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 ]· x H 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 ·3.6 n (1,2-Cl 2 C 6 H 4 )·2 n CHCl 3 , [Zn 2 (hfacac) 4 (1)] n · n MeC 6 H 5 ·1.8 n CHCl 3 , [Cu 2 (hfacac) 4 (2)] n · n MeC 6 H 5 ·2 n H 2 O, [Cu 2 (hfacac) 4 (2)] n ·2.8 n C 6 H 5 Cl and [Cu 2 (hfacac) 4 (2)] n ·2 n (1,2-Cl 2 C 6 H 4 )·0.4 n CHCl 3 ·0.5 n H 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.