The unreliability of association constants or organic charge-transfer complexes derived from optical absorption spectra—I

Tetrahedron ◽  
1965 ◽  
Vol 21 (10) ◽  
pp. 2843-2849 ◽  
Author(s):  
P.H. Emslie ◽  
R. Foster ◽  
C.A. Fyfe ◽  
I. Horman
Keyword(s):  
Charge Transfer ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Association Constants ◽  
Charge Transfer Complexes ◽  
Optical Absorption Spectra

scholarly journals Энергетический спектр и оптическое поглощение эндоэдральных комплексов Er-=SUB=-2-=/SUB=-C-=SUB=-2-=/SUB=-@C-=SUB=-90-=/SUB=- на основе изомеров N 21 и N 44

2021 ◽  
Vol 129 (9) ◽  
pp. 1111
Author(s):  
А.И. Мурзашев ◽  
А.П. Жуманазаров ◽  
М.Ю. Кокурин
Keyword(s):  
Experimental Data ◽  
Charge Transfer ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Coulomb Interaction ◽  
Energy Spectra ◽  
Optical Absorption Spectra ◽  
Endohedral Complexes

The article simulates the optical absorption spectra (OAS) of endohedral complexes Er2C2 @ C90 based on isomers No. 44 (C2) No. 21 (C1) of fullerene C90. For this purpose, the energy spectra of the indicated isomers have been calculated. The calculation was carried out within the framework of two models. Within the framework of the first model, which is traditional, only hops of π-electrons from site to site were taken into account (the integral of hopping to the nearest sites B ~ -2.6 eV). Within the framework of the second model, developed in a series of our works [1-5], in addition to hopping from site to site (the integral of hopping to the nearest sites B ~ -1.0 eV), the intrasite Coulomb interaction (ICCI) of π-electrons was also taken into account (the integral of the Coulomb interaction U ~ 7.0 eV). Comparison of the OSS curves obtained by us with the experimental data [5] convincingly indicates that the second model adequately describes the OSS of the endohedral Er2C2 @ C90 complexes based on the investigated isomers. The magnitude of charge transfer from the Er2C2 system to the fullerene shell turned out to be -4e.

scholarly journals Theoretical Insight into the Spectral Characteristics of Fe(II)-Based Complexes for Dye-Sensitized Solar Cells—Part I: Polypyridyl Ancillary Ligands

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaoqing Lu ◽  
Shuxian Wei ◽  
Chi-Man Lawrence Wu ◽  
Ning Ding ◽  
Shaoren Li ◽  
...  
Keyword(s):  
Solar Cells ◽  
Charge Transfer ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Dye Sensitized Solar Cells ◽  
Optical Absorption Spectra ◽  
Ancillary Ligands ◽  
Dye Sensitized ◽  
Ligand Charge Transfer ◽  
Sensitized Solar Cells

The design of light-absorbent dyes with cheaper, safer, and more sustainable materials is one of the key issues for the future development of dye-sensitized solar cells (DSSCs). We report herein a theoretical investigation on a series of polypyridyl Fe(II)-based complexes of FeL2(SCN)2, [FeL3]2+, [FeL′(SCN)3]-, [FeL′2]2+, and FeL′′(SCN)2(L = 2,2′-bipyridyl-4,4′-dicarboxylic acid, L′ = 2,2′,2″-terpyridyl-4,4′,4″-tricarboxylic acid, L″= 4,4‴-dimethyl-2,2′ : 6′,2″ :6″,2‴-quaterpyridyl-4′,4″-biscarboxylic acid) by density functional theory (DFT) and time-dependent DFT (TD-DFT). Molecular geometries, electronic structures, and optical absorption spectra are predicted in both the gas phase and methyl cyanide (MeCN) solution. Our results show that polypyridyl Fe(II)-based complexes display multitransition characters of Fe → polypyridine metal-to-ligand charge transfer and ligand-to-ligand charge transfer in the range of 350–800 nm. Structural optimizations by choosing different polypyridyl ancillary ligands lead to alterations of the molecular orbital energies, oscillator strength, and spectral response range. Compared with Ru(II) sensitizers, Fe(II)-based complexes show similar characteristics and improving trend of optical absorption spectra along with the introduction of different polypyridyl ancillary ligands.

Optical absorption spectra of ultrathin PTCDA films on gold single crystals: Charge transfer beyond the first monolayer

2009 ◽  
Vol 10 (8) ◽  
pp. 1448-1453 ◽  
Author(s):  
Roman Forker ◽  
Christian Golnik ◽  
Giovanni Pizzi ◽  
Thomas Dienel ◽  
Torsten Fritz
Keyword(s):  
Charge Transfer ◽  
Optical Absorption ◽  
Single Crystals ◽  
Absorption Spectra ◽  
Optical Absorption Spectra

Poling behavior of optical absorption spectra in carbazoles with one‐ and two‐dimensional charge‐transfer character

1996 ◽  
Vol 104 (7) ◽  
pp. 2467-2475 ◽  
Author(s):  
Takashi Isoshima ◽  
Tatsuo Wada ◽  
Ya‐Dong Zhang ◽  
Eddy Brouyère ◽  
Jean‐Luc Brédas ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Two Dimensional ◽  
Optical Absorption Spectra

scholarly journals Optical and Luminescence Spectroscopy of Varicolored Gem Spinel from Mogok, Myanmar and Lục Yên, Vietnam

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 169
Author(s):  
Iveta Malíčková ◽  
Peter Bačík ◽  
Jana Fridrichová ◽  
Radek Hanus ◽  
Ľudmila Illášová ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Optical Spectrum ◽  
Optical Spectra ◽  
Luminescence Spectroscopy ◽  
Optical Absorption Spectra

We studied 12 crystal fragments of natural spinel from Mogok, Myanmar and Lục Yên, Vietnam. All samples were crystal fragments of various shapes and sizes and several of them had gemological quality. Studied samples are enriched in Cr, V, Fe2+, Fe3+, Zn, which are responsible for its resulting color. They could be divided into groups of V-Cr spinels with Cr 0.001–0.006 apfu, V 0.001–0.004 apfu, and Fe spinels containing increased Fe2+ (0.001–0.017 apfu) and Fe3+ (0.004–0.012 apfu). Some samples show luminescence bands at 677, 685, 697, 710, and 718 nm assigned to Cr3+. The optical absorption spectra of spinels were divided into two groups of V-Cr and Fe spinels based on the dominant element acting on optical spectra. The optical spectrum of V-Cr spinels can be divided into two zones (1) 420–550 nm (V3+ and Cr3+ absorption); (2) 640–1000 nm (Fe2+-Fe3+ charge transfer). The optical absorption spectra of Fe spinels can also be divided into two zones (1) 410–650 nm (Fe2+-Fe3+ charge transfer) and (2) 770–1000 nm (Fe2+). This variation in chromophores results in the differences in color: V-Cr spinels are pink to red, Fe spinels are in shades of blue as well as yellow and pink.

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