Assembly of 1,3,5-tris(2-alkylthiol-pyrimidin-4-yl)benzene) (alkyl = Me, n-Pr) with copper(I) iodide: effect of alkyl side chain

Abstract

Two π-conjugated organic building blocks, TMPB and TPPB (TMPB = 1,3,5-tris(2-methylthiol-pyrimidin-4-yl)benzene; TPPB = 1,3,5-tris(2-propylthiol-pyrimidin-4-yl)benzene), have been prepared which only differ in the length of linear side chain attached to sulfur. Structural comparison between complexes of TMPB and TPPB reveals that the side chain has a great effect in modulating both the molecular structure and the molecular alignment. Reactions of TMPB and TPPB with CuI under the same conditions show that the side chain can exert impact on the assembly of coordination polymer. Assembly reaction with CuI is sensitive to the change in length of side chain, that is the shorter the side chain, the faster the reaction. Reaction of TPPB with CuI gives a 1-D chain structure of [Cu4I4(TPPB)2]n (1) based on two distinctive Cu4I4 clusters, whilst only microcrystalline powder or precipitate can be obtained for TMPB. The side chain can, thus, tune the assembly of coordination polymer in terms of the assembly structure as well as its packing manner.