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8436906 
Journal Article 
Magnesium Bromide-Tetrahydrofuran Complexes: MgBr2(C4H8O)2, MgBr2(C4H8O)3, MgBr2(C4H8O)4, and MgBr2 (C4H8O)4(H2O)2. A Reagent For the Preparation of Anhydrous Magnesium Phosphodiester Salts 
Ramirez, F; Sarma, R; Chaw, YF; Mccaffrey, TM; Marecek, JF; Mckeever, B; Nierman, D 
1977 
Yes 
Journal of the American Chemical Society
ISSN: 0002-7863
EISSN: 1520-5126 
99 
16 
5285-5289 
English 
The reaction of magnesium metal with mercuric bromide in anhydrous tetrahydrofuran gives, after removal of mercury, a solution containing two complexes in equilibrium: MgBr2(C4HsO)3 + C4H8O ⇌ MgBr2 (CUH8O)4 The former is obtained as a microcrystalline powder at temperatures >30 °C, and the latter as tetragonal crystals at temperatures >5 °C. These complexes are in equilibrium with a third one in dichloromethane solution: MgBr2(C4H8O)3 ⇌ MgBr2(C4H8O)2 + C4H8O; the latter is obtained as orthorhombic crystals by addition of hexane to the dichloromethane solution. The three complexes are converted into MgBr2(C4H8O)4(H2O)2 (triclinic) in THF containing 2 molar equiv of water. All complexes are transformed into MgBr2(H2O)6 in aqueous solution. The microcrystalline complex is an excellent reagent for the preparation of anhydrous magnesium phosphodiester salts in dichloromethane solution: 2(R1O)(R2O)P(O)OCH3 + MgBr2(C4H8O)3 → [(R1O)(R2O)P(O)OhMg + 2CH3Br + 3C4HgO. The compositions of the complexes are established by elemental analysis and by 1H NMR spectrometry in CDC13 containing dimethylformamide as internal reference. Single-crystal x-ray diffraction analyses of the new orthorhombic and triclinic complexes are presented in a companion paper. The unit cell dimensions of the tetragonal complex agree with those previously reported by Perucaud and LeBihan, and by Schroder and Spandau. © 1977, American Chemical Society. All rights reserved.