The aim of this article was to illustrate the ease with which electronic scientific articles can be enhanced by including extra information that is impossible to provide in normal printed articles. This extra information can be in the form of valuable scientific content (the 3D structure of a molecule, the x-y data for an infra-red spectrum, the movement path of a reactant along a reaction coordinate, etc.) - or it can simply be stunning visualisations of chemical processes which improve the readability of the article, and help to communicate complex ideas and phenomena. All this extra benefit can now be created by non-experts using cheap (or free) software available for desktop computers.
One aspect I have not touched upon, however, is the way an author and a reader deal with the non-linear narrative inherent in interactive web pages. The author has to be aware that a reader may no longer start at the beginning of the article and read it line-by-line until the end. Web pages in general, and interactive ones especially, allow readers to jump back and forth throughout the document, sampling paragraphs and trying the interactive examples in a non-linear fashion. Authors need to write their documents accordingly, with each section or interactive example being self-contained, with all the relevant facts close by on the same page. This is to prevent the reader being 'side-tracked', and while looking for extra information about the figure following a whole series of interesting hyperlinks to other web pages, and then forgetting what they were looking at in the original document. This may require a whole new style of writing scientific documents. For example, papers could divided into numerous short pages of one or two paragraphs each, with references at the end of each page. Figures, diagrams and interactive examples may each have their own separate pages, with very detailed captions. Any external hyperlinks can be made to open in a separate browser window - this ensures that a reader reads the whole document without losing their place in the original document.
Another aspect I have not really mentioned is that all this extra information needs to be classified in some way, so that electronic search engines can find and tell the difference between different types of chemical information. With the rapid increase in the number of web sites and huge amount of information now available on the internet, it is vital that the data is managed in a standardised fashion. To do this it is necessary to include 'metadata' with each piece of information. Metadata is information about data which facilitates the processing and the indexing of the data, and a good introduction to the subject can be found in Ref.[16]. So, for example, a spectrum might have some text associated with it that describes what the spectrum is, how it is to be displayed, what format it is, etc. The browser will not display this information, so it will remain 'hidden', but it is still there for search engines to use. If scientists are to enhance their electronic publications in the ways shown in this article, they should also include the relevant metadata statements describing which types of chemical information the document contains, 3D structure files, whole spectra, VRML models, etc. That way, search engines can be made more effective, rapidly returning only those web pages containing the exact type of information a user requires. Perhaps the most elegant way to include such metadata in electronic chemical documents is to use XML (extended markup language) which separates the chemical content from the display parameters. A version of XML specifically designed for chemical documents is called Chemical Markup Language (CML) [15], and this may be the way forward - allowing even more complex and visually impressive chemical presentations to be written in future years.
I would like to thank Steve Ashworth for creating some of the original CO2 xyz animations, and the Chime scripts to connect them to the JCAMP spectra. I would also like to thank Adrian Mulholland and Lars Ridder for allowing me the use of their xyz animation of the PHBH reaction, and to Frank Oellien of the University of Erlangen for permission to use screen shots of his VRML applets, and for many helpful comments and suggestions for this article.