ChemInform Abstract: SPECTROSCOPIC AND ELECTROCHEMICAL PROPERTIES OF THE DIMER TETRAKIS(2,2′‐BIPYRIDINE)(μ‐2,3‐BIS(2‐PYRIDYL)PYRAZINE)DIRUTHENIUM(II) AND ITS MONOMERIC ANALOG

Braunstein, Carlos; Baker, A. D.; Strekas, Thomas C.; Gafney, Harry D.

doi:10.1002/chin.198427312

Cited by 1 publication

(1 citation statement)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…16,17 In the cases of the Ir−Ir homobimetallic systems, positive scans gave a high-current anodic peak at 1.51 V for 3 or a couple of anodic peaks in the range of 1.0−1.4 V for 4, but no cathodic peak was observed upon reverse scanning. The irreversible behavior again contrasted with the reversible electrochemical oxidation of the Ru−Ru 18 and Os− Os homobimetallic systems, 19 indicating that the characteristics of the iridium complexes were different from those of the ruthenium and osmium analogues.…”

Section: Inorganic Chemistrymentioning

confidence: 99%

Photophysics and Excited-State Properties of Cyclometalated Iridium(III)–Platinum(II) and Iridium(III)–Iridium(III) Bimetallic Complexes Bridged by Dipyridylpyrazine

et al. 2017

View full text Add to dashboard Cite

We investigated the electrochemical and excited-state properties of 2,3-bis(2-pyridyl)pyrazine (dpp)-bridged bimetallic complexes, (L)Ir-dpp-PtCl [1, L = 2-(4',6'-difluorophenyl)pyridinato-N,C (dfppy); 2, L = 2-phenylpyridinato-N,C (ppy)] and [(L)Ir](dpp) [3, L = dfppy; 4, L = ppy] compared to monometallic complexes, (L)Ir-dpp (5, L = dfppy; 6, L = ppy) and dpp-PtCl (dpp-PtCl; 7). The single-crystal X-ray crystallographic structures of 1, 3, 5, and 6 showed that 1 and 3 have approximately coplanar structures of the dpp unit, while the noncoordinated pyridine ring of dpp in 5 and 6 is largely twisted with respect to the pyrazine ring. We found that the properties of the bimetallic complex significantly depended on the electronic and geometrical modulations of each fragment: (1) electronic structure of the main L (C^N) ligand in an iridium chromophore (L = dfppy or ppy) and (2) planarity of the bridging ligand (dpp). Their electrochemical and photophysical properties revealed that efficient electron-transfer processes predominated in the bimetallic systems regardless of the second metal participation. The low efficiencies of photoluminescence of dpp-bridged Ir-Pt and Ir-Ir bimetallic complexes (1-4) could be explained by assuming the involvement of crossing to platinum- and iridium-based d-d states from the emissive state. Such stereochemical and electronic situations around dpp allowed thermally activated crossing to platinum- and iridium-based d-d states from the emissive triplet metal-to-ligand charge-transfer (MLCT) state, followed by cleavage of the dpp-Pt and (L)Ir-dpp bonds. The transient absorption study further confirmed that the planarity of the dpp bridging ligand, which was defined as the magnitude of tilt between the pyridine ring and pyrazine, had a direct correlation with the degree of nonradiative decay from the emissive iridium-based MLCT to the Ir d-d or Pt d-d state, leading to photoinduced dissociation of bimetallic complexes. From the dissociation pattern of metal complexes analyzed after photoirradiation, we found that their dissociation pathways were directly related to the quenching direction (either Ir d-d or Pt d-d) with a significant dependency on the relativeMLCT levels of the (L)Ir-dpp component.

show abstract

Section: Inorganic Chemistrymentioning

confidence: 99%

Photophysics and Excited-State Properties of Cyclometalated Iridium(III)–Platinum(II) and Iridium(III)–Iridium(III) Bimetallic Complexes Bridged by Dipyridylpyrazine

et al. 2017

View full text Add to dashboard Cite

show abstract

ChemInform Abstract: SPECTROSCOPIC AND ELECTROCHEMICAL PROPERTIES OF THE DIMER TETRAKIS(2,2′‐BIPYRIDINE)(μ‐2,3‐BIS(2‐PYRIDYL)PYRAZINE)DIRUTHENIUM(II) AND ITS MONOMERIC ANALOG

Abstract: Durch Reaktion von cis‐Dichloro‐bis‐[2,2′‐bipyridyl]‐ruthenium(II) mit dem Pyrazinderivat in 95proz. EtOH bei Rückflußtemp.

Cited by 1 publication

References 1 publication

Photophysics and Excited-State Properties of Cyclometalated Iridium(III)–Platinum(II) and Iridium(III)–Iridium(III) Bimetallic Complexes Bridged by Dipyridylpyrazine

Photophysics and Excited-State Properties of Cyclometalated Iridium(III)–Platinum(II) and Iridium(III)–Iridium(III) Bimetallic Complexes Bridged by Dipyridylpyrazine

Contact Info

Product

Resources

About