Highly selective colorimetric fluorescence sensor for Cu2+: cation-induced ‘switching on’ of fluorescence due to excited state internal charge transfer in the red/near-infrared region of emission spectra

2010 ◽  
Vol 51 (42) ◽  
pp. 5563-5566 ◽  
Author(s):  
Shyamaprosad Goswami ◽  
Debabrata Sen ◽  
Nirmal Kumar Das ◽  
Giridhari Hazra
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Near Infrared ◽  
Emission Spectra ◽  
Infrared Region ◽  
Fluorescence Sensor ◽  
Near Infrared Region ◽  
Internal Charge Transfer ◽  
Internal Charge

Schwingungs-und Elektronenspektren der bindungsisomeren Hexakis(thiocyanato(N)-thiocyanato(S))-osmate(III) und (IV) / Vibrational and Electronic Spectra of Bond-Isomeric Hexakis(thiocyanato(N)-thiocyanato(S))osmates(III) and (IV)

1988 ◽  
Vol 43 (4) ◽  
pp. 371-381 ◽  
Author(s):  
K. Bütje ◽  
W. Preetz
Keyword(s):  
Charge Transfer ◽  
Vibrational Spectra ◽  
Near Infrared ◽  
Bathochromic Shift ◽  
Infrared Region ◽  
Hypsochromic Shift ◽  
Linkage Isomers ◽  
Near Infrared Region ◽  
Ir And Raman ◽  
Metal Ligand

AbstractWell-resolved IR and Raman spectra of the two sets of all 10 isomeric complexes [Os(NCS)n(SCN)6-n]3-/2-, n = 0-6, have been recorded. For both series, νCS(N) > νCS(S) and δNCS > δSCN; for the Os(III) complexes, vCN(N) ~ vCN(S) and vOsN ≥ vOsS while for the Os(IV) compounds, vCN(N) < vCN(S) and vOsN ~ vOsS. The vibrational spectra of the n = 0 and n = 6 members of both sets are assigned according to D3d and Oh point symmetry, respectively. For the mixed linkage isomers the band pattern is strongly influenced by pseudo-octahedral coupling wherever frequencies of N- and S-bonded groups coincide. The metal-ligand stretching region is therefore assigned according rather to pseudo-Oh, pseudo-D3d and pseudo-D4h symmetry than to D4h, C4v, C3v and C2v microsymmetry. The charge-transfer spectra of both series are similar, showing a parallel hypsochromic shift with increasing n value. Upon oxidation, a bathochromic shift of the CT bands by an average of 5400 cm-1 is observed, and the intensity increases by a factor 2-2.5. Weak absorptions in the near infrared region are assigned to intraconfigurational transitions.

Charge-transfer complexes of dinuclear ruthenium compounds/polyoxometalates for multistate electrochromism covering ultraviolet, visible, and near-infrared region

2017 ◽  
Vol 5 (26) ◽  
pp. 6442-6449 ◽  
Author(s):  
Dandan Chong ◽  
Xinhua Wan ◽  
Jie Zhang
Keyword(s):  
Charge Transfer ◽  
Near Infrared ◽  
Infrared Region ◽  
Charge Transfer Complexes ◽  
Ruthenium Compounds ◽  
Dinuclear Ruthenium ◽  
Near Infrared Region ◽  
Full Absorption

Novel charge-transfer electrostatic complexes between the anionic polyoxometalates and cationic dinuclear ruthenium compounds display the full absorption covering ultraviolet, visible, and near-infrared region.

Femtosecond Excited State Studies of the Two-Center Three-Electron Bond Driven Twisted Internal Charge Transfer Dynamics in 1,8-Bis(dimethylamino)naphthalene

2005 ◽  
Vol 109 (16) ◽  
pp. 3535-3541 ◽  
Author(s):  
Grzegorz Balkowski ◽  
Anna Szemik-Hojniak ◽  
Ivo H. M. van Stokkum ◽  
Hong Zhang ◽  
Wybren J. Buma
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Charge Transfer Dynamics ◽  
Internal Charge Transfer ◽  
Internal Charge

1,3,5-Triarylpyrazolines — pH-driven off-on-off molecular logic devices based on a “receptor1-fluorophore-spacer-receptor2” format with internal charge transfer (ICT) and photoinduced electron transfer (PET) mechanisms

2015 ◽  
Vol 93 (2) ◽  
pp. 199-206 ◽  
Author(s):  
Ramon Zammit ◽  
Maria Pappova ◽  
Esther Zammit ◽  
John Gabarretta ◽  
David C. Magri
Keyword(s):  
Electron Transfer ◽  
Excited State ◽  
Charge Transfer ◽  
Photoinduced Electron Transfer ◽  
Photophysical Properties ◽  
Molecular Probes ◽  
Quantum Yields ◽  
Ph Sensing ◽  
Internal Charge Transfer ◽  
Internal Charge

The excited state photophysical properties of the 1,3,5-triarylpyrazolines 1–4 were studied in methanol and 1:1 (v/v) methanol–water, as well as 1:4 (v/v) methanol–water and water by fluorescence spectroscopy. The molecules 2–4 incorporate a “receptor1-fluorophore-spacer-receptor2” format while 1 is a reference compound based on a “fluorophore-receptor1” design. The molecular probes operate according to photoinduced electron transfer (PET) and internal charge transfer (ICT) processes. At basic and neutral pHs, 2–4 are essentially nonfluorescent due to PET from the electron-donating dimethylamino moiety appended on the 5-phenyl ring to the excited state of the 1,3,5-triarylpyrazoline fluorophore. At proton concentrations of 10−3 mol/L, the dimethylamino unit is protonated resulting in a strong blue fluorescence about 460 nm with significant quantum yields up to 0.54. At acid concentrations above 10−2 mol/L, fluorescence quenching is observed by an ICT mechanism due to protonation of the pyrazoline chromophore. Symmetrical off-on-off fluorescence–pH profiles are observed, spanning six log units with a narrow on window within three pH units. Hence, 2–4 are novel examples of ternary photonic pH sensing molecular devices.

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