Solid-State ⁶³Cu, ⁶⁵Cu, and ³¹P NMR Spectroscopy of Photoluminescent Copper(I) Triazole Phosphine Complexes

Abstract

The results of a solid-state (63/65)Cu and (31)P NMR investigation of several copper(I) complexes with functionalized 3-(2'-pyridyl)-1,2,4-triazole and phosphine ligands that have shown potential in the preparation of photoluminescent devices are reported. For each complex studied, distinct NMR parameters, with moderate (63)Cu nuclear quadrupolar coupling constant (CQ) values ranging from -17.2 to -23.7 MHz, are attributed to subtle variations in the distorted four-coordinate environments about the copper nuclei. The spans of the copper chemical shift (CS) tensors, δ11-δ33, for the mono- and bisphosphine complexes are also similar, ranging from 1000 to 1150 ppm, but that for a complex with a strained bidentate phosphine ligand is only 650 ppm. The effects of residual dipolar and indirect spin-spin coupling arising from the (63/65)Cu- (31)P spin pairs, observed in the solid-state (31)P NMR spectra of these complexes, yield information about the orientations of the copper electric field gradient (EFG) tensors relative to the Cu-P bond. Variable-temperature (31)P NMR measurements for [Cu(bptzH)(dppe)]ClO4 (bptzH = 5-tert-butyl-3-(2'-pyridyl)-1,2,4-triazole; dppe = 1,2-bis(diphenylphosphino)ethane), undertaken to investigate the cause of the broad unresolved spectra observed at room temperature, demonstrate that the broadening arises from partial self-decoupling of the (63/65)Cu nuclei, a consequence of rapid quadrupolar relaxation. Ab initio calculations of copper EFG and CS tensors were performed to probe relationships between NMR parameters and molecular structure. The analysis demonstrated that CQ((63/65)Cu) is negative for all complexes studied here and that the largest components of the EFG tensors are generally coincident with δ11.

CuV2S4: A High Rate Capacity and Stable Anode Material for Sodium Ion Batteries

“…Spectra were acquired with a rotor-synchronized Hahn-echo pulse sequence with a π/2 pulse length of 2.3 μs and a recycle delay of 1 s. The spectra were referenced to an aqueous solution of 1 M NaCl at 0 ppm. 63 Cu resonances observed during these 23 Na NMR measurements were additionally referenced to CuCl powder as a secondary reference (−333.2 ppm at 298 K) …”

“…63 Cu resonances observed during these 23 Na NMR measurements were additionally referenced to CuCl powder as a secondary reference (−333.2 ppm at 298 K). 46 Electrochemical Test. CuV 2 S 4 electrodes were prepared from 80 wt % CuV 2 S 4 , 10 wt % SUPER C65 Carbon (Timcal, Switzerland), and 10 wt % PVdF (Solvay, Germany) suspended in NMP (N-methyl-2-pyrrolidone).…”

Lead-Halide Scalar Couplings in 207Pb NMR of APbX3 Perovskites (A = Cs, Methylammonium, Formamidinium; X = Cl, Br, I)

“…J-couplings to quadrupolar nuclei are known to be self-decoupled, due to their fast relaxation induced by the quadrupole. The fact that in these perovskite materials the couplings are clearly visible, indicates a relatively slow quadrupolar relaxation of the halides 76 . Once observed, the J-coupling could be, in principle, correlated to the atomic structure.…”

A solid state highly emissive Cu(i) metallacycle: promotion of cuprophilic interactions at the excited states

“…The rational design of phosphorescent d 10 metal complexes as new materials for the development of multifunctional lighting applications has attracted extensive attention in recent years. 1 Recently, the community has stepped up efforts to develop Cu(I) derivatives 2 which has given rise to attractive new solid-state emitters based on a cheap and abundant metal ion.…”