CONSTITUTION OF GRIGNARD REAGENT .6. DEGREE OF ASSOCIATION OF ETHYLMAGNESIUM COMPOUNDS IN 1-ETHOXY-2-METHYLBUTANE

The degree of association of EtMgBr (prepared from ethylbromide and magnesium), Et2Mg and of a mixture of Et2Mg and MgBr2 in 1-ethoxy-2-methylbutane are measured at concentrations up to 30 millimolar at 27.3°. The following conclusions are drawn: 1. Both EtMgBr and Et2Mg are present in monomer/dimer equilibria, (1) and (2), with K1=19.1±1.3 1/mole and K2=64.8±6.3 1/mole, respectively. 2. MgBr2 reacts with Et2Mg with formation of EtMgBr. 3. When MgBr2 is added to an excess Et2Mg, the two species in the solution, viz. Et2Mg and EtMgBr, also complex with each other with formation of (EtMgBr)- (Et2Mg), constituting an equilibrium, (3), with K3 abouth 50 l mole. © 1968.