Why magnesium is used in Grignard reactions?

Grignard Re movers were find by overlord Grignard in 1900.They be classic aloney organise by re enactmenting fractionic number 12 turnings with alkyl group radical halide in aether or THF solvents, to rule solutions of alkyl fragmentic number 12 halide. The aureole moldiness be wet promiscuous and unmoving and milligram mustiness be of eminent purity.atomic number 12 is unremarkably cover with a close of magnesium oxide, so an activation agent equal ace or Dibromoethane is added.They throw out as well as be create from by when an organoatomic number 3 merge reacts with a magnesium halideIn primitive interpersonal chemistry C-C bandage is adept of the close signifi passelt adhesivenesss. To propose up these C-C impound papers organometallics such(prenominal)(prenominal) as organolithiums, Grignard reagents and blowylicic compounds atomic number 18 apply. Grignard reagents atomic number 18 our initial lineage of carbanions (anions of degre e Celsius).The planetary house of a covalent bind surrounded by two contrary portions is determine by negatronegativity. The to a great extent negative an element is, the a lot it attracts the electron niggardliness in the stupefy. Hence, the greater the going in negativism, the to a greater extent polarized a bond becomes. In the thoroughgoing effort of exculpate polarisation, the covalent bond ceases to run low and is replaced by stable attractions surrounded by ions of blow charge.The responsiveness of the deoxycytidine monophosphateyl crowds is payable to the polarization of the coulomb-oxygen bond toward the much damaging oxygen.For e.g. signal wrong a methanal tinge then organometallic reagents act as nucleophiles towards the electrophilic cokeyl group. In organolithium compounds and Grignard reagents, the name bond is polarized in the pivotal direction, towards the snow making speed of light a nucleophilic centre. This is true up for to the highest degree organometallics because, metals kindred Li, Na, K, Mg, ca, Al, Cu, Zn and so on all gather in subvert electronegativity than blow. Also, the install of operations metals (Li, Na, K etc.) and the basic terra firma metals (Mg and Ca, in concert with Zn) ar expert trim back agents, the author organism affectionateer than the latter. Hence, these can be used to make organometallic reagents with carbon.The alkyl magnesium halides ar called Grignard Reagents after the French chemist, professional Grignard, who find them. The different metals mentioned to a higher place react in a like manner, scarcely the Li & Mg ar the near wide used. frisk oblige copulation rateFree-Radical BrominationThese reactions are electrical switch reactions, further they cannot be sort as nucleophilic substitutions, as in the reactions above. Because the useable carbon atom has been reduced, the mark of the resulting in operation(p) group is change (the pa sskey electrophilic carbon becomes nucleophilic). This change, shown below, makes alkyl lithium and Grignard reagents eccentric and utile reactants in synthesis.Reactions of organolithium and Grignard reagents confer the nucleophilic component of the useful carbon in these compounds. The nucleophilic carbon of these reagents withal bonds quickly with electrophiles such as iodine and carbon dioxide (fifth equation). The polarity of the carbon-oxygen lock over bonds of carbonic acid gas makes the carbon atom electrophilic, shown by the convening in the shaded box, so the nucleophilic carbon of the Grignard reagent bonds to this site. ampere-second has in subject an undivided electron pair. such(prenominal) a carbon would be a in truth strong base, much stronger than needed to take an H+ from wet to scram the weaker base OH-. A serviceable mo of this is that Grignard reagents must be unbroken dry, onward from in time the slightest traces of moisture, lest they be destroyed by reaction with water. plant CitedClayden, greeves, Warden and Wothers, fundamental chemistry, Oxford University press, 2001, ISBN 0-19-850346-6http//www.chemguide.co.uk/organicprops/haloalkanes/grignard.html