Lithiumperchlorat

BeschreibungLithium perchlorate,is an oxysalt that is a colorless, deliquescent crystal. Oxysalt “per-ate” compounds are loaded with excess oxygen and will readily give it up in a reaction. Lithium perchlorate is a powerful oxidizing agent. It has more available oxygen than does liquid oxygen on a volume basis. Lithium perchlorate has a specific gravity of 2.429, which is heavier than water, and is water soluble. It is a dangerous fire and explosion risk in contact with organic materials and is an irritant to skin and mucous membranes. The primary use of lithium perchlorate is as a solid rocket propellant. Chlorates are strong oxidizing agents. When heated, they give up oxygen readily. Contact with organic or other combustible materials may cause spontaneous combustion or explosion. They are incompatible with ammonium salts, acids, metal powders, sulfur, and finely divided organic or combustible substances.

VerwendenThe big advantage of lithium perchlorate is its high density and oxygen availability for combustion. A quite interesting methodology involves the use of lithium perchlorate anhydrides complexes in the acylation of activated aromatic compounds.Lithium perchlorate is frequently utilized as promoter to accelerate the acylation process and to increase the yield in the reaction catalyzed by metal triflates.However, lithium perchlorate itself can act as a very efficient catalyst in the acylation of variously substituted methoxy and methylbenzenes with AAN affording the aryl ketones in 65%–99% yield. The exceptional activation is ascribed to the formation of a complex with a strong electrophilic character between lithium perchlorate and AAN in neat AAN. The observed pararegioselectivity can be interpreted in terms of the high steric requirement of the lithium perchlorate– AAN complex. A further important feature of this process is the possibility of quantitatively recovering and reusing the catalyst after activation. It must be underlined, however, that lithium perchlorate is an oxidizing compound and can undergo devastating explosions; consequently, it must be handled with maximum care.