title: Fluorescent modular boron systems based on NNN- and ONO-tridentate ligands: self-assembly and cell imaging.
abstract: We have synthesized a series of new fluorescent boron systems 1a-c and 2a-d based on nitrogen (NNN) or nitrogen and oxygen (ONO)-containing tridentate ligands. These novel dyes are characterized by high thermal and chemical stability. They show large Stokes shifts (mostly above 3200 cm(-1)) and quantum yields in solution and in the solid state up to 40%. The easy, modular synthesis facilitates the convenient variation of the axial substituent on the central boron atom, allowing the functionalization of this dye for biochemical use. Introducing a long alkyl chain with a phenyl spacer at this axial position enables the self-assembly of the boron compound 2d to form a fluorescent vesicle, which is able to encapsulate small molecules such as sulforhodamine. Additionally, boron compound 2d was found to serve as a dye for cell imaging since it has the capability of binding to the nuclear membranes of HeLa cells. With phospholipids such as DOPC, giant unilamelar vesicles (GUV) are formed. These results demonstrate the wide applicability of this new boron system in supramolecular and medicinal chemistry.
authors.affiliation: Organic Chemistry Institute, Westfälische Wilhelms-Universität, Corrensstr. 40, 48149 Münster, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Glotzbach
authors.forename: Ulrike
authors.initials: U
authors.lastname: Kauscher
authors.forename: Jens
authors.initials: J
authors.lastname: Voskuhl
authors.forename: N Seda
authors.initials: NS
authors.lastname: Kehr
authors.forename: Marc C A
authors.initials: MC
authors.lastname: Stuart
authors.forename: Roland
authors.initials: R
authors.lastname: Fröhlich
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Galla
authors.forename: Bart Jan
authors.initials: BJ
authors.lastname: Ravoo
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nagura
authors.forename: Shohei
authors.initials: S
authors.lastname: Saito
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Ernst-Ulrich
authors.initials: EU
authors.lastname: Würthwein
mesh_terms: D001896:Boron Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D006367:HeLa Cells; D006801:Humans; D008024:Ligands; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D009584:Nitrogen / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D011789:Quantum Theory; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D001896:Boron Compounds; D005456:Fluorescent Dyes; D008024:Ligands; D009584:Nitrogen; D010100:Oxygen