{"title":"Can an Amine Be a Weaker and a Stronger Base at the Same Time? Curious Cases of Chameleonic Ionization","authors":"Robert Fraczkiewicz*, ","doi":"10.1021/acsphyschemau.3c00029","DOIUrl":null,"url":null,"abstract":"<p >We discovered an anomalous basic dissociation in certain multiprotic compounds. An amine group placed in the middle of a given compound is predicted to behave unusually─at certain pH ranges, its averaged degree of protonation actually <i>increases</i> with pH (!) resulting from interactions with other ionizable groups. This chameleonic behavior results in two p<i>K</i><sub>50</sub> values: one corresponding to a weaker base and the other to a stronger base for the same group.</p>","PeriodicalId":29796,"journal":{"name":"ACS Physical Chemistry Au","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsphyschemau.3c00029","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Physical Chemistry Au","FirstCategoryId":"1085","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acsphyschemau.3c00029","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
We discovered an anomalous basic dissociation in certain multiprotic compounds. An amine group placed in the middle of a given compound is predicted to behave unusually─at certain pH ranges, its averaged degree of protonation actually increases with pH (!) resulting from interactions with other ionizable groups. This chameleonic behavior results in two pK50 values: one corresponding to a weaker base and the other to a stronger base for the same group.
期刊介绍:
ACS Physical Chemistry Au is an open access journal which publishes original fundamental and applied research on all aspects of physical chemistry. The journal publishes new and original experimental computational and theoretical research of interest to physical chemists biophysical chemists chemical physicists physicists material scientists and engineers. An essential criterion for acceptance is that the manuscript provides new physical insight or develops new tools and methods of general interest. Some major topical areas include:Molecules Clusters and Aerosols; Biophysics Biomaterials Liquids and Soft Matter; Energy Materials and Catalysis