A novel tetrakis(pyrazolyl)borate ligand bearing triphenylphosphine oxide substituents.

A new tetrakis(pyrazolyl)borate ligand bearing triphenylphosphine oxide moieties appended to the 3-position of the pyrazolyl rings is reported and shown to display varied coordination chemistry from tridentate N(2)O coordination with thallium to hexadentate N(3)O(3) coordination with europium.