title: Stable Alkali-Metal Complexes of Hybrid Disila-Crown Ethers.
abstract: The complexation ability of hybrid disilane and ethylene containing crown ether ring systems was analyzed using 1,2-disila[12]crown-4 (1), 1,2-disila[15]crown-5 (2), 1,2-disila[18]crown-6 (3), and 1,2,7,8-tetrasila[12]crown-4 (7). Alkali-metal complexes (Li(+), Na(+), K(+)) were obtained and analyzed via X-ray diffraction. The complex stability of [Li(1,2-disila[12]crown-4)](+) and [Li(1,2,7,8-tetrasila[12]crown-4)](+) was determined, in relation to the lithium complex of [12]crown-4, by density functional theory (DFT) calculations employing the BP86/def2-TZVP level of theory. In solution, the exchange of lithium cations between pure [12]crown-4 and hybrid [12]crown-4 is on even terms, as has been shown from the relative binding affinity of compounds 1 and 7 by means of dynamic proton nuclear magnetic resonance (NMR) spectroscopy.
authors.affiliation: Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg , Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Reuter
authors.affiliation: Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg , Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
authors.forename: Magnus R
authors.initials: MR
authors.lastname: Buchner
authors.affiliation: Department of Chemistry, University of California , 210 Lewis Hall, Berkeley, California 94720, United States.
authors.forename: Günther
authors.initials: G
authors.lastname: Thiele
authors.affiliation: Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg , Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: von Hänisch
mesh_terms: D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D043844:Crown Ethers / Q000138:chemical synthesis / Q000737:chemistry*; D007554:Isotopes; D008094:Lithium / Q000737:chemistry; D008672:Metals, Alkali / Q000737:chemistry*; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry; D066244:Proton Magnetic Resonance Spectroscopy; D011789:Quantum Theory; D012964:Sodium / Q000737:chemistry
chemical_list: D056831:Coordination Complexes; D043844:Crown Ethers; D007554:Isotopes; D008672:Metals, Alkali; D017646:Organosilicon Compounds; D008094:Lithium; D012964:Sodium; D011188:Potassium