Complexes of calcium halides with 1,2-dimethoxyethane (DME)

The solvento calcium bromide CaBr2(DME) has been prepared by reacting anhydrous calcium acetate with acetyl bromide in dimethoxyethane (DME), while refluxing a suspension of CaCl2 in DME/SOCl2 gave CaCl2(DME), high yields being secured in both cases. Crystals of the ionic [CaBr(DME)(2)(H2O)(2)]Br (1), were shown to contain heptacoordinated calcium (II) with bidentate DME. Two polyinorphs of the mononuclear, CaBr2(DME)(2)(MeCOOH) (2), differing for their packing efficiency, have been studied by X-ray diffractometry. Compound 2 loses one DME and the coordinated acetic acid under vacuum at 30 degrees C, yielding CaBr2(DME). Coordinated DME in CaX2(DME) was found to be substituted by nitrogen bases in toluene, the adducts CaX(2)py(2) (X=Cl, Br), CaBr2(DMEDA)(2), (DMEDA = N,N'-dimethylethylenediammine) and CaBr2(L-L-L) [L-L-L = 2,6-bis(3,5-dimethyl-N-pyrazolyl)pyridine)] being obtained in good yields. (c) 2006 Elsevier B.V. All rights reserved.