Chain Length Effect on the Structural and Emission Properties of the CuI/Bis((4-methoxyphenyl)thio)alkane Coordination Polymers.

A systematic chain length variation of the ligand -MeOCHS(CH)SCHOMe (1 ≤ ≤ 8) was performed to study its effect on the structures and photophysical properties of the coordination polymers (CP) when reacted with CuI. Indeed, direct correlations are noted between these features and . When is an odd number, the secondary building unit is systematically the common closed-cubane CuI cluster, rendering the material strongly luminescent (, emission quantum yield, Φ > 20%), and the CP is one-dimensional (1D). However, when is 2, 4, and 6, the SBUs exhibit rare polymeric motifs of (CuI): staircase ribbon, fused poly(rhombic pseudo-dodecahedron), and accordion ribbon, respectively, and the emission intensities are either very weak (Φ < 0.001%) or of medium intensity (Φ ∼ 10% when = 6). When = 8 (. the most flexible chain), the SBU is a closed-cubane CuI and the emission intensity is medium (Φ ∼ 10%). A special case was observed for = 3, where a co-crystallization of the molecular cluster CuI(NCCH) is observed in the lattice, which turns out to be quite important for the stability of the network.