Stabilisierung des reaktiven Methylcarbonat-Ions im Kronenether- Komplex [Cs(18-Krone-6)(CH3CO3)] und dessen Hydrolyseprodukt / Stabilization of the Reactive Methylcarbonate Ion in the Crown Ether Complex [Cs(18-crown-6)(CH3CO3)], and its Hydrolysis Product

Abstract

[Cs(18-crown-6)(CH3CO3)] (1) has been obtained by the reaction of CsOCH3 with 18-crown-6 (1,4,7,10,13,16-hexaoxacyclooctadecane) in methanol in a CO2 atmosphere. The compound crystallizes in the monoclinic space group P21/n (no. 14) with a = 12.141(3), b = 8.610(1), c = 17.985(4) Å , β = 91.17(2)° and V = 1879.6(7) Å3. Cs is tenfold coordinated by six oxygen atoms of the crown ether and four oxygen atoms of two methyl carbonate anions which act as bidentate ligands. The slow hydrolysis of the methylcarbonate results in the hydrogencarbonate complex {Cs2(18-crown- 6)2 · [H2(CO3)2] · H2O · CH3OH} (2), the basic structural constitution of the starting material being retained. This new compound crystallizes in the monoclinic space group P21/c with a = 8.657 (7), b = 22.601 (2), c = 19.619 (15) Å, β = 92.09 (6)° and V = 3836.5 (6) Å3.