A Tandem Conjugate Addition–Intramolecular Horner–Wadsworth–Emmons Olefination Approach to the Synthesis of Cyclopentene[c]chroman-2-ones and Cyclopent-1-enecarboxylates

A strategically new approach to cyclopentene[c]chroman- 2-ones and cyclopent-1-enecarboxylates by tandem Michael– Horner–Wadsworth–Emmons reaction of 2,5-hexanedione with 3-(diethoxyphosphoryl)coumarins is described. The products were obtained as single diastereoisomers in high yields

The mineralization effect on chitosan hydrogel structure containing collagen and alkaline phosphatase

Introducing collagen the basic ingredient of bone tissue into the structure of chitosan gels that are formed at physiological body temperature, aims to create so-called biomimetic structures, which are close in composition to the natural composition of bone tissue. The aim of this study was to determine the influence of mineralization on the structural properties of thermosensitive chitosan-collagen gels containing alkaline phosphatase (ALP) by SEM, XRD FTIR and XPS analyses, compared to the previously presented structure of chitosan-collagen gels before mineralization

Molecular and crystalline architectures based on HgI : from metallamacrocycles to coordination polymers

We report the synthesis and X-ray characterization of three metallamacrocycles and one coordination polymer obtained by using coordination driven self-assembly of the HgI2 salt with four different ligands

Novel bimetallic 1%M-Fe/Al2O3-Cr2O3 (2:1) (M = Ru, Au, Pt, Pd) catalysts for Fischer-Tropsch synthesis

The main objective of this work was to study the physicochemical and catalytic properties of bimetallic supported catalysts [1%M-Fe/Al2O3-Cr2O3 (2:1) (M = Ru, Au, Pt, Pd)] in Fischer-Tropsch synthesis. Furthermore, the study investigated the effect of noble metal addition to iron-supported catalysts on their physicochemical properties and reactivity. The physicochemical properties of the catalysts were studied using a range of characterization techniques such as X-ray diffraction (XRD), temperature-programmed reduction (TPR-H2), temperature-programmed desorption of ammonia (TPD-NH3) and BET (Brunauer – Emmett - Teller method). The activity tests were performed by Fischer-Tropsch synthesis in a high-pressure fixed-bed reactor using a gas mixture of H2 and CO with a molar ratio of 1:1. The correlation between the physicochemical properties of the investigated catalysts and their catalytic performance in CO hydrogenation was also investigated. The reactivity results showed that the most active system exhibited a high specific surface area, the highest total acidity and was the most reducible catalyst compared to the other catalysts tested. In addition, the Au–Fe system showed high selectivity towards liquid product formation during CO hydrogenation

Evaluation of rhodamine b photocatalytic degradation over batio3-mno2 ceramic materials

This research was funded by UIDB/50006/2020 with funding from FCT/MCTES through national funds and from the Institute of General and Ecological Chemistry of Lodz University of Technology. Susana L.H. Rebelo and Iwona Kuźniarska-Biernacka thank FCT (Fundação para a Ciência e Tecnologia) for funding through program DL 57/2016–Norma transitória (RE-QUIMTE/EEC2018/30 (SLHR) and REQUIMTE/EEC2018/14 (IKB)).Ferroelectric ceramics (BaTiO3_MnO2 ) with different Mn admixtures were prepared using solid-state synthesis. Elemental analysis, powder X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and impedance spectroscopy confirmed that the BaTiO3 and MnO2 coexisted in the ceramics. In addition, the high purity and homogeneity of the element distributions in the ceramic samples were confirmed. The adsorptive and photocatalytic properties of the BaTiO3 (reference sample, BTO) and BaTiO3_MnO2 materials (BTO_x, where x is wt.% of MnO2 and x = 1, 2 or 3, denoted as BTO_1, BTO_2 and BTO_3, respectively) were evaluated using Rhodamine B (RhB) as the model dye in a photocatalytic chamber equipped with a UV lamp (15 W) in the absence of additional oxidants and (co)catalysts. No adsorption of RhB dye was found for all the materials during 360 min (dark experiment). All samples were photocatalytically active, and the best results were observed for the BTO_3 material, where RhB was 70% removed from aqueous solution during 360 min of irradiation. The photodegradation of RhB in the presence of MnO2-modified BTO ceramics followed a pseudo-first order model and the rate constant of BTO_3 was about 10 times higher than that of BTO, 2 times that of BTO_2, and 1.5 times that of BTO_1. The photocatalysts could be successfully reused after thermal activation. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Published under the CC BY 4.0 license.Fundação para a Ciência e Tecnologia RE-QUIMTE/EEC2018/30, REQUIMTE/EEC2018/14; Institute of General and Ecological Chemistry of Lodz University of Technology; Ministério da Ciência, Tecnologia e Ensino Superior; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2

Synthesis and Characterization of Low Loss Dielectric Ceramics Prepared from Composite of Titanate Nanosheets with Barium Ions

We report a strategy for preparing barium titanate precursor, being the composite of titanate nanosheets (TN) with barium ions (Ba-TN), which subjected to step sintering allows obtaining TiO2 rich barium titanate ceramics of stoichiometry BaTi4O9 or Ba2Ti9O20. These compounds are important in modern electronics due to their required dielectric properties and grains’ size that can be preserved in nanometric range. The morphology studies, structural characterization, and dielectric investigations were performed simultaneously in each step of Ba-TN calcinations in order to properly characterize type of obtained ceramic, its grains’ morphology, and dielectric properties. The Ba-TN precursor can be sintered at given temperatures, so that its dielectric permittivity can be tuned between 25 and 42 with controlled temperature coefficients that change from negative 32 ppm/°C for Ba-TN sintered at 900°C up to positive 37 ppm/°C after calcination at 1300°C. XRD analysis and Raman investigations performed for the Ba-TN in the temperature range of 900÷1250°C showed that below 1100°C we obtained as a main phase BaTi4O9, whereas the higher calcinations temperature transformed Ba-TN into Ba2Ti9O20. Taking into account trend of device miniaturization and nanoscopic size requirements, temperatures of 900°C and 1100°C seem to be an optimal condition for Ba-TN precursor calcinations that guarantee the satisfactory value of dielectric permittivity (ε=26 and 32) and ceramic grains with a mean size of ~180 nm and ~550 nm, respectively

Triple-Decker Pentalene Complex of Iron and Cobalt

In [1(1,2,3,3a,6a-ƞ)-1,4-dihydropentalenyl][µ-1](1,2,3,3a,-6a-ƞ):2(3a,4,5,6,6a-ƞ)-pentalene][2(ƞ5)-pentamethylcyclopentadienyl]cobaltiron, [CoFe(C8H7)Cp*(C8H6)] (Cp*=C10H15), the Cp*-Co and (C8H7)-Fe moieties reside on opposite sides of the fused bridging pentalene ring system

2,9-Di-3-pentyl­anthra[1,9-def:6,5,10-d′e′f′]diisoquinoline-1,3,8,10-tetrone

The asymmetric unit of the title compound, C34H30N2O4, contains four independent half-mol­ecules, the complete mol­ecules being generated by inversion symmetry. The mol­ecules each have planar (within 4σ) perylene­tetra­carb­oxy­lic diimide fragments with bent side chains. In one of the independent mol­ecules, each 3-pentyl fragment is disordered over two conformations in a 7:3 ratio. In the crystal, π–π inter­actions link mol­ecules into stacks propagated in [010]. The crystal packing also exhibits weak inter­molecular C—H⋯O hydrogen bonds

Highly Stretchable Bacterial Cellulose Produced by <i>Komagataeibacter hansenii</i> SI1

A new strain of bacteria producing cellulose was isolated from Kombucha and identified as Komagataeibacter hansenii, named SI1. In static conditions, the strain synthesises bacterial nanocellulose with an improved ability to stretch. In this study, utilisation of various carbon and nitrogen sources and the impact of initial pH was assessed in terms of bacterial nanocellulose yield and properties. K. hansenii SI1 produces cellulose efficiently in glycerol medium at pH 5.0–6.0 with a yield of 3.20–3.60 g/L. Glucose medium led to the synthesis of membrane characterised by a strain of 77%, which is a higher value than in the case of another Komagataeibacter species. Supplementation of medium with vitamin C results in an enhanced porosity and improves the ability of bacterial nanocellulose to stretch (up to 123%). The properties of modified membranes were studied by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and mechanical tests. The results show that bacterial nanocellulose produced in SH medium and vitamin C-supplemented medium has unique properties (porosity, tensile strength and strain) without changing the chemical composition of cellulose. The method of production BNC with altered properties was the issue of Polish patent application no. P.431265