# Molecular Orbitals in Inorganic Chemistry L1-L4

### Course information:

All the information you need for this course will be accessible from this site.

use the sidebar to access a specific lecture, workshop and other materials.

### Need some help!

#### The recommended text for this course:

Group Theory for Chemists, Kieran C. Molloy, Harwood Publishing, Chichester, 2004.Tutorials and homework form part of this course and are examinable. Extra reading material is associated with each lecture, this is entirely optional! However, if you want to find out still more please contact me, I can recommend a wider variety of texts, including those which cover material in more detail.

#### Check the questions answered list!

I will add questions that people ask me, along with my answers! here: Questions answered.#### Ask your class mates and friends

This is good for you and them, teaching and explaining something really helps you understand it yourself. You could also get together with your friends and try to talk material through, discussing material is actually a good way to learn.#### Ask your tutor

As usual, use your tutorial time to ask your tutor about any material you are having trouble with. Your tutor can also talk with you individually outside of tutorials, just ask!#### Contact Me

I'm very happy to revceive questions via e-mail:If a group of students are having problems I'm very happy to arrange a lunchtime tutorial. I'm also happy to send feedback via a pdf/word file.

### Revision and Introductory Material

(updated for 2019)- key lecture material from last year:
- from 1st Year Inorganic Chemistry
- Symmetry
- Molecular orbitals

- How to build the MO diagram for a homonuclear diatomic
- revision notes: pdf
- these notes also cover the MO mixing in some detail, as feedback has been that this was difficult

- Carrying out calculations
- revise your 1st year workshop
- Calculate the MOs for N
_{2}and F_{2} - the revision notes above include discussion on the MOs of these compounds
- you can also find out how to visualise orbitals on your own computer here Computational examples

### Lecture 1

(updated for 2019)- notes for the lecture: pdf
- slides from the lecture for printing: pdf
- slides as presented in the lecture: high resolution pdf 20.4 MB
- slides as presented in the lecture: low resolution pdf 1.7 MB good for mobile devices
- keynote live link
- a link to the Panopto recording lecture 1
- flow chart and character tables handouts (bring to class every week!):
- model answers
- resources related to this lecture optional
- a bit more detail on how to find the characters for degenerate representations pdf
- how to find the improper rotations for the D
_{3h}point group pdf - extra for experts, improper rotations for the O
_{h}point group pdf - Part 1: Symmetry from Group Theory for Chemists
- if you like doing things in a problem based format the following is very good, Programme 1: Symmetry Elements and Operations from Molecular Symmetry and Group Theory (2nd Edition), Alan Vincent, John Wiley & Sons Ltd, Chichester, 2001.
- imperial chemistry department symmetry web-site has 3D movable examples of symmetry elements for water good

- famous theoreticians: optional
- in 2009 Prof. Eisenstein a theoretical chemist recieved the American Chemical Society award for organometallic chemisty Interview with Prof Eisenstein
- Emily Carter Professor in Energy and the Environment Princeton University and elected as a Fellow of the American Chemical Society in 2012
- Sharon Hammes-Schiffer elected as a Member of the National Academy of Sciences, 2013
- the nobel prize in chemisty 1981 went to Fukui and Hoffmann
- the nobel prize in chemisty 1998 went to Kohn and Pople
- the nobel prize in physics 2008 went to Yoichiro Nambu, Makoto Kobayashi, Toshihide Maskawa
- the nobel prize in chemisty 2013 went to Martin Karplus, Michael Levitt, Arieh Warshell
- Who was Christopher Longuet-Higgins?

### Lecture 2

(updated for 2019)- notes for the lecture: pdf
- slides from the lecture for printing: pdf
- slides as presented in the lecture: high resolution pdf 11.1 MB
- slides as presented in the lecture: low resolution pdf 1.9 MB mobile
- a link to the Panopto recording when it becomes available lecture 2
- model anwers
- in class probems: pdf
- self-study problems / exam preparation: pdf
- you should run the jobs yourself, but you can also check them against mine, to view you will first need to download the file!
- pop_beh2_opt_freq.fchk
- pop_nh3_opt_freq.fchk

- extra notes and reading related to this lecture optional
- catch-up, more on the very basics of AOs, their equations and shapes pdf
- a student has asked me where the symbols for the irreducible representations come from, normally this is covered in my later course, but if you are interested have a look at this file pdf
- Programmes 2-4 from Molecular Symmetry and Group Theory
- Chapter 7: H2O-Linear or Angular from Group Theory for Chemists
- Chapter 8: NH3-Planar or Pyramidal from Group Theory for Chemists
- Chapter 5: Molecular Orbitals Inorganic Chemistry (4th Edition) Gary Miessler and Donald Tar, Prentice Hall, Boston, 2011

- resources optional
- find out more about H3+ h3plus.uiuc.edu
- 2008 Nobel prize in physics is for symmetry breaking!
- wiki on symmetry breaking
- wiki on Noether's theorem
- wiki on symmetry in general

### Lecture 3

(updated for 2019)- notes from the lecture:pdf
- slides from the lecture for printing: pdf
- slides as presented in the lecture: high resolution pdf 9.2 MB
- slides as presented in the lecture: low resolution pdf 1.3 MB mobile
- a link to the Panopto recording when it becomes available lecture 3
- model anwers
- in class probems: pdf
- self-study problems / exam preparation: pdf
- you should run the jobs yourself, but you can also check them against mine, to view you will first need to download the file!
- pop_hf2_opt_freq.fchk
- pop_allene_opt_freq.fchk

- resources related to molecular orbitals optional
- atomic orbitals and bonding/antibonding interactions pdf "The Orbitron"
- some reading: Chapter 1.11-1.13 from Inorganic Chemistry, Catherine Housecroft and Alan Sharpe, 2nd Edition, Pearson, Prentice Hall, Harlow, 2005
- web page for exploring atomic orbitals:
- all those equations: Section 5.5 from Quanta, Matter and Change, Peter Atkins, Julio de Paula and Ronald Friedman, Oxford University Press, 2009

- Revision for diatomic molecules continued: heteronuclear diatomics
- questions and model answers for homonuclear diatomic molecules pdf
- contains
- Problem 1: CN- pop_cn_minus_opt_freq.fchk
- Problem 2: CO pop_co_opt_freq.fchk
- Problem 3: N
_{2}pop_n2_opt_freq.fchk - Problem 4: NO+ pop_no_plus_opt_freq.fchk
- Problem 5: O
_{2}pop_o2_triplet_opt_freq.fchk

- On-line interactive tutorial on CN- try it!
- 3D rotatable orbitals of CN-
- Bonding in simple diatomic molecules is still of interest today!

Bond Order and Chemical Properties of BF, CO, and N_{2}, Ryan J. Martinie, Jarred J. Bultema, Mark N. Vander Wal, Brandon J. Burkhart, Douglas A. Vander Griend, and Roger L. DeKock,*J. Chem. Educ.*,**2011**, 88 (8), pp 1094-1097 - Bonding in simple diatomic molecules is not straight forward!

Connections between Concepts Revealed by the Electronic Structure of Carbon Monoxide Ying Liu, Bihui Liu, Yue Liu, and Michael G. B. Drew,*J. Chem. Educ.*,**2012**, 89 (3), pp 355-359 - for experts! A paper on the complexity of mixing in diatomic molecules

Role of s-p Orbital Mixing in the Bonding and Properties of Second-Period Diatomic Molecules" F. Matthias Bickelhaupt, Jeffrey K. Nagle and William L. Klemm, J.*Phys. Chem. A***2008**, 112, 2437-2446

### Lecture 4

(notes updated for 2019)- notes from the lecture:pdf
- slides from the lecture for printing: pdf
- slides as presented in the lecture: high resolution pdf 16.2 MB
- slides as presented in the lecture: low resolution pdf 3.3 MB mobile
- a link to the Panopto recording when it becomes available lecture 4
- model anwers
- in class probems: pdf
- homework/tutorial/exam problems: pdf
- you should run the jobs yourself, but you can also check them against mine, to view you will first need to download the file!
- pop_ch2N_opt_freq.fchk
- pop_i3_anion_opt_freq.fchk

- resources related to forming complex MO diagrams optional
- there are a number of ways of generating the MOs for B2H6. I have shown you one way which is covered in p 124-127 of Inorganic Chemistry, Catherine Housecroft and Alan Sharpe, 2nd Edition, Pearson, Prentice Hall, Harlow, 2005
- Another way of treating the MOs of diborane is to assume sp2 hyrbids on the B atoms, this is covered in p89-90 of the course text: Group Theory for Chemists. This section offers some additional insight but you do not need to know how to use hybrid orbitals in this way!
- Have a look at these papers: for experts

"Qualitative molecular orbital study of ethane and diborane" by B.M. Gimarc, J. Am. Chem. Soc, 1973, 95(5), p1417-1421 DOI: 10.1021/ja00786a010.

"Strengths of A-A Single Bonds io Symmetric A2Bzn Molecules and Ions" by B. Gimarc, S. Khan and M.Kohn, J. Am. Chem. Soc, 1978, 100(7), p1996-2003 DOI: 10.1021/ja00475a004. If you are interested and unable to download a copy for yourself I can provide one.

### Tutorial 1

(updated for 2019)Tutors were asked to

- cover question 1 from Lecture 1 study-problems, the point group and symmetry elements of BH
_{3}because students will need this for the first problems class - to cover degenerate orbitals and improper rotations because students typically have problems these
- to take students into the computer room and get them to compute and look at the orbitals of BeH
_{2}, the first problem from Lecture 2. - to please impress upon students that they are expected to have used the computers to study the examples in the tutorial problems and that they can expect to be asked to analyse "real" orbitals from a calculation in the exam. They will have a lab next term to facilitate this, but practice is good.

**If your tutor hasn't covered these points please do them on your own!**

### Problems Class 1

(updated for 2019)- the MO diagram of BH
_{3}: model answers pdf - run a calcualtion to visualise the MOs of BH
_{3}yourself - check it against mine, to view you will first need to download this file, if your browser changes the extension, change it back so that it reads *.fchk then open with gaussview or avagadro: pop_bh3_opt_freq.fchk
- for beginners some extra notes on orthogonality pdf
- to make room for more work with MOs of TM some material has been removed, this was on the mathematics/symmetry derivation of orbitals. This is well worth reading if you have the time!
- old notes related to symmetry adapted orbitals
- bonding models very interesting a good article to discuss with your tutors in tutorials

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