scholarly journals Band Spectrum of Sodium Hydride

Nature ◽  
1941 ◽  
Vol 147 (3734) ◽  
pp. 643-643 ◽  
Author(s):  
R. C. PANKHURST
Keyword(s):  
Sodium Hydride ◽  
Band Spectrum

Isotope Effect in the Band Spectrum of Sodium Hydride

Nature ◽  
1934 ◽  
Vol 134 (3392) ◽  
pp. 697-698 ◽  
Author(s):  
E. OLSSON
Keyword(s):  
Isotope Effect ◽  
Sodium Hydride ◽  
Band Spectrum

In-band Spectrum Sensing without Quiet Period for OFDM System in Cognitive Radio

2011 ◽  
Vol 30 (11) ◽  
pp. 2638-2641
Author(s):  
Dong Chen ◽  
Jian-dong Li ◽  
Ji-yong Pang ◽  
Jing Ma
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Band Spectrum ◽  
Quiet Period ◽  
Ofdm System

Macropolyhedral Boron-Containing Cluster Chemistry. A Metallathiaborane from S2B17H17: Isolation and Characterisation of [(PMe2Ph)2PtS2B16H16]; A neo-arachno Ten-Vertex Cluster Shape, and the Constitution of the [arachno-B10H15]- Anion

2005 ◽  
Vol 70 (4) ◽  
pp. 430-440 ◽  
Author(s):  
Michael J. Carr ◽  
Michael G. S. Londesborough ◽  
Jonathan Bould ◽  
Ivana Císařová ◽  
Bohumil Štíbr ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Sodium Hydride ◽  
Hydrogen Atoms ◽  
Subsequent Reaction ◽  
Cluster Chemistry ◽  
Cluster Shape ◽  
Open Face

The deprotonation of S2B17H17 with sodium hydride and subsequent reaction with [PtCl2(PMe2Ph)2] gives the new macropolyhedral metallathiaborane [(PMe2Ph)2PtS2B16H16], of which the cluster consists of a conventional eleven-vertex nido {SB10} unit, fused, with two boron atoms in common, with a {PtSB8} unit of unique ten-vertex neo-arachno constitution and geometry. The latter geometry suggests a configuration for the previously structurally uncharacterised [B10H15]- anion; starting from this configuration, DFT calculations of structure and thence of boron nuclear shieldings, which are found very closely to mimic those found experimentally, thence support a fluxional structure for [B10H15]- with three {BHB(bridging)} and two {BH(endo)} hydrogen atoms around a six-membered open face.

scholarly journals Sustainable Myrcene-Based Elastomers via a Convenient Anionic Polymerization

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 838
Author(s):  
David Hermann Lamparelli ◽  
Magdalena Maria Kleybolte ◽  
Malte Winnacker ◽  
Carmine Capacchione
Keyword(s):  
Anionic Polymerization ◽  
Sodium Hydride ◽  
Reactivity Ratios ◽  
Molecular Weights ◽  
Styrene Copolymers ◽  
Wide Range ◽  
Elastomeric Materials ◽  
Complete Study ◽  
Anionic Copolymerization ◽  
Trialkylaluminum Derivatives

Soluble heterocomplexes consisting of sodium hydride in combination with trialkylaluminum derivatives have been used as anionic initiating systems at 100 °C in toluene for convenient homo-, co- and ter-polymerization of myrcene with styrene and isoprene. In this way it has been possible to obtain elastomeric materials in a wide range of compositions with interesting thermal profiles and different polymeric architectures by simply modulating the alimentation feed and the (monomers)/(initiator systems) ratio. Especially, a complete study of the myrcene-styrene copolymers (PMS) was carried out, highlighting their tapered microstructures with high molecular weights (up to 159.8 KDa) and a single glass transition temperature. For PMS copolymer reactivity ratios, rmyr = 0.12 ± 0.003 and rsty = 3.18 ± 0.65 and rmyr = 0.10 ± 0.004 and rsty = 3.32 ± 0.68 were determined according to the Kelen–Tudos (KT) and extended Kelen–Tudos (exKT) methods, respectively. Finally, this study showed an easy accessible approach for the production of various elastomers by anionic copolymerization of renewable terpenes, such as myrcene, with commodities.

An Elegant Synthetic Route to 3-Cyano-5,6-dihydro-2-ethoxy-4-phenyl-pyrido[2,3-a]carbazoles

2004 ◽  
Vol 59 (1) ◽  
pp. 106-108 ◽  
Author(s):  
Isravel A. Danish ◽  
Karnam J. R. Prasad
Keyword(s):  
Elemental Analysis ◽  
Spectral Methods ◽  
Title Compound ◽  
Sodium Hydride ◽  
Synthetic Route ◽  
Mass Spectral ◽  
Plausible Mechanism

Abstract 2-Benzylidene-1-oxo-1,2,3,4-tetrahydrocarbazoles (1a - e) obtained from the corresponding 1- oxo-1,2,3,4-tetrahydrocarbazoles on reaction with malononitrile in dry benzene with sodium hydride afforded 3-cyano-5,6-dihydro-2-ethoxy-4-phenyl-pyrido[2,3-a]carbazoles (2a - e) in good yields. A plausible mechanism for the formation of the title compound has been proposed and all the compounds were characterised by IR, NMR, mass spectral methods and elemental analysis.

scholarly journals C-Band and X-Band Switchable Frequency-Selective Surface

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 476
Author(s):  
Umer Farooq ◽  
Adnan Iftikhar ◽  
Muhammad Farhan Shafique ◽  
Muhammad Saeed Khan ◽  
Adnan Fida ◽  
...  
Keyword(s):  
Bottom Layer ◽  
Frequency Selective Surface ◽  
Transverse Magnetic ◽  
Unit Element ◽  
Angular Stability ◽  
Band Spectrum ◽  
Pin Diode ◽  
Pin Diodes ◽  
X Band ◽  
Frequency Selective

This paper presents a highly compact frequency-selective surface (FSS) that has the potential to switch between the X-band (8 GHz–12 GHz) and C-band (4 GHz–8 GHz) for RF shielding applications. The proposed FSS is composed of a square conducting loop with inward-extended arms loaded with curved extensions. The symmetric geometry allows the RF shield to perform equally for transverse electric (TE), transverse magnetic (TM), and 45° polarizations. The unit cell has a dimension of 0.176 λ0 and has excellent angular stability up to 60°. The resonance mechanism was investigated using equivalent circuit models of the shield. The design of the unit element allowed incorporation of PIN diodes between adjacent elements for switching to a lower C-band spectrum at 6.6 GHz. The biasing network is on the bottom layer of the substrate to avoid effects on the shielding performance. A PIN diode configuration for the switching operation was also proposed. In simulations, the PIN diode model was incorporated to observe the switchable operation. Two prototypes were fabricated, and the switchable operation was demonstrated by etching copper strips on one fabricated prototype between adjacent unit cells (in lieu of PIN diodes) as a proof of the design prototypes. Comparisons among the results confirmed that the design offers high angular stability and excellent performance in both bands.

Simple formula for the ground band spectrum of even-mass rotational nuclei

1982 ◽  
Vol 25 (5) ◽  
pp. 2837-2840 ◽  
Author(s):  
A. Partensky ◽  
C. Quesne
Keyword(s):  
Simple Formula ◽  
Band Spectrum ◽  
Ground Band

Cyclization of 2-(2-bromoethoxy)-acetophenones and 5-(ω-haloalkoxy)-1,5-dihydro-2H-pyrrol-2-ones – Formation of five- to eight-membered oxygen-containing heterocycles via intramolecular alkylation

2004 ◽  
Vol 82 (5) ◽  
pp. 571-578 ◽  
Author(s):  
Kirill V Nikitin ◽  
Nonna P Andryukhova
Keyword(s):  
Sodium Hydride ◽  
Spiro Compounds ◽  
Lithium Diisopropylamide ◽  
Intramolecular Alkylation ◽  
High Yields

Under basic conditions (lithium diisopropylamide or sodium hydride in THF) 2-(2-bromoethoxy)-acetophenones were transformed to 3,4-dihydro[1]benzoxepin-5(2H)-ones (homochromanones) in high yields. The preparation of novel tetrahydropyrano[2,3-b]pyrrol-6(2H)-ones and 3,4-dihydro-2H-pyrrolo[2,1-b][1,3]oxazin-6(8aH)-ones and spiro compounds was performed using similar cyclization in moderate to good yields.Key words: cyclization, lithiation, spiro heterocycles.

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