tCO2

TcO2, or technetium(IV) oxide, is an inorganic compound that represents technetium in its +4 oxidation state. It typically appears as a black to gray solid that is insoluble in water and common inorganic solvents. In air, TcO2 is relatively stable at room temperature but can slowly oxidize to higher oxides such as Tc2O7 at elevated temperatures.

Preparation of TcO2 usually involves the reduction of higher-valence technetium oxides or salts, such as pertechnetate (TcO4−) compounds, using hydrogen or carbon monoxide at elevated temperatures. It can also be produced via hydrolysis of hydrated technetium oxides to form TcO2·xH2O, which upon dehydration yields anhydrous TcO2. In laboratory settings, TcO2 is often encountered as a starting material for preparing lower-valent technetium species.

Structurally, TcO2 adopts a rutile-type framework in which technetium is six-coordinate to oxygen, forming octahedra that share edges in a tetragonal lattice. The Tc–O bonds are characteristic of oxide rutile structures, and the solid is generally nonvolatile and highly refractory.

Reactivity and stability: TcO2 is relatively inert toward many common acids but can be oxidized by strong oxidants to higher-valent technetium oxides and, under sufficiently oxidizing conditions, to pertechnetate (TcO4−). It is generally insoluble in water and many solvents, making it useful as a stable oxide form in technetium chemistry.

Uses: TcO2 serves as a stable Tc(IV) oxide useful in studying technetium chemistry and as a precursor for preparing other technetium compounds. It also functions as a non-radioactive surrogate for certain laboratory investigations in radiopharmaceutical research and technetium processing.

Safety: Handling technetium compounds requires appropriate radiation protection and waste management due to radioactivity associated with most technetium isotopes.