Technetium compounds

The most prevalent form of technetium that is easily accessible is sodium pertechnetate, Na[TcO4].

The majority of this material is produced by radioactive decay from [99MoO4]2−:[1][2] Pertechnetate (tetroxidotechnetate) TcO−4 behaves analogously to perchlorate, both of which are tetrahedral.

In concentrated sulfuric acid, [TcO4]− converts to the octahedral form TcO3(OH)(H2O)2, the conjugate base of the hypothetical triaquo complex [TcO3(H2O)3]+.

Technetium halides exhibit different structure types, such as molecular octahedral complexes, extended chains, layered sheets, and metal clusters arranged in a three-dimensional network.

β-TcCl3 features octahedral Tc centers, which are organized in pairs, as seen also for molybdenum trichloride.

Instead it has the structure of molybdenum tribromide, consisting of chains of confacial octahedra with alternating short and long Tc—Tc contacts.

TcI3 has the same structure as the high temperature phase of TiI3, featuring chains of confacial octahedra with equal Tc—Tc contacts.

The binary tetrahalides can be converted to the hexahalides [TcX6]2− (X = F, Cl, Br, I), which adopt octahedral molecular geometry.

[18] Technetium forms a variety of coordination complexes with organic ligands.

[19] Technetium forms a variety of compounds with Tc–C bonds, i.e. organotechnetium complexes.

Similar carbonyls are formed by technetium's congeners, manganese and rhenium.