The near-infrared spectrum of the guanidinium ion: a local-mode analysis

1992 ◽  
Vol 31 (20) ◽  
pp. 4122-4127 ◽  
Author(s):  
Ian M. Walker ◽  
Paul J. McCarthy
Keyword(s):  
Infrared Spectrum ◽  
Near Infrared ◽  
Mode Analysis ◽  
Local Mode ◽  
Local Mode Analysis ◽  
Near Infrared Spectrum

Single crystal polarized spectra in the near-infrared region: a local-mode analysis of the spectra of CsMnCl3•2X2O (X = H, D)

1994 ◽  
Vol 72 (5) ◽  
pp. 1211-1217 ◽  
Author(s):  
Ian M. Walker ◽  
Paul J. McCarthy
Keyword(s):  
Hydrogen Bond ◽  
Near Infrared ◽  
Infrared Region ◽  
Chloride Ions ◽  
Mode Analysis ◽  
Local Mode ◽  
Local Modes ◽  
Near Infrared Spectra ◽  
Parameter Values ◽  
Local Mode Analysis

Polarized near-infrared spectra of single crystals of CsMnCl3•2X2O (X = H, D) were recorded at 10 K. Those bands which could be assigned to O—H or O—D stretch overtones were analyzed using local-mode theory specifically adapted for systems having less than C2v symmetry. Both O—H oscillators form nearly linear hydrogen bonds to neighboring chloride ions at different distances. As a result, the local-mode harmonic frequency and anharmonicity parameters show characteristic shifts from their gas-phase values. The parameter values cover an unusually narrow range in this crystal, considering the spread in hydrogen-bond distances. Assignment of stretch overtone bands to specific oscillators in the crystal was made by using the polarization behavior expected of local modes in the oriented gas model. Several of the overtone bands show combinations with lattice modes or low-energy hydrogen-bond modes in unusual detail.

Single-crystal polarized spectra in the near-infrared region: a local-mode analysis of the spectra of M2MnCl4•2X2O (M = Cs, Rb; X = H, D)

1996 ◽  
Vol 74 (2) ◽  
pp. 246-253 ◽  
Author(s):  
Ian M. Walker ◽  
Paul J. McCarthy
Keyword(s):  
Hydrogen Bond ◽  
Single Crystal ◽  
Near Infrared ◽  
Infrared Region ◽  
Fermi Resonance ◽  
Mode Analysis ◽  
Local Mode ◽  
Bending Mode ◽  
Near Infrared Region ◽  
Local Mode Analysis

The polarized crystal spectra of M2MnCl4•2X2O (M = Cs, Rb; X = H, D) have been measured at 10 K in the near-infrared region. The data have been analyzed using a local-mode model that includes the bending mode. The resulting parameters are related to hydrogen bonding in the crystals. The spectra of partially deuterated species show a large number of bands due to HOD vibrations. The parameters from these spectra are compared to those from the H2O and D2O spectra. Arguments as to the importance of Fermi resonance in these spectra are presented. Key words: near-infrared, single crystal, hydrogen bond, Fermi resonance.

scholarly journals Nanopatterned metallic transparent electrodes for the near-infrared spectrum

AIP Advances ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 045005
Author(s):  
Aliaksandr Hubarevich ◽  
Mikita Marus ◽  
Yauhen Mukha ◽  
Aliaksandr Smirnov ◽  
Xiao Wei Sun
Keyword(s):  
Infrared Spectrum ◽  
Near Infrared ◽  
Transparent Electrodes ◽  
Near Infrared Spectrum

An electrically driven whispering gallery polariton microlaser

Nanoscale ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 5448-5459
Author(s):  
Mingming Jiang ◽  
Peng Wan ◽  
Kai Tang ◽  
Maosheng Liu ◽  
Caixia Kan
Keyword(s):  
Infrared Spectrum ◽  
Near Infrared ◽  
Whispering Gallery ◽  
Near Infrared Spectrum

An electrically driven whispering gallery polariton microlaser composed of a ZnO:Ga microwire and a p-GaAs template was fabricated. Its working characteristics of polariton lasing in the near-infrared spectrum were demonstrated.

scholarly journals Theoretical Simulation of Near-Infrared Spectrum of Piperine: Insight into Band Origins and the Features of Regression Models

2021 ◽  
pp. 000370282110279
Author(s):  
Justyna Grabska ◽  
Krzysztof B. Beć ◽  
Sophia Mayr ◽  
Christian W. Huck
Keyword(s):  
Infrared Spectrum ◽  
Regression Models ◽  
Near Infrared ◽  
Computing Time ◽  
Black Pepper ◽  
Partial Least Square ◽  
Least Square ◽  
Complex Nature ◽  
Chemical Information ◽  
Near Infrared Spectrum

We investigated the near-infrared spectrum of piperine using quantum mechanical calculations. We evaluated two efficient approaches, DVPT2//PM6 and DVPT2//ONIOM [PM6:B3LYP/6-311++G(2df, 2pd)] that yielded a simulated spectrum with varying accuracy versus computing time factor. We performed vibrational assignments and unveiled complex nature of the near-infrared spectrum of piperine, resulting from a high level of band convolution. The most meaningful contribution to the near-infrared absorption of piperine results from binary combination bands. With the available detailed near-infrared assignment of piperine, we interpreted the properties of partial least square regression models constructed in our earlier study to describe the piperine content in black pepper samples. Two models were compared with spectral data sets obtained with a benchtop and a miniaturized spectrometer. The two spectrometers implement distinct technology which leads to a profound instrumental difference and discrepancy in the predictive performance when analyzing piperine content. We concluded that the sensitivity of the two instruments to certain types of piperine vibrations is different and that the benchtop spectrometer unveiled higher selectivity. Such difference in obtaining chemical information from a sample can be one of the reasons why the benchtop spectrometer performs better in analyzing the piperine content of black pepper. This evidenced direct correspondence between the features critical for applied near-infrared spectroscopic routine and the underlying vibrational properties of the analyzed constituent in a complex sample.

Functional Classification of Feed Items in Pampa Grassland, Based on Their Near-Infrared Spectrum

2020 ◽  
Vol 73 (3) ◽  
pp. 358-367
Author(s):  
Júlio Cezar Rebés Azambuja Filho ◽  
Paulo Cesar de Faccio Carvalho ◽  
Olivier Jean François Bonnet ◽  
Denis Bastianelli ◽  
Magali Jouven
Keyword(s):  
Infrared Spectrum ◽  
Near Infrared ◽  
Functional Classification ◽  
Near Infrared Spectrum
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