical states distributed along the zigzag edges, which were detected as weak zero‐bias resonances in scanning tunneling spectra. These spectral features reveal the partial Kondo screening of a high‐spin state. Through a combination of several simulation tools, we find that the observed distribution of radical states is explained by a quintet ground state (S=2), instead of the quartet state (S=3/2) expected for the neutral species. This confirms that electron transfer to the metal substrate raises the spin of the ground state. We further provide a qualitative description of the change of (anti)aromaticity introduced by N‐substitution, and its role in the charge stabilization on a surface, resulting in an S=2 aza‐triangulene on Au(111)