含胺-亞胺異官能雙牙配位基平面四邊形鈀(II)金屬錯合物之合成、幾何異構化及反應活性的研究

Study of the Square Planar Methylpalladium (II) Complexes Bearing Unsymmetrical α-Aminoaldimine Bidentate Ligands of Hetero Functionalities: Synthesis, Geometrical Isomerism and Reactivity

王育恒(Yu-Heng Wang)

指導教授 ： 陳竹亭

國立臺灣大學/理學院/化學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.01258

摘要

一系列含胺-亞胺不對稱異官能雙牙配位基，R1R2NCMe2CH=NR (R1, R2 = Me, Et, c-C4H8 or R1 = iPr, tBu, R2 = H; R = Me, Et, iPr, tBu)，成功地藉由二甲基胺異丁醛和胺類的縮合反應製備而成。中性胺-亞胺鈀(II)金屬錯合物可以藉由上述配位基置換起始物((COD)Pd(Me)Cl)中的1,5-環辛二烯合成獲得。晶體結構分析顯示產物之胺-亞胺鈀金屬錯合物為平面四邊形的結構，並且只有單一的幾何異構物。晶體之構形取決於溶液中反式和順式異構物之相對含量；倘若順式異構物於溶液狀態下比例具有優勢，獲得晶體之構型即為順式，反之亦然。錯和物於溶液中有幾何異構化的現象。胺-亞胺鈀金屬錯合物之幾何異構物相對比例可以藉由胺-亞胺上的取代基之立體效應微調控制，其幾何異構化的動力學和反應機構的研究是以變溫氫譜核磁共振儀作為輔助工具。不同溫度下的幾何異構物速率常數分別為：6.97 × 10-5 s-1 (-10℃)、5.29 × 10-4 s-1 (0.0℃)和3.49 × 10-3 s-1 (10℃)，反應之活化能為120 kJ/mol。活化焓和活化熵的數值證明幾何異構化的反應機構乃是經由亞胺的解離以及重新配位。CO-和CNR-對於胺-亞胺鈀金屬錯合物的嵌入反應之產物依然具有幾何異構物。幾何異構物的反應活性差異乃是研究丁炔二酸二甲酯(DMAD)的嵌入反應。順式和反式幾何異構物的反應速率、反應機構和反應產物之差異於本文中清楚地呈現。

關鍵字

不對稱雙牙基 ； 甲基鈀 ； 幾何異構物 ； 結晶學分析 ； 一氧化碳和丁炔二酸二甲酯嵌入反應

並列摘要

A series of unsymmetrical bidentate ligands of α-aminoaldimines in the form of R1R2NCMe2CH=NR (R1, R2 = Me, Et, c-C4H8 or R1 = iPr, tBu, R2 = H; R = Me, Et, iPr, tBu) have been synthesized using condensation of 2,2-aminoethylpropanal with such ligands can replace COD in (COD)PdMeCl to give neutral methylchloropalladium complexes contain geometrical isomers with square planar configuration, and cis-trans isomerism was observed in solutions. However, it is interested that crystallographic analysis gives only single form crystal. Which geometrical isomers could be available depending on the relative stability in solution. The equilibrium constant of the isomerization may be fine-tuned in terms of the variation of the ligand substituents. Kinetic and mechanistic studies for the substitution and isomerization reactions are investigated by varied temperature 1H NMR. The rate constant of isomerization is 6.97 × 10-5 s-1 at -10℃, 5.29 × 10-4 s-1 at 0℃, and 3.49 × 10-3 s-1 at 10℃, and the activation energy is 120 kJ/mol. The geometrical isomerization is proposed to proceed via an imine dissociation and re-coordination. The CO- and CNR- inserted products of [R1R2NCMe2CH=NR]PdMeCl also contain geometrical isomers, and the reactivity is differentiated toward DMAD. Here we report the variation in insertion rate constant and proposed mechanism between cis and trans form.

並列關鍵字

unsymmetrical bidentate ligand ； methylpalladium ； geometrical isomer ； crystallographic analysis ； CO, DMAD Insertion

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