scholarly journals Ultrafast amidation of esters using lithium amides under aerobic ambient temperature conditions in sustainable solvents

2020 ◽  
Vol 11 (25) ◽  
pp. 6500-6509 ◽  
Author(s):  
Michael Fairley ◽  
Leonie J. Bole ◽  
Florian F. Mulks ◽  
Laura Main ◽  
Alan R. Kennedy ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Organometallic Chemistry ◽  
Room Temperature ◽  
Temperature Conditions ◽  
Lithium Amides ◽  
Sustainable Solvents

Using 2-methyl THF as solvent enables efficient and ultrafast amidation of esters by lithium amides at room temperature in air, edging closer towards reaching air- and moisture-compatible polar organometallic chemistry.

Combination of Aerobic/Moisture/Ambient Temperature Compatible Organolithium Chemistry with Sustainable Solvents: Selective and Efficient Synthesis of Guanidines and Amidines

2021 ◽  
Author(s):  
Joaquín García-Álvarez ◽  
David Elorriaga ◽  
Fernando Carrillo-Hermosilla ◽  
Antonio Antiñolo ◽  
Blanca Parra-Cadenas
Keyword(s):  
Ambient Temperature ◽  
Primary Amine ◽  
Efficient Synthesis ◽  
Acid Base ◽  
Highly Efficient ◽  
Lithium Amides ◽  
Sustainable Solvents ◽  
Organolithium Chemistry

Highly-efficient and selective fast addition of in-situ generated lithium amides [LiN(H)R] (obtained via acid-base reaction between n-BuLi and the desired primary amine) into carbodiimides (R-N=C=N-R) or nitriles (R-C≡N) has been...

Formation of Dislocation Channels in Neutron Irradiated Molybdenum

1972 ◽  
Vol 30 ◽  
pp. 672-673
Author(s):  
S. Mahajan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ambient Temperature ◽  
Room Temperature ◽  
Channel Formation ◽  
Early Stages ◽  
Transmission Electron ◽  
Three Stages ◽  
Two Stages ◽  
Polycrystalline Molybdenum

The evolution of dislocation channels in irradiated metals during deformation can be envisaged to occur in three stages: (i) formation of embryonic cluster free regions, (ii) growth of these regions into microscopically observable channels and (iii) termination of their growth due to the accumulation of dislocation damage. The first two stages are particularly intriguing, and we have attempted to follow the early stages of channel formation in polycrystalline molybdenum, irradiated to 5×1019 n. cm−2 (E > 1 Mev) at the reactor ambient temperature (∼ 60°C), using transmission electron microscopy. The irradiated samples were strained, at room temperature, up to the macroscopic yield point.Figure 1 illustrates the early stages of channel formation. The observations suggest that the cluster free regions, such as A, B and C, form in isolated packets, which could subsequently link-up to evolve a channel.

scholarly journals Lithium-mediated Ferration of Fluoroarenes

2020 ◽  
Vol 74 (11) ◽  
pp. 866-870
Author(s):  
Lewis C. H. Maddock ◽  
Alan Kennedy ◽  
Eva Hevia
Keyword(s):  
Hydrogen Atom ◽  
Organometallic Chemistry ◽  
Room Temperature ◽  
Structural Elucidation ◽  
Side Reactions ◽  
Metal Base ◽  
Lithium Amide ◽  
Mixed Metal ◽  
Important Challenge

While fluoroaryl fragments are ubiquitous in many pharmaceuticals, the deprotonation of fluoroarenes using organolithium bases constitutes an important challenge in polar organometallic chemistry. This has been widely attributed to the low stability of the in situ generated aryl lithium intermediates that even at –78 °C can undergo unwanted side reactions. Herein, pairing lithium amide LiHMDS (HMDS = N{SiMe3}2) with FeII(HMDS)2 enables the selective deprotonation at room temperature of pentafluorobenzene and 1,3,5-trifluorobenzene via the mixed-metal base [(dioxane)LiFe(HMDS)3] (1) (dioxane = 1,4-dioxane). Structural elucidation of the organometallic intermediates [(dioxane)Li(HMDS)2Fe(ArF)] (ArF = C6F5, 2; 1,3,5-F3-C6H2, 3) prior electrophilic interception demonstrates that these deprotonations are actually ferrations, with Fe occupying the position previously filled by a hydrogen atom. Notwithstanding, the presence of lithium is essential for the reactions to take place as Fe II (HMDS)2 on its own is completely inert towards the metallation of these substrates. Interestingly 2 and 3 are thermally stable and they do not undergo benzyne formation via LiF elimination.

An efficient construction of CN bond under catalyst‐free and room temperature conditions

2021 ◽  
Vol 58 (5) ◽  
pp. 1179-1191
Author(s):  
Jinpeng Zhang ◽  
Jing Liu ◽  
Lei Dai ◽  
Yuqian Ge ◽  
Linlin Xu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Catalyst Free ◽  
Temperature Conditions ◽  
Efficient Construction

scholarly journals Advancing Air‐ and Moisture‐Compatible s‐Block Organometallic Chemistry Using Sustainable Solvents

2021 ◽  
Author(s):  
Sergio E. García‐Garrido ◽  
Alejandro Presa Soto ◽  
Eva Hevia ◽  
Joaquín García‐Álvarez
Keyword(s):  
Organometallic Chemistry ◽  
Sustainable Solvents

scholarly journals Advancing Air and Moisture Compatible s‐Block Organometallic Chemistry using Sustainable Solvents

2021 ◽  
Author(s):  
Sergio Emilio García-Garrido ◽  
Alejandro Presa Soto ◽  
Eva Hevia ◽  
Joaquin García-Álvarez
Keyword(s):  
Organometallic Chemistry ◽  
Sustainable Solvents

Design and Fabrication of a Magnetocaloric Microcooler

2005 ◽  
Author(s):  
Sangchae Kim ◽  
Bharath Bethala ◽  
Simone Ghirlanda ◽  
Senthil N. Sambandam ◽  
Shekhar Bhansali
Keyword(s):  
Magnetic Field ◽  
Ambient Temperature ◽  
Temperature Change ◽  
Entropy Change ◽  
Temperature Sensors ◽  
Experimental Results ◽  
Maximum Temperature ◽  
Alternative Technology ◽  
Temperature Conditions ◽  
Si Wafer

Magnetocaloric refrigeration is increasingly being explored as an alternative technology for cooling. This paper presents the design and fabrication of a micromachined magnetocaloric cooler. The cooler consists of fluidic microchannels (in a Si wafer), diffused temperature sensors, and a Gd5(Si2Ge2) magnetocaloric refrigeration element. A magnetic field of 1.5 T is applied using an electromagnet to change the entropy of the magnetocaloric element for different ambient temperature conditions ranging from 258 K to 280 K, and the results are discussed. The tests show a maximum temperature change of 7 K on the magnetocaloric element at 258 K. The experimental results co-relate well with the entropy change of the material.

Change in the Properties of a Lead-acid Battery Depending on the Cycling Speed and the Ambient Temperature

2021 ◽  
Vol 105 (1) ◽  
pp. 119-134
Author(s):  
Jana Zimáková ◽  
Petr Baca ◽  
Martin Langer ◽  
Tomáš Binar
Keyword(s):  
Ambient Temperature ◽  
High Temperatures ◽  
Room Temperature ◽  
Lead Acid Battery ◽  
Ambient Temperatures ◽  
Lead Acid Batteries ◽  
Temperature Dependences ◽  
Cycling Speed ◽  
Lead Acid

This work deals with lead-acid batteries, their properties and individual types that are available on the market. The temperature dependences of the battery parameters at different ambient temperatures and at different discharging and charging modes are measured. 6 batteries are tested at different charging currents, which provides information about their behavior both during discharge and at the time of charging. During the experiments, testing is not only performed at room temperature, but the batteries are also exposed to high temperatures up to 75 °C.

Effects of B Vitamins, Liver and Yeast on Growth under Cold Room and Room Temperature Conditions

1948 ◽  
Vol 35 (1) ◽  
pp. 39-48 ◽  
Author(s):  
E. D. Smith ◽  
B. H. Ershoff ◽  
R. J. Winzler ◽  
H. J. Deuel
Keyword(s):  
Room Temperature ◽  
B Vitamins ◽  
Temperature Conditions ◽  
Cold Room
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