Theoretical analysis and evaluation of reaction routes by "three-parameter difference".

How to choose a high-efficiency, green and inherent safety synthetic route is an important issue for the development of the chemical industry. "Three-parameter difference" is a complex parameter with the calculation of Gibbs free energy, atom utilization and inherent safety index, and can be used to comprehensively evaluate the thermodynamic feasibility, greenness and safety of chemical reactions. This parameter has been proposed and established, but the reliability has not been determined. In this study, the parameter has been corrected to make it more universal. It was calculated and studied in the synthesis of dimethyl carbonate and toluene diisocyanate, separately. The results showed that the reaction pathways for synthesizing dimethyl carbonate from the gas-phase oxidative carbonylation of methanol by a one-step process, and toluene diisocyanate from dimethyl carbonate-ionic liquid hydroxylamine have obvious advantages and future research prospects. They are consistent with the existing actual research, which can prove the reliability of the "three-parameter difference". More importantly, the parameter provides a theoretical basis and has an adequate practical guidance significance to design and evaluate a new synthesis route.

Recovery of isoflavone aglycones from soy whey wastewater using foam fractionation and acidic hydrolysis.

The purpose of this work was to recover isoflavone aglycones from industrial soy whey wastewater, where the isoflavone aglycones mainly existed in the form of ß-glycosides. First, foam fractionation was used for effectively concentrating the total soy isoflavones, including isoflavone aglycones and ß-glycosides, from the wastewater. Fourier transform infrared spectroscopy indicated the existence of complexes of soy isoflavones and soy proteins. When soy proteins were used as the collectors, a high enrichment ratio of 3.68 was obtained under the optimal operating conditions of temperature of 50 °C, pH of 5.0, volumetric air flow rate of 100 mL/min, and loading liquid height of 400 mm. Subsequently, acidic hydrolysis was used for hydrolyzing ß-glycosides in the foamate into aglycones. Using response surface methodology, a hydrolytic percentage could reach 96% under the optimum hydrolysis conditions of hydrolytic temperature of 80 °C, hydrochloric acid concentration of 1.37 mol/L, and hydrolytic time of 90 min.

[Synthesis and structure characterization of bis (4-butoxycarbonylaminocyclohexyl) methane].

Bis(4-butoxycarbonylaminocyclohexyl) methane (H12 MDU) was prepared using dicyclohexylmethane-4,4'-diisocyanate and 1-butanol as raw materials and two solid products A and B were obtained. The structures of the two solid products were characterized separately by melting point measurement, infrared spectroscopy, elemental analysis, NMR spectrum analysis and mass spectrum analysis. The results show that both A and B are the target products H12 MDU. The solid A is trans-trans-H12 MDU while the solid B is a mixture including trans-trans-Hiz MDU and at least one of cis-trans-H12MDU and cis-cis-H12 MDU.

[The application of chemical imaging to detection and enhancement of latent fingerprints].

Chemical imaging (CI) integrates conventional imaging and spectroscopy to attain both spectral and spatial components and structural information from an object simultaneously. Vibrational spectroscopic methods, such as infrared and Raman spectroscopy, combined with imaging are particularly useful. In recent years, CI has found important application in the field of forensic science due to its advantage of highly sensitive, rapid, non-destructive features and it can provide qualitative and quantitative information about specimen at one time. There are many methods for detection and enhancement of latent fingerprints. CI is an emerging platform technology with great potential to visualize latent fingerprints on many objects without any pre-treatment. CI can enhance the quality of the fingerprints developed by conventional methods, then form larger contrast with the background. With the advancement of instruments, the application of CI in the field of fingerprint detection will be more widely used. This paper provides an overview of the principal and classification of CI instrumentation, and reviews the application of CI to detection and enhancement of latent fingerprints. Finally, the direction of CI technology development is viewed.

[A study of developing fingermarks by nano-titanium dioxide shielding ultraviolet-ray].

In view of the difficulty in developing fingermarks on the color or strong fluorescence surface, the present paper reported a novel method to develop fingermark by shielding ultraviolet-ray. Nano-titanium dioxide with rutile phase had extremely high shielding ability of ultraviolet-ray. The TEM indicated that the average particle size of rutile titanium dioxide in experiment was about 30 nm, and they were mostly sphericity. The UV-Vis spectra indicated that the rutile nanoparticles shield UV with wavelength less than 400 nm. The rutile nanoparticles were physically adsorbed on the ridges of fingermarks on the color or strong fluorescence surface adequately and were not or a little adsorbed on the object surface by dusting or shaking. The ridges of the developed fingermarks were dark and the background was light under irradiation of 365 nm. We could obtain good images, and the contrast of lightness between the ridge and the background was obvious. In contrast to traditional developing technique-superglue fuming-Rhodamine 6G (or BBD) dyeing strengthening technique, the effect of nano-titanium dioxide shielding ultraviolet-ray detection technique was better. By the new detection technique, the ridges of the developed fingermarks were smooth and the detail characteristics of the developed fingermarkes were clear. The research results indicate that the nano-titanium dioxide particle is an effective and convenient developer of fingermark on the color or strong-fluorescence or color-strong fluorescence surface under irradiation of 365 nm with its shielding ultraviolet-ray property. Especially, the developer also has quite satisfactory effect on old fingermarks on the non-porous objects in contrast to traditional methods. The new detection technique is convenient, efficient, fast, and economical and has a wide application foreground in the field of fingermark developing.

[Study on analysis of copy paper by Fourier transform infrared spectroscopy].

A new method of fast identification of copy papers by Fourier transform infrared spectroscopy (FTIR) was developed. The kinds of filler and the cellulosic degree of crystallinity were analyzed by FTIR, and the ageing curves of cellulosic paper were studied with heating and ultraviolet light. The cellulosic degree of crystallinity was showed by the ratio of absorbance at 1 429 cm(-1) to that at 893 cm(-1), the standard deviation of different brands of copy papers was 0.010 7-0.016 0, and the standard deviation of the same brands of copy papers was 0.014 8. The kinds of filler and the cellulosic degree of crystallinity were different in copy papers from different brands of different manufacturing plants, different brands of same manufacturing plants and different manufacturing times of the same brands from the same manufacturing plants, and the curves of ageing were different with heating and ultraviolet light. The results of fast identification of copy papers by FTIR are satisfactory.

[Analysis of roller ball pen water ink by capillary electrophoresis with photodiode array detector].

The analytical method of roller ball pen water inks was established by capillary electrophoresis with photodiode array (PDA) detector scanning in row. First test was for the type, concentration, pH value of buffer solution, as well as the impact of separation voltage of electrophoresis on the analysis results. The test results of PDA detector were studied by fused silica capillaries with diameters of 50, 75 and 100 nm. Experiments show that the capillary diameter is directly proportional to the intensity of light absorption. With ensuring the performance of separation as the premise, using 100 nm diameter of the capillary increased the absorption intensity of signal detection, so the absorption peak can be detected in the range of ultraviolet and visible light wavelength. After optimizing conditions, 20 mmol x L(-1) borate buffer at pH 8.5, 100 microm x4 0 cm fused silica capillary column, separation voltage 15 kV, PDA detector and scanning range 190-600 nm were adopted in experiment. Different roller ball pen inks can be analysed from characteristics of electrophoresis absorption in three-dimensional electrophoregrams with scanning in row in UV-visible wavelength range.

[Application of IR spectrum to the research on mechanism of synthesis of 2,4-toluene dicarbamate catalyzed by zinc acetate].

The methoxycarbonylation mechanism of synthesizing 2,4-toluene dicarbamate from 2,4-toluene diamine and dimethyl carbonate catalyzed by anhydrous zinc acetate was investigated by Fourier transform infrared spectroscopy. The result shows that the new coordination complex was formed by oxygen atom of dimethyl carbonate's carbonyl group attaching to zinc atom of anhydrous zinc acetate to form the Zn-O coordination bond, and the anhydrous zinc acetate changed from a bidentate ligand to a unidentate ligand. Simultaneously, dimethyl carbonate's carbonyl group was activated. 2,4-toluene diamine was a nucleophilic reagent, and it's amidos attacked the activated carbon of dimethyl carbonate's carbonyl group in the new coordination complex to produce the methoxycarbonylation compound 2,4-toluene dicarbamate, then the Zn-O coordination bond in the new coordination complex was broken. At the same time, the anhydrous zinc acetate returned to a bidentate ligand.

Application of CdSe nanoparticle suspension for developing latent fingermarks on the sticky side of adhesives.

Nanometer-sized fluorescent particles were synthesized in an aqueous solution using TGA (mercaptoacetic acid) as the stabilizer. The prepared solution was characterized by fluorescence spectroscopy and applied for detection of latent fingermarks on adhesives. The effects of stabilizer, precursor, pH value, the concentration of cadmium ion and shell structure on fluorescence were also discussed. The results indicated that the intensity of fluorescence was remarkably increased and the selectivity was well improved when using CdSe nanoparticles, it produced significantly less background development and better contrast after 15 min developing process.

1-Phenyl-1-[(1-phenyl-ethyl)sulfonyl-methyl-sulfon-yl]ethane.

There are two mol-ecules in the asymmetric unit of the title compound, C(17)H(20)O(4)S(2). There are slight differences in the twist of the two rings relative to the S-C-S chain [dihedral angles of 48.41 (18) and 87.58 (16)° in the first mol-ecule and 45.98 (18) and 87.02 (18)° in the second] and the difference in the C-S-C-S torsion angles [176.68 (17) and -77.6 (2)° for the two independent mol-ecules].

(4RS)-3-Benzyl 5-methyl 2,6-dimethyl-4-(4-nitro-phen-yl)-1,4-dihydro-pyridine-3,5-dicarboxyl-ate.

In the title compound, C(23)H(22)N(2)O(6), the crystal packing is stabilized by inter-molecular N-H⋯O hydrogen bonds, which link the mol-ecules into chains running parallel to the c axis. Inter-molecular C-H⋯O hydrogen bonds are also present in the structure.

[Study on amidation reaction between CdS/PAMAM and amino acid and its application to latent fingerprint development].

A new method for the development of latent fingerprints by CdS/PAMAM nanocomposites was explored in the present research. Amidation reaction between terminal carboxylate groups of amino acids and terminal amino groups of PAMAM G4. 5 dendrimers was studied by FTIR spectrometry. The reacting processes under different conditions were monitored by H(1267/1735) (the relative ratio of peak height) in order to find out the optimized condition and developing method. The results indicated that the reacting processes were affected remarkably by the changes in temperature. The reaction was efficient under 90 degrees C within 4 hours, while the reacting speed decreased after 3 hours under 120 degrees C. CdS/PAMAM was utilized as the latent fingerprint developing reagent and compared with the routine one. The results indicated that the fluorescence intensity of the former is 65 times higher than that of the latter. Great predominance in florescence could be observed when CdS/PAMAM and the routine developing reagent were compared. Latent fingerprints on the surface of different objects were developed under 120 degrees C within 0.5-3 h. Good developing results could be obtained under the optimized condition. The method is simple, rapid, highly sensitive, safe and economical.

[Investigation of accelerated aging in light and writing age of roller pen inks].

The aging of roller pen ink entries was accelerated in sunlight and ultraviolet, and the extracts of roller pen inks on paper were analyzed by capillary zone electrophoresis, photo diode array (PDA) detector. Scanning range of 190-600 nm was adopted in experiment and the change curves were obtained by the plot of the ratio of peak areas in electrophoretogram vs. accelerated aging. The rule of accelerated aging of roller pen ink was investigated by relative changes in content between different dyes in inks. In addition, the relative writing age of roller pen entries was investigated.

[Determination of writing age of blue ballpoint pen inks by high performance liquid chromatography].

As it is a frequently encountered problem in the laboratory of forensic science nowadays to distinguish whether the questioned documents, such as deeds, contracts, and receipts, written in ballpoint pen inks are true or not, and identify the writing age of them, it is very essential to establish a simple, sensitive and accurate method to examine the similarities and differences of the ballpoint pen inks and identify the writing age. The present paper introduces a technique that allows identifying the kind and the writing age of the blue ballpoint pen inks. The technique is based on using a high performance liquid chromatographic method for distinguishing the similarities and differences in dyes of blue ballpoint pen inks and determining changes in dyes of blue ballpoint pen inks developed with age, and these changes can be evaluated by the ratio of peak areas.

[Synthesis and crystal structure of a porous coordination polymer [Nd2 (C6H8O4)3 (H2O)2]n x n (4,4'-bpy)].

A novel porous coordination polymer [Nd2 (C6H8O4)3 (H2O)2]n x n (4,4'-bpy) was synthesized by hydrothermal synthesis reaction of hexyl acid, 4,4'-bpy with NdCl3 x XH2O. The structure was characterized by elemental analysis, thermal gravimetric analysis, IR spectroscopy, and X-ray single crystal analysis. The crystal data are of an orthorhombic crystal system, Pbcn space group. Crystallographic data are: a = 2.201 2 nm(6), b = 0.777 8 nm(2), c = 1.972 4 nm(5), alpha = beta = gamma = 90 degrees, V = 337.70 nm(15)3, Z = 4, D(c) = 1.796 g x cm(-3), mu = 3.108 mm(-1), F(000) = 1 800, R = 0.043 0 and wR2 = 0.056 0. X-ray analysis reveals that three-dimensional porous nets were formed between Nd3+ and Nd3+ by carboxyl of hexyl acid.