Mechanochemical Encapsulation of Fullerenes in Peptidic Containers Prepared by Dynamic Chiral Self‐Sorting and Self‐Assembly

Molecular capsules composed of amino acid or peptide derivatives connected to resorcin[4]arene scaffolds through acylhydrazone linkers have been synthesized using dynamic covalent chemistry (DCC) and hydrogen‐bond‐based self‐assembly. The dynamic character of the linkers and the preference of the peptides towards self‐assembly into β‐barrel‐type motifs lead to the spontaneous amplification of formation of homochiral capsules from mixtures of different substrates. The capsules have cavities of around 800 ų and exhibit good kinetic stability. Although they retain their dynamic character, which allows processes such as chiral self‐sorting and chiral self‐assembly to operate with high fidelity, guest complexation is hindered in solution. However, the quantitative complexation of even very large guests, such as fullerene C₆₀ or C₇₀, is possible through the utilization of reversible covalent bonds or the application of mechanochemical methods. The NMR spectra show the influence of the chiral environment on the symmetry of the fullerene molecules, which results in the differentiation of diastereotopic carbon atoms for C₇₀, and the X‐ray structures provide unique information on the modes of peptide–fullerene interactions.     

Environmentally sensitive hydrogel functionalized with electroactive and complexing‐iron(III) catechol groups

Thermoresponsive pNIPA (poly (N‐isopropylacrylamide)) gels modified with dopamine methacrylamide were synthesized using free‐radical polymerization. In this way, the catechol groups were introduced into the polymer network. The presence of dopamine in the gel led to a significant shift in the volume phase transition temperature (VPTT). It was found that hydrogels were electroactive and that oxidation of catechol groups also led to a strong shift in the VPTT. The temperature window, that is, the range of temperature where volume of the gel could be substantially changed by oxidation of the catechol groups, for the gel formed from the polymerization solution containing 5% of the dopamine derivative, was 30–40 °C. Additionally, the influence of Fe³⁺ ions, which form the most stable complexes with dopamine, on swelling behavior of the gels was investigated at various pH. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3236–3242     

Local buckling of composite channel columns

Continuum Mechanics and Thermodynamics - The investigation concerns local buckling of compressed flanges of axially compressed composite channel columns. Cooperation of the member flange and web is...     

π-Extended Donor–Acceptor Porphyrins and Metalloporphyrins for Antimicrobial Photodynamic Inactivation

Free base, zinc and palladium π-extended porphyrins containing fused naphthalenediamide units were employed as photosensitizers in antimicrobial photodynamic therapy (aPDT). Their efficacy, assessed by photophysical and in vitro photobiological studies on Gram-positive bacteria, was found to depend on metal coordination, showing a dramatic enhancement of photosensitizing activity for the palladium complex.     

The High Temperature Vibrational Partition Function of Stretching of Triatomic Systems

Plasma Chemistry and Plasma Processing - The statistical thermodynamic model for the vibrational partition function with separated stretching and bending is developed. The model is studied on the...     

Synthesis of Monofunctionalized Silsesquioxanes (RSiMe2O)(iBu)7Si8O12 via Alkene Hydrosilylation

The research presented in this work comprehensively describes hydrosilylation of a wide spectrum of alkenes which contain one or more reactive groups with (HSiMe₂O)(iBu)₇Si₈O₁₂, in the presence of different types of catalysts. Special attention is paid to the influence of alkene, catalyst, and reaction conditions on process effectiveness and selectivity by the precise monitoring of the experiments with in situ FTIR and NMR spectroscopies. More than twenty silsesquioxanes bearing reactive groups (OH, Br, NR₂, CO, COOR, NCO, epoxy, SiR₃) commonly used in organic and polymer chemistry, were obtained, isolated and characterized by ¹H, ¹³C, ²⁹Si NMR and MALDI TOF. Importantly, in the presented syntheses, commercially available reagents and catalysts were used, meaning that the presented methods could be easily repeated, rapidly scaled up, and widely applied.     

A Spin‐Active,Electrochromic, Solvent‐Free Molecular Liquid Based on Double‐Decker Lutetium Phthalocyanine Bearing Long Branched Alkyl Chains

Synthesis and characterization of a novel, multifunctional, solvent‐free room‐temperature liquid based on alkylated double‐decker lutetium(III) phthalocyanine (Pc₂Lu) are described. Lowering of the melting point and viscosity of intrinsically solid Pc₂Lu compounds has been achieved through the attachment of flexible, bulky, and long branched‐alkyl chains, that is, thio‐2‐octyldodecyl, to the periphery of the Pc₂Lu unit. The embedded Pc₂Lu unit maintains its inherent molecular functions, such as spin‐active nature and electrochromic behavior in the liquid state. Comparison of the properties with a solid‐like Pc₂Lu derivative, functionalized with shorter alkyl chains, that is, thio‐2‐ethylhexyl, underlines the importance of the hampering effect on the π–π interactions of neighboring Pc₂Lu molecules by bulkier and longer branched‐alkyl chains. This study could possibly pave the way for novel multifunctional liquids whose spin‐activities are associated with their rheological or optoelectronic properties.