scholarly journals Rational design and convenient synthesis of a novel family of ruthenium complexes with O,N-bidentate ligands

2005 ◽  
Vol 3 (3) ◽  
pp. 404-416 ◽  
Author(s):  
Renate Drozdzak ◽  
Nele Ledoux ◽  
Bart Allaert ◽  
Ileana Dragutan ◽  
Valerian Dragutan ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Rational Design ◽  
Chemical Properties ◽  
13C Nmr Spectroscopy ◽  
Synthetic Approach ◽  
Bidentate Ligands ◽  
Step Procedure ◽  
Convenient Synthesis ◽  
Ru Complexes ◽  
Physical And Chemical

AbstractA two step procedure for the synthesis of a novel family of homogeneous and immobilized Ru-complexes containing Schiff bases as O,N-bidentate ligands is described. The new Ru-complexes have been structurally characterized by IR, Raman,1H-,13C-NMR spectroscopy. The Schiff bases were associated with a diversity of inorganic and organic ligands such as chloride, phosphane, arenes, various carbenes (alkylidene, vinylidene, indenylidene and allenylidene as well as N-heterocyclic carbenes) and cyclodienes. By choosing a selective range of substituents for the Schiff base, useful physical and chemical properties of the prepared Rucomplexes can be induced. This synthetic approach is promising in creating a valuable and diverse selection of Ru-complexes, valuable for future applications.

In vitro Degradation Analysis of 3D-architectured Gelatin-based Hydrogels

MRS Advances ◽  
2019 ◽  
Vol 5 (12-13) ◽  
pp. 633-642
Author(s):  
Jun Hon Pang ◽  
Christian Wischke ◽  
Andreas Lendlein
Keyword(s):  
Rational Design ◽  
Loss Modulus ◽  
Hydrolytic Stability ◽  
Hydrolytic Degradation ◽  
Chemical Properties ◽  
In Vitro Models ◽  
Polypeptide Backbone ◽  
Tan Δ ◽  
Physical And Chemical

ABSTRACT:Multifunctional biopolymer-based materials are promising candidates for next generation regenerative biomaterials. Understanding the degradation behavior of biomaterials is vital for ensuring biological safety, as well as for better control of degradation properties based on rational design of a material’s physical and chemical characteristics. In this study, we decipher the degradation of a hydrogel prepared from gelatin and lysine diisocyanate ethyl ester (LDI) using in vitro models, which simulate hydrolytic, oxidative and enzymatic degradation (collagenase). Gravimetrical, morphological, mechanical and chemical properties were evaluated. Notably, the hydrogels were relatively resistant to hydrolytic degradation, but degraded rapidly within 21 days (>95% mass loss) under oxidative and collagenase degradation. Oxidative and collagenase degradation rapidly decreased the storage and loss modulus of the hydrogels, and slightly increased their viscous component (tan δ). For each degradation condition, the results suggest different possible degradation pathways associated to the gelatin polypeptide backbone, urea linkages and ester groups. The primary degradation mechanisms for the investigated gelatin based hydrogels are oxidative and enzymatic in nature. The relative hydrolytic stability of the hydrogels should ensure minimal degradation during storage and handling prior to application in surgical theatres.

scholarly journals A Convenient Synthesis of Antimony Nanorods using 1,2,4,5-Benzenetetracarboxylic Acid

2019 ◽  
Vol 31 (6) ◽  
pp. 1301-1304
Author(s):  
NTAOTE DAVID SHOOTO
Keyword(s):  
Coordination Polymers ◽  
Chemical Properties ◽  
Carboxyl Groups ◽  
Physical And Chemical Properties ◽  
X Ray ◽  
Ideal Candidate ◽  
Convenient Synthesis ◽  
Physical And Chemical ◽  
Coordination Configuration ◽  
And Chemical Properties

1,2,4,5-Benzenetetracarboxylic acid (H4Btec) is an ideal candidate for the synthesis of new coordination polymers compounds because of its four carboxyl groups bridging moieties with antimony ions having distorted coordination configuration. This work reports a new compound of coordination polymer, namely, [Sb2(C4H4O6)2(Btec)(H2O)]n, [(C4H4O6)2 = tartrate and Btec4− = 1,2,4,5-benzenetetracarboxylic anion] has been synthesized under reflux. The physical and chemical properties of coordination polymers; Sb2(C4H4O6)2(Btec)(H2O) was affirmed by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray powder diffraction, thermogravimetric analyses and photoluminescence spectroscopy.

C−H•••F−C Interactions: A Guide for Designing Fluorous Monodentate Ligands for the Highly Linear-Selective Hydroformylation at Near-Ambient Pressure

2021 ◽  
Author(s):  
Yuchao Deng ◽  
Xiaofang Liu ◽  
Baiyin Wei ◽  
Zhimin Zhou ◽  
Kaimin Hua ◽  
...  
Keyword(s):  
Crystal Packing ◽  
Ambient Pressure ◽  
Chemical Properties ◽  
Bidentate Ligands ◽  
Organofluorine Compounds ◽  
Mild Conditions ◽  
Phosphite Ligands ◽  
Monodentate Ligands ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract Organofluorine compounds often exhibit unique catalytic capabilities with novel structural scaffold, reactivity and mechanisms. Herein, we report a Rh-catalyzed hydroformylation under mild conditions using monodentate phosphite ligands P(OCH2CF3)3 (TTFP) and P(OCH2CF2CH3)3 (TDFP). The ligand were designed with the principle that the inclusion of fluorine-rich group can significantly change the physical and chemical properties of the complex through H•••F hydrogen bonds, the existence of which has been confirmed by crystal-packing studies. These monodentate phosphite ligands self-assemble to form bidentate ligands through C–H•••F–C interactions, and catalysts based on these ligands deliver extremely high regioselectivities in hydroformylation. Aldehydes were formed with up to 92% chemoselectivity, with linear aldehydes formed in high regioselectivity (n:iso=28/1) under a syngas pressure of only 2 atm.

scholarly journals Tailoring the Size and Shape—New Path for Ammonium Metavanadate Synthesis

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3446
Author(s):  
Marta Prześniak-Welenc ◽  
Małgorzata Nadolska ◽  
Barbara Kościelska ◽  
Kamila Sadowska
Keyword(s):  
Room Temperature ◽  
Chemical Properties ◽  
Ph Control ◽  
Ammonium Metavanadate ◽  
Step Procedure ◽  
One Step ◽  
The One ◽  
Physical And Chemical ◽  
Ammonium Compounds ◽  
And Chemical Properties

Ammonium metavanadate, NH4VO3, plays an important role in the preparation of vanadium oxides and other ammonium compounds, such as NH4V3O8, (NH4)2V3O8, and NH4V4O10, which were found to possess interesting electrochemical properties. In this work, a new route for the synthesis of NH4VO3 is proposed by mixing an organic ammonium salt and V2O5 in a suitable solvent. The one-step procedure is carried out at room temperature. Additionally, the need for pH control and use of oxidants necessary in known methods is eliminated. The mechanism of the NH4VO3 formation is explained. It is presented that it is possible to tailor the morphology and size of the obtained NH4VO3 crystals, depending on the combination of reagents. Nano- and microcrystals of NH4VO3 are obtained and used as precursors in the hydrothermal synthesis of higher ammonium vanadates. It is proven that the size of the precursor particles can significantly affect the physical and chemical properties of the resulting products.

Rational Design and Convenient Synthesis of a Novel Family of Ruthenium Complexes with O,N-Bidentate Ligands

ChemInform ◽  
2006 ◽  
Vol 37 (39) ◽  
Author(s):  
Renate Drozdzak ◽  
Nele Ledoux ◽  
Bart Allaert ◽  
Ileana Dragutan ◽  
Valerian Dragutan ◽  
...  
Keyword(s):  
Rational Design ◽  
Ruthenium Complexes ◽  
Bidentate Ligands ◽  
Convenient Synthesis

scholarly journals Synthesis of μ-ABC Tricyclic Miktoarm Star Polymer via Intramolecular Click Cyclization

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 877 ◽  
Author(s):  
Tomoki Shingu ◽  
Takuya Yamamoto ◽  
Kenji Tajima ◽  
Takuya Isono ◽  
Toshifumi Satoh
Keyword(s):  
Self Assembly ◽  
Diblock Copolymers ◽  
Glycidyl Ether ◽  
Chemical Properties ◽  
Star Polymer ◽  
Synthetic Approach ◽  
Glycidyl Ethers ◽  
Miktoarm Star ◽  
Functional Initiators ◽  
Physical And Chemical

Cyclic polymers exhibit unique physical and chemical properties because of the restricted chain mobility and absence of chain ends. Although many types of homopolymers and diblock copolymers possessing cyclic architectures have been synthesized to date, there are relatively few reports of cyclic triblock terpolymers because of their synthetic difficulties. In this study, a novel synthetic approach for μ-ABC tricyclic miktoarm star polymers involving t-Bu-P4-catalyzed ring-opening polymerization (ROP) of glycidyl ethers and intramolecular copper-catalyzed azido-alkyne cycloaddition (CuAAC) was developed. First, the t-Bu-P4-catalyzed ROP of decyl glycidyl ether, dec-9-enyl glycidyl ether, and 2-(2-(2-methoxyethoxy) ethoxy) ethyl glycidyl ether with the aid of functional initiators and terminators was employed for the preparation of a clickable linear triblock terpolymer precursor possessing three azido and three ethynyl groups at the selected positions. Next, the intramolecular CuAAC of the linear precursor successfully produced the well-defined tricyclic triblock terpolymer with narrow dispersity in a reasonable yield. The present strategy is useful for synthesizing model polymers for studying the topological effects on the triblock terpolymer self-assembly.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Biophysical Measurement of Molecular Weight of Foot-and-Mouth Disease RNA Fragments

1974 ◽  
Vol 32 ◽  
pp. 262-263
Author(s):  
Sydney S. Breese ◽  
Howard L. Bachrach
Keyword(s):  
Chemical Properties ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Distilled Water ◽  
Bovine Plasma ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Carbon Coated ◽  
Rna Fragments ◽  
Physical And Chemical

Continuing studies on the physical and chemical properties of foot-and-mouth disease virus (FMDV) have included electron microscopy of RNA strands released when highly purified virus (1) was dialyzed against demlneralized distilled water. The RNA strands were dried on formvar-carbon coated electron microscope screens pretreated with 0.1% bovine plasma albumin in distilled water. At this low salt concentration the RNA strands were extended and were stained with 1% phosphotungstic acid. Random dispersions of strands were recorded on electron micrographs, enlarged to 30,000 or 40,000 X and the lengths measured with a map-measuring wheel. Figure 1 is a typical micrograph and Fig. 2 shows the distributions of strand lengths for the three major types of FMDV (A119 of 6/9/72; C3-Rezende of 1/5/73; and O1-Brugge of 8/24/73.

Tailoring microstructures of materials through biomimetics

1993 ◽  
Vol 51 ◽  
pp. 500-501
Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Chemical Properties ◽  
Design And Synthesis ◽  
Structure Sensitive ◽  
Macro Scale ◽  
Methods Of Synthesis ◽  
Successive Level ◽  
Engineering Materials ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Synthesis Of Materials

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.

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