Self-Assemblies of New Rigid Angular Ligands and Metal Centers toward the Rational Construction and Modification of Novel Coordination Polymer Networks

Self-assemblies of rigid angular ligands with 120° molecular angle and metal centers have been investigated with the aim of achieving the rational construction and modification of coordination polymer structures. The reactions of Co(NCS)2 with 1,3-bis(trans-4styrylpyridyl)benzene (L1), 2,6-bis(trans-4-styrylpyridyl)pyridine (L2), 1,3-bis(trans-4-styrylpyrimidyl)benzene (L3), and 1,3-bis(trans-4styrylquinoly)benzene (L4) afford complexes [Co(L1)2(NCS)2](infinity) (1), [Co(L2)2(NCS)2] (infinity) (2), Co(L3)2(NCS)2(CH3OH)2 (3), and [Co(L4)(NCS)2] (infinity) (4), respectively. The resulting complexes exhibit open framework, stairlike hydrogen-bonded chain and single-stranded helical coil structures, which are controlled by the variation of the geometry around the coordination site in ligands. Moreover, the coordination of L1 and L2 to Mn(hfac)2 (hfac = 1,1,1,5,5,5-hexafluoroacetylacetonate) yields single-stranded helical coordination polymers of [Mn(L1)(hfac)2] (infinity) (5) and [Mn(L2)(hfac)2] (infinity) (6), respectively.