Birch reduction - Wikipedia
WEBThe Birch reduction is an organic reaction that is used to convert arenes to 1,4-cyclohexadienes. The reaction is named after the Australian chemist Arthur Birch and involves the organic reduction of aromatic rings in an amine solvent (traditionally liquid ammonia) with an alkali metal (traditionally sodium) and a proton source (traditionally ...
WEBReduction in low molecular weight amines (in the absence of alcohol additives) furnishes more extensively reduced products than are obtained under Birch conditions (M, NH3, ROH). Comparison of Methods Using Lithium/Amine and Birch Reduction Systems: Kaiser, E. M. Synthesis 1972, 391-415.
Birch Reduction of Aromatic Rings – Master Organic Chemistry
WEBOct 17, 2019 · Mechanism Of The Birch Reduction. Ammonia (NH 3) is a gas at room temperature, boiling at a balmy –33 °C. Gaseous ammonia can be condensed to a liquid using a dry ice/acetone (–78°C) cold-finger, where it can serve as a solvent for alkali metals (e.g. Li, Na, and K).
(Barely) Solid Li(NH3)4: The Electronics of an Expanded Metal
WEBFeb 22, 2011 · The highly expanded metal, lithium (0)tetraamine, and its electronic structure is as full of complexity and surprises as the lithium solutions in anhydrous ammonia from which it crystallizes at 90 K...
Communications: The electronic spectrum of Li(NH3)4
WEBApr 22, 2010 · Li (NH 3) 4 has been proposed as a key entity in lithium-ammonia solutions, but its spectral signature has so far proved impossible to distinguish from other species in these solutions. Here we report the first electronic spectrum …
Alkyne Reduction by Lindlar's Catalyst or Na/NH3 - Chemistry Steps
WEBTrans alkenes are prepared by reducing alkynes by dissolving Na or Li in NH 3. The reaction goes through a radical mechanism and the hydrogen is added in anti fashion: The reaction starts by an electron transfer from lithium (or sodium) atoms to the triple bond of the alkyne forming a radical anion which deprotonates ammonia.
THE STRUCTURE OF Li(NH3)4 - ScienceDirect
WEBJan 1, 1970 · Mammano and Sienko 1 have shown Li(NH3)4 to exist as a stable crystalline solid below 90°K and have suggested a crystal structure at 77°K in which the basic tetrahedra formed by the four NH3 molecules are related to each other by a twofold screw axis through the centre of the primitive hexagonal cell.
WEBThe Strongly Distorted Li(NH3)4 Complex We have performed a single–point calculation using the structural parameters found in Ref. [1] with a = 14.8131 A. In this structure three of the Li–N bond lengths are short, 1.984˚ A,˚ and one is elongated, 2.488 A. This structure was computed as being 0.298 eV per Li(NH˚ 3)4
Tetraamminelithium triamminelithium trisulfide, [Li (NH3)4] [Li …
WEBNov 1, 2012 · In contrast to the isolated Se 3 2–-anion in [Li(NH 3) 4]Se 3, the two crystallographically different S 3 2–-anions build mono anionic [Li(NH 3) 3 S 3]--aggregates with triammine complexes. Therein, the lithium atoms are pseudo-tetrahedrally surrounded by three nitrogen and one sulfur atom.
Synthesis and crystal structure of [Li (NH3)4]4 [Sn9]·NH3 and [Li …
WEBThe reduction of an excess of Sn or Pb with a concentrated solution of Li in liquid ammonia yielded black crystals of [Li (NH3)4]4 [Sn9]·NH3 or [Li (NH3)4]4 [Pb9]·NH3 as main product, respectively. The compounds are isotypic and crystallise in space group P21/c.
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