We describe the development of Lewis’s ideas concerning the chemical bond and in particular the concept of the electron pair bond and the octet rule. We show that the concept of the electron pair bond has endured to the present day and is now understood to be a consequence of the Pauli principle. In contrast the octet rule is now regarded as much less important than was originally generally bel...

In order to understand the physics behind the surface properties and nano-scale phenomena, we are motivated first to investigate the inner bond strengths as well as the effect of number of neighboring atoms and their relative distance in addition to space positions (crystallography). Therefore, in order to study the effect of the nature of metallic bond on their physico-chemical properties, we ...

Biological catalysis frequently causes changes in noncovalent bonding. By building on Pauling's assertion that any long-lived, chemically distinct interaction is a chemical bond, this article redefines enzyme catalysis as the facilitated making and/or breaking of chemical bonds, not just of covalent bonds. It is also argued that nearly every ATPase or GTPase is misnamed as a hydrolase and actua...

B3LYP/6-31G* calculations were carried out on adducts formed by the interaction of a cyclic unsaturated aminocarbene with carbenoid moieties CH2, SiH2, NH, PH, O or S. The bonding mode has been described using the Natural Bond Orbital (NBO) partitioning schemes, the Charge-Decomposition Analysis (CDA) and the topological analysis of the Electron Localization Function (ELF). A donor–acceptor int...

In this research, IR and frontier molecular orbital (FMO) computations were employed for investigating the performance of B12N12 as a novel recognition element for fabrication of quetiapine thermal and electrochemical sensors. All of the computations were done by density functional theory method in the B3LYP/6-31G(d) level of theory and in the aqueous ph...

Based on single molecule manipulation experiments in a combined scanning tunneling microscope/frequency modulated atomic force microscope, we quantify the individual binding energy contributions to an organic-metal bond experimentally. The method allows the determination of contributions from, e.g., local chemical bonds, metal-molecule hybridization, and van der Waals interactions, as well as t...

Theories of the chemical bond aim to explain the structures and stabilities of molecules, and different theories aim for different levels of explanation. The most important theories are those that give simple explanations for the structures and stabilities of the most stable molecules ; broadly speaking, those that we find in bottles on the shelf of a laboratory. However, as experimental chemis...

The involvement of chemical exchange in 2D IR heterodyne echo spectroscopy is characterized through the hydrogen-bond exchange between CH3OH and the CN of CH3CN. The exchange dynamics on the hydrogen-bond potential surfaces associated with different quantum states of the high-frequency CN stretching mode contributes to strong cross peaks between CN groups in two different chemical configuration...

antioxidants are compounds which can prevent biological and chemical substances from oxidative damage by reactive oxygen species. flavonoids are the most important class of polyphenolic compounds that because of their antioxidant characters possess biological activities and pharmacological effects. chrysin-6-c-fucopyranoside and chrysin-3-malonyl-6-c-fucopyranoside are mono c-glycosyl derivativ...

Hardness is too complex to be described by first principles. Based on the dielectric chemical bond theory, a semiempirical approach for the evaluation of the hardness of ionic oxide crystals has been proposed. It was applied to predict the hardness of complex crystals such as the optical crystals yttrium aluminum garnet, the LaMgAl11O19 aluminates, and the high-Tc superconductor YBa2Cu3O7. The ...