[Study on Panax notoginseng and its processed products by FTIR spectroscopy].

The chemical differences of panax notoginseng before and after processing were analyzed by Fourier transform Infrared spectroscopy (FTIR) combined with two-dimensionalcorrelation spectroscopy (2D-IR). Compared with conventional IR spectra of the samples, the FTIR spectra of panax notoginseng and its processed products were similar in the range of 1 200-400 cm(-1). The difference was that prepared panax notoginseng had strong and characteristic peaks at 2 925, 2 855, 1 746, 1 460, 1 376 and 1 158 cm(-1), which all arose from the characteristic vibration of peanut oil. This was because there was some peanut oil left in the panax notoginseng, when panax notoginseng after processing. Obvious differences were observed between 2D-IR spectra of them, in the range of 1 400-1 700 cm(-1), there was only one auto peaks at 1 650 cm(-1) in the spectra of panax notoginseng, but there were auto peaks at 1 469 and 1 640 cm(-1) in the spectra of prepared panax notoginseng. In the range of 1 400-1 700 cm(-1), the 2D-IR spectra of panax notoginseng and its processed product present characterstic peaks at 1 139 (1 137), 1 194 (1 196), 1 121 (1 221)cm(-1) respectively, but the relative intensities of auto peaks were changed. For example, auto peak around 1 139 cm(-1) was enhanced, but auto peak around 1 194 cm(-1) was weakened. The results of 2D-IR correlation spectroscopy indicated the decomposition of flavonoids, saccharides and saponins. This method can track dynamically the processing procedure of panax notoginseng and reveal the main tansformations, so it can explain the pharmacology of panax notoginseng and its processed product by FTIR and 2D-IR.

[Study on infrared spectrum change of Ganoderma lucidum and its extracts].

From the determination of the infrared spectra of four substances (original ganoderma lucidum and ganoderma lucidum water extract, 95% ethanol extract and petroleum ether extract), it was found that the infrared spectrum can carry systematic chemical information and basically reflects the distribution of each component of the analyte. Ganoderma lucidum and its extracts can be distinguished according to the absorption peak area ratio of 3 416-3 279, 1 541 and 723 cm(-1) to 2 935-2 852 cm(-1). A method of calculating the information entropy of the sample set with Euclidean distance was proposed, the relationship between the information entropy and the amount of chemical information carried by the sample set was discussed, and the authors come to a conclusion that sample set of original ganoderma lucidum carry the most abundant chemical information. The infrared spectrum set of original ganoderma lucidum has better clustering effect on ganoderma atrum, Cyan ganoderma, ganoderma multiplicatum and ganoderma lucidum when making hierarchical cluster analysis of 4 sample set. The results show that infrared spectrum carries the chemical information of the material structure and closely relates to the chemical composition of the system. The higher the value of information entropy, the much richer the chemical information and the more the benefit for pattern recognition. This study has a guidance function to the construction of the sample set in pattern recognition.

[Infrared spectroscopic analysis of Guilin watermelon frost products].

The objective of the present study is to analyze different products of Guilin watermelon frost by Fourier transform infrared spectroscopy (FTIR), second derivative infrared spectroscopy and two-dimensional correlation spectroscopy (2D-IR) under thermal perturbation. The structural information of the samples indicates that samples from the same factory but of different brands had some dissimilarities in the IR spectra, and the type and content of accessories of them were different compared with conventional IR spectra of samples, peaks at 638 and 616 cm(-1) all arise from anhydrous sodium sulfate in watermelon frost spray and watermelon frost capsule; the characteristic absorption peaks of the sucrose, dextrin or other accessories can be seen clearly in the spectra of watermelon frost throat-clearing buccal tablets, watermelon frost throat tablets and watermelon frost lozenge. And the IR spectra of watermelon frost lozenge is very similar to the IR spectra of sucrose, so it can be easily proved that the content of sucrose in watermelon frost lozenge is high. In the 2D-IR correlation spectra, the samples presented the differences in the position, number and relative intensity of autopeaks and correlation peak clusters. Consequently, the macroscopical fingerprint characters of FTIR, second derivative infrared spectra and 2D-IR spectra can not only provide the information about main chemical constituents in medical materials, but also analyze and identify the type and content of accessories in Guilin watermelon frost. In conclusion, the multi-steps IR macro-fingerprint method is rapid, effective, visual and accurate for pharmaceutical research.

[Similar spectrum of infrared spectrum and its application in identification of Chinese herbs].

In the present paper, the similar spectra of 18 samples, which include Astragalus, red-blue Astragalus and Codonopsis, were obtained in the range of 1600-700 cm(-1). The result showed that all kinds of herbs have their own characteristic similar spectra, and 18 samples can be identified according to the characteristic similar spectra. Furthermore, three correlation coefficients of 93 ganoderma samples were calculated which is in the range of 1560-1502, 1460-1421 and 1319-1260 cm(-1) according to the information of similar spectrum of infrared spectrum of ganoderma. Without priori knowledge of the classification of these samples, the K-means cluster analysis can successfully divide them into four classes, i.e., Ganoderma lucidum and Ganoderma sinensis, Ganoderma atrum, Ganoderma aoshiba, Ganoderma multiplicatum. This result is consistent with the result of morphological classification.

Strong hydrogen binding within a 3D microporous metal-organic framework.

A 3D microporous cadmium(II) metal-organic framework based on 1H-tetrazole exhibits strong hydrogen binding with an initial enthalpy of adsorption of 13.3 kJ/mol, due to the smaller pore sizes and the high hydrogen binding affinity of the tetrazolyl-ring-decorated inner surface of the pores.

Three-dimensional lanthanide anionic metal-organic frameworks with tunable luminescent properties induced by cation exchange.

Three 3D lanthanide anionic metal-organic frameworks {K(5)[Ln(5)(IDC)(4)(ox)(4)]}(n) x (20H(2)O)(n) with 1D channels were synthesized under hydrothermal conditions [Ln = Gd (1), Tb (2), and Dy (3)]. The K(+) ions within the 1D channel are easily exchanged with various cations. The emission intensities of Tb(III) in 2 increased significantly upon the addition of Ca(2+) ions, while the introduction of other metal ions caused the intensities to be either unchanged or weakened.

[Di-n-butytin tridentate acylhydrazone Schiff base complexes: synthesis and studies by infrared spectroscopy].

Four tridentate acylhydrazone schiff base ligands H2L [H2L1:C6H5C(O)NHN = CHC6H4OH-2, H2L2:C6H5C(O)NHN = CHC6H3(OH)(2)-2,4, H2L3:NC5H4C(O)NHN = CHC6H4OH-2, H2L4:NC5H4C(O)NHN = CHC6H3(OH)(2)-2,4] were synthesized and use to form four novel di-n-Butytin complexes of the type (n-Bu)2SnL with di-n-Butytin oxide [(n-Bu)2SnO]. All these ligands and complexes were characterized by elemental analysis and infrared spectroscopy. Their principal infrared spectral absorption peaks were assigned and discussed for the region of 4,000-400 cm-1. A comparison of the infrared spectra of the ligands with those of the corresponding complexes reveals that the disappearance of the bands assigned to carbonyl unambiguously confirms that the ligands coordinate with tin in the enol form. The coordination manner for tridentate acylhydrazone schiff base ligands with tin atom in the complexes was determined. The results indicated that the Sn atom in these complexes is five-coordinated.

A {Cr2Dy4} compressed octahedron: the first sulfate-based single-molecule magnet.

A unique compressed octahedral {Cr(III)(2)Dy(III)(4)} aggregate is the first sulfate-based single-molecule magnet (SMM) with U(eff)/k(B) = 39.7 K and τ(0) = 2.9 × 10(-9) s. Its synthesis opens a new avenue to prepare 3d-4f coordination clusters.

3D porous metal-organic framework exhibiting selective adsorption of water over organic solvents.

A 3D porous metal-organic framework (MOF) with 1D open channels has been constructed hydrothermally using Zn(II) and a rigid planar ligand IDC(3)- (imidazole-4,5-dicarboxylate). This MOF can adsorb water selectively over organic solvents and can be regenerated and reused. It also represents a rare example of a MOF with open channels that form/collapse reversibly upon hydration/dehydration.

Two stable 3D metal-organic frameworks constructed by nanoscale cages via sharing the single-layer walls.

Two stable 3D metal-organic frameworks are constructed by the hydrothermal reactions of Cd(NO3)2.4H2O and IDC3- using bpy and Bu4NBr as templates. Both structures show the same frameworks, which are composed by the nanoscale cages via sharing the single-layer walls.