Synthesis and Characterization of Polysilane-Organometallic Complexes

2007 ◽  
Vol 19 (5-6) ◽  
pp. 510-519 ◽  
Author(s):  
Liviu Sacarescu ◽  
Rodinel Ardeleanu ◽  
Gabriela Sacarescu ◽  
Mihaela Simionescu
Keyword(s):  
Metal Complex ◽  
Electronic Structures ◽  
Condensation Reaction ◽  
Organometallic Complexes ◽  
System Behavior ◽  
Gelation Point ◽  
New Material ◽  
Polymeric Ligand ◽  
Polymeric Structures

A new polysilane with pendant metal complex segments was synthesized and characterized. For this purpose a macroligand has been prepared starting from a iodopropyl-functionalized polysilane and a bis(salicylideneimine) derivative. Under mild reaction temperature this polymeric ligand was able to form crosslinked structures. The material was then doped with metal cations and was investigated to observe the system behavior near the gelation point. The UV-vis spectrum of the new material indicated that the electronic structures of the conjugate polysilane chain and metal complex remained unaffected by the condensation reaction process. Similar polymeric structures could be useful to build new organic electroconductive devices.

Characterization of a monolayer graphitic structure

1994 ◽  
Vol 52 ◽  
pp. 760-761
Author(s):  
X. Lin ◽  
X. K. Wang ◽  
V. P. Dravid ◽  
J. B. Ketterson ◽  
R. P. H. Chang
Keyword(s):  
Three Dimensional ◽  
Single Layer ◽  
Synthesis Process ◽  
Graphitic Structure ◽  
Positive Gaussian Curvature ◽  
Graphitic Sheet ◽  
Structural And Electronic Properties ◽  
New Material ◽  
Hexagonal Network

For small curvatures of a graphitic sheet, carbon atoms can maintain their preferred sp2 bonding while allowing the sheet to have various three-dimensional geometries, which may have exotic structural and electronic properties. In addition the fivefold rings will lead to a positive Gaussian curvature in the hexagonal network, and the sevenfold rings cause a negative one. By combining these sevenfold and fivefold rings with sixfold rings, it is possible to construct complicated carbon sp2 networks. Because it is much easier to introduce pentagons and heptagons into the single-layer hexagonal network than into the multilayer network, the complicated morphologies would be more common in the single-layer graphite structures. In this contribution, we report the observation and characterization of a new material of monolayer graphitic structure by electron diffraction, HREM, EELS.The synthesis process used in this study is reported early. We utilized a composite anode of graphite and copper for arc evaporation in helium.

scholarly journals Design and Characterization of Gypsum Mortars Dosed with Polyurethane Foam Waste PFW

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1497 ◽  
Author(s):  
Isabel Santamaría Vicario ◽  
Lourdes Alameda Cuenca-Romero ◽  
Sara Gutiérrez González ◽  
Verónica Calderón Carpintero ◽  
Ángel Rodríguez Saiz
Keyword(s):  
Natural Resources ◽  
Construction Industry ◽  
Polyurethane Foam ◽  
Industrial Waste ◽  
Vapour Permeability ◽  
Polyurethane Waste ◽  
New Material ◽  
Technical Specifications ◽  
Mechanical Strengths

The properties and the behaviour of plaster mortars designed with Polyurethane Foam Waste (PFW) are studied in this investigation. A characterization of the mixtures is completed, in accordance with the technical specifications of European Norms. The incorporation of polyurethane waste foam can yield porous and lighter mortars, with better resistance to water-vapour permeability, although with weaker mechanical strength and higher levels of absorbency. Nevertheless, suitable mechanical strengths were achieved, resulting in a new material that is compliant with the requirements of the construction industry. The use of PFW in the the manufacture of gypsum mortars for construction reduces the consumption of natural resources and, at the same time, recovers an industrial waste that is otherwise difficult to recycle.

scholarly journals Molar mass determination of lignins and characterization of their polymeric structures by multi-detector gel permeation chromatography

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Evamaria C. Gaugler ◽  
Wolfgang Radke ◽  
Andrew P. Vogt ◽  
Dawn A. Smith
Keyword(s):  
Molar Mass ◽  
Lithium Bromide ◽  
Gel Permeation Chromatography ◽  
Mass Determination ◽  
Organosolv Lignin ◽  
Gel Permeation ◽  
Softwood Kraft Lignin ◽  
Polymeric Structures

AbstractMolar masses, Mark-Houwink-Sakurada (MHS) exponents, and refractive index increments (dn/dc) for three lignins were determined without derivatization by multi-detector gel permeation chromatography (GPC) in dimethylformamide (DMF) with 0.05 M lithium bromide (LiBr). The lack of effectiveness of fluorescence filters on molar mass determination by GPC-multi-angle laser light scattering (MALS) was confirmed for softwood kraft lignin (Indulin AT) and revealed for mixed hardwood organosolv lignin (Alcell) as well as soda straw/grass lignin (Protobind 1000). GPC with viscometry detection confirmed that these lignins were present as compact molecules. The MHS exponent α for Indulin AT and Alcell was in the order of 0.1. Additionally, the intrinsic viscosity of Protobind 1000 for a given molar mass was much lower than that of either Alcell or Indulin AT. This is the first report of dn/dc values for these three lignins in DMF with 0.05 M LiBr.

Synthesis and characterization of periphery-functionalized porphyrazines containing mixed pyrrolyl and pyridylmethylamino groups

2009 ◽  
Vol 13 (02) ◽  
pp. 223-234 ◽  
Author(s):  
Tomasz Goslinski ◽  
Ewa Tykarska ◽  
Wojciech Szczolko ◽  
Tomasz Osmalek ◽  
Aleksandra Smigielska ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Chemical Sensors ◽  
Electronic Materials ◽  
Condensation Reaction ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Coordination Properties ◽  
Perpendicular Orientation ◽  
Selective Sensor

The condensation reaction of 2-amino-3-[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile with a series of diketones led to novel dinitriles, of which 2-(2,5-dimethyl-1H-pyrrol-1-yl)-3-[methyl(3-pyridylmethylene)amino]-2(Z)-butene-1,4-dinitrile, the product of the Paal-Knorr reaction, was successfully utilized in the Linstead macrocyclization towards symmetrical and unsymmetrical porphyrazines. NMR and X-ray study revealed an almost perpendicular orientation of the pyrrolyl groups in relation to the porphyrazine platform. The newly synthesized macrocycles with different peripheral groups show interesting spectroscopic and electrochemical properties. Due to selective sensor/coordination properties they are expected to find applications as chemical sensors and electronic materials.

scholarly journals Metal-Rich Metallaboranes: Synthesis, Structures and Bonding of Bi- and Trimetallic Open-Faced Cobaltaboranes

Inorganics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 28
Author(s):  
Kriti Pathak ◽  
Chandan Nandi ◽  
Jean-François Halet ◽  
Sundargopal Ghosh
Keyword(s):  
Electronic Structures ◽  
Density Functional ◽  
Room Temperature ◽  
Electron Pair ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Cluster 2 ◽  
Cobalt Center

Synthesis, isolation, and structural characterization of unique metal rich diamagnetic cobaltaborane clusters are reported. They were obtained from reactions of monoborane as well as modified borohydride reagents with cobalt sources. For example, the reaction of [Cp*CoCl]2 with [LiBH4·THF] and subsequent photolysis with excess [BH3·THF] (THF = tetrahydrofuran) at room temperature afforded the 11-vertex tricobaltaborane nido-[(Cp*Co)3B8H10] (1, Cp* = η5-C5Me5). The reaction of Li[BH2S3] with the dicobaltaoctaborane(12) [(Cp*Co)2B6H10] yielded the 10-vertex nido-2,4-[(Cp*Co)2B8H12] cluster (2), extending the library of dicobaltadecaborane(14) analogues. Although cluster 1 adopts a classical 11-vertex-nido-geometry with one cobalt center and four boron atoms forming the open pentagonal face, it disobeys the Polyhedral Skeletal Electron Pair Theory (PSEPT). Compound 2 adopts a perfectly symmetrical 10-vertex-nido framework with a plane of symmetry bisecting the basal boron plane resulting in two {CoB3} units bridged at the base by two boron atoms and possesses the expected electron count. Both compounds were characterized in solution by multinuclear NMR and IR spectroscopies and by mass spectrometry. Single-crystal X-ray diffraction analyses confirmed the structures of the compounds. Additionally, density functional theory (DFT) calculations were performed in order to study and interpret the nature of bonding and electronic structures of these complexes.

Highly Selective Separation and Enrichment of Phosphopeptides by Uranyl-Salophen Immobilized Silica Gel Material

2015 ◽  
Vol 1095 ◽  
pp. 341-344 ◽  
Author(s):  
Can Hui Xu ◽  
Guang Liang Zhang ◽  
Xin Zhou ◽  
Xi Lin Xiao ◽  
Chang Ming Nie ◽  
...  
Keyword(s):  
Silica Gel ◽  
Metal Ion ◽  
High Selectivity ◽  
Separation Efficiency ◽  
Solid Phase ◽  
Tetradentate Ligand ◽  
Peptide Mixtures ◽  
New Material ◽  
Solid Phase Material

The characterization of phosphoproteins requires highly specific methods for the separation and enrichment of phosphopeptides. Here we report a novel metal ion-immobilized solid phase material for the separation and enrichment of phosphopeptides. The material is uranyl-salophen-silica gel (USSG) particles in which salophen is a tetradentate ligand of uranyl ion. In USSG salophen is connected on the surface of silica gel and uranyl is bound on the surface through its coordination with salophen. Phosphopeptides can be selectively retained by USSG because uranyl-salophen can bind phosphate moiety with strong affinity and high selectivity. The new material USSG has been successfully used for the separation of phosphopeptides from peptide mixtures with the separation efficiency of 97.0% to 97.4%.

Thermal and mechanical characterization of a new material based on two gypsums from different localities : High Atlas of Marrakech and Safi Basin, Morocco

2021 ◽  
Author(s):  
imane baba ◽  
Mounsif Ibnoussina ◽  
Omar Witam ◽  
Latifa Saadi
Keyword(s):  
Setting Time ◽  
Density Measurement ◽  
Mechanical Resistance ◽  
Mechanical And Thermal Properties ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
High Atlas ◽  
New Material ◽  
Indoor Comfort

<p>Over the last few decades, the construction industry has become interested in materials that are durable, environmentally friendly and easily recyclable. This interest is due to the advantages these materials offer, among others local availability, low carbon footprint, energy efficiency and indoor comfort. The objective of this work is to study the properties of plasters prepared from a mixture of two types of gypsum. We were interested in the evolution of thermal conductivity, mechanical resistance and setting time as a function of the percentage of addition.</p><p>Two types of gypsum were studied, the first one belongs to the Safi basin and the second one comes from the High Atlas of Marrakech.</p><p>The characterization of the gypsums was necessary to determine its physical and geotechnical properties, its mineralogy, its thermal behavior and its microscopic structure. Several analyses were developed such as density measurement by pycnometer, X-ray diffraction, infrared spectroscopy and scanning electron microscopy.</p><p>We have made samples, of standardized dimensions, of mixtures based on both types of plaster. The water/gypsum mass ratio was set at 0.75.</p><p>The results revealed that the properties of gypsum as well as the percentage of addition affect the mechanical and thermal properties and the setting time of the composite material. The addition of the High Atlas gypsum of Marrakech allowed improving the material in terms of thermal insulation. The results of the other tests will be communicated later.</p>

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