title: Effect of Extended π Conjugation on the Spectroscopic and Electrochemical Properties of Boron Difluoride Formazanate Complexes.
abstract: The effect of extended π conjugation on the spectroscopic and electrochemical properties of boron difluoride (BF2) formazanate complexes was studied by the systematic comparison of phenyl- and naphthyl-substituted derivatives. Each of the BF2 complexes described was characterized by (1)H, (13)C, (11)B, and (19)F NMR spectroscopy, cyclic voltammetry, infrared spectroscopy, UV-vis absorption and emission spectroscopy, and mass spectrometry. X-ray crystallography and electronic structure calculations were used to rationalize the trends observed, including direct comparison of 3-cyano-, 3-nitro-, and 3-phenyl-substituted BF2 formazanate complexes. In all cases, the wavelengths of maximum absorption and emission were red-shifted as π conjugation was systematically extended (by replacing phenyl with naphthyl), fluorescence quantum yields increased (up to 10-fold), and electrochemical conversion of the formazanate complexes to their radical anion and dianion forms occurred at less negative potentials (easier to reduce).
authors.affiliation: Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, 1151 Richmond Street North, London, Ontario, Canada N6A 5B7.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Barbon
authors.affiliation: Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, 1151 Richmond Street North, London, Ontario, Canada N6A 5B7.
authors.forename: Viktor N
authors.initials: VN
authors.lastname: Staroverov
authors.affiliation: Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research (CAMBR), The University of Western Ontario, 1151 Richmond Street North, London, Ontario, Canada N6A 5B7.
authors.forename: Joe B
authors.initials: JB
authors.lastname: Gilroy