title: Unique Eu(II) Coordination Environments with a Janus Cryptand.
abstract: Two new Eu(II)-containing cryptates were prepared with a new nitrogenous cryptand functionalized with three benzo groups. The introduction of three aromatic rings into the ligand backbone imparts lopsided geometrical features on the resulting Eu(II) coordination environments. In both complexes, the interactions between Eu and the amines on the aromatic side of the molecule are weaker than those on the nonaromatic side, resulting in one discrete unit with two distinct faces. One of the new complexes is, to the best of our knowledge, the first direct observation of a bis-aquo Eu(II)-containing cryptate with two nonadjacent inner-sphere water molecules. In addition to solid-phase structure, the electronic UV-visible and emission spectra of the new complexes were studied in acetonitrile. Experimental results show that the decreased Lewis basicity of the aromatic face hypsochromically shifts absorbances and emissions from a structurally related compound without the benzo groups.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Normal University , Jinan 250014, P. R. China.|Department of Chemistry, Wayne State University , Detroit, Michigan 48202, United States.
authors.forename: Guo-Xia
authors.initials: GX
authors.lastname: Jin
authors.affiliation: Department of Chemistry, Wayne State University , Detroit, Michigan 48202, United States.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Bailey
authors.affiliation: Department of Chemistry, Wayne State University , Detroit, Michigan 48202, United States.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Allen