Conformational studies of dicyclohexylthallium chloride, bis(4‐methylcyclohexyl)thallium chloride and bis(4‐tert‐butylcyclohexyl)thallium chloride by 1H NMR

Vicinal thallium–hydrogen coupling constants are used to discuss conformations in dicyclohexylthallium chloride, bis(4‐methylcyclohexyl)thallium chloride and bis(4‐tert‐butylcyclohexyl)thallium chloride. Thallium does not have a very strong preference for equatorial positions in dicyclohexylthallium chloride, whereas bis(4‐alkylcyclohexyl)thallium chlorides exist largely in one conformation. Bis(4‐methylcyclohexyl)thallium chloride exists in three isomeric forms; the major product appears to be the cis‐isomer (equatorial methyl, axial thallium), with the other two isomers probably containing thallium trans to the methyl group (axial thallium being preferred). The preference for the cis‐isomer (equatorial tert‐butyl, axial thallium) of bis(4‐tert‐butylcyclohexyl)thallium chloride is such that other isomers are not obtained.