MolBase: A collaborative database of inorganic compounds
Dr Mark J Winter
Department of Chemistry, University of Sheffield, Sheffield S3 7HF, UK
An online database of inorganic compounds suitable for undergraduate use, and with data contributed by undergraduates, will be produced. In Year 1 the system will be developed in Sheffield and in Year 2 and beyond students from other universities will be invited to use and contribute. In addition to learning how to add data to online databases (requiring some library work), students will be able to retrieve data that appears not to be readily available elsewhere.
Students often have little perspective upon arrival at university of what geometries of compounds are common or uncommon, what oxidation states are common or uncommon, and so on. Textbooks often contain useful charts and tables displaying common and less common geometries and oxidation states, but what is "common" and what is "uncommon" is not well quantified. Users of the database will be able to construct useful questions or tasks such as:
- Identify tetrahedral compounds of copper(II)
- Show trigonal bipyramidal compounds of iron(O) containing phosphine ligands
- List all Fe(IV) complexes
- Show me anionic sulphur compounds
- Show me a colour-coded grid of oxidation states for first row d-block elements
- Compare the proportions of octahedral and tetrahedral geometries of d5 metal complexes with neutral ligands. And then with anionic ligands.
- Show me the geometries associated with bromine compounds.
- Show high spin d5 first row complexes, and the same for third row complexes.
- Find all examples of MX22L4 complexes of chromium (using mlxz classification)
- Show me compounds with a N4O2 donor set
The data will be entered by undergraduates. As the database becomes larger, the responses to the above queries will become more and more useful. The idea is that many undergraduate students entering a little data results in an extensive database. This will improve the contributor's literature search and use of databases.
In the early stages, the database will contain only well-characterised distinct mononuclear molecular species. A certain amount of information must be included for any compound to be added to the system. The minimum required is the charge, the central atom, and the identity of the attached groups. The system will calculate oxidation numbers, formulae, donor sets, element percentages, probable geometry, mlxz classification, and other information based only upon that information.
Each compound will be designated as "owned" by the initial contributor, but additions/modifications to an entry for a compound can be made subsequently by others. Such additions might include spectra and other data such as uses and reactions, and molecular coordinates. The database will include literature references to compounds. Most compounds will contain a tructural diagram drawn by the student. Each entry will have an area where comments can be added for any compound by registered users of the system.
Contributors will have a short web page so that people know who they are, and to ensure students have a sense of pride in their entries. Entries will be "refereed", perhaps by postgraduate students to ensure some standing in the chemical community for the database. As for the contributors, the referees name will be attached to individual entries to help ensure some professional pride in the refereeing process.
In year 1, a development year, addition of data will be within Sheffield only. In year 2 and beyond the aim is to invite other Universities in the UK to participate. Part of the funding will be used to visit other departments to establish mechanisms for students at other Universities to contribute in year 2 and beyond.