Electronic spectra of tris(2,2′-bipyridyl) complexes—I

König, E.; Herzog, S.

doi:10.1016/0022-1902(70)80269-x

Cited by 101 publications

(22 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…14, 15 The two intense transitions at low energies can be assigned to LMCT by comparison with those found for [Cr(bipy) 3 ] 2ϩ in methanol (8700 cm Ϫ1 (ε = 10000 M Ϫ1 cm Ϫ1 ) and 9900 cm Ϫ1 (ε = 2900 M Ϫ1 cm Ϫ1 )). 14 The series of poorly resolved bands in the range 11000-24000 cm Ϫ1 correspond to overlapping d-d transitions possessing significant CT character and whose tentative assignments are given in Table 1. 14 Compared to [Cr(bipy) 3 ] 2ϩ , 14 the Cr IIcentred d-d transitions in (HHH)-[LnCrL 3 ] 2ϩ are of similar intensities, but are systematically shifted toward lower energies in agreement with the weaker ligand field produced by bidentate pyridylbenzimidazole (pybzim) binding units (10Dq = We conclude that low-spin Cr II is coordinated by three bidentate pyridylbenzimidazole segments in a trigonally-distorted pseudo-octahedral arrangement.…”

Section: Resultsmentioning

confidence: 99%

A kinetically inert and optically active CrIII partner in thermodynamically self-assembled heterodimetallic non-covalent d–f podates

Cantuel

Bérnardinelli²,

Imbert

et al. 2002

J. Chem. Soc., Dalton Trans.

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

A kinetically inert and optically active CrIII partner in thermodynamically self-assembled heterodimetallic non-covalent d–f podates

Cantuel

Bérnardinelli²,

Imbert

et al. 2002

J. Chem. Soc., Dalton Trans.

View full text Add to dashboard Cite

show abstract

“…Tris(bipyridine)chromium(III) perchlorate was prepared according to the published procedure (3) and the purity was checked by comparison with the reported UV-vis spectra (14). Deuterium oxide (99.9 atom % D) was obtained from Aldrich and was used as received.…”

Section: Methodsmentioning

confidence: 99%

Quantum yield of singlet dioxygen and elucidation of the quenching mechanism for the reaction between the doublet excited states of tris(bipyridine)chromium(III) and triplet dioxygen

Tiyabhorn¹,

Zahir²

1996

Can. J. Chem.

View full text Add to dashboard Cite

Abstract:The formation of singlet dioxygen (lo2) in the reaction between the doublet excited states of tris(bipyridine)chromium(III) and triplet dioxygen in deuterium oxide was detected using near-infrared luminescence corresponding to singlet dioxygen decay. In addition, luminescence intensity measurements were used to determine the quantum yield of singlet dioxygen produced. A value of 0.86 ? 0.08 was obtained for the yield of lo2. Based on these quantum yield measurements, it is proposed that the major quenching mode is energy transfer quenching. However, considering that the lo2 yield is less than unity and electron transfer quenching is not a viable pathway, it is proposed that, in addition to the energy transfer quenching, physical quenching involving spin-catalyzed deactivation of Cr(bpy),,+ may also be operative as a minor quenching pathway.Key words: Cr(bpy)33+, singlet dioxygen, quenching, quantum yield.Resume : Utilisant la luminescence infrarouge correspondant j. la dksactivation du dioxygkne singulet, on a dktectk la formation de dioxygkne singulet ('0,) au cours de la rkaction des Ctats doublement excitks du tris(bipyridine)chrome(III) et du dioxygkne triplet dans l'oxyde de deutkrium. De plus, on a utilisk des mesures d'intensitk de la luminescence pour dkterminer le rendement quantique du dioxygkne singulet produit. On a obtenu une valeur de 0,86 0,08 pour le rendement de lo2. Sur la base de ces mesures de rendements quantiques, il est proposk que le mode majeur de dksactivation soit un transfert d'knergie. Toutefois, si l'on considkre que le rendement en lo2 est plus petit que un et que la dksactivation par un transfert d'klectron n'est pas une voie rkactionelle viable, il est suggkrk que, en plus de la dksactivation par transfert d'knergie, la dksactivation physique impliquant une dksactivation du cr(bpy),,+ catalyske par le spin puisse aussi agir comme voie rnineure de dksactivation.

show abstract

“…65,42,43 The absorption spectrum of CrL ( Figure S41; Table S4) displays the expected ligand-centered high energy 1 π*←π bands (> 27000 cm -1 ; ε ≈ 10000-70000 Lmol -1 cm -1 ), some intense ligandto-metal charge transfer absorptions (LMCT; 25000-27000 cm -1 ; ε ≈ 5000-20000 Lmol -1 cm -1 ) and moderately intense ligand-centered spin-forbidden transitions 3 π*←π and metal-centered spin-allowed transition Cr III ( 4 T2← 4 A2) (20000-25000 cm -1 ; ε ≈ 100-5000 Lmol -1 cm -1 ). 39,114,115…”

Section: Photophysical Propertiesmentioning

confidence: 99%

Key Strategy for the Rational Incorporation of Long-Lived NIR Emissive Cr(III) Chromophores into Polymetallic Architectures

et al. 2020

View full text Add to dashboard Cite

The Cr III N6 chromophores are particularly appealing for low energy sensitization via energy transfer processes since they show extremely long excited state lifetime reaching millisecond range in the technologically crucial near-infrared domain. However, their properties were barely harnessed in multimetalic structures because of the lack of both monitoring methods and 2 accessible synthetic pathways. We herein report a remedy to monitor and control the formation of Cr III-containing assemblies in solution via the design of a Cr III N6 inert "complex-as-ligand" that can be included into polymetalic architectures. As a proof of concept, these CrN6 building blocks were reacted in solution with Zn II or Fe II to give extended trinuclear linear Cr-M-Cr assemblies, the structure of which could be addressed by NMR spectroscopy despite the presence of two slow relaxing Cr III paramagnetic centers. In addition to long Cr III excited state lifetimes and weak sensitivity to oxygen quenching, these polymetallic assemblies display controlled Cr III to M II energy transfers, which pave the way for use of the "complex-as-ligand" strategy for introducing photophysically active Cr III probes into light-converting polymetalic devices. General procedures, synthetic procedures, titration procedures and photophysical details are reported in the associated electronic supporting information ASSOCIATED CONTENT Supporting Information. The Supporting Information is available free of charge and contains synthetic procedures, NMR characterizations, NMR titration spectrum, ESI-HRMS characterization, crystallographic data, absorption and emission spectrum, list of transition band and list of emission lifetimes. The following files are available free of charge.

show abstract

Electronic spectra of tris(2,2′-bipyridyl) complexes—I

Cited by 101 publications

References 51 publications

A kinetically inert and optically active CrIII partner in thermodynamically self-assembled heterodimetallic non-covalent d–f podates

A kinetically inert and optically active CrIII partner in thermodynamically self-assembled heterodimetallic non-covalent d–f podates

Quantum yield of singlet dioxygen and elucidation of the quenching mechanism for the reaction between the doublet excited states of tris(bipyridine)chromium(III) and triplet dioxygen

Key Strategy for the Rational Incorporation of Long-Lived NIR Emissive Cr(III) Chromophores into Polymetallic Architectures

Contact Info

Product

Resources

About