STEREOCHEMISTRY OF POLYNUCLEAR COMPOUNDS OF MAIN GROUP ELEMENTS .8. CRYSTAL STRUCTURE OF BIS[2-DIMETHYLAMINOETHYL(METHYL)AMINO]DI(METHYLMAGNESIUM)

The crystal structure of bis[2-dimethylammoethyl(methyl)amino]di(methylmagnesium), [(CH3)2N(CH2)2NCH3MgCH3]2, has been determined by three-dimensional single-crystal X-ray diffractometer studies. A full-matrix least-squares refinement using 1812 reflections resulted in a final unweighted discrepancy factor of 4.5%. The compound crystallizes as dimers in the triclinic space group P1, with two molecules in a reduced cell of dimensions a = 7.244 (2) Å, b = 10.387 (3) Å, c = 12.454 (4) Å, α - 82.10 (6)°, β = 88.61 (17)°, and γ = 80.37 (9)°, where Z = 2, σcalcd = 1.04 g/cm3, and σobsd = 1.03 g/cm3. The dimers are located on crystallographic centers of inversion and consist of two magnesium atoms bridged by amino groups from two different 2-dimethylaminoethyl (methyl )amino ligands. An amine nitrogen of the chelate and a methyl group occupy the remaining nearly tetrahedral coordination sites on each magnesium atom. The average Mg to bridging N and Mg to terminal N distances are 2.104 ± 0.003 and 2.196 ± 0.003 Å, respectively. Within the four-membered MgNMg′N′ ring, the average MgNMg′angle is 88.5 ± 0.1° and the NMgN′ angle is 91.5 ± 0.1°. © 1969, American Chemical Society. All rights reserved.