Cooperativity in Amide Hydrogen Bonding Chains. A Comparison between Vibrational Coupling through Hydrogen Bonds and Covalent Bonds. Implications for Peptide Vibrational Spectra

2003 ◽  
Vol 107 (34) ◽  
pp. 6688-6697 ◽  
Author(s):  
Nadya Kobko ◽  
J. J. Dannenberg
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Vibrational Spectra ◽  
Amide Hydrogen ◽  
Covalent Bonds ◽  
Vibrational Coupling

Investigation of the Origin of Voltage Generation in Potentized Homeopathic Medicine through Raman Spectroscopy

Homeopathy ◽  
2019 ◽  
Vol 108 (02) ◽  
pp. 121-127 ◽  
Author(s):  
Tara Bhattacharya ◽  
Payaswini Maitra ◽  
Debbethi Bera ◽  
Kaushik Das ◽  
Poonam Bandyopadhyay ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Raman Spectroscopy ◽  
Hydrogen Bonding ◽  
Electrical Properties ◽  
Hydrogen Bonds ◽  
Vibrational Spectra ◽  
Strong Hydrogen Bond ◽  
Oh Groups ◽  
Homeopathic Medicine ◽  
Presence And Absence

Background For the study of homeopathic medicines in proper perspective, emerging techniques in material science are being used. Vibrational spectroscopy is one such tool for providing information on different states of hydrogen bonding as an effect of potentization. The associated change in electrical properties is also correlated with this effect. Objective From the vibrational spectra, the changes in hydrogen bonding due to dilution followed by unidirectional vigorous shaking (together termed potentization) of 91% ethanol and two homeopathic medicines Chininum purum and Acidum benzoicum have been studied. The aim was to correlate the result with the change in the electrical properties of the system. Methods Raman spectroscopy was used to study the vibrational spectra. A U-shaped glass tube (electrochemical cell), where one arm contained bi-distilled water and the other arm alcohol/homeopathic medicine (the arms being separated by a platinum foil), was used to measure the voltage generated across two symmetrically placed platinum electrodes. Results For all samples, it was observed that potentization affected the intensity of OH stretching bands at the frequencies 3240 cm−1, 3420 cm−1 and 3620 cm−1, corresponding to strong hydrogen bond, weak hydrogen bond and broken hydrogen bond, respectively. With the increase in potency, in the presence and absence of the two medicines in ethanol, the number of OH groups linked by strong hydrogen bonds decreased, while the number of OH groups with weak hydrogen bonds increased. With the increase in potentization, the number of OH groups with broken hydrogen bonds showed a difference in the presence and absence of the medicine.The voltage measurements for ethanol show that, with succussion, the magnitude of voltage increased with the two medicines at lower potencies, but not at higher potency where the voltage is lower. Acidum benzoicum, which is acidic in nature, had higher voltage values (113mV, 130 mV and 118 mV at 6C, 30C and 200C, respectively), compared with Chininum purum, which is basic in nature (20 mV, 85 mV and 65 mV at 6C, 30C and 200C, respectively). Conclusion The experimental results indicate a correlation between the vibrational and electrical properties of the homeopathic medicines Acidum benzoicum and Chininum purum at different potencies.

Crystalline structure and vibrational spectra of cis-dichlorodiammine-trans-dihydroxo- platinum(IV), PtCl2(NH3)2(OH)2

1982 ◽  
Vol 60 (4) ◽  
pp. 529-534 ◽  
Author(s):  
R. Faggiani ◽  
H. E. Howard-Lock ◽  
C. J. L. Lock ◽  
B. Lippert ◽  
B. Rosenberg
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystalline Structure ◽  
Vibrational Spectra ◽  
Platinum Atom ◽  
X Ray Diffraction ◽  
Standard Methods ◽  
X Ray ◽  
Cell Dimensions

The structure of cis-dichlorodiammine-trans-dihydroxoplatinum(IV), PtCl2(OH)2(NH3)2, has been determined by X-ray diffraction. The tetragonal space group, P42/n has cell dimensions a = 7.328(4), c = 11.362(5) Å and has four formula units in the cell. Intensities were measured using MoKα radiation and a Syntex P21 diffractometer. The crystal structure was determined by standard methods and refined to R1 = 0.0460, R2 = 0.0639 based on 447 independent reflections. The platinum atom has roughly octahedral coordination and Pt—Cl, Pt—N, Pt—O distances (2.306(4), 2.00(1), 2.00(1) Å) are normal. The crystal is held together by hydrogen bonds, and the vibrational spectra have been correlated with observed features of the hydrogen bonding.

scholarly journals Hydrogen Bonds: Raman Spectroscopic Study

2021 ◽  
Vol 22 (10) ◽  
pp. 5380
Author(s):  
Boris A. Kolesov
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Spectroscopic Study ◽  
Raman Spectra ◽  
Temperature Region ◽  
Vibrational Frequency ◽  
Chemical Compounds ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
Proton Dynamics

The work outlines general ideas on how the frequency and the intensity of proton vibrations of X–H×××Y hydrogen bonding are formed as the bond evolves from weak to maximally strong bonding. For this purpose, the Raman spectra of different chemical compounds with moderate, strong, and extremely strong hydrogen bonds were obtained in the temperature region of 5 K–300 K. The dependence of the proton vibrational frequency is schematically presented as a function of the rigidity of O-H×××O bonding. The problems of proton dynamics on tautomeric O–H···O bonds are considered. A brief description of the N–H···O and C–H···Y hydrogen bonds is given.

Synthesis, crystal and molecular structure, and vibrational spectra of the complex (COOH)2•2H2O•18-crown-6

1986 ◽  
Vol 64 (1) ◽  
pp. 142-147 ◽  
Author(s):  
Suzanne Deguire ◽  
François Brisse ◽  
Jacques Ouellet ◽  
Rodrigue Savoie
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Oxalic Acid ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Crystal And Molecular Structure ◽  
Unit Cell ◽  
Infrared And Raman Spectra ◽  
O 18 ◽  
Stoichiometric Complex

A stoichiometric complex of formula (COOH)2•2H2O•18-crown-6 has been obtained from oxalic acid and the macrocyclic polyether 18-crown-6. The crystals of the complex have a monoclinic unit cell and belong to the P21/c space group. The components in the adduct are linked through hydrogen bonds in a polymer-like fashion: -crown–H2O–HOOCCOOH–OH2–crown–, where the oxalic acid molecules are present in two distinct disordered orientations. The infrared and Raman spectra of the complex are also reported and interpreted.

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