What is quantum chemical descriptors?

Quantum chemical descriptors and empirical parameters are two different types of chemical parameters that play the fundamental roles in chemical reactivity and model development. However, previous studies have lacked detail regarding the relationship between quantum chemical descriptors and empirical constants.

Which is a quantum chemical parameter?

Quantum chemical parameters such as LUMO energy, HOMO energy, ionization energy (I), electron affinity (A), chemical potential ( ), hardness ( ) electronegativity ( ), philicity ( ), and electrophilicity ( ) of a series of aliphatic compounds are calculated at the B3LYP/6-31G(d) level of theory.

What is molecular descriptors in drug design?

Molecular descriptors are readily calculated from the chemical structure and provide an abundance of chemical and physical information about the compounds [42-48]. Molecular descriptors are generally correlated with structure-activity relationships, which are expected to include a compound’s ability to obtain a charge.

Which is a molecular descriptor for QSAR?

A molecular descriptor is a structural or physicochemical property of a molecule or part of a molecule. A QSAR model for predictive toxicology is a mathematical relationship between a chemical’s quantitative molecular descriptors and its toxicological endpoint [9,44].

What is QSAR in medicinal chemistry?

Quantitative structure-activity relationships (QSAR) have been applied for decades in the development of relationships between physicochemical properties of chemical substances and their biological activities to obtain a reliable statistical model for prediction of the activities of new chemical entities.

What is quantitative structure property relationship?

Quantitative structure–activity relationships/quantitative structure–property relationships (QSARs/QSPRs) are mathematical models of the relationship between a drug’s structural properties and its biological behavior [26].

What is quantum chemical calculation?

Quantum chemical calculations are currently used by researchers in various fields of physics and chemistry more and more often. In difficult cases, the use of quantum chemical calculations can predict the behavior of molecules in various cases.

What is computational chemistry used for?

Computational chemistry is a branch of chemistry that uses computer simulation to assist in solving complex chemical problems. It exploits methods of theoretical chemistry, incorporated into efficient computer programs, to calculate the structures, the interactions, and the properties of molecules [43].

What are 1D 2D and 3D descriptors?

The main classes of theoretical molecular descriptors are: 1) 0D-descriptors (i.e. constitutional descriptors, count descriptors), 2) 1D-descriptors (i.e. list of structural fragments, fingerprints),3) 2D-descriptors (i.e. graph invariants),4) 3D-descriptors (such as, for example, 3D-MoRSE descriptors, WHIM descriptors …

What are 2D descriptors?

The 2D descriptors are calculated from the 2D structure of a molecule, though some of them such as logP and fragment counts are called 1D descriptors in the literature. The 2D descriptor’s counts of atoms are different from those in the 1D descriptors since different types of atoms are counted.

What are molecular descriptors and fingerprints?

Fingerprints or descriptors are an abstract representation of certain structural features of a molecule. These descriptors may represent a structural key within a molecule. This might be as simple as a count of a particular atom type, S, N etc, or halogen, or sp3.

What is the difference between SAR and QSAR?

Quantitative SAR (QSAR) model is regarded as a special case of SAR (when relationships become quantified), and this model relates a set of “predictor” variables (X) to the potency of the response variable (Y) to predict the activity of chemicals.

How do molecular descriptors affect QSAR model performance?

Molecular descriptors, as the core feature parameters of QSAR models, are among the key factors in determining the model performance.

What is the importance of QC and QSAR in chemistry?

The combination of QC descriptors, which can accurately describe the electronic structure properties and physical and chemical meaning of a system, and the QSAR model, which can quantitatively describe the relationship between the chemical structure and properties, has played a very important role in modern chemistry research.

Are OEE descriptors useful in Medicinal Chemistry?

There is no doubt that OEE descriptors have considerable application potential in supramolecular chemistry, biochemistry, and medicinal chemistry, which involve numerous complex ion–π interactions.

Who are the authors of transition state design in chemistry?

Doo-Hyun Kwon, Jack T. Fuller, III, Uriah J. Kilgore, Orson L. Sydora, Steven M. Bischof, and Daniel H. Ess . Computational Transition-State Design Provides Experimentally Verified Cr (P,N) Catalysts for Control of Ethylene Trimerization and Tetramerization.