Copper(I) Halides (X = Br, I) Coordinated to Bis(arylthio)methane Ligands: Aryl Substitution and Halide Effects on the Dimensionality, Cluster Size, and Luminescence Properties of the Coordination Polymers

Abstract

Bis(phenylthio)methane (L1) reacts with CuI to yield the 1D-coordination polymer [{Cu 4 (μ 3 -I) 4 }(μ-L1) 2 ] n (1) bearing cubane Cu 4 I 4 clusters as connecting nodes. The crystal structures at 115, 155, 195, and 235 K provided evidence for a phase transition changing from the monoclinic space group C2/c to P2 1 /c. The self-assembly process of CuI with bis(p-tolylthio)methane (L2), bis(4-methoxyphenylthio)methane (L3), and bis(4-bromophenylthio)methane (L4) affords the 1D-coordination polymers [{Cu 4 (μ 3 -I) 4 }(μ-Lx) 2 ] n (x = 2, 3, or 4). Compounds 2 and 4 are isostructural with C2/c low temperature polymorph of 1, whereas the inversion centers and 2-fold axes are lost in 3 (space group Cc). The use of bis(m-tolylthio)methane (L5) has no impact on the composition and overall topology of the resulting 1D ribbon of [{Cu 4 (μ 3 -I) 4 }(μ-L5) 2 ] n (5). Even the coordination of the sterically crowded dithioether bis(5-tert-butyl-2-methylphenylthio)methane (L8) does not alter the network topology generating the 1D polymer [{Cu 4 (μ 3 -I) 4 }(μ-L8) 2 ] n (8). The 1D polymer [{Cu(μ 2 -Br) 2 Cu}(L1) 2 ] (9) results from the coordination of L1 with CuBr in a 1:1 metal-to-ligand ratio. In contrast to the mean Cu•••Cu distances, which are <2.8 Å noted for the Cu 4 (μ 3 -I) 4 clusters in the 1D polymers 1−8, the Cu•••Cu contact within the Cu(μ 2 -Br) 2 Cu rhomboids of 9 [2.9194(8) Å] is above the sum of the van der Waals radii of two Cu atoms. The structural arrangement of 1D polymer [{Cu(μ 2 -Br) 2 Cu}(L3) 2 ] n (11) is quite similar to that of 9. While the reaction of CuBr with L5 results in a similar 1D polymer [{Cu(μ 2 -Br) 2 Cu}(L5) 2 ] n (12), the reaction of CuBr with L2 leads to the dinuclear complex [{Cu(μ 2 -Br) 2 Cu}(η 1 -L2) 4 ] (10) ligated by four pendent bis(p-tolylthio)methane ligands. The ligation of bis(o-tolylthio)methane, L6, on CuBr also yields a discrete complex [{Cu(μ 2 -Br) 2 Cu}(MeCN) 2 (η 1 -L6) 2 ] (13) bearing MeCN and dangling dithioether ligands. A strong luminescence is detected for all CuI polymers, all exhibiting emission lifetimes in the microsecond time scale (i.e., phosphorescence). The polymers containing the Cu 4 I 4 core (1−8) exhibit the typically observed low-energy band and sometimes a weaker high-energy band. The nature of the low-energy band was proposed based on literature DFT and TDDFT computations and is predicted to be a mixture of cluster-centered (CC*) and metal/halide-to-ligand charger transfer (M/XLCT). An approximate relationship between the Cu•••Cu distance and the emission maxima corroborates the CC* contribution to the nature of the excited states. The emission of the rhomboid-containing materials is assigned to M/XLCT based on literature works on similar motifs.

On the Nature of Luminescence Thermochromism of Multinuclear Copper(I) Benzoate Complexes in the Crystalline State

“…Although temperature-dependent phosphorescence observed and characterised by us for crystals of the studied tetranuclear copper complex Cu 4 is similar to the luminescence thermochromism reported for the Cu 4 I 4 -core-containing compounds [52][53][54][55], its nature differs substantially between the two systems due to cluster cores chemical and geometrical features. In Cu 4 , four copper atoms form almost flat parallelogram-like cluster centre instead of a cubane copper-iodine core characteristic for the Cu 4 I 4 -type molecules.…”

Designs of 3-Dimensional Networks and MOFs Using Mono- and Polymetallic Copper(I) Secondary Building Units and Mono- and Polythioethers: Materials Based on the Cu–S Coordination Bond

“…This 3D polymer is weakly luminescent. This characteristic is common for rhomboid-containing species [33][34][35][36][37]. Moreover, this very low intensity luminescence property is more pronounced for CuX-containing materials when X = Cl and Br [34].…”

Crystal structure of di-μ-iodido-bis[bis(acetonitrile-κN)copper(I)]

“…The title molecule is the active species used for the synthesis of luminescent compounds with (CuI) n moieties, prepared by treatment with sulfur ligands. For more details of syntheses and properties of these compounds, see: Knorr et al (2012Knorr et al ( , 2014Knorr et al ( , 2015. The N-Cu-N angle of 100.47 (10) in the title compound is comparable with that found in the pyridinecoordinated CuI dimer (Dyason et al, 1984).…”