Cofacial boron dipyrromethene (Bodipy) dimers: synthesis, charge delocalization, and exciton coupling. 2010

Andrew C Benniston, and Graeme Copley, and Anthony Harriman, and David Howgego, and Ross W Harrington, and William Clegg
Molecular Photonics Laboratory, School of Chemistry, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom. a.c.benniston@ncl.ac.uk

A series of compounds containing two boron dipyrromethene (Bodipy) units has been synthesized and fully characterized in which the spacer between the two Bodipy groups is varied from dibenzothiophene (BD1), to dibenzofuran (BD2), to 9,9-dimethylxanthene (BD3), and finally to diphenyl ether (BD4 and BD5). For BD1-BD4 the Bodipy units adopt, to varying degrees, cofacial conformations that allow for systematic variations of both the mutual orientation and the mean separation of the two Bodipy residues. In the remaining dimer, BD5, the Bodipy units are well-separated and cannot come into close proximity. Single-crystal X-ray structures have been determined for BD1-BD3 and reveal that the "bite angle" between the two Bodipy residues decreases progressively along the series with individual values of 41.33(5) degrees, 36.95(6) degrees, and 8.57(3) degrees. Detailed (1)H and (19)F NMR studies for BD3 and BD4 show the methylene protons to be diastereotopic due to restricted rotation of the two Bodipy groups. For BD4 conformational rocking is invoked to explain the variable-temperature NMR spectra, whereby the methyl and methylene groups become inequivalent. Cyclic voltammetry indicates reversible oxidation and reduction of the Bodipy groups. However, the close proximity of the Bodipy groups in BD3 and BD4 results in two well-resolved waves in the anodic region, and slight splitting of the cathodic wave. Peak splitting is attributed to charge delocalization. Spectroelectrochemical measurements at a fixed oxidative potential reveal an optical intervalence charge-transfer (IVCT) absorption band. This IVCT band is attributed to electron exchange between the cofacially arranged neutral and mono-oxidized Bodipy units. Various levels of exciton coupling are observed for BD1-BD4, but not BD5 since here the Bodipy groups remain isolated.

UI MeSH Term Description Entries
D009682 Magnetic Resonance Spectroscopy Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING). In Vivo NMR Spectroscopy,MR Spectroscopy,Magnetic Resonance,NMR Spectroscopy,NMR Spectroscopy, In Vivo,Nuclear Magnetic Resonance,Spectroscopy, Magnetic Resonance,Spectroscopy, NMR,Spectroscopy, Nuclear Magnetic Resonance,Magnetic Resonance Spectroscopies,Magnetic Resonance, Nuclear,NMR Spectroscopies,Resonance Spectroscopy, Magnetic,Resonance, Magnetic,Resonance, Nuclear Magnetic,Spectroscopies, NMR,Spectroscopy, MR
D011162 Porphobilinogen
D001895 Boron A trace element with the atomic symbol B, atomic number 5, and atomic weight [10.806; 10.821]. Boron-10, an isotope of boron, is used as a neutron absorber in BORON NEUTRON CAPTURE THERAPY. Boron-11,Boron 11
D005456 Fluorescent Dyes Chemicals that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags. Flourescent Agent,Fluorescent Dye,Fluorescent Probe,Fluorescent Probes,Fluorochrome,Fluorochromes,Fluorogenic Substrates,Fluorescence Agents,Fluorescent Agents,Fluorogenic Substrate,Agents, Fluorescence,Agents, Fluorescent,Dyes, Fluorescent,Probes, Fluorescent,Substrates, Fluorogenic
D015394 Molecular Structure The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds. Structure, Molecular,Molecular Structures,Structures, Molecular
D018360 Crystallography, X-Ray The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) X-Ray Crystallography,Crystallography, X Ray,Crystallography, Xray,X Ray Crystallography,Xray Crystallography,Crystallographies, X Ray,X Ray Crystallographies
D019281 Dimerization The process by which two molecules of the same chemical composition form a condensation product or polymer. Dimerizations

Related Publications

Andrew C Benniston, and Graeme Copley, and Anthony Harriman, and David Howgego, and Ross W Harrington, and William Clegg
October 2011, The Journal of organic chemistry,
Andrew C Benniston, and Graeme Copley, and Anthony Harriman, and David Howgego, and Ross W Harrington, and William Clegg
January 2015, Chemical communications (Cambridge, England),
Andrew C Benniston, and Graeme Copley, and Anthony Harriman, and David Howgego, and Ross W Harrington, and William Clegg
December 2011, The Journal of organic chemistry,
Andrew C Benniston, and Graeme Copley, and Anthony Harriman, and David Howgego, and Ross W Harrington, and William Clegg
April 2022, Journal of the American Chemical Society,
Andrew C Benniston, and Graeme Copley, and Anthony Harriman, and David Howgego, and Ross W Harrington, and William Clegg
April 2022, Molecules (Basel, Switzerland),
Andrew C Benniston, and Graeme Copley, and Anthony Harriman, and David Howgego, and Ross W Harrington, and William Clegg
May 2016, Physical chemistry chemical physics : PCCP,
Andrew C Benniston, and Graeme Copley, and Anthony Harriman, and David Howgego, and Ross W Harrington, and William Clegg
May 2013, Physical chemistry chemical physics : PCCP,
Andrew C Benniston, and Graeme Copley, and Anthony Harriman, and David Howgego, and Ross W Harrington, and William Clegg
May 2013, Bioorganic & medicinal chemistry,
Andrew C Benniston, and Graeme Copley, and Anthony Harriman, and David Howgego, and Ross W Harrington, and William Clegg
November 2019, Bioorganic & medicinal chemistry letters,
Andrew C Benniston, and Graeme Copley, and Anthony Harriman, and David Howgego, and Ross W Harrington, and William Clegg
October 2010, Chemistry (Weinheim an der Bergstrasse, Germany),
Copied contents to your clipboard!