title: Coordination of 1,10-phenanthroline and 2,2'-bipyridine to Li+ in different ionic liquids. How innocent are ionic liquids?
abstract: On the basis of (7)Li NMR measurements, we have made detailed studies on the influence of the ionic liquids [emim][NTf(2)], [emim][ClO(4)], and [emim][EtSO(4)] on the complexation of Li(+) by the bidentate N-donor ligands 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen). For each of the employed ionic liquids the NMR data implicate the formation of [Li(bipy)(2)](+) and [Li(phen)(2)](+), respectively. X-ray diffraction studies were performed to determine the coordination pattern in the solid state. In the case of [emim][ClO(4)] and [emim][EtSO(4)], crystal structures confirmed the NMR data, resulting in the complexes [Li(bipy)(2)ClO(4)] and [Li(phen)(2)EtSO(4)], respectively. On the contrary, the ionic liquid [emim][NTf(2)] generated the C(i) symmetric, dinuclear, supramolecular cluster [Li(bipy)(NTf(2))](2), where the individual Li(+) centers were found to be bridged by two [NTf(2)] anions. Density functional theory (DFT)-calculations lead to further information on the effect of stacking on the coordination geometry of the Li(+) centers.
authors.affiliation: Inorganic Chemistry, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schmeisser
authors.forename: Frank W
authors.initials: FW
authors.lastname: Heinemann
authors.forename: Peter
authors.initials: P
authors.lastname: Illner
authors.forename: Ralph
authors.initials: R
authors.lastname: Puchta
authors.forename: Achim
authors.initials: A
authors.lastname: Zahl
authors.forename: Rudi
authors.initials: R
authors.lastname: van Eldik
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry*; D018360:Crystallography, X-Ray; D052578:Ionic Liquids / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010618:Phenanthrolines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D052578:Ionic Liquids; D009942:Organometallic Compounds; D010618:Phenanthrolines; D015082:2,2'-Dipyridyl; D008094:Lithium; C025205:1,10-phenanthroline