The mononuclear copper(II) complexes of the following potentially hexadentate podand ligands have been prepared and crystallographically characterised: tris[3-{2-(methylsulfanyl)phenyl}pyrazol-1-yl]hydroborate [L¹]^-, phenyltris[3-(2-pyridyl)pyrazol-1-yl]methane (L²), and tris[3-{(6-methyl)-pyrid-2-yl}pyrazol-1-yl]hydroborate [L³]^-. Of these, [L¹]^- [a potentially N₃S₃ donor with three pyrazolyl and three thioether groups, based on a tris(pyrazolyl)borate core] and L² [a potentially N₆ donor with three pyrazolyl and three pyridyl groups, based on a tris(pyrazolyl)methane core] have been prepared for the first time. In [Cu(L¹)][PF₆] the Cu(II) centre is in a five-coordinate N₃S₂ coordination environment which is approximately square pyramidal; the pendant thioether group has a weak, long-range interaction with the sixth coordination site of Cu(II). [Cu(L¹)][PF₆] undergoes a reversible Cu(I)–Cu(II) redox conversion. In [Cu(L²)(MeOH)][PF₆]₂ the ligand is four-coordinate via two bidentate pyridyl/pyrazolyl arms, with the third arm pendant; an axial methanol ligand completes the square-pyramidal coordination. In [Cu(L³)(H₂O)][PF₆], which is five coordinate and approximately trigonal bipyramidal, [L³]^- acts as an N₄ donor via all three pyrazolyl groups but only one pyridyl group; the two pendant pyridyl groups are involved in O–H···N hydrogen-bonding interactions with the coordinated water molecule. This ‘second-sphere’ stabilisation of a coordinated ligand is strongly reminiscent of the cooperative interactions by which substrates are bound to the active sites of metalloproteins. The EPR spectra of this complex are solvent-dependent, showing a change from a d_z² ground state in non-donor solvents to a d_x²-y² ground state in donor solvents.