644-33-7Relevant articles and documents
Ethylene-Bridged Tetradentate Bis(amidines): Supramolecular Assemblies through Hydrogen Bonding and Photoluminescence upon Deprotonation
Calderón-Díaz, Alvaro,Arras, Janet,Miller, Ethan T.,Bhuvanesh, Nattamai,McMillen, Colin D.,Stollenz, Michael
, p. 3243 - 3250 (2020)
Sterically crowded tetradentate bis(amidines) encapsulate their N–H functionalities or unveil them to undergo inter- and intramolecular hydrogen bonding both in solid state and solution, depending on a subtle interplay between the amidine backbone substituents. X-ray crystallography reveals for four distinct ZZ(syn/syn) and EE(syn/syn) bis(amidines) that bulky terminal N-Mes groups in combination with N2C-tBu or N2C-Ph substituents result in steric protection of the N–H moieties, whereas less crowded terminal p-tBu(C6H4) groups either show encapsulation (N2C-tBu) or hydrogen bonding (N2C-Ph), the latter resulting in a bis(amidine) dimer formed by inter- and intramolecular hydrogen bonds. Moreover, a supramolecular solvent adduct consisting of one bis(amidine) and four ethanol molecules is presented. DFT calculations show that both the dimerization and formation of the solvent adduct is associated with a significant energy gain (dimerization: ΔE = –27.7 kcal/mol; formation of ethanol adduct: ΔE = –64.3 kcal/mol). The corresponding four Li bis(amidinates) are weakly blue to green-emissive in THF solution. Overall, a new series of highly flexible bis(amidines) has been examined.
One-Pot Anodic Conversion of Symmetrical Bisamides of Ethylene Diamine to Unsymmetrical gem-Bisamides of Methylene Diamine
Golub, Tatiana,Dou, Gui-Yuan,Zeng, Cheng-Chu,Becker, James Y.
supporting information, p. 7961 - 7964 (2019/10/11)
Symmetrical bisamides of ethylene diamine of type ArCONHCH2CH2NHCOAr undergo anodic C-C bond cleavage in acetonitrile-LiClO4 under controlled-potential electrolysis. The electrogenerated carbocation intermediates react with the solvent acetonitrile to afford unsymmetrical gem-bisamides of type ArCONHCH2NHCOMe in a one-pot reaction. The yields of the latter products are moderate (up to 60%). Other minor products involve two symmetrical gem-bisamides of type ArCONHCH2NHCOAr and MeCONHCH2NHCOMe and fragmentation products (e.g., ArCONHCHO, ArCONH2, and ArCN).
Structure-property relationships of aromatic polyamides and polythioamides: comparative consideration with those of analogous polyesters, polythioesters and polydithioesters
Nagasawa, Masayuki,Ishii, Tatsuya,Abe, Daisuke,Sasanuma, Yuji
, p. 96611 - 96622 (2015/11/24)
Conformational characteristics and configurational properties of aromatic polyamides and polythioamides, analogues of common aromatic polyesters such as poly(ethylene terephthalate) and poly(trimethylene terephthalate), have been investigated via NMR experiments and molecular orbital calculations on model compounds, and the refined rotational isomeric state calculations for the polymers. The polyamides and polythioamides were actually synthesized and characterized in terms of solubility, molecular weight, crystallinity, thermal transition, and thermal stability. Herein, the experimental results are discussed mainly from the viewpoint of the conformational characteristics and compared with those obtained from analogous aromatic polyesters, polythioesters, and polydithioesters to reveal the effects of the heteroatoms O, S, and NH included in the backbone on the polymer structures and properties.
