Hydrogen bond dynamics and water structure in glucose-water solutions by depolarized Rayleigh scattering and low-frequency Raman spectroscopy

2007 ◽  
Vol 127 (2) ◽  
pp. 024504 ◽  
Author(s):  
Marco Paolantoni ◽  
Paola Sassi ◽  
Assunta Morresi ◽  
Sergio Santini
2011 ◽  
Vol 75 (2) ◽  
pp. 379-394 ◽  
Author(s):  
T. Armbruster ◽  
B. Lazic ◽  
F. Gfeller ◽  
E. V. Galuskin ◽  
I. O. Galuskina ◽  
...  

AbstractDellaite crystals of close to end-member composition, Ca6(Si2O7)(SiO4)(OH)2, and with ∼1.5 wt.% Cl. yielding Ca6(Si2O7)(SiO4)(OH)1.75Cl0.25 have been found in skarns within the gabbroid rocks of the Birkhin complex (Eastern Siberia, Russia). The greatest Cl content analysed in a dellaite domain in this skarn is 5.2 wt.% Cl corresponding to 0.8 Cl p.f.u. Dellaite occurs in altered merwmite-larnite-bredigite-gehlenite skarns and also in calcio-olivine skarns with residual larnite. The crystal structures of Cl-free and Cl-bearing (∼1.5 wt.% Cl) dellaite have been refined, including hydrogen positions, from single-crystal X-ray data to R1 = 3.7 and 3.8%, respectively. In addition, both dellaite varieties were studied by Raman spectroscopy indicating stronger hydrogen bonds for the Cl-bearing sample, which agrees with the structural data. Cl is strongly selective and enriches at one (O6) of the two OH positions allowing for the formation of a stronger hydrogen bond O8—H8…C16 compared to O8—H8…O6. Raman spectra of the domain with ∼0.8 Cl p.f.u. confirm the general enhancement of a low-frequency band in the OH range suggesting the dominance of the O—H…Cl hydrogen bond systems.Dellaite and killalaite, Ca3.2(H0.6Si2O7)(OH), have related modular structures, differentiated only by the Si2O7 units in killalaite and alternating Si2O7 and SiO4 units in dellaite. The similarity in cell dimensions and chemical composition suggests that trabzonite, Ca4Si3Oi0-2H2O, with Si3Oi0 trimers also belongs to the same family of structures.


Author(s):  
O. Faurskov Nielsen ◽  
D. H. Christensen ◽  
C. Trandum ◽  
M. Gniadecka ◽  
H. C. Wulf

2010 ◽  
Vol 114 (32) ◽  
pp. 10628-10633 ◽  
Author(s):  
Francesco D’Amico ◽  
Filippo Bencivenga ◽  
Alessandro Gessini ◽  
Claudio Masciovecchio

1973 ◽  
Vol 27 (1) ◽  
pp. 22-26 ◽  
Author(s):  
S. M. Craven ◽  
F. F. Bentley ◽  
D. F. Pensenstadler

The low frequency infrared spectra from 450 to 75 cm−1 of seven oximes and five aldoximes have been recorded for pure samples and for dilute solutions in cyclohexane. An intense characteristic band is present in the solution spectra at 367 ± 10 cm−1. This characteristic band shifts to 275 ± 10 cm−1 in the spectra of the OD compounds. The 367 ± 10 cm−1 and 275 ± 10 cm−1 bands are assigned to OH and OD torsional vibrations. A comparison of the solution spectra with spectra of the solid samples indicated that the OH … N hydrogen bond stretch of oximes and aldoximes occurs in 300 to 200 cm−1 region. Strong bands also are present in 140 to 100 cm−1 region which are due to OH … N bending modes or perhaps lattice vibrations.


Author(s):  
Saurav Arora

Until few years, the so-called implausible science, homeopathy, was on the verge of being rejected on conventional physicochemical grounds. The mere selection of ultrahigh dilutions (UHD) (homeopathic potencies) for experimentation by mainstream scientists seemed impossible, but the curiosity to explore the science behind homeopathy kept igniting intellectual alma mater who subjected homeopathy to laboratories and test tubes, to know beyond its clinical application. Still, there exist a huge gap and a challenge to convince a conventional scientist to go beyond his domains and look for something which is apparently invisible (beyond Avogadro). But gradually we are overcoming this dogma and exploring the finer aspects and applications of UHDs. Much research has been undertaken, at least, to protect the identity of UHDs, and we are now verge of proving the plausibility of homeopathy from every aspect. This issue of International Journal of High Dilution Research features two interesting articles on nature of UHDs and their unconventional application. The first article by NC Sukul et al aimed to decipher the nature of the water structure of UHDs of two commonly used homeopathic drugs Natrum muriaticum and Sulphur by Laser Raman Spectroscopy. This work is in the series undertaken by the group, who earlier experimented using Nuclear Magnetic Resonance; Electronic, Vibrational and Raman spectroscopy to shown differences in UHDs of various drugs. The present experiment could differentiate the intensities (potencies) of Nat-m and Sulph when compared to their controls, on the basis of hydrogen bond strength and free OH groups. The second article by Nandy et al proposes a new dimension to the application of UHD. In an interesting manner, the author used UHDs of Ferrum metallicum and Zincum oxidatum to improve the electrical properties of the electroactive Poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP). The PVDF-HFP composite films were synthesized in their usual way, but an incorporation of Ferrum and Zinc-o could make the film as homeo-PVDF-composite. This enhancement of the electrical properties and are possibly due to the presence of nanoparticle, as hypothesized by the group. The nature and application of UHDs are promising but challenging areas, which can only be validated through extensive research and validation. The realm of UHDs is expanding, and the day is not far when plausibility of homeopathy would be proved from every aspect, but at the same time we should also keep the momentum of research at pace in clinical research too!


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