Engineering 2D → 2D parallel interpenetration using long alkoxy-chain substituents

The structural consequences of reducing the length of the alkoxy substituents on going from the ditopic ligand 1,4-bis(n-octoxy)-2,5-bis(4,2':6',4 ''-terpyridin-4'-yl)benzene (1) to 1,4-bis(methoxy)-2,5-bis(4,2': 6',4 ''-terpyridin-4'-yl)benzene (2) on reactions of the ligands with zinc(II) halides are described. Reaction of 1 with ZnBr2 under conditions of room temperature crystallization gives [{Zn2Br4(1)}](n) in which 1 acts as a planar 4-connecting node. 2D -> 2D parallel interpenetrated (4,4)-nets assemble; extended octoxy chains are aligned through the sheets. Replacing the octoxy tails by methoxy groups results in loss of the interpenetrated network. The coordination polymers [{Zn2Br4(2)}center dot 2C(6)H(4)Cl(2)](n) and [{Zn2I4(2)}center dot 2.3C(6)H(4)Cl(2)](n), consist of 2-dimensional (4,4)-nets in which the methoxy substituents are directed above and below the sheet; corrugated sheets pack with the 4,2':6',4 ''-tpy domains of adjacent sheets engaging in face-to-face pi-interactions. (C) 2015 Elsevier Ltd. All rights reserved.