Three in One: TSA, TSA‘, and SA Units in One Crystal Structure of a Yttrium(III) Complex with a Monophosphinated H₄dota Analogue

Compound [Y(Hdo3aPABn)(H2O)][Y(Hdo3aPABn)]·6H2O·iPrOH, where H4do3aPABn is 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic-10-methyl(4-aminobenzylphosphinic) acid, a monophosphinate analogue of H4dota, was prepared in the solid state and studied using X-ray crystallography. In contrast to all single-crystal structures of complexes of H4dota-like ligands published before, three distinct units were found in one cell: two species adopting a twisted-square-antiprismatic configuration with (TSA) and without (TSA‘) a coordinated water molecule and one isomer with a square-antiprismatic configuration (SA). In addition, this is the first complex with the H4dota-like ligand for which the structures of three possible species were determined in the solid state.