Coordination networks assembled from Co(NCS)2 and 4'-[4-(naphthalen-1-yl)phenyl]-3,2':6',3''-terpyridine: role of lattice solvents

The preparation and characterization of 4′ -[4-(naphthalen-1-yl)phenyl]-3,2′ :6′ ,3′′ -terpyridine ( 1 ) are described. Reactions of 1 with Co(NCS)2 under conditions of crystal growth by layering using different solvent combinations produced crystals of [Co( 1 )2(NCS)2] n ⋅2 n CHCl3 and [Co( 1 )2(NCS)2] n ⋅2 n C6H5Me, each of which comprised a (4,4) net. The orientations of 1 with respect to the planar network defined by the Co atoms are significantly different in [Co( 1 )2(NCS)2] n ⋅2 n C6H5Me compared to [Co( 1 )2(NCS)2] n ⋅2 n CHCl3, and the toluene molecules in [Co ( 1 )2(NCS)2] n ⋅2 n C6H5Me are involved in π-stacking interactions. The solvent-accessible void-space in the latter consists of a series of interlinked cavities in contrast to the open channels in [Co( 1 )2(NCS)2] n ⋅2 n CHCl3. Thermogravimetric analysis was used to investigate solvent loss and uptake in the two coordination networks. After solvent loss from [Co( 1 )2(NCS)2] n ⋅2 n CHCl3, CHCl3, CDCl3 or CH2Cl2 could be taken up by the lattice. In contrast, removal of toluene from [Co( 1 )2(NCS)2] n ⋅2 n C6H5Me was found to be irreversible