12 CFU - 2° Semester

**Physical Chemistry II**The course is aimed to provide students with the basic physico-chemical knowledge necessary for the understanding of chemical bond, molecular spectroscopy and chemical kinetics. At the end of the course the student will be able to understand the basic principles of quantum-mechanical and spectroscopic methods and their applications to the determination of electronic and geometric structure of molecules. Also, he will know the basics of chemical kinetics and the main methodologies for the theoretical and experimental study of chemical reactions.

**Module II**The course's main objective is to provide to the student with specific knowledge in the field of Physical Chemistry

In particular, the student is expected to develop base theoretical knowledge in Physical Chemistry and to be able to apply it practically. This goal will be obtained via various laboratory experiences.

**Physical Chemistry II**Classes and class exercises

**Module II**The course will consist of

_ Class lectures to introduce laboratory experiences

_ Laboratory experiences

_ PC exercises for the analysis and the interpretation of experimental data

**Physical Chemistry II****I – The quantum description of atoms and molecules**- Crisis of classical physics and birth of quantum theory.
- Postulates of quantum mechanics. Wave functions and operators. Schrödinger equation.
- Application to some simple systems. Particle in a one-dimensional box. Particle in a three-dimensional box. Tunnel Effect. Harmonic and anharmonic oscillator. Rigid rotor.
- The hydrogen atom.
- Polyelectronic atoms. Approximate methods for solving the Schrödinger equation: perturbative methods (outline); the variational method. Helium atom. Orbital approximation. Hartree-Fock self-consistent field method. Correlation energy. Independent electron theory for complex atoms. The Pauli principle. Aufbau.
- The chemical bond in diatomic molecules. Born-Oppenheimer approximation. The molecular orbital method and its application to the hydrogen ion molecule. Overlap, coulomb and exchange integrals and their contribution to the stability of the chemical bond. Bonding and antibonding molecular orbitals. Diatomic molecules with many electrons. Electronic structure in the MO scheme. σ and π orbitals. Aufbau for molecular orbitals. Electronic configuration and properties of homonuclear diatomic molecules.
- Polyatomic molecules. The Huckel method applied to ethylene, butadiene, cyclobutadiene, benzene. Delocalization energy. Charge distributions in a π system. π- and total bond order - Relationship between bond order and bond length. Extension of the Hückel method to heteroatom-containing molecules. Experimental evidence of the existence of molecular orbitals.
- Introductory outline of the electronic structure of solids.

**II – Radiation-matter interaction and molecular spectroscopy**- Basic principles of molecular spectroscopy. Interaction of electromagnetic radiation with matter. Time-dependent Schrödinger equation. Timr-dependent perturbation theory (outline). Selection rules for radiative transitions. Population of states and Boltzmann distribution. Conventional and non-conventional spectroscopies. Born-Oppenheimer approximation for spectroscopies. Diatomic molecules: separation of vibrational and rotational modes.
- Rotational Spectroscopy. Rotational energy levels and rotational spectra of diatomic molecules. Introduction to the classification of molecules from a rotational point of view (linear, spherical, symmetric, asymmetric) and related spectra.
- Vibrational spectroscopy. Vibrational spectra of diatomic molecules and selection rules according to the model of the harmonic oscillator. Application of the anharmonic oscillator model - Normal modes in polyatomic systems and vibrational spectra. Vibration-rotation spectra of di- and triatomic molecules.
- Electronic spectroscopy. Electronic transitions in diatomic and polyatomic molecules. Selection rules. The Franck-Condon principle and vibronic transitions. Photoelectron spectroscopy. The photoelectron spectrum of CO. Spectra of hydrides the VI group elements. Photoelectron spectra of substituted benzenes.
- The fate of excited electronic states. Photophysical processes. Einstein coefficients, spontaneous emission and stimulated emission. Fluorescence spectroscopy. Lasers and laser spectroscopy. Photochemical processes.

**III - Chemical kinetics**- The rate of chemical reactions. Simple kinetic laws and rate constants. Integration of simple kinetic equations. Temperature dependence of reaction rates. Reaction mechanisms. Elementary reactions. Consecutive and parallel reactions. Principle of the detailed balance. The steady state approximation. Complex reactions. Enzymatic kinetics.
- The dynamics of reactions. The collision theory: collision sphere, cross section, impact energy and steric factor. Transition state theory. Experimental study of molecular collisions. Angular distribution and velocities of reaction products. Rebound, stripping and complex formation mechanisms. Potential energy surfaces. The study of ultrafast reactions: femtochemistry

**Module II**Contents: Laboratory safety, Analysis ad interpretation of experimental data (some knowledge of error theory will be also provided), Chemical kinetics, Introduction to spectroscopy, Introduction to thermodynamics of surfaces and interfaces

Laboratory experiences: Kinetics of acetone ioduration, Kinetics of ethyl acetate hydrolysis, Confirmation of the Stern-Volmer law, FT-IR spectra solid and liquid carbonylic compounds, Electronic absorption spectrum of iodine, Calculation of surface free energy, Langmuir Isotherms

**Physical Chemistry II**- D.A. McQuarrie, J.D. Simon - Physical Chemistry- A molecular approach - University Science Books
- G.K.Vemulapalli - Physical Chemistry - Prentice Hall
- P.W.Atkins, J. de Paula - Physical Chemistry – Oxford University Press
- P.W.Atkins, R.S.Friedman - Molecular quantum mechanics - Oxford University Press
- J.M. Hollas, Modern spectroscopy - Wiley
- Lecture notes and slides, and further didactic material directly supplied by the teacher.

**The student is free to use, in alternative or in addition to the proposed textbooks, any other textbook (university level) of physical chemistry and molecular spectroscopy.****Module II**1. Notes and Slides from Lectures

2. Physical Chemistry, by Julio De Paula and Peter Atkins

3. Introduction to Error Analysis, by J.R.Taylor