title: Evaluation of Anisole-Substituted Boron Difluoride Formazanate Complexes for Fluorescence Cell Imaging.
abstract: Evaluation of three subclasses of boron difluoride formazanate complexes bearing o-, m-, and p-anisole N-aryl substituents (Ar) as readily accessible alternatives to boron dipyrromethene (BODIPY) dyes for cell imaging applications is described. While the wavelengths of maximum absorption (λmax ) and emission (λem ) observed for each subclass of complexes, which differed by their carbon-bound substituents (R), were similar, the emission quantum yields for 7 a-c (R=cyano) were enhanced relative to 8 a-c (R=nitro) and 9 a-c (R=phenyl). Complexes 7 a-c and 8 a-c were also significantly easier to reduce electrochemically to their radical anion and dianion forms compared to 9 a-c. Within each subclass, the o-substituted derivatives were more difficult to reduce, had shorter λmax and λem , and lower emission quantum yields than the p-substituted analogues as a result of sterically driven twisting of the N-aryl substituents and a decrease in the degree of π-conjugation. The m-substituted complexes were the least difficult to reduce and possessed intermediate λmax , λem , and quantum yields. The complexes studied also exhibited large Stokes shifts (82-152 nm, 2143-5483 cm(-1) ). Finally, the utility of complex 7 c (Ar=p-anisole, R=cyano), which can be prepared for just a few dollars per gram, for fluorescence cell imaging was demonstrated. The use of 7 c and 4',6-diamino-2-phenylindole (DAPI) allowed for simultaneous imaging of the cytoplasm and nucleus of mouse fibroblast cells.
authors.affiliation: Department of Chemistry, The University of Western Ontario, 1151 Richmond St. N., London, Ontario N6A 5B7 (Canada).|The Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, 1151 Richmond St. N., London, Ontario N6A 5B7 (Canada).
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Maar
authors.affiliation: Department of Chemistry, The University of Western Ontario, 1151 Richmond St. N., London, Ontario N6A 5B7 (Canada).|The Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, 1151 Richmond St. N., London, Ontario N6A 5B7 (Canada).
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Barbon
authors.affiliation: Department of Chemistry, The University of Western Ontario, 1151 Richmond St. N., London, Ontario N6A 5B7 (Canada).
authors.forename: Neha
authors.initials: N
authors.lastname: Sharma
authors.affiliation: Department of Oncology, London Regional Cancer Program, 790 Commissioners Rd. E., London, Ontario N6A 4L6 (Canada).
authors.forename: Hilary
authors.initials: H
authors.lastname: Groom
authors.affiliation: Department of Chemistry, The University of Western Ontario, 1151 Richmond St. N., London, Ontario N6A 5B7 (Canada). lluyt@uwo.ca.|Department of Oncology, London Regional Cancer Program, 790 Commissioners Rd. E., London, Ontario N6A 4L6 (Canada). lluyt@uwo.ca.|Department of Medical Imaging, The University of Western Ontario, 1151 Richmond St. N., London, Ontario N6A 5B7 (Canada). lluyt@uwo.ca.
authors.forename: Leonard G
authors.initials: LG
authors.lastname: Luyt
authors.affiliation: Department of Chemistry, The University of Western Ontario, 1151 Richmond St. N., London, Ontario N6A 5B7 (Canada). joe.gilroy@uwo.ca.|The Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, 1151 Richmond St. N., London, Ontario N6A 5B7 (Canada). joe.gilroy@uwo.ca.
authors.forename: Joe B
authors.initials: JB
authors.lastname: Gilroy
mesh_terms: D000840:Anisoles / Q000737:chemistry*; D001896:Boron Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003952:Diagnostic Imaging; D003959:Diamines / Q000737:chemistry*; D005347:Fibroblasts / Q000737:chemistry*; D005453:Fluorescence; D007211:Indoles / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011162:Porphobilinogen / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: C000607851:4',6-diamino-2-phenylindole; C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D000840:Anisoles; D001896:Boron Compounds; D003959:Diamines; D007211:Indoles; C579460:boron difluoride; C507544:dipyrromethene; D011162:Porphobilinogen; C060998:anisole
keywords: boron; cell imaging; fluorescent dyes; formazanate ligands; substituent effects