Macrocyclic Cu(ii)-organophosphonate building block with room temperature magnetic ordering.

Engineering a copper coordination sphere with organoimine ligands and tuning the organophosphonate protonation states produced [{Cu(2,2'-bpy)}2(HO3P(CH2)8PO3H2)4] (1) and [{Cu(terpy)}2(2,7-FDA-H2)2]·(2,7-FDA-H4)(2H2O) (2) (2,7-FDA-H4 = 2,7-fluorenonediphosphonic acid) macrocyclic copper-organophosphonate building blocks. 1 exhibits high temperature magnetic ordering, while 2 is paramagnetic. The structures were characterized by single crystal X-ray diffraction.