Two different one-dimensional supramolecular chains formed from the reaction of 2-[1-(pyridin-4-ylmethyl)1H-benzimidazol-2-yl] quinoline with two different precursors, Co(NO3)2 and CoCl2

Two different one-dimensional supramolecular chains with Co-II cations have been synthesized based on the semi-rigid ligand 2-[1-(pyridin-4-ylmethyl)-1H-benzimidazol-2-yl] quinoline (L), obtained by condensation of 2-(1H-benzimidazol-2-yl) quinoline and 4-(chloromethyl) pyridine hydrochloride. Starting from different Co-II salts, two new compounds have been obtained, viz. catena-poly[[[dinitratocobalt(II)]-mu-2-[1-(pyridin-4-ylmethyl)-1H-benzimidazol-2-yl] quinoline] dichloromethane monosolvate acetonitrile monosolvate], {[Co( NO3)(2)(C22H16N4)]center dot CH2Cl2 center dot CH3CN}(n), (I) and catena-poly-[[[dichloridocobalt(II)]-mu-2-[1-(pyridin-4-ylmethyl)-1H-benzimidazol- 2-yl] quinoline] methanol disolvate], {[CoCl2-(C22H16N4)]center dot 2CH(3)OH}(n), (II). In (I), the Co-II centres lie in a distorted octahedral [CoN3O3] coordination environment. {Co(NO3)(2)L}(n) units form one-dimensional helical chains, where the L ligand has different directions of twist. The helical chains stack together via interchain pi-pi interactions to form a two-dimensional sheet, and another type of pi-pi interaction further connects neighbouring sheets into a threedimensional framework with hexagonal channels, in which the acetonitrile molecules and disordered dichloromethane molecules are located. In (II), the Co-II centres lie in a distorted trigonal-bipyramidal [CoCl2N3] coordination environment. {CoCl2L} n units form one-dimensional chains. The chains interact via C-H center dot center dot center dot pi and C-H center dot center dot center dot Cl interactions. The result is that two-dimensional sheets are generated, which are further linked into a three-dimensional framework via interlayer C-H center dot center dot center dot Cl interactions. When viewed down the crystallographic b axis, the methanol solvent molecules are located in an orderly manner in wave-like channels.