This module explains how detailed information about structure, stereochemistry and the behaviour of chemical species in solution and in the solid state can be obtained by using luminescence spectroscopy, electron paramagnetic resonance (EPR) spectroscopy and diffraction techniques (specifically X-ray diffraction, neutron diffraction and electron diffraction, as well as electron microscopy).

1.     describe the fundamental principles of luminescence spectroscopy, EPR spectroscopy, X-ray diffraction, neutron diffraction, electron diffraction and electron microscopy;

2.     describe the different types of electronically excited states associated with organic and inorganic molecules;

3.     describe and interpret the key physical parameters that characterize different excited states;

4.     describe the processes that contribute to non-radiative deactivation (quenching) of excited states, including energy transfer mechanisms;

5.     understand different classifications of luminescence such as bioluminescence, chemoluminescence and electroluminescence;

6.     apply knowledge of excited state molecules to various applications such as chemosensors and photodynamic therapy;

7.     describe the use of the spin Hamiltonian to interpret EPR spectra in solution and in the solid state;

8.     explain the major features of EPR spectra, and their correlations with structure;

9.     predict the appearance of EPR spectra of organic radicals and simple paramagnetic metal complexes;

10.   interpret isotropic and anisotropic EPR spectra, and assign structures;

11.   understand the fundamental processes involved in the interaction of X-rays, neutron beams and electron beams with solids;

12.   describe the fundamental similarities and differences between X-ray diffraction, neutron diffraction and electron diffraction;

13.   understand the types of information about solid state structures that can be obtained from X-ray diffraction, neutron diffraction and electron diffraction techniques;

14.   understand the basis of electron microscopy techniques;

15.   appreciate the specific areas of application of X-ray diffraction, neutron diffraction and electron diffraction techniques;

16.   formulate the optimum experimental strategy for exploring specific aspects of solid-state structure.

22 Lectures(each lecture of one hour duration, with an approximately equal number of lectures for each of the three components of the module: Luminescence Spectroscopy, EPR Spectroscopy and Diffraction techniques).

3 Tutorials(each tutorial is a whole-class tutorial of one hour duration, with one tutorial allocated to each of the three components of the module: Luminescence Spectroscopy, EPR Spectroscopy and Diffraction Techniques). The tutorial sessions are non-assessed.

1 Assessed Workshop(the assessed workshop comprises a problem sheet for students to tackle at home, and to be submitted against a specified deadline which will be on a date after all the lectures and tutorials have been completed; the assessed workshop will include questions from all three components of the module: Luminescence Spectroscopy, EPR Spectroscopy and Diffraction Techniques).

Interpretation of EPR spectra for paramagnetic species in solution and in the solid state.

Formulating optimum experimental strategies (involving the use of one or more of the X-ray diffraction, neutron diffraction, electron diffraction or electron microscopy techniques) for exploring specific aspects of solid-state structure.

Ability to select appropriate techniques for determination of structure in solution or in the solid state for a range of chemical situations, and to assess the advantages/disadvantages for each particular purpose.

The module is summatively assessed via in course assessments.

There is no examination for this module.

The module is sub-divided into the following three components, which have essentially equal weight:

Luminescence Spectroscopy

Selection rules; quantized description; Jablonski diagrams.

Stokes shift; quantum yield; lifetimes.

Fluorescence; phosphorescence.

Types of chromophores; effect of structure on emission; donor-acceptor.

Energy transfer: Dexter versusFörster.

Quenching pathways: O₂; photoinduced electron transfer.

Applications to coordination complexes: TM; lanthanides.

Chemosensors; imaging; LEDs; PDT.

Chemoluminescence; bioluminescence; electroluminescence.

EPR Spectroscopy

Basic principles of Electron Paramagnetic Resonance (EPR).

Origin and significance of the electron Zeeman and nuclear Zeeman effects.

Derivation of simple spin Hamiltonian for a two spin system (S= ½, I= ½).

Interaction of the electron with its environment – anisotropy and symmetry effects in EPR spectra.

Applications of EPR to characterize paramagnetic systems.

Analysis and interpretation of EPR spectra of organic radicals in solution, as well as main group radicals and transition metal ions in frozen solution.

Interpretation of spin Hamiltonian parameters gand A(hyperfine) values.

Diffraction Techniques

Fundamentals:

Properties of X-rays.

Properties of electron beams.

Properties of neutron beams.

Production of X-rays and other radiation (conventional sources and synchrotron radiation).

Fundamentals of diffraction by crystalline solids.

Applications, Scope and Limitations of Techniques:

X-Ray diffraction (XRD): applications of X-ray diffraction, single-crystal versuspowder X-ray diffraction, advantages of using synchrotron radiation, limitations of X-ray diffraction.

Neutron diffraction (ND): applications of neutron diffraction, neutron diffraction versusX-ray diffraction.

Electron diffraction and electron microscopy: electron diffraction (ED), transmission electron microscopy (TEM), scanning electron microscopy (SEM), low energy electron diffraction (LEED).