A new aromaticity definition is advanced as the compactness formulation through the ratio between atoms-in-molecule and orbital molecular facets of the same chemical reactivity property around the pre- and post-bonding stabilization limit, respectively. Geometrical reactivity index of polarizability was assumed as providing the benchmark aromaticity scale, since due to its observable character;...

Electronegativity is a fundamental concept in chemistry. Despite its importance, the experimental determination has been limited only to ensemble-averaged techniques. Here, we report a methodology to evaluate the electronegativity of individual surface atoms by atomic force microscopy. By measuring bond energies on the surface atoms using different tips, we find characteristic linear relations ...

Electronegativity is a well-known property of atoms and substituent groups. Because there is no direct way to measure it, establishing a useful scale for electronegativity often entails correlating it to another chemical parameter; a wide variety of methods have been proposed over the past 80 years to do just that. This work reports a new approach that connects electronegativity to a spectrosco...

The PM3 semiempirical quantum-mechanical method was found to systematically describe intermolecular hydrogen bonding in small polar molecules. PM3 shows charge transfer from the donor to acceptor molecules on the order of 0.02-0.06 units of charge when strong hydrogen bonds are formed. The PM3 method is predictive; calculated hydrogen bond energies with an absolute magnitude greater than 2 kcal...

The main interaction between pyridine and zeolites leads to form a hydrogen bond between the N atom of pyridine and OH groups of zeolites. The present work reports a theoretical study about the structural, vibrational and topological properties of the charge distribution of the molecular complexes between pyridine and a series of acids sites of zeolites. The calculated structural parameters...

The inhibition activity of thione–thiol tautomers of 2-mercapto-1-methylimidazole (MMI), namely 1-methyl-1Himidazole-2 (3H)-thione (M1) and 1-methyl-1H-imidazole-2-thiol (M2) has been performed using density functional theory (DFT) B3LYP/6-311G (d, P) basis set level in order to elucidate the different inhibition efficiencies of these compounds as corrosion inhibitors. The calculated structural...

Double-layers sDLsd were observed in the expanding region of an inductively coupled plasma with Ar–SF6 gas mixtures. No DL was observed in pure argon or SF6 fractions below a few percent. They exist over a wide range of power and pressure although they are only stable for a small window of electronegativity stypically between 8% and 13% of SF6 at 1 mTorrd, becoming unstable at higher electroneg...

The entha lpy AH of general d isplacement react ions A B + C D A D + C B is der ived w i t h the a id of the ion ic app rox ima t i on to chemica l bond ing . T h i s entha lpy compares favourab ly w e l l w i t h Pau l ing 's cor responding equat ion AH—— 46 (%B— ̂ d ) (%A — XC)These expressions are used as a basis to discuss var ious aspects of chemical r eac t i v i t y : reversals i n react ...