When Cu4I4 cubane meets Cu3(pyrazolate)3 triangle: dynamic interplay between two classical luminophores functioning in a reversibly thermochromic coordination polymer

Abstract

A supramolecular dual emissive system incorporating two classical copper(I)-cluster-based luminophores, namely, Cu(4)I(4) and Cu(3)Pz(3) (Pz = pyrazolate), is reported. The targeted luminescent coordination polymer exhibits reversible thermochromism spanning from green to orange-red.

Luminescent Metal–Organic Frameworks (MOFs) as a Chemopalette: Tuning the Thermochromic Behavior of Dual‐Emissive Phosphorescence by Adjusting the Supramolecular Microenvironments

“…[7a] Given the various origins of MOF luminescence (mostly ligand-based, lanthanide-based, charge-transfer, and guest-induced luminescence), [7] it is possible to achieve dual emissions [8] by simultaneously incorporating diverse luminophores into one matrix by means of supramolecular interactions. This is an advantage relative to those of molecule-based dual emissions, [8a-d] which are usually bounded by Kashas rule [9] that permits only the lowest excited state to emit.In our previous work, [10] a supramolecular dual-emissive MOF, namely, [Cu 4 I 4 A C H T U N G T R E N N U N G (NH 3 )Cu 3 (L1) 3 ] n (hereafter denoted as 1·NH 3 , L1 = 3-(4-pyridyl)-5-(p-tolyl)pyrazolate), which contains two classical copper(I)-cluster-based luminophores, Cu 4 I 4 and [Cu 3 Pz 3 ] 2 (Scheme 1; Pz = pyrazolate), was reported. The tetrahedral Cu 4 I 4 cluster is the most documented member in the copper(I) halide family, [11] but it is still of considerable research interest because of its structural applicability to act as the secondary building unit of MOFs, [12] and its well-studied, yet still developing, photophysical functionality.…”

Designed Cluster Assembly of Multidimensional Titanium Coordination Polymers: Syntheses, Crystal Structure and Properties

“…Unlike other previously reported Cu 4 I 4 -containing materials with emissionp eaks occurring at l = 590 nm, [37] the peaks observed for compounds 1, 2, 3, 5,a nd 7 exhibit blue shifts,o bviously,w hich are likely attributed to the cooperative effect between the Cu 4 I 4 clusters and the TOCs. [38] In contrast, compound 4,w hich contains the Cu 2 I 2 rhomboidm otif, displays ar elatively weak emission peak at l = 421 nm. For compound 8,f eaturing wing-shaped Cu 2 I 2 and tetrahedral Cu 4 I 4 clusters,t he luminescence spectrum exhibits ab road emission band spreading from l = 350 to 550 nm with three well-refined peaks at l = 407,4 21,a nd 433 nm,.…”

Cu(I) hybrid inorganic–organic materials with intriguing stimuli responsive and optoelectronic properties

“…An interesting series of metal-organic frameworks (MOF) based on the two luminophores Cu 4 I 4 and Cu 3 Pz 3 was reported by Li et al [34,35]. [Cu 4 I 4 (NH 3 )Cu 3 (L) 3 ] n (L=3-(4-pyridyl)-5-p-tolylpyrazolate), 11, and [Cu 4 I 4 (NH 2 CH 3 )Cu 3 (L) 3 ] n , 12, prepared by reaction of CuI with the corresponding ligand under solvothermal conditions, exhibit at room temperature and in the solid state a dual emission in the 520-540 and in the 630-680 nm regions, originated from a thermal equilibrium between a *CC (for Cu 4 I 4 ) and a *[Cu 3 ] 2 (for [Cu 3 Pz 3 ] 2 ) excited states respectively.…”