Directing 2D-Coordination Networks: Combined Effects of a Conformationally Flexible 32′:6′3″-Terpyridine and Chain Length Variation in 4′-(4-n-Alkyloxyphenyl) Substituents

摘要

The synthesis and characterization of 4′-(4- -propoxyphenyl)-3,2′:6′,3″-terpyridine is described. Five 2D-coordination networks have been isolated by crystal growth at room temperature from reactions of Co(NCS) with 4′-(4- -alkyloxyphenyl)-3,2′:6′,3″-terpyridines in which the -alkyl group is ethyl, -propyl, -butyl, -pentyl and -hexyl in ligands – , respectively. The single-crystal structures of [{Co( ) (NCS) } 0.6CHCl ] , [{Co( ) (NCS) } 4CHCl 0.25H O] , [{Co( ) (NCS) } 4CHCl ] , [Co ( ) (NCS) ] and [Co( ) (NCS) ] have been determined, and powder X-ray diffraction has demonstrated that the single-crystal structures are representative of the bulk materials. Each compound possesses a (4,4) net with Co centres as 4-connecting nodes. For the assemblies containing , and , the (4,4) net comprises two geometrically different rhombuses, and the nets pack in an ABAB... arrangement with cone-like arrangements of -alkyloxyphenyl groups being accommodated in a similar unit in an adjacent net. An increase in the -alkyloxy chain length has two consequences: there is a change in the conformation of the 3,2′:6′,3″-tpy metal-binding domain, and the (4,4) net comprises identical rhombuses. Similarities and differences between the assemblies with ligands – and the previously reported [{Co( ) (NCS) } 3MeOH] and [{Co( ) (NCS) } 2.2CHCl ] in which is 4′-(4-methoxyphenyl)-3,2′:6′,3″-terpyridine are discussed. The results demonstrate the effects of combining a variable chain length in the 4′-(4- -alkyloxyphenyl) substituents of 3,2′:6′,3″-tpy and a conformationally flexible 3,2′:6′,3″-tpy metal-binding domain.