Novel phosphorescent tetradentate bis-cyclometalated C∧C*N∧N-coordinated platinum complexes: Structure, photophysics, and a synthetic adventure
Novel phosphorescent tetradentate bis-cyclometalated C∧C*N∧N-coordinated platinum complexes: Structure, photophysics, and a synthetic adventure
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DOI：
10.1016/j.poly.2012.06.078
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发表时间：
2013-03-22
期刊：
影响因子：
2.6
通讯作者：
Li, Yumin
中科院分区：
文献类型：
--
作者：
Huo, Shouquan;Harris, Caleb F.;Li, Yumin
描述了一篇关于合成四齿双环金属C布尔型和C*N布尔型和N配位铂配合物的长篇但富有冒险意味的期刊，其中C布尔型和C和N布尔型和N表示五元络合，C*N表示六元络合。最初的配体设计导致了选择性的环铂反应，形成了一个三齿配位络合物。所合成的三齿配位化合物的结构经X-射线单晶研究确证。分析了三齿配位络合物的选择性形成，从而得出了配体15和16的最终设计。配体15和16的不同之处仅在于N布尔和N基序；基于联吡啶的N布尔和N用于15，以及基于吡唑基吡啶的N布尔和N用于16。在这两种情况下，强制连续的双环铂化反应将可能形成C布尔型和C*N布尔型和N配位的铂络合物。如预期的那样，配体15和16与K2PtCl4在冰醋酸中回流反应分别得到17和18。X-射线衍射法证实了配合物17的配位构型。在分子堆积中发现了正方形平面构型和双分子间的pi-pi和pT-pT相互作用。研究了配合物的光物理性质。结果表明，在室温下，配合物18在脱氧溶液中发出强烈的黄色磷光，而配合物17在冰冻的玻璃基质中发出红光。这两种化合物的激发态寿命都在微秒量级。用密度泛函理论计算了配合物的前线轨道，用来解释配合物的电子光谱。(C)2012爱思唯尔有限公司。保留所有权利。
A long but adventurous journal to the synthesis of tetradentate bis-cyclometalated C boolean AND C*N boolean AND N-coordinated platinum complexes is described, where C boolean AND C and N boolean AND N denote a five-membered chelation and C*N denotes a six-membered chelation. Initial ligand designs resulted in the selective cycloplatination to form a tridentate coordination complex. The structures of the tridentate coordination complexes were confirmed by the X-ray crystallographic studies. The selective formation of the tridentate coordination complexes was analyzed, which led us to an ultimate design of the ligand 15 and 16. Ligands 15 and 16 differ only in the N boolean AND N motif; a bipyridine-based N boolean AND N for 15 and a pyrazolylpyridine-based N boolean AND N for 16, respectively. In both cases, a forced consecutive double cycloplatination would be possible to form a C boolean AND C*N boolean AND N-coordinated platinum complex. As expected, the reaction of ligand 15 and 16 with K2PtCl4 in acetic acid at reflux produced 17 and 18, respectively. The coordination geometry was confirmed by the X-ray crystallography of the complex 17. The square planar geometry and dual intermolecular pi-pi and Pt-Pt interactions were revealed in the molecular packing. The photophysical properties of the complexes were studied. It was found that the complex 18 emitted intensely yellow phosphorescence at room temperature in deoxygenated solution, while complex 17 emitted red emission in a frozen glass matrix. Both compounds have the lifetime of the excited states in the scale of micro seconds. The DFT calculations were carried out to elucidate the frontier orbitals of the complexes, which are used in interpreting the electronic spectra of the complexes. (C) 2012 Elsevier Ltd. All rights reserved.