Versatility within (4,4) networks assembled from 1,4-bis(n-alkyloxy)-2,5-bis(3,2':6',3''-terpyridin-4'-yl)benzene and [Cu(hfacac)₂] (Hhfacac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione)

The reactions of 1,4-bis( n -alkyloxy)-2,5-bis(3,2':6',3''-terpyridin-4'-yl)benzene ligands with methoxy ( 1 ), ethoxy ( 2 ), n -propoxy ( 3 ), n -butyloxy ( 4 ), n -pentyloxy ( 5 ), n -hexyloxy ( 6 ), n -heptyloxy ( 7 ) and n -octyloxy ( 8 ) substituents with [Cu(hfacac) 2 ] . H 2 O (Hhfacac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione) under conditions of crystal growth by layering have been investigated using different combinations of solvents. The products have been structurally characterized and in all cases, Cu(II) is octahedrally sited in a trans -{Cu(hfacac) 2 (N) 2 } environment in which N is a pyridine donor in one of the outer rings of a 3,2':6',3''-tpy unit. The coordination assemblies fall into four categories. The most populated class consists of (4,4) nets in which each bis(3,2':6',3''-tpy) ligand 1 and 4-8 acts as a 4-connecting node and the Cu(II) centres lie within the plane defined by the nodes; changes in conformation of the 3,2':6',3''-tpy units do not affect the assembly of the (4,4) network. One of two assemblies isolated with ligand 2 is also a (4,4) net, but powder X-ray diffraction (PXRD) data indicate that this is not representative of the bulk material. [Cu2(hfacac)4(3)] n . 5.5nC6H5Cl exhibits a unique structure consisting of a (4,4) net with the Cu(II) centres lying above and below the plane of the net. A third class of assembly was found for [Cu3(hfacac)6(5)2] n and comprises a (4,4) net in which half of the ligands are 4-connecting nodes and half coordinate through two pyridine rings and are therefore linkers; the efficient packing in this structure leaves no solvent-accessible voids. A 1D-coordination polymer in which all the bis(3,2':6',3''-tpy) ligands are 2-connecting linkers was observed for [Cu 2 (hfacac) 4 ( 2 ) 2 ] n . 1.5 n CHCl 3 . 4 n MeOH and PXRD data confirm that the structure is representative of the bulk material. Structural studies have been complemented by thermogravimetic analyses of selected compounds