Alkali Cation Ligating Iodocuprate(I)-Based Coordination Networks with the Thiacrown Ether 1,10-Dithia-18-crown-6

Abstract

The lamellar coordination polymer 2∞[CuI(1,10DT18C6)] (1) (1,10DT18C6=1,10-dithia-18-crown-6) may be prepared by reaction of CuI with the thiacrown ether in acetonitrile. 1 crystallizes in the monoclinic space group P21/n with a=10.764(2), b=14.317(3), and c=12.335(3) Å, β=98.08(3)°, V=1882.0(7) Å3, Z=4, R=0.041, wR2=0.102 for 5480 reflections and contains (CuI)2 rhomboid dimers as characteristic building units. Performing the reaction in the presence of an equimolar quantity of alkali metal halide MI (M+=Na+, K+) in acetonitrile solution at 100°C leads to formation of ion-ligating iodocuprate(I)-based two-dimensional coordination networks in 2∞[{Na(CH3CN)}{Cu5I6(1,10DT18C6)}] (2) and 2∞[K{Cu4I5(1,10DT18C6)2}] (3). Both anionic frameworks contain characteristic iodocuprate(I) chains that are bridged in a μ-S1,S10 manner by 1,10DT18C6 macrocycles. However, the structure-directing influence of the alkali metal cation manifests itself in both the connectivity pattern and the stoichiometry of the resulting CuI-based network. 2 is chiral and crystallizes in the monoclinic space group P21 with a=10.456(4), b=13.674(6), and c=11.535(5) Å, β=92.82(3)°, V=1647.3(12) Å3, Z=2, R=0.049, wR2=0.110 for 3018 reflections. 3 is likewise monoclinic, space group P2/n with a=11.418(6), b=12.521(7), and c=15.398(7) Å, β=96.58(3)°, V=2187(2) Å3, Z=2, R=0.064, wR2=0.176 for 3858 reflections. After losing their coordinated acetonitrile molecules at 180°C, the lamellar coordination networks of 2 retain their integrity up to 230°C before loss of their bridging thiacrown ethers.