The CuI-derived inorganic−organic hybrid compounds are considered as promising phosphors for the lighting industry. Herein, exploiting N-monoalkylated hexaminium salts, [R-HMTA]X (R = Me, Et, Pr, and propargyl; X = Cl and I), as multibridging ligands, we have designed and synthesized a unique class of one-dimensional and two-dimensional hybrid CuImaterials. The reactions of these salts with CuI give rise to Allin-One (AIO) type compounds combining ionic and dative bonds between inorganic and organic components. The latter is formed by structurally unique inorganic [Cu x I y ] (y−x)− clusters, chains, or sheets interconnected through [R-HMTA] + cations via multiple Cu−N bonds. The so-designed compounds at ambient temperature exhibit tunable luminescence spanning from deep blue to red color (λ em = 430−625 nm) with microsecond lifetimes and the quantum efficiency of up to 78%. Remarkably, the AIO materials feature nontrivial excitation-(ED) and temperature-dependent (TD) luminescence, allowing their emission color to be finely adjusted from deep blue to red through changing the excitation wavelength and/or temperature. Based on the TD emission spectroscopy and theoretical calculations, a possible mechanism of the luminescence has been proposed. The very interesting luminescence characteristics coupled with good thermal and photostability render these AIO hybrid materials possible candidates for applications in energy-efficient lighting devices.
Unprecedented organic-inorganic hybrid complexes, [Mn(L)3]MnHal4, containing both four- and hexacoordinated Mn2+ ions were synthesized by reacting MnCl2 or MnBr2 with bis(phosphine oxide) ligands (L) such as dppmO2, dppeO2, and 2,3-bis(diphenylphosphinyl)-1,3-butadiene (dppbO2). In the [Mn(L)3]2+ cation of the complexes, the Mn2+ ion features a [MnO6] octahedral coordination environment (Oh), and the [MnHal4]2- anion adopts a tetrahedral geometry (Td). These "two-in-one" complexes exhibit strong long-lived luminescence (τav = 12-15 ms at 300 K) having interesting thermochromic behavior attributed to the thermal equilibrium between two emission bands. So, in an emission spectrum of the typical complex [Mn(dppbO2)3]MnBr4, the intense "red" (ca. 620 nm) and weak "green" (ca. 520 nm) bands, originating from Mn2+ ions in Oh and Td environments, respectively, are observed. Cooling from 300 to 77 K simultaneously leads to (i) redshift of both bands by ca. 20 nm, (ii) increasing their intensities, and (iii) causing a substantial change of their integral intensity ratio from about 4 : 1 to 2 : 1. As a result, the colour of the emission changes from orange (CIE 0.56, 0.45) at 300 K to deep red (CIE 0.62, 0.39) at 77 K. This behavior was rationalized using steady-state and time-resolved fluorescent spectroscopy at various temperatures. The high photoluminescence quantum yields (up to 61% at 300 K) and fascinating dual-emissive phosphorescence coupled with high thermal stability and solubility suggest a high potential of this novel class of emissive Mn2+ complexes as promising emitters for OLED devices and potential stimuli-responsive materials.
A suite
of paddle-wheel shaped [Cu2(PymPPh2)3(Lan)
n
](PF6)2 complexes showing efficient thermally activated delayed fluorescence
(TADF) has been synthesized. In these complexes, Cu(I) ions are P,N-bridged by three diphenyl(2-pyrimidyl)phosphine
(PymPPh2, L) ligands in a “head-to-tail”
fashion, and one or both metals are also capped by the ancillary ligand
(Lan = MeOH, Me2CO, MeCN, PhCN). At ambient
temperature, the solid complexes emit TADF with the quantum yield
of up to 85% and the lifetimes of from 9.6 to 27 μs. The ancillary
ligands, whose orbitals negligibly contribute to the radiative 1(M + L + Lan)LCT state, remarkably adjust emission
energies and ΔE(S1–T1) energy splitting magnitudes of the emitters obtained. Thus,
depending on structure and/or number of the Lan molecules,
the emission maxima vary from 500 to 563 nm, and the ΔE(S1–T1) gaps range 550–1100
cm–1. Such tunable TADF characteristics coupled
with the excellent solubility and air-stability make the complexes
presented to be promising TADF materials.
Remarkable solvation-induced emission enhancement is discovered on a new Ag(i) complex showing sky-blue thermally activated delayed fluorescence (TADF).
A series of Cu(i) halide complexes showing thermally activated delayed fluorescence (TADF) combined with room temperature phosphorescence are reported.
Can arsine ligands be preferred over similar phosphines to design Cu(I)-based TADF materials? The present study reveals that arsines can indeed be superior to reach shorter decay times of Cu(I)...
The first example of a triply bridging (μ3‐P) phosphine ligand has been discovered in the crown‐shaped [Cu3(μ2‐Hal)3L] (Hal=Cl, Br, or I) complexes supported by tris[2‐(2‐pyridyl)ethyl]phosphine (L). Theoretical analysis completely confirms the observed μ3‐P‐bridging pattern, revealing the interaction of the same lone pair of phosphorus with three valence 4s‐orbitals of Cu atoms. The presented complexes exhibit outstanding blue phosphorescence (λem=442–465 nm) with the quantum efficiency reaching 100 %. The complex [Cu3(μ2‐I)3L] also exhibits remarkable thermo‐ and mechanochromic luminescence resulting in a sharp change in the emission colour upon external stimuli. These findings essentially contribute to coordination chemistry of the pnictine ligands.
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