Hydrogen bonding: HOC=O···H–N vs. HOC=O···H–C

Autor:	Sanjeev K. Dey, Suchitra Datta, David A. Lightner
Rok vydání:	2014
Předmět:	chemistry.chemical_classification chemistry.chemical_compound Monomer chemistry Hydrogen bond Stereochemistry Carboxylic acid Intramolecular force Proton NMR Lactam General Chemistry Ring (chemistry) Pyrrole
Zdroj:	Monatshefte für Chemie - Chemical Monthly. 145:1595-1609
ISSN:	1434-4475 0026-9247
Popis:	A chloroform-soluble dipyrrinone, 8,9-bis-(5-carboxypentyl)-2,3-bis-(2-methoxyethoxy)-10H-dipyrrin-1-one, with solubilizing 2-methoxyethoxy β-substituents on the lactam ring and two hexanoic acid groups (one at C(9), the other at C(8) of the pyrrole ring) was synthesized to determine its ability to form intramolecular hydrogen bonds to the lactam unit from either carboxylic acid, whether in the syn-(Z) or anti-(Z) conformation. In the syn-(Z) conformation, such intramolecular hydrogen bonds can also include the pyrrole N–H. In the anti-(Z), intramolecular hydrogen bonds can include the pyrrole C(7)-H. Evidence for both monomer conformations in equilibrium is provided by 1H NMR analyses, which indicate that the syn-(Z) is favored over the anti-(Z) and predict an interconversion barrier of approximately 40 kJ mol−1.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::0e1c08a0ef2c36c16fb3bedad1d1cb54 https://doi.org/10.1007/s00706-014-1257-y Zobrazit plný text záznamu Full text from SpringerLink