title: A structural study of alkaline earth metal complexes with hybrid disila-crown ethers.
abstract: Compounds consisting of [M(1,2-disila-[3n]crown-n)]2+(M = Mg, Ca, Sr, Ba; n = 5, 6) and [Ba(1,2-disila-benzo[18]crown-6)]2+cations and different anions were obtained by equimolar reaction of the hybrid disila-crown ethers 1,2-disila[15]crown-5 (1), 1,2-disila[18]crown-6 (2) and 1,2-disila-benzo[18]crown-6 (7) with alkaline earth metal salts. Even with strongly coordinating anions such as Br-or I-stable complexes could be obtained, showing the good coordination ability of these ligands. The structures of all coordination compounds were determined via single crystal X-ray diffraction (XRD). By means of DFT calculations, the complexation ability of 1,2-disila[15]crown-5 (1) towards magnesium bromide was determined to be considerably higher compared to [15]crown-5. The opposite case was observed in solution as the exchange of calcium cations between [18]crown-6 and 1,2-disila[18]crown-6 (2) was studied via dynamic proton nuclear magnetic resonance (NMR) spectroscopy.
authors.affiliation: Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Straße 4, D-35032, Marburg, Germany. haenisch@chemie.uni-marburg.de.
authors.forename: Fabian
authors.initials: F
authors.lastname: Dankert
authors.forename: Kirsten
authors.initials: K
authors.lastname: Reuter
authors.forename: Carsten
authors.initials: C
authors.lastname: Donsbach
authors.forename: Carsten
authors.initials: C
authors.lastname: von Hänisch