I think there may be a misunderstanding of what I wrote. I'll try to clarify so that I'm not misconstrued as saying that lanthanides don't have fun chemistry.
The f-block
elements have plenty of interesting chemistry. The question, though, was about the coordination chemistry of
f-electrons themselves. Specifically, how do you count them? I take this as asking what is the f-electron character of bonds that f-block elements make and such and how does group theory predict the bonds that are made.
For MANY compounds the f-block electrons are too closely bound and so usually a very small amount of the electronic character in bonds is f type. Instead they donate their two s electrons and usually a third electron which is actually d type. This is true for most ionic lanthanides. As I said before, the general rule breaks down in some cases, especially with actinide elements but also sometimes with lanthanides. Cerium is a good example of a lanthanide.
Since the relevant orbitals are s,p, or d in character it is most accurate to say that as a general rule the coordination chemistry of lanthanide chemicals is dominated by s, p, and d coordination chemistry. F-electrons participating strongly in bonding is the exception rather than the rule. This is what I meant, and it is something that most lanthanide chemists I know (including myself) would agree with as a general statement.
To delve into the specifics of f-electron bonding this paper is as good as any as a starting point:
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6X43-46G2TS5-98&_user=1082852&_coverDate=12%2F31%2F1980&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1573673716&_rerunOrigin=google&_acct=C000051401&_version=1&_urlVersion=0&_userid=1082852&md5=504b94e515be397d90adf7f95224311e&searchtype=aNotice, though, that f-electrons rarely contribute to the
coordination of the compound until you get to something like Uranium.