Conformational diversity and dynamics of distally disubstituted calix and thiacalix[4]arenes in solution

According to the quantum chemical calculations and Dynamic NMR experiments in the distally disubstituted classical and thiacalix[4]arenes (CCA and TCA) in addition to the C2v symmetrical pinched cone (PC) conformation, the distorted cone (DC) form with an approximate Cs overall symmetry (with two OH groups bonded to one oxygen atom) also corresponds to the energy minimum. Moreover, in DC form, two different mutual orientations of O-R groups at a lower rim lead to two stable conformations: the first - with both these groups directed outward, the second - with both these groups pointing toward the same direction. In CCA, the PC is essentially favoured over the DC, while in TCA, energies of these forms are similar or the latter may be even preferable. Copyright © 2013 John Wiley & Sons, Ltd

Thiacalix[4]monocrowns with terpyridine functional groups as new structural units for luminescent polynuclear lanthanide complexes

© 2016 © 2016 A.E. Arbuzov Institute of Organic and Physical Chemistry.The synthesis and structure of thiacalix[4]monocrowns in 1,3-alternate configuration substituted by terpyridyl fragments on the lower rim are being discussed. It has been shown that the number of oxyethylene units in oligoethylene glycol chain affects the distribution of the yields of the cross-linking products leading to either thiacalix[4]monocrowns or bisthiacalix[4]arenes. Their complexation ability towards alkali metal and lanthanide ions has been studied using liquid extraction and MALDI TOF MS, in addition to luminescent properties of ligands and their lanthanide complexes. The NMR titration data discovered the participation of both crown ether and terpyridyl fragment in the coordination of lanthanide cations. The fluorescent titration showed the nonlinear emission response to the amount of lanthanide ions

Nitrothiacalixarenes with alkyl groups at the lower rim: design, synthesis and aggregation behaviour at the air–water interface and in solution

© 2017 Di-n-octylated tetranitrothiacalix[4]arene, a new multidipolar D-π-A chromophore has been synthesized and the dependence of its aggregation in solution and at the air–water interface on the concentration of solution and spreading solvent has been evaluated

Volitional self-regulation and emotional burnout of professional sambo-athletes who suffered from sports injuries

Objective: to study the level of volitional self-regulation and emotional burnout in male sambo-athletes who underwent sports injuries of various degrees of severity. Materials and methods: 60 male sambo-athletes were examined. They were divided into 3 groups of 20 people in each group based on types of sports injuries. Results: significantly (p=0.001) lower level of volitional self-regulation was found in the third group who underwent more injuries (total scale: Q1=6,0; Me=8,0; Q3=10,0; «perseverance»: Q1=5,0; Me=5,5; Q3=8,0; «self-control»: Q1=4,0; Me=4,5; Q3=5,0). More pronounced emotional burnout occured in athletes who had more injuries (Q1=64,5; Me=69,0; Q3=71,0; p=0,001). Inadequate emotional response and emotional and moral disorientation was leveled down with aggravation of the severity of injuries (Q1=25,0; Me=44,0; Q3=61,0; p=0,039). Adaptation systems strain is manifested by a marked emotional exhaustion and decrease in volitional self-regulation with an increase in the number of injuries. Conclusions: if incidence and severity of injuries increases in sambo-athletes the level of volitional self-regulation reduces and emotional burnout occurs, which is characterized by the stress of the system of psychological adaptation

Motion capture systems: medical and technical assessment of the current stage of technology development. Literature review

Objective: to conduct a comparative medical and technical analysis of existing motion capture systems.Materials and methods: open data sources (e-library, Scopus, PubMed, etc.) were used as a scientific base to achieve this aim. The search depth is not limited.Results: information about marker-free and marker motion capture systems, including inertial, mobile, mechanical, optoelectronic, magnetic and systems using virtual reality technology, is consistently presented. A comparative analysis of the medical and technical characteristics of the presented systems was carried out.Conclusion: it is shown that motion capture systems are a promising direction for the development of a whole group of tools for the diagnosis of locomotor function, which can be successfully integrated into a sports medicine clinic. Motion capture systems vary in their technical parameters, which requires a deep analytical approach in their use to solve different clinical problems

Thiacalix[4]monocrowns substituted by sulfur-containing anchoring groups: New ligands for gold surface modification

Crown containing calix[4]arenes 2a-f with thioacetate-functionalized carbon chains on lower rim in 1,3-alternate conformation were synthesized starting from corresponding bromo-derivatives. The use of thiacalixcrowns monolayer films improves adhesion between gold and biomolecules (cytochrome c and catalase). The structures of these monolayers were analyzed using contact angle measurements and AFM visualization by discontinuous contact mode. © ISUCT Publishing

A new type of polytopic coordination compound: The synthesis and NMR studies of the first hybrid thiacalix[4]arenoclathrochelates

Nucleophilic substitution of the reactive chlorine atoms of iron(II) dichloroclathrochelate with thiol-terminated thiacalix[4]arene nucleophiles in the 1,3-alternate conformation afforded the first hybrid calixarenoclathrochelates with both ring-closed and ring-opened structures. The 1:1, 1:2 and 1:3 condensations of tetra-O-substituted thiacalix[4]arenes with thiol-terminated spacer substituents at the lower rim of the macrocyclic platform were performed. These thiol-terminated calixarene precursors were obtained from their O-ω-bromoalkyl precursors in the 1,3-alternate conformation, which are the products of alkylation of the parent thiacalix[4]arene with a series of homological α,ω-dibromoalkanes. The complexes obtained were characterized using elemental analysis, MALDI-TOF and ESI mass spectrometry, IR, 1H, 19F, 11B and 13C{1H} NMR spectra; their molecular structures in solution were thoroughly studied by one- and two-dimensional NMR spectroscopy as well as by molecular mechanics calculations. The formation of the thiacalix[4]arenoclathrochelates depends on the length of their ribbed spacer substituents in the chelate α-dioximate fragments of the cage frameworks; those with four bridging methylene groups seem to be optimal for the synthesis of the ring-closed hybrid molecules with two metal-encapsulating macrobicycles. © 2012 Elsevier Ltd. All rights reserved