A novel binary Cu2I2 and Cu6S6 cluster-based red emission compound and sensing of Cr(VI) in water

Structural Diversity of Copper(I) Cluster-Based Coordination Polymers with Pyrazine-2-thiol Ligand

“…The Cu−N, Cu−S, and Cu−Br distances are in the span of 1.998(3)− 2.043(3), 2.2238(9)−2.2698(9), and 2.3772(6)−2.689(2) Å, respectively, which are similar to those of compound 1 and 2, and are in good agreement with earlier reports (Table S2). 40,41,50,51 The acute Cu−Br−Cu bond angles of 63.3°are analogous to the reported dumbbell motif {Cu 2 Br 2 } (Table S2). 60−62 The average Cu−Cu distance in {Cu 6 S 6 } and {Cu 2 Br 2 } cluster is 2.903 and 2.671 Å, respectively, which is close to the sum of the van der Waals radii (2.8 Å) of Cu(I) centers, 58 suggesting clear cuprophilic interactions like compound 1.…”

“…The {Cu 6 S 6 } cluster contains an octahedral {Cu 6 } core surrounded by six individual pzt − anions, wherein each copper center displays distorted triangular geometries, clearly signifying the monovalent nature of the Cu atoms and coordinates to one nitrogen and two sulfur atoms from three S2). 40,41,50,51 In the {Cu 1g. This framework has a 16.3% solvent-accessible void as indicated by PLATON.…”

“…The tetrahedral {Cu 4 } core is protected by four independent pzt − anions (Figure 3 S2). 40,41,50,51 Each pzt − anion ligates to five Cu(I) ions using a rare μ 5κ 1 N :κ 1 N :κ 3 S coordination fashion (Figure 2d). However, two different kinds of bridged chlorine ion (μ 2 and μ 3 ) are presented in 2.…”

“…The red emission of 1 may be tentatively assigned to the triplet clustercentered ( 3 CC) excited state, which is in good agreement with previously reported Cu 6 S 6 cluster molecules. 40,41,50,56,64 Upon cooling from 293 to 113 K, the λ max = 755 nm at 293 K gradually red-shifted to 788 nm (Δλ = 33 nm) with 6-fold enhancement of emission intensity (Figure 7a). The emission color change of a selected crystal at the different temperatures is shown in Figure 7b.…”

“…To the best of our knowledge, only a few examples of high-dimensional CPs containing {Cu 6 S 6 } cluster have been described so far. 40,50,51 Furthermore, CPs containing {Cu 4 S 4 } have rarely been explored. 52−56 Therefore, Hpzt ligand was chosen owing to its rigid structure, multiple coordinated sites, and excellent coordinated ability.…”