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Amines
Published in Michael B. Smith, A Q&A Approach to Organic Chemistry, 2020
Reduction of lactams gives cyclic amines. Reduction of 2-pyrrolidinone gives pyrrolidine. What is the structure of sodium azide?
Apparent molar volume, compressibility, and spectroscopic studies of ionic surfactants in aqueous solutions of antibiotic gemifloxacin
Published in Journal of Dispersion Science and Technology, 2023
Muhammad Sohail, Hafiz Muhammad Abd ur Rahman, Muhammad Nadeem Asghar, Saadia Shoukat
The GMF-DTAB/SDS interactions can be classified as: Hydrophobe-hydrophobe interactions between the nonpolar moieties of GMF and the alkyl chains of surfactants;Hydrophobe-hydrophile interactions between the alkyl chains of surfactants and hydrophilic groups (-C = O, -N, and -F) of GMF;Hydrophobe-ion interactions between the nonpolar moieties of GMF and the ionic groups of surfactants, and between the nonpolar tail of surfactants and ionic groups of GMF;Hydrophile-ion interactions between hydrophilic groups of GMF and ionic groups of surfactants;Ion-ion interactions between OSO3- of SDS or Br- of DTAB and NH3+ group (5-amine of pyrrolidine) of GMF, and between Na+ of SDS or -N+(CH3)3 of DTAB and -COO- moiety of GMF. Moreover, the ionic interactions due to presence of PBS cannot be overlooked in all investigated systems;Hydrogen bonding among GMF, water, and surfactant molecules.
A review on the recent progress, opportunities, and challenges of 4D printing and bioprinting in regenerative medicine
Published in Journal of Biomaterials Science, Polymer Edition, 2023
Parvin Pourmasoumi, Armaghan Moghaddam, Saba Nemati Mahand, Fatemeh Heidari, Zahra Salehi Moghaddam, Mohammad Arjmand, Ines Kühnert, Benjamin Kruppke, Hans-Peter Wiesmann, Hossein Ali Khonakdar
Some smart polymers can react to pH changes as another environmental stimulus. pH-responsive materials have been widely studied because pH varies in different tissues and healthy and diseased conditions [85]. These polymers change their structure from linear to network conformations, and some of them create gels, micelles, hydrogels, and the like. A change in pH usually leads to ionic and hydrophobic interactions, hydrogen bonding alteration, reversible microphase separation, or self-organization phenomenon [86]. Polymer protonation can occur by proton acceptance of ionizable groups such as carboxylic, tertiary amine, and pyrrolidine at low pH and by proton loss at high pH [87]. Dendrimers swell in response to pH changes. In general, polymers with carboxyl pyridine, sulfonic, phosphate, and amine groups can respond to pH changes [88, 89]. For instance, acrylonitrile − butadiene − styrene (ABS) can be added to poly(2-vinylpyridine) (P2VP) to produce filaments with optimal mechanical properties and suitable printability [90, 91]. Polyethlenamine is a polycation polymer with a pH response that can be used in the 4 D printing process [87]. In addition, poly(ethylene glycol) (PEG), polyacrylic acid (PAA), poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) and poly(N,N-diethylaminoethyl methacrylate) (PDEAEMA) are other pH-responsive materials [92]. This type of 4 D printed smart polymer can be used for controllable tissues. For instance, 3 D printed pH-responsive poly(2-vinylpyridine) was used to produce a flow-regulating valve to regulate flow rate by controlling the changes in pH [93].
Design and application of a novel and effective ligand for the Cu-catalyzed amination of aryl halides in water
Published in Green Chemistry Letters and Reviews, 2023
Lifang Wang, Xinhai Zhu, Zexuan Liang, Manna Huang, Yiqian Wan
A wide range of aryl chlorides were aminated with amines under the optimized conditions to explore the scope of this catalyst system. As shown in Figure 3, both activated and unactivated aryl chlorides reacted with anilines to afford the desired products in good to excellent isolated yields (Figure 3(a–g)); the aryl chlorides reacted smoothly with the more nucleophilic anilines with no surprises (Figure 3(h–i)). For aliphatic amines, the expected results were obtained (Figure 3(j–q)) due to the stronger nucleophilicities of benzylamine and cyclohexanamine than those of the anilines. Pyrrolidine, which is a secondary cyclic amine, reacted well with aryl chlorides and produced fair to good yields, although higher amine hindrance decreased the rate of the conversion of the aryl chlorides (Figure 3(r–u)).