Solvent-free organic synthesis , Solvent-free organic synthesis , کتابخانه دیجیتال جندی شاپور اهواز

Solvent-free organic synthesis

Two-dimensionally extended, polycyclic heteroaromatic molecules (heterocyclic nanographenes) are a highly versatile class of organic materials, applicable as functional chromophores and organic semiconductors. In this Review, we discuss the rich chemistry of large heteroaromatics, focusing on their synthesis, electronic properties, and applications in materials science. This Review summarizes the historical development and current state of the art in this rapidly expanding field of research, which has become one of the key exploration areas of modern heterocyclic chemistry.

Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds: Synthetic Routes, Properties, and Applications

The analysis of nitrated polycyclic aromatic hydrocarbons (nitro-PAH) in diesel particulate extracts using a combination of high-performance liquid chromatography, gas chromatography/mass spectrometry, high-resolution mass spectrometry, and mass spectrometry/mass spectrometry (MS/MS) techniques is described. Triple stage quadrupole (TSQ)-MS/MS operated in the constant neutral loss mode is described for the rapid qualitative screening of nitro-PAH isomer groups in solvent extracts of diesel particulates. Twenty such isomer groups of nitro-PAH derivatives were found, many of these groups containing a large number of possible compounds. Mass analyzed ion kinetic energy spectrometry (MIKES)-MS/MS was found to be much less selective than the TSQ-MS/MS for the analysis of nitro-PAH in unfractionated diesel extracts. HPLC prefractionation was required to remove interferences in the MIKES analysis. Fused silica capillary GC/MS using on-column injection was found to be necessary for identifying specific nitro-PAH isomers and minimizing decomposition. The highly mutagenic 1-nitropyrene (1-NP) was the only compound found in the nitro(pyrenes and fluoranthenes) isomer group. The MIKES and TSQ techniques gave comparable results for the quantitation of 1-NP.

Analysis of nitrated polycyclic aromatic hydrocarbons in diesel particulates

The highly complex matrix of a diesel particulate extract was analyzed for nitrated polynuclear aromatic hydrocarbons (nitro-PAH) by use of fused-silica capillary column GC/thermionic nitrogen-phosphorus (GC/NPD) analysis of HPLC fractions. These samples were found to contain at least 100 nitro-PAH. Positive isomer identification for 17 nitro-PAH has been made utilizing the GC retention times of authentic standards and low- and high-resolution mass spectra as criteria. An additional 45 nitro-PAH were tentatively identified by using one or more of these techniques. Quantitative GC/MS analysis of 1-nitropyrene, 1,3-dinitropyrene, 1,6-dinitropyrene, and 1,8-dinitropyrene was facilitated by the use of perdeuterated analogues of these compounds as internal standards. Detection limits by the GC/NPD method range between 0.2 and 0.5 ppm for the HPLC fractionated samples. 4 figures, 2 tables.

Determination of nitrated polynuclear aromatic hydrocarbons in particulate extracts by using capillary column gas chromatography with nitrogen selective detection

Milton C. Kloetzel

Papers

Reactions of Nitroparaffins. I. Synthesis and Reduction of Some γ-Nitroketones

The Wohl-Aue Reaction. I. Structure of Benzo [a] phenazine Oxides and Syntheses of 1,6-Dimethoxyphenazine and 1,6-Dichlorophenazine1

Synthetic analogs of cortical hormones. i. homogentisic acid and ,2,5-trihydroxyacetophenone derivatives from 2,5-diacetoxy--diazoacetophenone

Reactions of nitroparaffins; addition of nitroparaffins to unsaturated esters.

Polymethyl Aromatic Hydrocarbons. IV. The Reaction of Alkylnaphthalenes with Maleic Anhydride1