title: Tailoring Oxygen Sensitivity with Halide Substitution in Difluoroboron Dibenzoylmethane Polylactide Materials.
abstract: The dual-emissive properties of solid-state difluoroboron β-diketonate-poly(lactic acid) (BF2bdkPLA) materials have been utilized for biological oxygen sensing. In this work, BF2dbm(X)PLA materials were synthesized, where X = H, F, Cl, Br, and I. The effects of changing the halide substituent and PLA polymer chain length on the optical properties in dilute CH2Cl2 solutions and solid-state polymer films were studied. These luminescent materials show fluorescence, phosphorescence, and lifetime tunability on the basis of molecular weight, as well as lifetime modulation via the halide substituent. Short BF2dbm(Br)PLA (6.0 kDa) and both short and long BF2dbm(I)PLA polymers (6.0 or 20.3 kDa) have fluorescence and intense phosphorescence ideal for ratiometric oxygen sensing. The lighter halide-dye polymers with hydrogen, fluorine, and chlorine substitution have longer phosphorescence lifetimes and can be utilized as ultrasensitive oxygen sensors. Photostability was also analyzed for the polymer films.
authors.affiliation: Department of Chemistry, University of Virginia , Charlottesville, Virginia 22904, United States.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: DeRosa
authors.affiliation: Department of Chemistry, University of Virginia , Charlottesville, Virginia 22904, United States.
authors.forename: Caroline
authors.initials: C
authors.lastname: Kerr
authors.affiliation: Department of Chemistry, University of Virginia , Charlottesville, Virginia 22904, United States.
authors.forename: Ziyi
authors.initials: Z
authors.lastname: Fan
authors.affiliation: Department of Chemistry, University of Virginia , Charlottesville, Virginia 22904, United States.
authors.forename: Milena
authors.initials: M
authors.lastname: Kolpaczynska
authors.affiliation: Department of Chemistry, University of Virginia , Charlottesville, Virginia 22904, United States.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Mathew
authors.affiliation: Department of Chemistry, University of Virginia , Charlottesville, Virginia 22904, United States.
authors.forename: Ruffin E
authors.initials: RE
authors.lastname: Evans
authors.affiliation: Department of Chemistry, University of Virginia , Charlottesville, Virginia 22904, United States.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, University of Virginia , Charlottesville, Virginia 22904, United States.
authors.forename: Cassandra L
authors.initials: CL
authors.lastname: Fraser
mesh_terms: D015374:Biosensing Techniques; D001896:Boron Compounds / Q000737:chemistry*; D005453:Fluorescence; D006859:Hydrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry / Q000302:isolation & purification*; D011091:Polyesters / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry
chemical_list: D001896:Boron Compounds; D011091:Polyesters; D011108:Polymers; C522801:difluoroboron dibenzoylmethane polylactide; D006859:Hydrogen; D010100:Oxygen
keywords: difluoroboron β-diketonate complexes; heavy atom effect; photostability; poly(lactic acid); room-temperature phosphorescence