A flexible bipyridyl-type linking ligand and its coordination polymers of cobalt, zinc and cadmium: [Co(L)(NO3)2], [Zn(L)(NO3)2], [CdL2(NO3)2] and [CdL2(NO3)2](C6H6)2 (L = (4-py)–CH2–NH–(CH3)C6H3–C6H3(CH3)–NH–CH2–(4-py))

A long, flexible bipyridyltype linking ligand L [(4py)–CH2–NH–(CH3)C6H3–C6H3(CH3)–NH–CH2–(4-py)], which possesses two terminal 4-pyridyl groups, was prepared by reducing its parent diimine ligand (4-py)–CHN–(CH3)C6H3–C6H3(CH3)–NCH–(4-py). Four novel polymeric species based on L, [Co(L)(NO3)2] (1), [Zn(L)(NO3)2] (2), [CdL2(NO3)2] (3) and [CdL2(NO3]2](C6H6)2 (4), could be synthesized under solvothermal conditions. Whereas polymers 1 and 2 have a 1D zigzag-chain structure, polymers 3 and 4 have a 2D network structure. The N⋯N separation between the two pyridyl groups in L (the free ligand) is 19.871(3) Å, whereas this distance varies from 11.934(4) to 16.373(8) Å in its coordination polymers.

Graphical abstractA long flexible bipyridyl-type linking ligand L [(4-py)–CH2–NH–(CH3)C6H3–C6H3(CH3)–NH–CH2–(4-py)] was prepared by reducing its parent diimine ligand. Four coordination polymers [Co(L)(NO3)2], [Zn(L)(NO3)2], [CdL2(NO3)2] and [CdL2(NO3]2](C6H6)2 could be synthesized under solvothermal conditions.Figure optionsDownload full-size imageDownload as PowerPoint slide