Spectroscopic evaluation of the global hardness of the atoms

A novel method for the calculation of bond stretching force constants of diatomic molecules

Chemical hardness is one of the chemical reactivity descriptors of chemical species and this concept has widely benefited from the development of Density Functional Theory (DFT). In the present report, chemical hardness values for approximately fifty diatomic molecules have been calculated using a new molecular hardness (η(M)) equation derived by us in recent times. Then, correlation between force constant (k) and chemical hardness for the above mentioned diatomic molecules that situate hydrides, halides, oxides and sulfides among them has been investigated. Consequently, a relation that can be presented by a simple equation between chemical hardness with bond stretching force constants has been found.

Nonlinear absorption in tetrathia[22]porphyrin(2.1.2.1)s: visualizing strong reverse saturable absorption at non-resonant excitation

meso-Substituted neutral, aromatic tetrathia[22]porphyrin(2.1.2.1)s represent a new entry in the family of nonlinear optically active porphyrins. The low fluence threshold values of these porphyrins endorse potential application as optical limiters.

An information-theoretic resolution of the ambiguity in the local hardness

A definition of the local hardness, suitable for application in the local hard/soft acid/base principle, is derived by applying information theory.