Structural diversity in the reactions of 4′-(pyridyl)-2,2′:6′,2-terpyridine ligands and bis{4′-(4-pyridyl)-2,2′:6′,2-terpyridine}iron(II) with copper(II) salts

We have demonstrated that treatment of [Fe(1)(2)](2+) (1 = 4'-(4-pyridyl)-2,2':6',2 ''-terpyridine) with an excess of CuCl2 center dot 2H(2)O leads to competition between coordination of copper(II) by the pendant pyridine donors in [Fe(1)(2)](2+), and transfer of ligand 1 from iron(II) to copper(II) to yield [{Cl3Cu(mu-1)Fe(mu-1)}(2)CuCl2(OH2)(2)]Cl-2 center dot 4H(2)O and [Cu(H1)Cl-2]Cl center dot 4H(2)O, respectively. Direct reaction of 1 with CuCl2 center dot 2H(2)O and variation in crystallization conditions results in the formation of either monomeric or polymeric complexes: [Cu(1)Cl-2]center dot 4.75H(2)O, [Cu(1)Cl-2]center dot H2O center dot MeOH and [Cu(1)Cl-2 center dot 2H(2)O](n). The reaction of 1 with Cu(NO3)(2)center dot 3H(2)O gives the coordination polymer [Cu(1)(ONO2)(2)center dot H2O](n). Magnetic data for [Cu(1)Cl-2 center dot 2H(2)O](n) and [Cu(1)(ONO2)(2)center dot H2O](n) are consistent with antiferromagnetically- coupled chains. Reactions of CuCl2 center dot 2H(2)O with ligands 2 and 3 (2 = 4'-(3-pyridyl)-2,2':6',2 ''-terpyridine, 3 = 4'-(2-pyridyl)-2,2':6',2 ''-terpyridine) lead to monomeric complexes. With the exception of [Cu(3)Cl-2], the mononuclear complexes show a propensity for the incorporation of water into their crystal lattices; in the case of [Cu(H1)Cl-2]Cl center dot 4H(2)O and [Cu(H1)Cl-2]Cl center dot 4.75H(2)O, the small change in water content leads to the assembly of (5.8(2))(2)(5.6.8)(4)(5(2).6)(2) or (4(2).6(2))(3)(4.6(2))(6) water-chloride ion nets.