# What is the mechanism of formation of Grignard's Reagent?

What is the mechanism of formation of Grignard reagents? I couldn't find much in my book or on the Internet. This page says something which I am unable to understand. Why are the $2$ electrons in the $\ce{Mg}$ separated? Shouldn't they be together?

• It is not entirely known. – Jori May 16 '15 at 23:18
• So why would the university website say that? Don't most things in organic chemistry have a probable mechanism rather than an actual one? – Karan Singh May 17 '15 at 18:36
• It is rather simplest version, certain simplification for students, but if you have problem even with that... Actually pure griniards aren't monomers and have multicenter bonds so... – Mithoron Aug 16 '15 at 12:12

In step 1, the shared electron pair in $\ce{R-X}$ has been split to form two radicals: $\ce{R}{\small{•}}$ and $\ce{X}{\small{•}}$. However the $\ce{X}{\small{•}}$ radical is further attacked by an electron, this time coming from the $\ce{Mg}$. Thus forming a free-radical magnesium halide: $\ce{X^-Mg^+}{\small{•}}$.