Since Mg+ ions are isoelectronic to Na atoms, an easy single electron transfer (SET) can be expected for MgBr. Even at 190 K, the radical MgBr (obtained via its sophisticated condensation) in a metastable solution transfers its electron to a diazadiene entity. A paramagnetic Mg(II) compound [MgBr(L1)˙]2 (4; L1 = DippN![[double bond, length as m-dash]](http://www.rsc.org/images/entities/char_e001.gif)
C(Me)C(Me)NDipp) is formed consisting of a singly reduced ligand. As shown by EPR investigations, dimeric 4 dissociates in ethereal solvents to two monomeric subunits. In addition, 4 can subsequently be reduced with potassium to furnish again a Mg(I) compound, namely [K(thf)3]2[Mg2(L1)2] (3).
![Graphical abstract: From MgBr via single-electron transfer (SET) to a paramagnetic Mg(ii) compound and back to Mg(i): [MgBr(L1)˙]2 and [K(thf)3]2[Mg2(L1)2], L1 = RN [[double bond, length as m-dash]] C(Me)C(Me) [[double bond, length as m-dash]] NR, R = 2,6-diisopropylphenyl](http://hg.y866.cn/compound/lib/scimg/usr/1/C4CC07680J.jpg)
