title: Self-assembly and molecular recognition of a luminescent gold rectangle.
abstract: A luminescent molecular rectangle [Au(4)(micro-PAnP)(2)(micro-bipy)(2)](OTf)(4) (1.(OTf)(4)) (PAnP = 9,10-bis(diphenylphosphino)anthracene, bipy = 4,4'-bipyridine, X = NO(3)(-) or OTf(-)), synthesized from the self-assembly of the molecular "clip" Au(2)(micro-PAnP)(OTf)(2) and bipy, shows a large rectangular cavity of 7.921(3) x 16.76(3) A. The electronic absorption and emission spectroscopy, and electrochemistry of the metallacyclophane, have been studied. The 1(4+) ions are self-assembled into 2D mosaic in the solid state via complementary edge-to-face interactions between the Ph groups. (1)H NMR titrations ratify the 1:1 complexation between 1(4+) and various aromatic molecules. Comparing the structures of the inclusion complexes indicates an induced-fit mechanism operating in the binding. The emission of 1(4+) is quenched upon the guest binding. The binding constants are determined by both (1)H NMR and fluorescence titrations. Solvophobic and ion-dipole effects are shown to be important in stabilizing the inclusion complexes.
authors.affiliation: Department of Chemistry, The National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore.
authors.forename: Ronger
authors.initials: R
authors.lastname: Lin
authors.forename: John H K
authors.initials: JH
authors.lastname: Yip
authors.forename: Ke
authors.initials: K
authors.lastname: Zhang
authors.forename: Lip Lin
authors.initials: LL
authors.lastname: Koh
authors.forename: Kwok-Yin
authors.initials: KY
authors.lastname: Wong
authors.forename: Kam Piu
authors.initials: KP
authors.lastname: Ho