GEORGETOWN UNIVERSITY
Department of Chemistry
CHEM 511 --Chemical Bonding (Prof. Miklos Kertesz)
The aim of the course to introduce the student to the basic principles and applications of the modern theory of bonding. After a review of the basics in quantum mechanics, the course outlines in detail the various concepts and approximate methods of quantum chemistry avoiding purely mathematical derivations as much as possible. Qualitative aspects of bonding will be emphasized. Specific calculations will be analyzed.
The following is a list of major subjects:
-Potential energy surfaces; introduction to using the Hyperchem package
-Preliminary survey of computational techniques in the theory of bonding
-Wave mechanical principles, orbitals
-Qualitative MO theory, Walsh diagrams
-MO vs. VB (and CI)
-Diatomic and polyatomic molecules
-Carbon compounds
-Hückel theory, aromaticity, long polyenes
-Transition metal compounds
-Introduction to using the Gaussian 03 package.
-Elements of reactivity theory, introduction to solvent effects
-Solids, metals (Fermi level), insulators and semiconductors, energy bands
-Hydrogen bonds, weak bonds
-Survey of quantum chemical methods (semi-empirical and ab initio)
-Applied group theory, selection rules
-Experimental probes of chemical bonding
Prerequisites:Physical Chemistry I and II, Calculus I and II.A review sessionon linear algebra will be held for those who need it.
Textbook: R.McWeeney, "Coulson's Valence"Oxford U.P., Oxford (Third Ed., 1979/80), (GU library code: QD469.C74)
Recommended texts:
Vincent, A. "Molecular Symmetry and GroupTheory" (QD461.V52) –The elements of group theory.
Leach, Andrew R, “Molecular modeling: principles and applications /Harlow, England ; New York : Prentice Hall, 2001 (QD480 .L43 2001)-An excellent molecular modeling book with an overview including applications in the materials area and biochemistry.
Contact: email: (Please use in all matters related to this course ‘CHEM 511’ in the subject field. My email system presorts all email, and I will not be able to respond if the subject is not exactly CHEM 511.)
Office hours: 12:15 – 1:00 pm after class on WF in 644. For other times, call or email: (Tel. x75761.)
Grading: graded homework assignments (10 assignments), 2 points each.20%
Midterm(at the level of the problems in the textbook)20%
Literature project supplemented by own calculations20%
Individual projects (organic or inorganic as appropriate)20%
Final exam (at the level of the problems in the textbook)20%
Bonus: any typo’s will be awarded with usually 1 point. These can occur in the textbook, my lecture notes or the recommended books. I reserve the right to limit the bonus points.
Individual project and final paper will be based on calculations and theirinterpretation using availablesoftware (primarily Hyperchem) and recent literature. Other program packages will be also available as necessary for your project. Projects are usually chosen from the area of structural inorganic chemistry, physical organic chemistry or solid state chemistry and are agreed upon with the student.
Please start planning your project ASAP. Literature project should to be submitted by February 15. Calculational project proposals should to be submitted by March 14 for approval.
Further useful books (most of them in the reference section of the Science Library)
The following two contain MO coefficients of many molecules:
Dictionary of π-Electron Calculations, by Coulson and
StreitweiserQD461.C66
Molecular Wave Functions and Properties, by L.C. Snyder and
H. BashQD462.S68
Structural data can be found in these:
Interatomic Distances (ed. L.E. Sutton) QD65.S1T3 + Suppl. 1972)
Molecular Structure and Dimensions ("CambridgeCrystallographic Data" CCD) Z5524.C8,M6 Vols. 1-15 + Index)
Continuation and current CCD is called "Cambridge Structural Database" (CSD), its use is mandatory in this course. It is available on several PC’s at Georgetown University.
Bond Index to the Determination of Inorganic Crystal Structure by I.D. Brown and C.P. Weiss (1969-1981) 1Z5524.C8B2 (inorganic, without organic parts)
Bibliography on ab initio calculations:
A Bibliography of ab Initio Molecular Wave Functions, by W.G. Richards et. al. (Z5524.P6R52.+Suppl1+Suppl2)
Quantum Chemistry Literature Database, by K. Ohno and K. Morokuma (1978-80) (Z5524Q35,038, 1982)
Continuations are being published in J. Mol. Struct. (Theochem) in various issues, irregularly.
The following books are for further reading and will be put on reserve for the course:
I.N. Levine:Quantum Chemistry, any edition (latest is 2005) –Considered by many as the top Q. Chem. text.
B.M. Gimarc: Molecular Structure and Bonding, 1979 (QD461.G56) –Qualitative MO theory.
Spectroscopic aspects of qualitative MO’s are covered e.g. in: H.M. Jaffe and M. Orchin: Theory and applications of UV Spectroscopy, J. Wiley, 1962.
Suggestions for Projects: (this is from a previous year, it will be updated for 2007)
1.Know the basic features of the method you plan to use (usually, ab initio DFT, or semi empirical, such as PM3, AM1 or EHT). Use the Hyperchem manual extensively, it is well written.
2.Identify the source of the geometry for your project, or sources for any other data that you use. Check, whether data are reasonable. E.g. are all bond distances, bond angles and dihedrals defined and are the values reasonable?
3.Construct the starting geometry. This is the most time consuming part, be patient and careful. use an atom numbering which is reasonable, which can accommodate the changes (geometrical or chemical) you plan to investigate. Choose your reference plane carefully, because you may have no other way to identify the symmetry of the orbitals you get at the end. (E.g. π- or σ-type.) If you have a conjugated part in your molecule or if there is some other symmetry (e.g. octahedral) choose your Cartesian axes such that the interpretation of the MO's will be easy: that you end up with as much as possible pure . π-,σor δ-bonds. The atom numbering is part of the report.
4.Check your geometry before submitting geometry optimization or even MO calculations. Check the elements of the distance matrix (contains atom-atom distances). If not OK, back to 3.
5.You should be ready with most of the calculations by April 15. Do consult me as often as needed to accomplish this. If by that date you have not seen me I will assume that the project is going according to plans. You must give me a written report (2-3 pages with references for the experimental data) by April 25.
6. The reports are not a mini-dissertation. State the problem, describe the methods and some details of the calculations and the conclusions. Compare with experimental evidence. There must be some experimental validation or comparison in the report. Time permitting we will have 10 min. presentations of all projects at the end of the semester. Excellent presentations will be awarded with up to 5 bonus points.
There are several books that contain excellent examples of small doable hands on quantum chemistry projects and we will use these for selecting some of the projects in the class. Organic chemistry examples are easier to find than inorganic ones.
A Laboratory book of computational organic chemistry / Warren J. Hehre, Alan J. Shusterman, W. Wayne Huang; Irvine, CA : Wavefunction inc, c1998 QD257 .H44 1998
Practical strategies for electronic structure calculations / Warren J. Hehre
Irvine, CA : Wavefunction, Inc., 1995QD461 .H44 1995
The following is extensively referring to the Gaussian package:
Exploring chemistry with electronic structure methods / James B. Foresman, Æleen Frisch
Pittsburgh, PA : Gaussian, Inc., 1996 QD461 .F72 1996.
Further information on how to perform ab initio calculations:
Please see:
Note: the earlier versions of the Gaussian 03 is called g98, and the above directions refer to this version. For your molecular applications you should not see any differences.
Manuals:
online:
See also copies of manuals in my lab, in 602F Reiss.
First I suggest you do a small calculation on a 3-4 atomic molecule with the results already known to you so that you can test your procedure.