Chemical reactions at the synapse
If you are interested it from the point of view of "chemical computations", you probably want literature which looks at signal transduction in detail. I would suggest Marks' et al textbook on signal transduction. I have not yet read it through (it is on my list), but I liked the clear writing style of the introduction, and, as you can see from the table of contents, it does have chapters which address synapses and their neurotransmitters specifically. 

I doubt that it will contain a complete list (there are several hundreds of compounds which can be considered to be neurotransmitters), but as an introductory textbook, it is likely to contain the major ones.