羥基對二芳基希夫堿的紫外吸收、核磁共振及還原電位性能的影響
發(fā)布時間:2018-11-14 14:35
【摘要】:本文設(shè)計合成了3組共69種含羥基的希夫堿模型化合物,即Ⅰ組:4-HOAr CH=NAr-Y~XAr CH=NAr OH-4’(4-HOBAY~XBAOH-4’),Ⅱ組:2-HOAr CH=NAr-Y~XAr CH=NAr OH-2’(2-HOBAY~XBAOH-2’)和Ⅲ組:3-HOAr CH=NAr-Y(3-HOBAY)。對其分子結(jié)構(gòu)進行了相關(guān)表征和確認(rèn)。通過實驗測試獲得了目標(biāo)化合物紫外吸收光譜、核磁共振譜及還原電位,對上述各性能的變化規(guī)律進行定量相關(guān)分析,并與已報導(dǎo)的類似化合物相應(yīng)性能變化規(guī)律進行比較。主要內(nèi)容如下。對Ⅰ組和Ⅱ組57種模型化合物的紫外吸收最大波長λ_(max)(nm)的能量(波數(shù):n_(max) cm-1)進行定量相關(guān)分析,并得到具有良好可靠性的定量相關(guān)方程。觀察到羥基OH對λ_(max)有反常的影響。與文獻(xiàn)報導(dǎo)的XAr CH=NAr Y希夫堿化合物的n_(max)變化規(guī)律相比較,4-OH和2-OH對n_(max)的影響與其它X、Y基團對n_(max)的影響相似,而4’-OH和2’-OH則對n_(max)表現(xiàn)出“反!庇绊:4’-OH對n_(max)產(chǎn)生紅移;2’-OH對n_(max)產(chǎn)生藍(lán)移。此外2-OH和2’-OH還存在鄰位立體效應(yīng),使n_(max)產(chǎn)生紅移。這些結(jié)果在希夫堿類化合物作為光學(xué)材料,進行分子設(shè)計時提供重要的理論參考。研究了Ⅰ組和Ⅱ組57種模型化合物中C=N雙鍵13C NMR化學(xué)位移值δ_C(C=N)受到取代基效應(yīng)的影響規(guī)律,得到良好的定量相關(guān)方程,并與文獻(xiàn)報導(dǎo)的XAr CH=NAr Y的δ_C(C=N)進行比較研究。結(jié)果表明取代基在目標(biāo)化合物中對δ_C(C=N)的影響與XAr CH=NAr Y中有很大不同。影響化合物4-HOBAY、XBAOH-4’的δ_C(C=N)的主要因素有4個:取代基X的誘導(dǎo)效應(yīng)、共軛效應(yīng)參數(shù)、取代基X和Y的相互作用以及OH,并且由于OH基在C=N橋鍵兩端位置的不同,對δ_C(C=N)的影響大小也不同。雖然取代基X的共軛效應(yīng)的很小,但是對于精確預(yù)測該類化合物的δ_C(C=N)有一定的作用。通過2-HOBAY和XBAOH-2’兩個系列化合物C=N雙鍵上碳原子的13C NMR化學(xué)位移δ_C(C=N)的比較得出:影響這兩類化合物的因素不同。影響2-HOBAY的化學(xué)位移值δ_C(C=N)主要因素有3個,分別是取代基Y的共軛效應(yīng)、取代基Y的激發(fā)態(tài)取代基參數(shù)以及基態(tài)取代基X和Y之間的相互作用;影響XBAOH-2’化學(xué)位移值δ_C(C=N)主要因素也有3個,分別是取代基X的誘導(dǎo)效應(yīng)、取代基X的激發(fā)態(tài)取代基參數(shù)以及基態(tài)取代基X和Y之間的相互作用。雖然激發(fā)態(tài)取代基參數(shù)對δ_C(C=N)值的影響較小,但對于精確計算該類化合物的δ_C(C=N)有一定的作用。2-HOBAY的δ_C(C=N)值普遍比XBAOH-2’的要高。測定28種模型化合物4-HOBAY~XBAOH-4’的還原電位E(Red),與之前研究的不含羥基的XBAYs的E(Red)相比,發(fā)現(xiàn)4/4’-OH基對模型化合物的E(Red)有一個額外的影響,導(dǎo)致其E(Red)減少了一個常量(-0.36V);歸納并總結(jié)出一個通用方程來定量表達(dá)單取代、二取代XBAYs的還原電位E(Red),并具有良好的可靠性。測得12種模型化合物3-HOBAY在無水乙醇中紫外吸收最大波長λ_(max)(nm),以λ_(max)的能量n_(max)(cm-1,n_(max)=1/λ_(max))代入相關(guān)文獻(xiàn)報導(dǎo)的定量相關(guān)方程,用計算機進行數(shù)據(jù)擬合,得到間位羥基(m-OH)的激發(fā)態(tài)取代基參數(shù))OH()(ex m CCs為0.47。采用的模型化合物的基團Y分布較廣(從Me O到CN,其sp從-0.27到-0.66,ex CCs從-0.5到0.56),所得的OH值經(jīng)計算模型化合物λ_(max)與實驗值對比,其值是可信的,可用于有機化合物的紫外光譜性能相關(guān)和光學(xué)分子設(shè)計。并得出間位羥基的激發(fā)態(tài)取代基常數(shù)可以從希夫堿的紫外吸收最大波長λ_(max)進行擬合提取這一結(jié)論。
[Abstract]:A total of 69 hydroxy-containing Schiff base model compounds, namely group I: 4-HOAr CH = Nur-Y-XAr CH = NAr OH-4 '(4-HOBAY-XBAOH-4), were synthesized in three groups. "), Group II: 2-HOAr CH = NAR-Y-XAr CH = NAr OH-2' (2-HOBAY-XBAOH-2 ') 3-HOAr CH = Nur-Y (3-HOBAY). The molecular structure was characterized and confirmed. The ultraviolet absorption spectrum, the nuclear magnetic resonance spectrum and the reduction potential of the target compound were obtained by the experiment test, and the variation law of the above properties was analyzed and compared with the corresponding performance rule of the similar compound. The main contents are as follows. The energy (wavenumber: n _ (max) cm-1) of the maximum wavelength of ultraviolet absorption of 57 model compounds in group I and group II was analyzed by quantitative correlation, and a quantitative correlation equation with good reliability was obtained. It was observed that the hydroxyl group OH had an abnormal effect on the molar ratio of P _ (max). The effect of 4-OH and 2-OH on n _ (max) was similar to that of other X and Y groups on n _ (max), while 4'-OH and 2 '-OH showed a 鈥渁bnormal鈥,
本文編號:2331444
[Abstract]:A total of 69 hydroxy-containing Schiff base model compounds, namely group I: 4-HOAr CH = Nur-Y-XAr CH = NAr OH-4 '(4-HOBAY-XBAOH-4), were synthesized in three groups. "), Group II: 2-HOAr CH = NAR-Y-XAr CH = NAr OH-2' (2-HOBAY-XBAOH-2 ') 3-HOAr CH = Nur-Y (3-HOBAY). The molecular structure was characterized and confirmed. The ultraviolet absorption spectrum, the nuclear magnetic resonance spectrum and the reduction potential of the target compound were obtained by the experiment test, and the variation law of the above properties was analyzed and compared with the corresponding performance rule of the similar compound. The main contents are as follows. The energy (wavenumber: n _ (max) cm-1) of the maximum wavelength of ultraviolet absorption of 57 model compounds in group I and group II was analyzed by quantitative correlation, and a quantitative correlation equation with good reliability was obtained. It was observed that the hydroxyl group OH had an abnormal effect on the molar ratio of P _ (max). The effect of 4-OH and 2-OH on n _ (max) was similar to that of other X and Y groups on n _ (max), while 4'-OH and 2 '-OH showed a 鈥渁bnormal鈥,
本文編號:2331444
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