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Wpływ jonów SiO4 4- na strukturę chemiczną oraz właściwości fizyko-chemiczne syntetycznego nanokrystalicznego hydroksyapatytu

Kolmas J., Przybylski A., Pajchel Ł., Kołodziejski W.

Engineering of Biomaterials

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2011

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Vol. 14, no. 106-108

54--61

PL

W pracy przedstawiono badania struktury chemicznej oraz morfologii nanokrystalicznych hydroksyapatytów: niedomieszkowanego oraz domieszkowanego jonami krzemianowymi SiO 4 4- . Próbki do badań uzyskano niekonwencjonalną techniką chemicznej kondensacji w fazie gazowej z wykorzystaniem niskociśnieniowego płomienia (CCVC). Do badań zastosowano mikroskopię elektronową TEM i SEM oraz metody spektroskopii NMR i IR w ciele stałym. Stwierdzono istotny wpływ jonów krzemianowych na strukturę chemiczną hydroksyapatytu.

EN

This paper reports a systematic investigation on Si-substituted and unsubstituted synthetic hydroxyapatites produced by the NanoSpray TM and combustion chemical vapor condensation (CCVC) process. The studies were focused on structural properties, crystal morphology and chemical composition of the samples. Various analytical methods, such as electron microscopy, high-resolution solid-state nuclear magnetic resonance (NMR) and infrared spectroscopy were used. A significant effect of silicate ions on the hydroxyapatite structure was found.

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Badania polimorfizmu związków bioorganicznych metodami spektroskopii NMR w fazie stałej

Kaźmierski S., Potrzebowski M.J.

Wiadomości Chemiczne

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2006

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[Z] 60, 11-12

723-745

EN

Polymorphism is one of the most important and amazing phenomenon in structural chemistry. The knowledge of this phenomenon is crucial both in experimental sciences (e.g.: chemistry, physics and crystallography) and in industry - especially in pharmaceutical industry. It is well known, that polymorphic forms of therapeutic compounds differ in their bioavailability - e.g. the rate of dissolution and equilibrium solubility. In extreme cases, one polymorph may be a medicine whilst the second may be very dangerous or even poisonous. In this light, the possibility to distinguish the desirable form of compound from the useless form, seems to be very important. In our article, some problems concerning the investigation of polymorphism phenomenon by applications of solid-state NMR are presented. The possibilities of current NMR techniques in searching of polymorphism as well as the practical aspects and applications are presented and discussed.

3

29Si and 13C Solid State NMR as a Tool to Study Thermal Processes in Epoxy-Silica Hybrids

Potrzebowski M., Ciesielski W., Ganicz K., Głuszek J., Szczygieł B, Kucharczyk B., Masalski J.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 7

1185-1194

EN

29Si CP/MAS and 13C CP/MAS measurements were carried out for epoxy-silica hybrids treated at 200 graduate C and 300 graduateC. For each sample, the 29Si spin lattice relaxation time was evaluated and compared with the corresponding values for reference samples prepared under the same conditions but without epoxy compound. This work clearly shows the sensitivity of the 29Si T1 to the morphology of composite materials. The mechanism of thermal decomposition is proposed on the basis of 13C CP/MAS experiments and analysis of changes of the 29Si T1 relaxation time.

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13C and 23Na Solid-State NMR Spectra of Organosodium Compounds; Part II

Jost S., Günther H.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 7

1141-1153

EN

For three organosodium complexes, diphenylmethylsodium (tmeda) (1), diphenylmethylsodium (pmdta) (2), and fluorenylsodium (tmpda) (3), 13C and 23Na solid state NMR spectra have been measured for the first time. They were analysed in terms of chemical shifts delta(13C) and sigma(23Na) as well as 23Na quadrupole coupling constants, chi(23Na). Due to non-equivalent 23Na atoms in the unit cellMQS-MAS spectra were used to resolve the individual 23Na resonances. The sensitivity of the NMR parameters for the structural features of the complexes is demonstrated.

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31P High Resolution solid State NMR Studies of Phosphoroorganic Compounds of Biological Interest

Potrzebowski M., Ganicz K., Kaźmierski S.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 8

1147-1169

EN

In this review several applications of 31P high resolution solid state NMR spectroscopy in structural studies of bioorganic samples is reported. The problem of pseudopolymorphism of bis[6-O,6_-O-(1,2:3,4-diisopropylidene-_-D-galactopyranosyl) phosphorothioyl] disulfide 1 and application of 31P CP/MAS experiment to investigate of this phenomenon is discussed. The influence of weak C-H___S intermolecular contacts on molecular packing of 1,6-anhydro-2-O-tosyl-4-S-(5,5-dimethyl-2-thioxa-1,3,2-dioxaphosphorinan-2-yl)- _-D-glucopyranose 2 and SP, RP diastereomers of deoxyxylothymidyl-3_-O-acetylthymidyl (3_,5_)-O-(2-cyanoethyl) phosphorothioate 3 and their implication on 31P NMR spectra is shown. The final part of review describes the recent progress in structural studies of O-phosphorylated amino acids (serine, threonine, tyrosine), relationship between molecular structure and 31P chemical shift parameters _ii and influence of hydrogen bonding on values of principal elements of chemical shift tensor.