2-Dimensional networks assembled using 4'-functionalized 4,2':6',4''-terpyridines and Co(NCS)2

A series of 2-dimensional (4,4) nets formed in reactions of Co(NCS)2 with divergent 4′-functionalized-4,2′:6′,4″-terpyridine ligands is reported, and the effects of the 4′-substituent R (ligand 1, R = tBu; 5, R = MeO; 6, R = EtO; 7, R = nPrO) on the packing of the nets are described. The 2D-coordination networks in [{Co(NCS)2(6)2}·4CHCl3]n and [{Co(NCS)2(7)2}·4CHCl3]n are essentially isostructural. On going to [{Co2(NCS)4(5)4}·2CHCl3·1.5MeOH]n, modification of both the geometry of the rhombuses that comprise the network, and the packing occurs. All three structures feature head-to-tail π-stacking of 4′-(4-alkoxyphenyl) units, but with variation in their relative orientations. In contrast, [{Co(NCS)2(1)2}·0.5H2O]n comprises double layers of (4,4) nets with hydrophobic coatings of tert-butyl groups, leading to alternating wide and close spacings between adjacent nets.