Emissive Heterobimetallic Copper(I) Dicyanoaurate‐Based Coordination Polymers

Abstract

Five new CuI/[Au(CN)2]−‐based coordination polymer materials—Cu(py)2[Au(CN)2] (1), Cu(PPh3)(MeCN)[Au(CN)2]⋅MeCN (2 a), Cu(PPh3)(MeCN)[Au(CN)2] (2 b), Cu3(THT)4[Au(CN)2]3 (3 a) and Cu(THT)[Au(CN)2] (3 b)—were prepared and characterized in terms of their structural and photoluminescence properties, and thermal stability (py=pyridine, THT=tetrahydrothiophene). While 1 and 2 a/2 b adopted one‐dimensional zig‐zag chain structures with no Au⋅⋅⋅Au (aurophilic) bonding, 3 a and 3 b exhibited much more complex three‐dimensional frameworks featuring numerous aurophilic interactions; bridging THT units formed either eight‐membered Cu4S4 rings (3 a) or helical (Cu/S)n chains (3 b). When these materials are excited using a broad‐band UV source (365 nm), they each emit light of a distinct colour (except for 2 a): light green for 1, pale blue for 2 b, deep blue for 3 a, and violet for 3 b (λmax=506 nm (1), 464 nm (2 b), 457 nm (3 a) and 404 nm (3 b)). The emission band in 1, 2 b and 3 b was assigned to CuI/ligand/CN−‐based MLCT transitions, while the emission band of 3 a appears to be influenced by the presence of the aurophilic interactions in the structure. Materials 1 and 3 a lose their bound pyridine and THT, respectively, at 110 and 95 °C, respectively, indicating their potential utility as sensory materials.

Crystal engineering of aurophilic supramolecular architectures and coordination polymers based on butterfly-like copper–dicyanoaurate complexes: vapochromism, P–T behaviour and multi-metallic cocrystal formation

“…Some other Cu(I)-dicyanoaurate compounds have been reported, but no nitrogen chelating ligand has been used until now. 38,48,49 In this system binuclear Cu(I) products have been reported using CuCN with the same ligand, 2,8,43 but no similar products have been obtained in this case.…”

“…They are stable to air and humidity. The employed synthetic procedure is similar to the one used by Leznoff and coworkers 38,48,49 and could be used with other ligands (yield: 90.5%, elemental analysis (%): calcd for C 32 -H 21 Au 2 N 11 Cu 2 : C, 35.56%; H, 1.95%; N, 14.25%; found: C, 35.35%; H, 1.89%; N, 14.33%. IR (ATR) cm −1 : 3073(w), 3002(w), 2152(s), 1604(m), 1515(w), 1449(w), 1254 (vs), 1170(s), 1037(s), 785(s), 771(m), 639(s), 519(w)).…”

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

“…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.…”

Heterobimetallic Ln(III)‐Containing Materials Based on One‐Dimensional Aurophilic Chains of Gold(I) Dithiolate Dimers and Their Vapochromic Response to DMF

“…This property was recently exploited to establish aurophilic networks of [Au 2 (i-mnt) 2 ] 2À units: hydrogen-bonding cations were utilized to reduce the Coulombic repulsion between each dinuclear, dianionic goldbearing unit, resulting in the formation of a 1-D aurophilic chain of [Au 2 (i-mnt) 2 ] 2À units bound together by intermolecular aurophilic interactions. [38] With the goal of employing the wellestablished M-NC bonding motif at the periphery of the [Au 2 (imnt) 2 ] 2À units to form heterobimetallic coordination polymers in an analogous fashion to the [Au(CN) 2 ]-based systems, [15,32,34,[39][40][41][42][43] the [Au 2 (i-mnt) 2 ] 2À building block, in conjunction with emissive lanthanide centres, was targeted in order to generate emissive lanthanide coordination polymers. Thus, the luminescence and structural characterization of the resulting ( n Bu 4 N)Ln(DMF) x [Au 2 (i-mnt) 2 ] 2 (Ln=Eu 3 + , Tb 3 + , Gd 3 + ; x = 5-8) coordination polymers is hereby described, along with the system's sensory response to various levels of dimethylformamide vapour.…”