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Acid Gas Processing and Disposal
Published in Arthur J. Kidnay, William R. Parrish, Daniel G. McCartney, Fundamentals of Natural Gas Processing, 2019
Arthur J. Kidnay, William R. Parrish, Daniel G. McCartney
The gas from the waste-heat exchanger then flows through a quench tower, where it is cooled to approximately 100°F (40°C) by externally cooled recycle water in countercurrent flow. The water from the tower is condensed, and the excess water is sent to a sour water stripper. Gas from the quench tower then contacts an aqueous amine solution in the absorption column. The amine is generally methyldiethanolamine (MDEA) or diisopropylamine (DIPA) to absorb H2S while slipping CO2. When extremely high selectivity is required, FLEXSORB™ solvent may be used (Crevier et al., 2009). The gas exiting the top of the absorber contains 10–250 ppm H2S and is incinerated. The rich amine that leaves the bottom of the absorber flows to the regenerator, where heat is applied to strip the H2S from the amine solution. The overhead from the regenerator is cooled to condense the water, and the H2S is recycled to the Claus unit feed. Lean amine is cooled and returned to the absorber.
Polypeptides
Published in Stanislaw Penczek, H. R. Kricheldorf, A. Le Borgne, N. Spassky, T. Uryu, P. Klosinski, Models of Biopolymers by Ring-Opening Polymerization, 2018
More information is obtained from end group analyses. Using 14C-labeled diethylamine, di-n-butylamine, and diisopropylamine, Goodman, Peggion, et al. could demonstrate108-114 that di-n-butylamine and diisopropylamine exclusively deprotonate NCAs (Equation 65), whereas diethylamine reacts as a base and as a nucleophile (Table 4). These conclusions were confirmed by kinetic and spectroscopic studies of the author.115N-acetyl-Gly-NCA was added to morpholine, diethylamine, diisopropylamine, and dicyclohexylamine-initiated polymerizations of Gly-NCA. Since N-acetyl-Gly-NCA is a stronger electrophile than Gly-NCA, it acylates the secondary amine before it can initiate polymerization if the amine reacts as a nucleophile (Equation 69). Such a reaction sequence was found for morpholine and diethylamine115 (Table 5). However, when diisopropylamine and dicyclohexylamine were used as initiators, N-acetyl-Gly-NCA reacted as cocatalyst and accelerated the polymerization. This acceleration effect results from the replacement of the slow initiation of Equation 66 by the faster initiation of Equations 70 and 71. Furthermore, IR and 1H NMR spectra revealed the incorporation of N-acetyl-Gly-NCA, and thus, clearly prove that diisopropylamine and dicyclohexylamine initiate the activated monomer mechanism (AMM) (Table 5).
Functionalization of Graphite and Graphene
Published in Titash Mondal, Anil K. Bhowmick, Graphene-Rubber Nanocomposites, 2023
Akash Ghosh, Simran Sharma, Anil K. Bhowmick, Titash Mondal
Amine-based graphene functionalization seeks attention in various fields like polymer solar cell, sensor, drug delivery, and energy storage. The epoxy and carboxylic groups were mainly used to react with the amine for surface anchoring. A similar strategy was utilized by Mondal et al. to modify the surface of the graphene oxide with blocked amine. 1-Methyl imidazole-based ionic liquid was used as the modifier for the graphene oxide. The ionic liquid modified graphene was further utilized in polyurethane-based foam composition to generate pores with uniformity (Mondal, Basak, and Bhowmick 2017). Bourlinos et al. used different amines and amino acids to modify the surface of graphene oxide. The epoxy group on the graphene oxide undergoes the substitution and nucleophilic reaction to modify the properties (Bourlinos et al. 2003). Using microwaves, Caliman et al. (2018) proposed a direct method to prepare amine functionalized graphene oxide. They produced four different amine functionalized graphenes by the use of dibenzyl amine, p-phenylenediamine, diisopropylamine, and piperidine. It was reported that the diisopropylamine and piperidine functionalized graphenes exhibit a better life cycle and specific capacitance of 290 F g−1 leading to its usage in the field of supercapacitors. Aguilar-Bolados and his co-workers reported the reductive amination of graphene oxide using the Leuckart reaction. Ammonium formate is used to reduce the carbonyl group present on the graphene oxide surface with simultaneous addition of amine (Aguilar-Bolados et al. 2017). Jeyaseelan et al. (2021) anchored the ethylenediamine molecule on graphene oxide for fluoride removal application.
Oxygenation of copper(I) complexes containing fluorine tagged tripodal tetradentate chelates: significant ligand electronic effects
Published in Journal of Coordination Chemistry, 2022
Runzi Li, Firoz Shah Tuglak Khan, Marcos Tapia, Shabnam Hematian
An aqueous solution of 2-(chloromethyl)-3-methyl-4-(2,2,2-trifluoroethoxy)pyridine hydrochloride (6.74 g, 0.024 mol) was prepared, brought to pH = 10 using NaOH pellets, then extracted using DCM (2 × 100 mL). The DCM fractions were evaporated under reduced pressure, then redissolved in THF (80 mL) and transferred to a three-neck round-bottom flask under argon. Under continuous argon flow, the THF solution was stirred with di(2-picolyl)amine (4.9 g, 0.024 mol) and diisopropylamine (25.3 mL, 0.15 mol) for 1 week. After one week, the reaction mixture was evaporated under reduced pressure and purification was performed on an alumina column. The product fraction was eluted with 3–4% MeOH:DCM, evaporated under reduced pressure, redissolved in hot diethyl ether, then cooled at –20 °C overnight to obtain the light-brown solid product, which was washed with cold ether and dried under vacuum. Yield: 5.8081 g (59%). 1H-NMR (400 MHz, CDCl3, δ, ppm): 8.52 (d, 2H), 8.31 (d, 1H), 7.62 (td, 2H), 7.46 (d, 2H), 7.13 (td, 2H), 6.58 (d, 1H), 4.35 (q, 2H), 3.89 (s, 2H), 3.83 (s, 4H) (supporting material Figure S5). 19F-NMR (376 MHz, CDCl3, δ, ppm): –73.79 (supporting material Figure S6). ESI-MS ([MeTFE-TMPA + H]+) calcd/found (m/z): 403.1746/403.1650 (supporting material Figure S7). FT-IR (solid): ν(C-H, Py and CH2) = 3067, 3012, 2949, and 2824 cm−1 (supporting material Figure S4).
A convenient four-component reaction for the synthesis of dithiocarbamates starting from naphthols in water
Published in Journal of Sulfur Chemistry, 2020
Maryam Khalili Foumeshi, Rohollah Haghi, Petr Beier, Azim Ziyaei Halimehjani
The scope of the method was examined using various amines and naphthol derivatives. The results are summarized in Table 2. Various secondary amines such as dimethylamine, ethylmethylamine, diethylamine, diallylamine, dipropylamine, dibutylamine, and cyclic amines of various sizes including azetidine, pyrrolidine, piperidine and azepane were applied successfully in this protocol. In addition, diisopropylamine a highly bulky amine gave the corresponding product 3d in 60% yield. On the other hand, primary amines are not suitable starting materials for this reaction. Naphthol derivatives including 2-naphthol, 6-bromo-2-naphthol, 6-methoy-2-naphthol, and naphthalene-2,7-diol gave satisfactory results with 55–92% yields. In addition, the scope of this reaction can be explored to 1-naphthol to afford the corresponding 2-(dithiocarbamatomethyl)-1-naphthols in excellent yields (Table 2, 3w-x). No desired product was obtained with other electron-rich arenes such as phenol, resorcinol, pyrocatechol, indole, 1,3,5-trimethoxybenzene, and N,N-dimethylaniline. It is notable that the reactions in water were carried out in heterogeneous system and the crude products can be isolated by simple filtration.
Linear and nonlinear dielectric properties of nanocomposites based on the organic ferroelectric of diisopropylammonium bromide
Published in Phase Transitions, 2019
Hoai Thuong Nguyen, S. V. Baryshnikov, A. Yu Milinskiy, I. V. Egorova, E.V. Charnaya
In this study, diisopropylammonium bromide was prepared from the reaction of diisopropylamine with 48% aqueous HBr solution (molar ratio of 1:1) according to the procedure, given in [16,17] through a subsequent recrystallization process from methyl alcohol at room temperature. The maximum size of obtained crystallites was of 2–3 mm. The results of experiments using differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) techniques for the synthesized samples are presented in Figure 1(a,b), respectively. The DSC signal is in good agreement with those reported in [10], while the crystalline structure of Р21 formed in DIPAB at room temperature contains all characteristic peaks matching with reference data of The Cambridge Crystallographic Data Centre (CCDC card No 770675).