本文選題：配合物 + 自由基�。� 參考：《山東師范大學(xué)》2017年碩士論文

【摘要】：自由基間磁耦合性質(zhì)的研究是近年來分子基磁學(xué)領(lǐng)域的前沿課題之一。鑒于自由基類配合物顯示了特殊的雙穩(wěn)態(tài)自旋躍遷的性質(zhì)而使其在分子器件領(lǐng)域具有潛在的廣泛應(yīng)用前景,因此,進(jìn)行配合物型自由基間的磁耦合機(jī)理的研究具有重要的理論與現(xiàn)實(shí)應(yīng)用意義。本論文設(shè)計(jì)合成了以dmit(1,3-dithiole-1,2-thione-4,5-dithiolate)和mnt(cis-1,2-dicyanothylene-1,2-dithiolate)為配體的四個(gè)文獻(xiàn)尚未報(bào)道的新型自由基配合物,即[N-MePhen-OCH3][Ni(dmit)2]、[Ni(phen)3][Ni(dmit)2]2CH3COCH3、[Ni(2,2’-bpy)3][Ni(mnt)2]2和[Ni(phen)3][Ni(mnt)2]2CH3CN。對(duì)這些配合物進(jìn)行了紅外表征、XRD表征、元素分析表征;使用X-射線單晶衍射法分別測(cè)定它們?cè)谑覝睾偷蜏貢r(shí)不同溫度下的晶體結(jié)構(gòu);測(cè)試了前三個(gè)配合物的變溫磁化率;根據(jù)其晶體結(jié)構(gòu)數(shù)據(jù)獲得了其在不同溫度條件下配陰離子間存在的短距離接觸相互作用;通過理論計(jì)算的方法獲得了自由基配陰離子間短距離接觸相互作用中的各原子上的電子自旋密度以及其短距離接觸原子間的重疊積分;探討了短距離接觸原子上的電子自旋密度及短距離接觸原子間的重疊積分與相應(yīng)的實(shí)驗(yàn)磁耦合強(qiáng)度的關(guān)聯(lián),獲得了如下有意義的研究結(jié)果:1.首次揭示了:自由基短距離接觸原子間的重疊積分絕對(duì)值越大其反鐵磁耦合強(qiáng)度則越大。2.首次揭示了:自由基間π-π重疊短距離接觸原子對(duì)上的自旋密度和相關(guān)的重疊積分是導(dǎo)致其反鐵磁耦合強(qiáng)度的主要兩關(guān)鍵因素。3.進(jìn)一步證實(shí)了:短距離接觸的一對(duì)原子上電子自旋密度同時(shí)大于0.1是導(dǎo)致相鄰自由基間產(chǎn)生強(qiáng)反鐵磁耦合的必要條件之一。本論文的研究結(jié)果將對(duì)設(shè)計(jì)合成具有理想的分子基磁性功能器件具有一定的理論和實(shí)驗(yàn)指導(dǎo)意義。
[Abstract]:The study of magnetic coupling between free radicals is one of the frontier topics in the field of molecular-based magnetism in recent years. In view of the special bistable spin-transition properties of free radical complexes, which make them have a potential wide application in the field of molecular devices, therefore, The study of magnetic coupling mechanism among complex free radicals has important theoretical and practical significance. In this paper, we have designed and synthesized four novel free radical complexes, [N-MePhen-OCH3] [Ni(dmit)2], [Ni(phen)3] [Ni(dmit)2] 2CH3COCH3, [Ni(mnt)2] 2 and [Ni(phen)3] [Ni(mnt)2] 2CH3COCH3, which are ligands of dmiton 1a 3-dithiole-1n (2-thione-4) and mntntccis-1n (2-dicyanothylene-1n 2-dithiolate), which are not reported in this paper. The complexes are as follows: [N-MePhen-OCH3] [Ni(dmit)2], [Ni(phen)3] [Ni(dmit)2] 2CH3COCH3, [Ni(mnt)2] 2 and [Ni(phen)3] [Ni(mnt)2] 2CH3CN. The complexes were characterized by XRD and elemental analysis. The crystal structures of these complexes at room temperature and low temperature were determined by X-ray single crystal diffraction, and the magnetic susceptibility of the first three complexes at different temperatures were measured. According to the crystal structure data, the short-distance contact interaction between the anions at different temperatures was obtained. The electron spin density of each atom in the short distance contact interaction between free radical and anions and the overlap integral between their short distance contact atoms are obtained by theoretical calculation. The correlation between the electron spin density on the short distance contact atom and the overlap integral between the short distance contact atoms and the corresponding experimental magnetic coupling strength is discussed. The results are as follows: 1. It is shown for the first time that the greater the absolute value of the overlap integral between the atoms in short distance contact, the greater the antiferromagnetic coupling strength is. 2. It is revealed for the first time that the spin density and the relative overlap integral on the 蟺-蟺 overlap short distance contact pairs between free radicals are the two key factors leading to the antiferromagnetic coupling strength. It is further confirmed that the spin density of electrons on a pair of atoms in short distance contact is at the same time greater than 0.1, which is one of the necessary conditions for strong antiferromagnetic coupling between adjacent free radicals. The results of this paper will be helpful to the design and synthesis of molecular magnetic functional devices.
【學(xué)位授予單位】：山東師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O641.4

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本文編號(hào)：1795674