A highly versatile fluorenone-based macrocycle for the sensitive detection of polycyclic aromatic hydrocarbons and fluoride anions

Reported herein is the high yielding synthesis of a new fluorenone-based triazolophane and its sensing capabilities for polycyclic aromatic hydrocarbons (PAHs) and fluoride anions. Fluorescence, UV/Vis and 1H NMR spectroscopy results showed the triazolophane has a high sensitivity for selected PAHs and binds the fluoride anion in a 2 : 1 stoichiometry via C–H hydrogen bonding with the triazole and fluorenone protons

Phthalocrowns: Isoindoline–Crown Ether Macrocycles

The reaction of diiminoisoindoline with amine-terminated polyethers results in the formation of phthalocrown macrocycles. For <i>n</i> = 1 (where <i>n</i> is the number of ether units), a 2 + 2 condensation takes place, but for <i>n</i> = 2 and 3, a 1 + 1 macrocycle formation occurs. The <i>n</i> = 2 phthalocrown is particularly stable due to a strong intramolecular hydrogen bond, but the <i>n</i> = 3 ring hydrolyzes to form a 3-imino-1-oxoisoindoline derivatized crown ether species. For the <i>n</i> = 1 phthalocrown, we observed dynamic behavior in the ¹H NMR spectrum, and using VTNMR were able to measure a Δ<i>G</i>^⧧ = 44.6 kJ/mol for proton exchange

Phthalocrowns: Isoindoline–Crown Ether Macrocycles

The reaction of diiminoisoindoline with amine-terminated polyethers results in the formation of phthalocrown macrocycles. For <i>n</i> = 1 (where <i>n</i> is the number of ether units), a 2 + 2 condensation takes place, but for <i>n</i> = 2 and 3, a 1 + 1 macrocycle formation occurs. The <i>n</i> = 2 phthalocrown is particularly stable due to a strong intramolecular hydrogen bond, but the <i>n</i> = 3 ring hydrolyzes to form a 3-imino-1-oxoisoindoline derivatized crown ether species. For the <i>n</i> = 1 phthalocrown, we observed dynamic behavior in the ¹H NMR spectrum, and using VTNMR were able to measure a Δ<i>G</i>^⧧ = 44.6 kJ/mol for proton exchange

Phthalocrowns: Isoindoline–Crown Ether Macrocycles

The reaction of diiminoisoindoline with amine-terminated polyethers results in the formation of phthalocrown macrocycles. For <i>n</i> = 1 (where <i>n</i> is the number of ether units), a 2 + 2 condensation takes place, but for <i>n</i> = 2 and 3, a 1 + 1 macrocycle formation occurs. The <i>n</i> = 2 phthalocrown is particularly stable due to a strong intramolecular hydrogen bond, but the <i>n</i> = 3 ring hydrolyzes to form a 3-imino-1-oxoisoindoline derivatized crown ether species. For the <i>n</i> = 1 phthalocrown, we observed dynamic behavior in the ¹H NMR spectrum, and using VTNMR were able to measure a Δ<i>G</i>^⧧ = 44.6 kJ/mol for proton exchange

Phthalocrowns: Isoindoline–Crown Ether Macrocycles

The reaction of diiminoisoindoline with amine-terminated polyethers results in the formation of phthalocrown macrocycles. For <i>n</i> = 1 (where <i>n</i> is the number of ether units), a 2 + 2 condensation takes place, but for <i>n</i> = 2 and 3, a 1 + 1 macrocycle formation occurs. The <i>n</i> = 2 phthalocrown is particularly stable due to a strong intramolecular hydrogen bond, but the <i>n</i> = 3 ring hydrolyzes to form a 3-imino-1-oxoisoindoline derivatized crown ether species. For the <i>n</i> = 1 phthalocrown, we observed dynamic behavior in the ¹H NMR spectrum, and using VTNMR were able to measure a Δ<i>G</i>^⧧ = 44.6 kJ/mol for proton exchange

Case Report: Stress Fracture in an International Triple Jumper: Importance of an Integrated Care Approach Which Also Incorporates Biomechanics

International audienceAthletes fear stress fracture (SF) injuries as they can put a premature end to their athletic careers. Understanding any mechanical constraints can suggest preventive management approach. Specifically, for the triple jump, the mechanical stresses that occur during the event appear to be the main factors for risk of injury. This clinical case describes three successive episodes of anterior tibial fracture in an international triple jumper between 2011 and 2013. The first fracture received surgical treatment involving intramedullary nailing. The second fracture occurred in the same location and was considered a recurrence requiring medical treatment, whilst the third was a complete fracture of the surgical material and required surgical revision. These recurrent fractures can be explained by the fatigue of materials (bone and nail) induced by triple jump practice and emphasize the importance of integrating biomechanics into an assessment of the case. The use of biomechanical modelization to identify these weaknesses could be an approach for clinical management of such patients. Observation of the intrinsic mechanical stresses during high-level triple jump may lead to identification of modifiable risk factors for bone fragility

A New Highly Fluorescent and Symmetric Pyrrole–BF₂ Chromophore: BOPHY

The new fluorescent chromophore BOPHY can be readily synthesized in two steps from commercially available reagents via the coupling of pyrrole-2-carboxaldehyde with hydrazine followed by reaction with BF₃. The resultant symmetric and dimeric tetracycle is composed of two BF₂ units in six-membered chelate rings appended with pyrrole units on the periphery. The quantum yields of fluorescence for the unmodified compound and the tetramethyl variant are near unity, with values of 95 and 92%, respectively, in CH₂Cl₂. We have probed the electronic structure of this compound via cyclic voltammetry and density functional theory analysis