Multitopic 3,2′:6′,3′′-terpyridine ligands as 4-connecting nodes in two-dimensional 4,4-networks

The tetratopic 1,4-bis(2-phenylethoxy)-2,5-bis(3,2′:6′,3′′-terpyridin-4′-yl)benzene (1) and 1,4-bis(3-phenylpropoxy)-2,5-bis(3,2′:6′,3′′-terpyridin-4′-yl)benzene (2) ligands have been prepared and fully characterised. Combination of ligand 1 or 2 and [M(hfacac)(2)]·xH(2)O (M = Cu, x = 1; M = Zn, x = 2) under conditions of crystal growth by layering led to the formation of [Cu(2)(hfacac)(4)(1)](n)·3.6n(1,2-Cl(2)C(6)H(4))·2nCHCl(3), [Zn(2)(hfacac)(4)(1)](n)·nMeC(6)H(5)·1.8nCHCl(3), [Cu(2)(hfacac)(4)(2)](n)·nMeC(6)H(5)·2nH(2)O, [Cu(2)(hfacac)(4)(2)](n)·2.8nC(6)H(5)Cl and [Cu(2)(hfacac)(4)(2)](n)·2n(1,2-Cl(2)C(6)H(4))·0.4nCHCl(3)·0.5nH(2)O. For each compound, single-crystal X-ray analysis revealed the assembly of a planar (4,4)-net in which the tetratopic ligands 1 or 2 define the nodes. The metal centres link two different bis(3,2′:6′,3′′-tpy) ligands via the outer pyridine rings; whereas copper(ii) has N-donors in a trans-arrangement, zinc(ii) has them in cis. This difference between the copper(ii) and zinc(ii) coordination polymers modifies the architecture of the assembly without changing the underlying (4,4)-network.