Thallothallic oxide, TlO

Thallothallic oxide, TlO or Tl₂O.Tl₂O₃, is obtained as a bluish-black, lustrous precipitate when 3 per cent, hydrogen peroxide is added to a solution of thallous sulphate which has been made strongly alkaline and cooled to -15°. It should be washed with cold alcohol and then with ether. The oxide absorbs carbon dioxide, forming thallic oxide and thallous carbonate; it absorbs oxygen at the ordinary temperature, forming thallic oxide; and it is decomposed by cold water, producing thallous hydroxide and thallic oxide.