Born–Oppenheimer Approximation

 Born–Oppenheimer Approximation (BOA)

The Born-Oppenheimer Approximation is a fundamental concept in quantum mechanics that simplifies the Schrödinger equation for many-body systems, like molecules, by separating nuclear and electronic motion.

Molecular Modeling Using Molecular Mechanics

 

Molecular Modeling Using Molecular Mechanics

Molecular models can be constructed in two main ways. Either researchers use an existing commercial force-field-based software package, or they build the molecule by assembling structural fragments stored in the molecular modeling program’s database.

 

Introduction to Quantum Mechanics

Quantum mechanics is the branch of chemistry and physics that describes the behavior of matter and energy at the atomic and molecular scale.

Molecular Mechanics (MM) and Force Field Methods

 

Molecular Mechanics (MM) and Force Field Methods

What is Molecular Mechanics?

Molecular Mechanics (MM) is a computational method used to study molecules by applying classical physics laws instead of quantum mechanics.  OR

Molecular mechanics is a computational method that calculates molecular structure and energy using classical mechanics and force field equations without explicitly considering electrons.

Difference Between Classical Physics and Quantum Mechanics

 

Difference Between Classical Physics and Quantum Mechanics

Classical physics explains the motion and energy of large objects such as cars, balls, and planets.

Quantum mechanics explains the behavior of tiny particles like electrons and atoms where classical laws fail.

Why we use computational chemistry over experimental work in this era?

 Why we use computational chemistry over experimental work?

We use computational chemistry to understand, predict, and design chemical systems using computers, often reducing the need for expensive and time-consuming laboratory experiments.

Introduction to computational chemistry, method, tools, and applications

 Computational Chemistry (Introduction)

Computational chemistry is a branch of chemistry that uses computer simulations, mathematical models and theoretical chemistry methods to study the structure, properties, and reactions of molecules. Instead of doing experiments only in laboratories, scientists use computers to predict molecular behavior, energies, and reaction mechanisms.

Or

Computational chemistry applies quantum mechanics, molecular mechanics, and statistical methods using computers to understand the chemical environment.

Reaction of alkene part 2

 Reactions of alkenes:

Reactions of alkenes part 1

 Reactions of alkenes:

Stability of Alkenes

 Stability of Alkenes

There are two factors for determining the stability of alkenes

Preparation of Alkene Part 4

 Wittig Reaction

The Wittig Reaction is a very useful method for the synthesis of alkenes. In this reaction, aldehydes and ketones react with phosphorus ylides to form alkenes.

Preparation of Alkene part 3

 Cope Reaction

When tertiary amine oxides are heated to about 150°C, they undergo thermal elimination to form alkenes. This reaction is known as the Cope Reaction.

Preparation of Alkenes Part 2

 Pyrolytic Eliminations

Pyrolytic elimination reactions are those in which the elimination occurs through heating and involves a cyclic transition state. These reactions occur without requiring the addition of external reagents like acids or bases. Instead, the heat provides the necessary energy to facilitate the elimination.

Preparation of Alkenes

Preparation of Alkenes

1. Dehydrohalogenation of alkyl halides:

Alkenes can be prepared by the elimination of hydrogen halide from an alkyl halide. Hydrogen and halogen are removed from adjacent carbon atoms, resulting in the introduction of a carbon-carbon double bond in the molecule.

Nomenclature of Alkenes

 Nomenclature of Alkenes

Introduction to Alkenes

 Alkenes

Introduction

Alkenes are hydrocarbons that contain at least one carbon-carbon double bond. They follow the general formula C_nH_2n. A double bond makes them unsaturated and more reactive than alkanes.

Olefins is another name for alkenes, derived from "olefiant gas" (oil-forming gas). This term historically referred to ethene () because it reacts with chlorine to form an oily liquid.

Reactions of Alkanes

 Reactions of Alkanes

1. Halogenation of Alkanes

Halogenation is a substitution reaction where hydrogen atoms in alkanes are replaced by halogens (Cl, Br). The reaction occurs via a free-radical mechanism involving initiation, propagation, and termination steps.

Preparation of Alkanes

Preparation of Alkanes:

1. Hydrogenation

Hydrogenation involves the addition of hydrogen to unsaturated hydrocarbons (alkenes or alkynes) in the presence of a metal catalyst such as Ni, Pd, or Pt, under elevated temperature (250°C).

Synthesis of Tris(ethylenediamine)cobalt(III) Chloride

Synthesis of Tris(ethylenediamine)cobalt(III) Chloride

Objective:

To synthesize tris(ethylenediamine)cobalt(III) chloride [Co(en)₃]Cl₃ ​, an octahedral coordination compound of cobalt(III) that exhibits optical activity.

Nomenclature of Alkanes (IUPAC Rules)

 

Nomenclature of Alkanes (IUPAC Rules):

The IUPAC (International Union of Pure and Applied Chemistry) system provides systematic rules for naming alkanes and other organic compounds. Here are the basic rules for naming alkanes:

Rule 1: Identify the longest continuous carbon chain in the molecule. This chain is referred to as the "parent chain," and its length determines the base name of the molecule (e.g., methane, ethane, propane, etc.).