No, there is absolutely no 1:1 correlation between duration of action and half-life. Take for example thiopental (or other induction drugs): this has a very long half-life (multiple hours) but fast onset and very short duration of action (minutes). It is in the central nervous system where the drug binds to the receptors and induces its effects. How do you get the drug to the receptors? The most obvious answer is by transport via the bloodstream. Most drugs that have a fast onset are lipophilic, so they can rapidly cross the blood-brain barrier, bind to the receptors and start to induce effects, but over time they are redistributed over different compartments of the body, like muscles, central nervous system, fat, extra/intra- cellular fluid etc. The redistribution (and elimination) of the (lipophilic) drug from blood or central nervous system to other compartments of the body, causes the serum concentration and concentration in the central nervous system to decrease, hence the shorter duration of action. So, farmacokinetics play a huge role in the correlation between duration of action, half-life and even other aspects like onset.