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Determinative Techniques to Measure Organics and Inorganics
Published in Paul R. Loconto, Trace Environmental Quantitative Analysis, 2020
The predominant reaction of the H3O+ reagent ions with VOCs (e.g. from contaminant air) represented by A (see below) is exothermic proton transfer; H3O++A→AH++H2OWhen proton transfer is quite exothermic (more than about 1 eV) then dissociative proton transfer may occur from AH+ as in some reactions with organic compounds such as alcohols, aldehydes, and carboxylic acids. This leads to elimination of H2O. The specific aldehyde shown in the example is hexanal (an aliphatic aldehyde) which serves as an example of a VOC drawn from contaminated air. The molecular structure for hexanal is shown below:
Catalytic Amination of Alcohols and Its Potential for the Synthesis of Amines
Published in John R. Kosak, Thomas A. Johnson, Catalysis of Organic Reactions, 2020
The mentioned FTIR studies [10] indicate that over copper/alumina the following steps occur: (1) the alcohol (hexanol) dehydrogenates to the corresponding surface alkylate (hexylate) and subsequently to surface-bound aldehyde (hexanal); (2) surface bound aldehyde (hexanal) is converted rapidly when dimethylamine is added to the reactant gas stream; (3) surface-bound aldehyde (hexanal) can also react with adsorbed or lattice oxygen to form the corresponding surface-bound carboxylate (hexanoate), which is considered a spectator species not taking part in the amination reaction.
Oxidation Reactions
Published in Michael B. Smith, A Q&A Approach to Organic Chemistry, 2020
Cyclohexanol is oxidized to cyclohexanone with PCC. Hexan-1-ol is oxidized to the aldehyde (hexanal) with PCC. PDC will oxide pent-2E-en-1-ol to pent-2E-al. 3-Methyloctan-3-ol is a tertiary alcohol and neither PCC nor PDC will oxidize this alcohol. The answer here is no reaction. In all cases, the reactions are performed at 25°C using dichloromethane as a solvent. These are typical reaction conditions.
An innovative approach for fatty acid reduction to fatty aldehydes
Published in Green Chemistry Letters and Reviews, 2021
Jens Johannsen, Gayoung Baek, Georg Fieg, Thomas Waluga
In this paper, the exemplary renewable starting material is hexanoic acid, which can be extracted from citrus fruit oils or coconut oil and is liquid, therefore easy to handle (7,26). Its end product hexanal is widely used in detergents, cleaning agents, waxes and as a fragrance in perfumes (7). The final aldehyde yield is evaluated in relation to the molar number of metal atoms available for the reduction reaction: therefore, in this work we present a characterization of the different metal particles, using laser-diffraction Particle Size Distribution (PSD) to calculate volume and surface area of the particles, and Atomic Force Microscopy (AFM) to determine surface roughness. In the following paragraphs, a practical idea for the simultaneous regeneration of the oxidized metal particles is also presented in order to allow for a smaller metal input, thereby increasing sustainability.
Inhalation exposure to volatile organic compounds in the printing industry
Published in Journal of the Air & Waste Management Association, 2019
Abdullah Alabdulhadi, Ashraf Ramadan, Peter Devey, May Boggess, Maya Guest
Hexanal was found at 50 ppb in the scientific printery and 70 ppb in the newspaper printery. Nonanal was found at 20 ppb in the scientific printery and 30 ppb in the newspaper printery. Nonanal was reported in only one previous printery study (Vilcekova and Meciarova 2016); we found no reference to hexanal in previous printery studies. Hexanal can cause irritation to the eyes and nose in humans (Ernstgård et al. 2006). Both hexanal and nonanal can cause pulmonary toxicity in rats (Cho et al. 2017; Choi, Song, and Ryu 2013).