Recently, I have become interested in the chemistry of chemical warfare agents, I have of course, no intention of actually making any of these compounds, with the sole exception of a novel mustard agent analogue for a legitimate chemical purpose as a methylating agent that is easy to prepare (the only other one I have acces to is methyl iodide, and I don't want to waste precious I2).
so to start off, how about selenium and tellurium (maybe even polonium if one was truly insane LOL) analogues of the V series nerve agents, where tellurium/selenium/polonium/(oxygen?) replaces the sulfur, also, substitution of alcohol groups, secondary alcohols tend usually to increase toxicity, and I wonder if tertiary alcohol groups increase it still further? maybe substituting very long chain alcohols would even form a solid, extremely toxic and highly persistant agent that would be active through skin contact/ingestion, yet pose little risk via inhalation due to being almost nonvolatile thereby causing area denial for an extended time period?
Now back to sulfur group substitution,
say for instance, VX is chemically: O-ethyl-S-(2-diisopropylaminoethyl) methylphosphonothioate, instead of using diisopropylaminothiol in the synthesis, using the corresponding selenols or tellurols to substitute Se or Te for the second S? this might increase the toxicity of the V agent a little bit, given the propensity of Se or Te compounds to be more unpleasant than the corresponding S compounds.
Besides, with substituted Te V agents, you add insult to injury, by ensuring that if the unfortunate recipient survives, his/her breath stinks infernally for months to come