title: Coordination-driven self-assembly of M3L2 trigonal cages from preorganized metalloligands incorporating octahedral metal centers and fluorescent detection of nitroaromatics.
abstract: The design and preparation of novel M(3)L(2) trigonal cages via the coordination-driven self-assembly of preorganized metalloligands containing octahedral aluminum(III), gallium(III), or ruthenium(II) centers is described. When tritopic or dinuclear linear metalloligands and appropriate complementary subunits are employed, M(3)L(2) trigonal-bipyramidal and trigonal-prismatic cages are self-assembled under mild conditions. These three-dimensional cages were characterized with multinuclear NMR spectroscopy ((1)H and (31)P) and high-resolution electrospray ionization mass spectrometry. The structure of one such trigonal-prismatic cage, self-assembled from an arene ruthenium metalloligand, was confirmed via single-crystal X-ray crystallography. The fluorescent nature of these prisms, due to the presence of their electron-rich ethynyl functionalities, prompted photophysical studies, which revealed that electron-deficient nitroaromatics are effective quenchers of the cages' emission. Excited-state charge transfer from the prisms to the nitroaromatic substrates can be used as the basis for the development of selective and discriminatory turn-off fluorescent sensors for nitroaromatics.
authors.affiliation: Department of Chemistry, University of Utah, 315 South 1400 East Salt Lake City, Utah 84112, United States.
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.forename: Vaishali
authors.initials: V
authors.lastname: Vajpayee
authors.forename: Sankarasekaran
authors.initials: S
authors.lastname: Shanmugaraju
authors.forename: Yao-Rong
authors.initials: YR
authors.lastname: Zheng
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhao
authors.forename: Hyunuk
authors.initials: H
authors.lastname: Kim
authors.forename: Partha Sarathi
authors.initials: PS
authors.lastname: Mukherjee
authors.forename: Ki-Whan
authors.initials: KW
authors.lastname: Chi
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Stang
mesh_terms: D000535:Aluminum / Q000737:chemistry; D018360:Crystallography, X-Ray / Q000379:methods; D005708:Gallium / Q000737:chemistry; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D008024:Ligands; D008670:Metals / Q000737:chemistry*; D009574:Nitro Compounds / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: D006841:Hydrocarbons, Aromatic; D008024:Ligands; D008670:Metals; D009574:Nitro Compounds; D009942:Organometallic Compounds; D012428:Ruthenium; D005708:Gallium; D000535:Aluminum