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

详细信息    查看全文

• 作者：Huaguang Yu ; Xiuzhen Tan ; Guy M. Bernard ; Victor V. Terskikh ; Jinglin Chen ; Roderick E. Wasylishen
• 刊名：Journal of Physical Chemistry A
• 出版年：2015
• 出版时间：July 30, 2015
• 年：2015
• 卷：119
• 期：30
• 页码：8279-8293
• 全文大小：664K
• ISSN：1520-5215

文摘

The results of a solid-state ^63/65Cu and ³¹P NMR investigation of several copper(I) complexes with functionalized 3-(2鈥?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 ⁶³Cu nuclear quadrupolar coupling constant (C_Q) values ranging from 鈭?7.2 to 鈭?3.7 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, 未₁₁鈥撐?sub>33, 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鈥搒pin coupling arising from the ^63/65Cu鈥?³¹P spin pairs, observed in the solid-state ³¹P NMR spectra of these complexes, yield information about the orientations of the copper electric field gradient (EFG) tensors relative to the Cu鈥揚 bond. Variable-temperature ³¹P NMR measurements for [Cu(bptzH)(dppe)]ClO₄ (bptzH = 5-tert-butyl-3-(2鈥?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 ^63/65Cu 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 C_Q(^63/65Cu) is negative for all complexes studied here and that the largest components of the EFG tensors are generally coincident with 未₁₁.