Understanding the Highly Varying pKa of Arylamines. A Perspective from the Average Local Ionization Condensed-to-Atom Framework.

J Phys Chem A

Departamento de Ciencias Quimicas. Facultad de Ciencias Exactas. Nucleus Millennium of Chemical Processes and Catalysis, Universidad Andres Bello, Avenida República 275, 8370146 Santiago, Chile.

Published: July 2015

The highly varying experimental pKa values for 36 arylamines spanning 7 orders of magnitude is carefully examined. Within this framework, a valence condensed-to-atom model for the average ionization energy is introduced and tested. The theoretical approach is connected to orbital Fukui functions directly mapped into semilocal or regional site-specific responses. It is revealed that the average local ionization energies associated with the amino nitrogen atom is linearly correlated to the basicity of the substituted arylamines, properly reproducing the experimental ordering of basicity. The condensed-to-atom descriptor exhibits a high predictive power, providing a new direct reactivity evaluation of significant value.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jpca.5b03252DOI Listing

Publication Analysis

Top Keywords

highly varying
8
average local
8
local ionization
8
understanding highly
4
varying pka
4
pka arylamines
4
arylamines perspective
4
perspective average
4
ionization condensed-to-atom
4
condensed-to-atom framework
4

Similar Publications

Background: One of the best ways to impart important skills to trainees is through simulation-based training, which is more reliable than the conventional clinical examination method. It is used in pediatric nursing training to allow nurses to practice and improve their clinical and conversational skills during an actual child encounter. A heel-prick is a complex psychomotor task that requires skill and knowledge from the pediatric nurse performing the procedure while applying for the National Newborn Screening Program.

View Article and Find Full Text PDF

Several recent investigations into montane regions have reported on excess mercury accumulation in high-altitude forest ecosystems. This study explored the Singalila National Park, located on the Singalila ridge of the Eastern Himalayas, revealing substantial mercury contamination. Particular focus was on Sandakphu (3636 m), the highest peak in West Bengal, India.

View Article and Find Full Text PDF

Thyroid cancer.

Med Clin (Barc)

January 2025

Servicio de Endocrinología y Nutrición, Hospital i Institut de Recerca Germans Trias i Pujol, Universitat Autònoma de Barcelona, España. Electronic address:

In recent decades, the diagnosis of thyroid cancer, especially the papillary type, has increased significantly due to the use of imaging techniques such as ultrasound. For this reason, it is essential to rationalize diagnosis and treatment, since the behavior of thyroid cancer varies from slow-progressing tumors to highly aggressive ones. The application of risk assessment systems for ultrasound images and the optimization of cytology incorporating molecular studies allows cases to be stratified in order to select therapy on an individual basis.

View Article and Find Full Text PDF

A comprehensive study was conducted on the life history parameters of an important vector Culicoides oxystoma Kieffer (Diptera: Ceratopogonidae), to standardize potential rearing procedures. Data on life history traits and rearing conditions are crucial for establishing laboratory colony and conducting vector competence-based studies utilizing specimens with a known rearing history. Six different substrate compositions were used to rear the larvae: S1: habitat mud containing cattle manure + nutrient broth + yeast, S2: yeast, S3: habitat mud containing cattle manure + nutrient broth, S4: nutrient broth, S5: sterile (habitat mud consisting cattle manure + nutrient broth + yeast) and S6: tap water.

View Article and Find Full Text PDF

Mechanisms for DNA Interplay in Eukaryotic Transcription Factors.

Annu Rev Biophys

January 2025

1CREST Center for Cellular and Biomolecular Machines, University of California, Merced, California, USA; email:

Like their prokaryotic counterparts, eukaryotic transcription factors must recognize specific DNA sites, search for them efficiently, and bind to them to help recruit or block the transcription machinery. For eukaryotic factors, however, the genetic signals are extremely complex and scattered over vast, multichromosome genomes, while the DNA interplay occurs in a varying landscape defined by chromatin remodeling events and epigenetic modifications. Eukaryotic factors are rich in intrinsically disordered regions and are also distinct in their recognition of short DNA motifs and utilization of open DNA interaction interfaces as ways to gain access to DNA on nucleosomes.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!