scholarly journals OS100: A Benchmark Set of 100 Digitized UV–Visible Spectra and Derived Experimental Oscillator Strengths

2022 ◽  
Author(s):  
Astrid S. Tarleton ◽  
Jorge C. Garcia-Alvarez ◽  
Anah Wynn ◽  
Cade M. Awbrey ◽  
Tomas P. Roberts ◽  
...  
Keyword(s):  
Oscillator Strengths ◽  
Visible Spectra ◽  
Uv Visible

scholarly journals OS100: A Benchmark Set of 100 Digitized UV-Visible Spectra and Derived Experimental Oscillator Strengths

2021 ◽  
Author(s):  
Astrid Tarleton ◽  
Jorge Garcia-Alvarez ◽  
Anah Wynn ◽  
Cade Awbrey ◽  
Tomas Roberts ◽  
...  
Keyword(s):  
Density Functional ◽  
Oscillator Strengths ◽  
Learning Approaches ◽  
Excitation Energies ◽  
Absorption Bands ◽  
Visible Absorption ◽  
Plain Text ◽  
Solvent Model ◽  
Visible Spectra ◽  
Uv Visible

Excited-state quantum chemical calculations typically report excitation energies and oscillator strengths, ƒ, for each electronic transition. On the other hand, UV-visible spectrophotometric experiments report energy-dependent molar extinction/attenuation coefficients, ε(v), that determine the absorption band line shapes. ε(v) and ƒ are related, but this relation is complicated by various broadening and solvation effects. We fit and integrated experimental UV-visible spectra to obtain ƒexp values for absorption bands and estimated the uncertainty in the fitting. We derived 164 ƒexp values from 100 organic molecules ranging in size from 6-34 atoms. The corresponding computed oscillator strengths (ƒcomp) were obtained with time-dependent density functional theory and a polarizable continuum solvent model. By expressing experimental and computed absorption strengths using a common quantity, we directly compared ƒcomp and ƒexp. While ƒcomp and ƒexp are well correlated (linear regression R2=0. 921), ƒcomp in most cases significantly overestimates ƒexp (regression slope=1.34). The agreement between absolute ƒcomp and ƒexp values was substantially improved by accounting for a solvent refractive index factor, as suggested in some derivations in the literature. The 100 digitized UV-visible spectra are included as plain text files in the supporting information to aid in benchmarking computational or machine-learning approaches that aim to simulate realistic UV-visible absorption spectra.

scholarly journals OS100: A Benchmark Set of 100 Digitized UV-Visible Spectra and Derived Experimental Oscillator Strengths

2021 ◽  
Author(s):  
Astrid Tarleton ◽  
Jorge Garcia-Alvarez ◽  
Anah Wynn ◽  
Cade Awbrey ◽  
Tomas Roberts ◽  
...  
Keyword(s):  
Density Functional ◽  
Oscillator Strengths ◽  
Learning Approaches ◽  
Excitation Energies ◽  
Absorption Bands ◽  
Visible Absorption ◽  
Plain Text ◽  
Solvent Model ◽  
Visible Spectra ◽  
Uv Visible

The scientific method involves validating computational theories and methods against experimental results. However, the comparison between theory and experiments is not always straightforward; in UV-visible spectroscopy, experiments provide a plot of wavelength-dependent molar extinction/attenuation coefficients (ε) while computations typically provide single-valued excitation energies and oscillator strengths (ƒ) for each band. ε and ƒ are related, but this relation is complicated by various broadening and solvation effects. We describe a protocol to fit and integrate experimental UV-visible spectra to obtain ƒexp values for absorption bands and to estimate the uncertainty in the fitting. We apply this protocol to derive 164 ƒexp values from 100 organic molecules ranging in size from 6-34 atoms. The corresponding computed oscillator strengths (ƒcomp) are obtained with time-dependent density functional theory and a polarizable continuum solvent model. By expressing experimental and computed absorption strengths using a common quantity, we directly compare ƒcomp and ƒexp. While ƒcomp and ƒexp are well correlated (linear regression R2=0. 914), ƒcomp in most cases significantly overestimates ƒexp (regression slope=1.31). The agreement between absolute ƒcomp and ƒexp values is substantially improved by accounting for a solvent refractive index factor, as suggested in some derivations in the literature. The 100 digitized UV-visible spectra are included as plain text files in the supporting information to aid in benchmarking computational or machine-learning approaches that aim to simulate realistic UV-visible absorption spectra.

Infrared and UV-visible spectra of layer semiconductors Gas, GaSe and GaTe

1977 ◽  
Vol 38 (10) ◽  
pp. 1293-1299 ◽  
Author(s):  
U. Giorgianni ◽  
G. Mondio ◽  
P. Perillo ◽  
G. Saitta ◽  
G. Vermiglio
Keyword(s):  
Visible Spectra ◽  
Uv Visible

Effect of NO2 substitution and solvent on UV-visible spectra, redox potentials and electron transfer mechanisms of copper β-nitrotriarylcorroles. Proposed electrogeneration of a Cu(I) oxidation state

2016 ◽  
Vol 20 (07) ◽  
pp. 753-765 ◽  
Author(s):  
Lina Ye ◽  
Zhongping Ou ◽  
Yuanyuan Fang ◽  
Yang Song ◽  
Bihong Li ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Soret Band ◽  
Redox Potentials ◽  
Nonaqueous Media ◽  
Initial Assignment ◽  
Visible Spectra ◽  
Phenyl Rings ◽  
Uv Visible ◽  
Electron Reduction ◽  
Transfer Mechanisms

Three copper triarylcorroles containing a [Formula: see text]-pyrrole nitro substituent were synthesized and characterized as to their spectral and electrochemical properties in nonaqueous media. The examined compounds are represented as [Formula: see text]-NO2(YPh)3CorCu, where Cor is the trianion of a triphenylcorrole and Y is a Cl, H or CH3 substituent at the para-position of the three meso-phenyl rings of the compound. The data from absorption spectra, electrochemistry and thin-layer spectroelectrochemistry are consistent with an initial assignment of Cu[Formula: see text]-Cor[Formula: see text] in CH2Cl2, DMF and pyridine and electrogeneration of a formal Cu(II) corrole with an unreduced macrocycle, represented as Cu[Formula: see text]-Cor[Formula: see text], after the first one-electron reduction in these solvents. The doubly reduced [Formula: see text]-nitrocorrole has a sharp Soret band at 439 nm and a well-defined Q-band at 611 nm in CH2Cl2. Similar absorption spectra are seen for the three examined doubly reduced nitrocorroles in DMF and pyridine, suggesting formation of a Cu(I) species with an unreduced macrocycle which is represented as Cu[Formula: see text]-Cor[Formula: see text]. Changes in redox potentials and absorption spectra of the nitrocorroles are examined as a function of solvent and substituents on the meso-phenyl rings of the compounds and comparisons are made between spectral and electrochemical data of the newly synthesized corroles and that of structurally related tetraarylcorroles lacking a [Formula: see text]-nitro group.

scholarly journals Synthesis, Characterization, and Biological Studies of a Piperidinyl Appended Dipicolylamine Ligand and Its Rhenium Tricarbonyl Complex as Potential Therapeutic Agents for Human Breast Cancer

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Amali Subasinghe ◽  
Inoka C. Perera ◽  
Svetlana Pakhomova ◽  
Theshini Perera
Keyword(s):  
Breast Cancer ◽  
Anticancer Agents ◽  
Human Breast Cancer ◽  
Human Breast ◽  
Tricarbonyl Complex ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Biological Studies ◽  
Visible Spectra ◽  
Uv Visible

A novel ligand bearing a central piperidinyl sulfonamide group, N(SO2pip)dpa, and its corresponding Re tricarbonyl complex, [Re(CO)3(N(SO2pip)dpa)]+, have been synthesized in good yield. The methylene CH2signal seen as a singlet (4.54 ppm) in a1H NMR spectrum of the ligand in DMSO-d6appears as two doublets (5.39, 5.01 ppm) in a spectrum of the [Re(CO)3(N(SO2pip)dpa)]+complex and confirms the presence of magnetically nonequivalent protons upon coordination to Re. Structural results revealed that the Re–N bond lengths fall within the normal range establishing coordination of ligand to metal. The presence of intraligandπ→π⁎andn→π⁎transitions is indicated by the absorption peaks around 200–250 nm in UV-visible spectra. Absorption peaks in UV-visible spectra around 300 nm for metal complexes were identified as MLCT transitions. The S–N stretch observed as a strong peak at 923 cm−1for N(SO2pip)dpa appeared at a shorter frequency, at 830 cm−1in an FTIR spectrum of the [Re(CO)3(N(SO2pip)dpa)]+. The intense fluorescence displayed by the N(SO2pip)dpa ligand has quenched upon coordination to Re. Relatively low IC50values given by human breast cancer cells, MCF-7, (N(SO2pip)dpa = 139 μM, [Re(CO)3(N(SO2pip)dpa)]+= 360 μM) indicate that N(SO2pip)dpa and [Re(CO)3(N(SO2pip)dpa)]+are promising novel compounds that can be further investigated on their usage as potential anticancer agents.

scholarly journals X-Ray, IR, NMR, UV-visible spectra and DFT analysis of 5-aryloxy-(1H)-tetrazoles, structure, conformation and tautomerism

2014 ◽  
Vol 3 (2) ◽  
pp. 85-96 ◽  
Author(s):  
Nader Noroozi Pesyan ◽  
Sadeghali Bavafa ◽  
Mohammad Samim Enayati ◽  
Sajedin Hoseinpour ◽  
Narges Ostadhosseini ◽  
...  
Keyword(s):  
X Ray ◽  
Visible Spectra ◽  
Uv Visible

The use of derivatives and chemometrics to interrogate the UV–Visible spectra of gin samples to monitor changes related to storage

2020 ◽  
Vol 227 ◽  
pp. 117548
Author(s):  
Nivetha Govindaraj ◽  
Sheeana Gangadoo ◽  
Vi Khanh Truong ◽  
James Chapman ◽  
Harsharn Gill ◽  
...  
Keyword(s):  
Visible Spectra ◽  
Uv Visible

Experimental and Theoretical Study of the High-Temperature UV–Visible Spectra of Aqueous Hydroquinone and 1,4-Benzoquinone

2016 ◽  
Vol 120 (40) ◽  
pp. 10547-10552 ◽  
Author(s):  
Fereshteh Samiee ◽  
Federico N. Pedron ◽  
Dario A. Estrin ◽  
Liliana Trevani
Keyword(s):  
High Temperature ◽  
Theoretical Study ◽  
Visible Spectra ◽  
Uv Visible
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