uu.seUppsala University Publications
Change search
Link to record
Permanent link

Direct link
BETA
Johansson, Olof
Publications (9 of 9) Show all publications
Abrahamsson, M., Jäger, M., Kumar, R. J., Österman, T., Persson, P., Becker, H.-C., . . . Hammarström, L. (2008). Bistridentate Ruthenium(II)polypyridyl-Type Complexes with Microsecond 3MLCT State Lifetimes: Sensitizers for Rod-Like Molecular Arrays. Journal of the American Chemical Society, 130(46), 15533-15542
Open this publication in new window or tab >>Bistridentate Ruthenium(II)polypyridyl-Type Complexes with Microsecond 3MLCT State Lifetimes: Sensitizers for Rod-Like Molecular Arrays
Show others...
2008 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 130, no 46, p. 15533-15542Article in journal (Refereed) Published
Abstract [en]

A series of bistridentate ruthenium(II) polypyridyl-type complexes based on the novel 2,6-di(quinolin-8-yl)pyridine (dqp) ligand have been synthesized and their photophysical properties have been studied. The complexes are amenable to substitution in the 4-position of the central pyridine with conserved quasi-C2v symmetry, which allows for extension to isomer-free, rod-like molecular arrays for vectorial control of electron and energy transfer. DFT calculations performed on the parent [Ru(dqp) 2](2+) complex (1) predicted a more octahedral structure than in the typical bistridentate complex [Ru(tpy)2](2+) (tpy is 2,2':6',2"-terpyridine) thanks to the larger ligand bite angle, which was confirmed by X-ray crystallography. A strong visible absorption band, with a maximum at 491 nm was assigned to a metal-to-ligand charge transfer (MLCT) transition, based on time-dependent DFT calculations. 1 shows room temperature emission (Phi = 0.02) from its lowest excited ((3)MLCT) state that has a very long lifetime (tau = 3 micros). The long lifetime is due to a stronger ligand field, because of the more octahedral structure, which makes the often dominant activated decay via short-lived metal-centered states insignificant also at elevated temperatures. A series of complexes based on dqp with electron donating and/or accepting substituents in the 4-position of the pyridine was prepared and the properties were compared to those of 1. An unprecedented (3)MLCT state lifetime of 5.5 micros was demonstrated for the homoleptic complex based on dqpCO2Et. The favorable photosensitizer properties of 1, such as a high extinction coefficient, high excited-state energy and long lifetime, and tunable redox potentials, are maintained upon substitution. In addition, the parent complex 1 is shown to be remarkably photostable and displays a high reactivity in light-induced electron and energy transfer reactions with typical energy and electron acceptors and donors: methylviologen, tetrathiofulvalene, and 9,10-diphenylanthracene. This new class of complexes constitutes a promising starting point for the construction of linear, rod-like molecular arrays for photosensitized reactions and applications in artificial photosynthesis and molecular electronics.

Place, publisher, year, edition, pages
ACS, 2008
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-95088 (URN)10.1021/ja804890k (DOI)000263311300058 ()19006410 (PubMedID)
Available from: 2006-11-09 Created: 2006-11-09 Last updated: 2017-12-14Bibliographically approved
Falkenström, M., Johansson, O. & Hammarström, L. (2007). Light-induced charge separation in ruthenium based triads: New variations on an old theme. Inorganica Chimica Acta, 360(3), 741-750
Open this publication in new window or tab >>Light-induced charge separation in ruthenium based triads: New variations on an old theme
2007 (English)In: Inorganica Chimica Acta, ISSN 0020-1693, E-ISSN 1873-3255, Vol. 360, no 3, p. 741-750Article, review/survey (Refereed) Published
Abstract [en]

Success with artificial photosynthesis requires control of the photoinduced electron transfer reactions leading to charge-separated states. In this review, some new ideas to optimize such charge-separated states in ruthenium(II) polypyridyl based three-component systems with respect to: (1) long lifetimes and (2) ability to store sufficient energy for catalytic water splitting, are presented. To form long-lived charge-separated states, a manganese complex as electron donor and potential catalyst for water oxidation has been used. The recombination reaction is unusually slow because it occurs deep down in the Marcus normal region as a consequence of the large bond reorganization following the manganese oxidation. For the creation of high energy charge-separated states, a strategy using bichromophoric systems is presented. By consecutive excitations of the two chromophores, the formation of charge-separated states that lie higher in energy than either of the two excited states could in theory be achieved, the first results of which will be discussed in this review.

Keywords
Artificial photosynthesis, Electron transfer, Light induced charge separation, Ruthenium, Manganese
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-24351 (URN)10.1016/j.ica.2006.06.046 (DOI)000244364600004 ()
Available from: 2007-04-05 Created: 2007-04-05 Last updated: 2017-12-07Bibliographically approved
Abrahamsson, M., Jäger, M., Österman, T., Eriksson, L., Persson, P., Becker, H.-C., . . . Hammarström, L. (2006). A 3.0 mu s room temperature excited state lifetime of a bistridentate Ru-II-polypyridine complex for rod-like molecular arrays. Journal of the American Chemical Society, 128(39), 12616-12617
Open this publication in new window or tab >>A 3.0 mu s room temperature excited state lifetime of a bistridentate Ru-II-polypyridine complex for rod-like molecular arrays
Show others...
2006 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 128, no 39, p. 12616-12617Article in journal (Refereed) Published
Abstract [en]

A bistridentate RuII-polypyridine complex [Ru(bqp)2]2+ (bqp = 2,6-bis(8'-quinolinyl)pyridine) has been prepared, which has a coordination geometry much closer to a perfect octahedron than the typical Ru(terpyridine)2-type complex. Thus, the complex displays a 3.0 mus lifetime of the lowest excited metal-to-ligand charge transfer (3MLCT) state at room temperature. This is, to the best of our knowledge, the longest MLCT state lifetime reported for a RuII-polypyridyl complex at room temperature. The structure allows for the future construction of rod-like, isomer-free molecular arrays by substitution of donor and acceptor moieties on the central pyridine units. This makes it a promising photosensitizer for applications in molecular devices for artificial photosynthesis and molecular electronics.

National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-95087 (URN)10.1021/ja064262y (DOI)000240795000014 ()17002333 (PubMedID)
Available from: 2006-11-09 Created: 2006-11-09 Last updated: 2017-12-14Bibliographically approved
Hammarström, L., Johansson, O. & Magnuson, A. (2006). Artificial Photosynthesis Edited by Anthony F. Collings and Christa Critchley. In: Angewandte Chemie, International Edition.
Open this publication in new window or tab >>Artificial Photosynthesis Edited by Anthony F. Collings and Christa Critchley
2006 (English)In: Angewandte Chemie, International Edition, 2006Chapter in book (Other (popular scientific, debate etc.))
Identifiers
urn:nbn:se:uu:diva-81376 (URN)1433-7851 (ISBN)
Available from: 2006-08-18 Created: 2006-08-18
Johansson, O. (2006). Pd-catalyzed amination of chloro-terpyridine for the preparation of amine-containing ruthenium(II) complexes. Synthesis (Stuttgart) (15), 2585-2589
Open this publication in new window or tab >>Pd-catalyzed amination of chloro-terpyridine for the preparation of amine-containing ruthenium(II) complexes
2006 (English)In: Synthesis (Stuttgart), ISSN 0039-7881, E-ISSN 1437-210X, no 15, p. 2585-2589Article in journal (Refereed) Published
Abstract [en]

The palladium-catalyzed amination reaction of commercially available 4'-chloro-2,2':6',2"-terpyridine opens an easy access to aminated mono- and ditopic terpyridine ligands. The obtained compounds were subsequently used to prepare new amine-containing ruthenium(II) polypyridyl complexes.

Keywords
palladium-catalyzed amination, terpyridine, ruthenium, photochemistry, switches
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-83695 (URN)10.1055/s-2006-942469 (DOI)000239924200021 ()
Available from: 2006-11-08 Created: 2006-11-08 Last updated: 2017-12-14Bibliographically approved
Borgström, M., Ott, S., Lomoth, R., Bergquist, J., Hammarström, L. & Johansson, O. (2006). Photoinduced energy transfer coupled to charge separation in a Ru(II)-Ru(II)-acceptor triad.. Inorganic Chemistry, 45(12), 4820-4829
Open this publication in new window or tab >>Photoinduced energy transfer coupled to charge separation in a Ru(II)-Ru(II)-acceptor triad.
Show others...
2006 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 45, no 12, p. 4820-4829Article in journal (Refereed) Published
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-81363 (URN)16749847 (PubMedID)
Available from: 2006-11-01 Created: 2006-11-01 Last updated: 2017-12-14
Ott, S., Borgström, M., Hammarström, L. & Johansson, O. (2006). Rapid energy transfer in bichromophoric tris-bipyridyl/cyclometallated ruthenium(II) complexes.. Dalton Trans (11), 1434-43
Open this publication in new window or tab >>Rapid energy transfer in bichromophoric tris-bipyridyl/cyclometallated ruthenium(II) complexes.
2006 (English)In: Dalton Trans, ISSN 1477-9226, no 11, p. 1434-43Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-81359 (URN)16518513 (PubMedID)
Available from: 2006-08-18 Created: 2006-08-18 Last updated: 2011-01-11
Abrahamsson, M., Wolpher, H., Johansson, O., Larsson, J., Kritikos, M., Eriksson, L., . . . Hammarström, L. (2005). A New Strategy for the Improvement of Photophysical Properties in Ruthenium(II) Polypyridyl Complexes: Synthesis and Photophysical and Electrochemical Characterization of Six Mononuclear Ruthenium(II) Bisterpyridine-Type Complexes. Inorganic Chemistry, 44(9), 3215-3225
Open this publication in new window or tab >>A New Strategy for the Improvement of Photophysical Properties in Ruthenium(II) Polypyridyl Complexes: Synthesis and Photophysical and Electrochemical Characterization of Six Mononuclear Ruthenium(II) Bisterpyridine-Type Complexes
Show others...
2005 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 44, no 9, p. 3215-3225Article in journal (Refereed) Published
Place, publisher, year, edition, pages
ACS, 2005
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-95084 (URN)10.1021/ic048247a (DOI)15847430 (PubMedID)
Available from: 2006-11-09 Created: 2006-11-09 Last updated: 2017-12-14Bibliographically approved
Johansson, O. & Lomoth, R. (2005). Rapid electrochemically induced linkage isomerism in a ruthenium(II) polypyridyl complex. Chemical Communications (12), 1578-80
Open this publication in new window or tab >>Rapid electrochemically induced linkage isomerism in a ruthenium(II) polypyridyl complex
2005 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, no 12, p. 1578-80Article in journal (Refereed) Published
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-75920 (URN)15770265 (PubMedID)
Available from: 2006-02-24 Created: 2006-02-24 Last updated: 2017-12-14
Organisations

Search in DiVA

Show all publications