含苯乙烯取代之2-苯吡啶環鉑(II)錯合物之合成與光化學性質之研究

Synthesis and Photochemical Properties of Cyclometalated Styryl-substituted 2-Phenylpyridinato Platinum (II) Complexes

林哲仁(Che-Jen Lin)

指導教授 ： 楊吉水

國立臺灣大學/理學院/化學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.10475

摘要

本論文之目的為合成一系列 [(C^N)Pt(O^O)] 及其分子模型計算並探討其光化學性質。C^N 為含有對胺基苯乙烯取代之苯吡啶 (PhDM, PhDP, PyDM, PyDP)期為單陰離子之配位基，而O^O為乙醯丙酮配位基。
我們利用X-ray繞射鑑定化合物PhDP與PtPhDP之晶體結構。DFT與TDDFT理論計算錯合物及其配位基之分子模型與激發態能階，並利用UV-Vis 吸收光譜、放射光譜及反式→順式光致異構化量子產率探討錯合物及其配位基之光化學性質。所有PtII錯合物含有配位基內電荷轉移 (ILCT) 之單重態激發態且錯合物PtPhDM 及PtPhDP相較於錯合物PtPyDM及PtPyDP含有較強的鄰位ILCT性質。
所有錯合物之磷光光譜是在低溫77 K測得，室溫下之磷光量子產率則非常低 (<10-3)。此外，激發態行為主要是由二苯乙烯或是含氮二苯乙烯部分所主導。激發態去活化路徑是由反式→順式異構化所主導，而跟取代基的位置與種類無關。最低三重激發態為配位基內電荷轉移 (3ILCT) 態。錯合物PtPyDM及PtPyDP之3ILCT激發態之分布主要是區域化在含氮二苯乙烯部分，而錯合物PtPhDM及PtPhDP之3ILCT激發態則是由胺基二苯乙烯至吡啶陽離子非定域分布。
從以上現象可知，對胺基苯乙烯取代之鉑錯合物其激發態主要是區域化在二苯乙烯及含氮二苯乙烯部分，且可由對位及鄰位共軛效應來解釋其光物理性質。

關鍵字

鉑 ； 二苯乙烯

並列摘要

The synthesis, molecular modeling, and photochemical properties of four Pt(II) complexes [(C^N)Pt(O^O)] are reported. C^N is a monoanionic cyclometalating styrene-incorporated phenylpyridine ligand (PyDM, PyDP, PhDM, and PhDP) and O^O is an acetylacetone (acac) ligand. The solid-state structures of PhDP and PtPhDP were characterized by X-ray diffraction. Molecular modeling was carried out with DFT and TD-DFT methods, and photochemical properties were investigated with UV-Vis absorption, steady-state luminescence, and the measurements of trans→cis photoisomerization quantum yield. The lowest singlet excited-state (S1) for all the Pt complexes is of ILCT character and it is more meta-ph ILCT character for PtPhDM and PtPhDP than for PtPyDM and PtPyDP. All PtII complexes show phosphorescence only at 77 K but not at room temperature. The major triplet deactivated pathway is the nonradiative trans→cis isomerization. Furthermore, the excited-state behavior which is independent of the substitution position mainly dictated by the stilbene and azastilbene moiety. The lowest excited state (T1) is an intraligand charge transfer state (3ILCT). The 3ILCT state is localized on the azastilbene moiety for PyDM and PyDP systems but is from aminostilbene to the pyridinium moiety for PhDM and PhDP systems. As a result, the behavior of these systems can be understood by a para vs meta conjugation effect.

並列關鍵字

platinum ； stilbene

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