title: New 9- or 10-dentate luminescent lanthanide chelates.
abstract: Polyaminocarboxylate-based luminescent lanthanide complexes have unusual emission properties, including millisecond excited-state lifetimes and sharply spiked spectra compared to common organic fluorophores. There are three distinct sections in the structure of the luminescent lanthanide chelates: a polyaminocarboxylate backbone to bind the lanthanide ions tightly, an antenna molecule to sensitize the emission of lanthanide ions, and a reactive group to attach to biomolecules. We have previously reported the modifications on the chelates, on the antenna molecules (commonly cs124), and on the reactive sites. In searching for stronger binding chelates and better protection from solvent hydration, here we report the modification of the coordination number of the chelates. A series of 9- and 10-dentate chelates were synthesized. Among them, the 1-oxa-4,7-diazacyclononane (N2O)-containing chelate provides the best protection to the lanthanide ions from solvent molecule attack, and forms the most stable lanthanide coordination compounds. The TTHA-based chelate provides moderately good protection to the lanthanide ions.
authors.affiliation: Department of Physics and Center for Biophysics and Computational Biology, University of Illinois, Urbana, Illinois 61801, USA.
authors.forename: Pinghua
authors.initials: P
authors.lastname: Ge
authors.forename: Paul R
authors.initials: PR
authors.lastname: Selvin
mesh_terms: D002614:Chelating Agents / Q000138:chemical synthesis / Q000737:chemistry*; D043844:Crown Ethers / Q000737:chemistry*; D004492:Edetic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D049449:Luminescence; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013997:Time Factors
chemical_list: D002614:Chelating Agents; D043844:Crown Ethers; D028581:Lanthanoid Series Elements; D009942:Organometallic Compounds; C026059:triethylenetetraminehexaacetic acid; D004492:Edetic Acid