Thallium(I) Sulfate Solution from Thallium Metal

In this video I demonstrate the creation of a thallium(I) sulfate solution for future synthetic and analytical work. Thallium has a fascinating chemistry. Due to relativistic effects thallium has a tendency to ionize to the +1 state instead of the +3 state like all the elements above it in the periodic table. In this state it mimics the potassium cation in both size and charge to such an extent that thallium(I) hydroxide and thallium(I) carbonate are soluble in water whereas most other metal hydroxides and carbonates are not. With strong oxidizers thallium can be ionized to the +3 cation where it's chemistry is more reflective of it being the heaviest stable member of the triels (the boron group; column 13 on the periodic table).

The thallium(I) cations mimicry of potassium is at the root of its high toxicity. It interferes with sodium and potassium transport systems which are vital for life. Although critical for all cells sodium and potassium gradients are especially crucial for cells in the heart and central nervous system and it is these organ systems that thallium damages most. The only antidote for thallium poisoning only works if the poisoning occurred because someone ingested thallium and it must be administered very soon after the exposure otherwise very little can be done. Chelation therapy is not recommended as it mobilizes thallium stored in other areas of the body and allows even more thallium to make it way into the brain. While dialysis might be helpful in this situation there is no way to survive being poisoned by thallium without having ones health shattered and their life essentially ruined.

Thallium has a colorful history as a murder weapon. This was especially prevalent in the 1950s when thallium sulfate was a popular rat poison. It is odorless, tasteless, and colorless and thus almost impossible to detect in food or drink. However, unless the dose is high death does not occur quickly and the progression of symptoms is very characteristic. Although these symptoms are generalized at first if the victim survives long enough for the hair loss phase of the poisoning to occur at which point many cases of thallium poisoning are detected. While thallium may have been an effective agent of assassination in the past today it is very easy to detect even decades after the victim has died. Elemental poisons do not degrade and thus can persist in bone and tissue for many years. Because of this and the lack of availability cases of thallium poisoning have dropped dramatically over the last several decades.