X-Ray Crystallographic Techniques, Advanced Main Group Chemistry and Applications

Learning Outcomes

Learning Outcomes

Having successfully completed this module you will be able to:

• Qualitatively rationalise the metal-ligand bonding in p-block complexes
• Conduct a basic structure solution and analysis from single crystal diffraction data.
• Define the meaning of a crystal structure, including what is implied by bond lengths, angles, thermal ellipsoids, intermolecular interactions, packing and the degree of confidence that can be placed in this information.
• Appreciate the trends in chemical and physical behaviour of main group metal compounds and how they may be controlled (tuned) by particular types of ligand.
• Define aspects of crystal structure including lattice shapes and the 3-dimensional symmetry associated with specific space group elements. Define diffraction theory and the interaction of radiation with crystalline material.
• Relate the properties of the complexes (reagents) to the choice of materials deposition technique for a particular application.
• Describe a series of diffraction experiments suitable for crystals, powders and other sample types, including the benefits of various radiation sources.
• Appreciate some of the important and emerging applications of main group compounds and materials and the key features necessary for these (semiconductor materials, PET imaging agents, main group catalysts, Frustrated Lewis Pairs).
• Explain qualitatively the data collection and analysis steps that are required to obtain structural information.
• Combine spectroscopic, structural and other experimental data to determine the identities of p-block coordination and organometallic compounds and to rationalise their structures and properties.

This module comprises two main elements –the determination and understanding of solid-state structure and aspects of advanced p-block coordination, materials and organometallic chemistry.

Firstly, the development of X-ray diffraction understanding will extend core year 2 knowledge with more advanced topics to allow interpretation of structures derived from these methods.

It will also provide further examples of the types of experiment that can be performed and the information that can be derived from them. A variety of examples will be examined in the course of this discussion – inorganic, organic and organometallic molecules, solid state materials, and macromolecular and biological systems. The topics covered include:

• History. Aspects of structure that can be studied using crystallography, including comparison with the information that can be derived from NMR and other methods, using examples that will then be revisited in more detail during the rest of the lectures.
• Lattices – revise from coverage in years 1 and 2. Introduce Laue equations. Comparison of single crystal and powder data.
• Point group & space group symmetry. How symmetry affects the diffraction pattern (systematic absences etc).
• Structure factors. Structure solution & refinement.
• Sample types – revisit powder vs single crystal, discuss issues with structure determination in powders, morphologies other than powders and single crystals.
• What equipment would you find in a typical diffraction lab. Use of non-standard radiation sources - synchrotrons, neutrons, electrons.
• Interpretation of crystal structure results – what does it mean? Accuracy and resolution of data. Confidence in the results. Variations between techniques and limitations of each.

Secondly, a research-led look at p-block coordination chemistry will focus on some important applications derived from compounds in this part of the periodic table – primarily in electronic materials, radiopharmaceuticals and organometallic chemistry:

A review of trends in the structures of the binary halides; relevant characterisation methods for p-block complexes (e.g. multinuclear NMR spectroscopy, single crystal X-ray diffraction).

• The * bonding model for p-block compounds – rationalising structures and Lewis acid behaviour in p-block complexes.
• Survey of Group 13-15 halide complexes with Group 15 & 16 donor ligands – preparations, structures, trends & properties/applications
• The motivation for studying main group coordination complexes – an overview of the range of applications of main group complexes, and materials derived from them
• Synthetic uses of main group complexes → oxidising/reducing agents
• Precursors for materials deposition e.g. CVD
• The deposition of thin films of materials, with a strong focus on Chemical Vapour Deposition (CVD)
• comparisons of bulk materials vs. thin films – effect on properties
• CVD vs other deposition techniques
• Principles of precursor design
• Post-deposition characterisation techniques
• An overview of the development of radio-labelled p-block complexes for applications in PET and SPECT imaging
• Boron chemistry – boranes and electron counting rules.
• Frustrated Lewis Pairs – definitions, identification, reaction chemistry eg - small molecule activation

Teaching methods: Lectures, Support classes, Bb online support, Problem classes, Workshops.

Learning methods: Independent study, student motivated peer group study, student driven tutor support, applied practical workshops

Summative

This is how we’ll formally assess what you have learned in this module.

Referral

This is how we’ll assess you if you don’t meet the criteria to pass this module.