【摘要】：分子基磁性材料具有結(jié)構(gòu)可調(diào)、磁損耗小、溶解性好、質(zhì)地輕等特點(diǎn),在高密度信息儲(chǔ)存器、分子開(kāi)關(guān)等領(lǐng)域具有巨大的應(yīng)用前景。目前已經(jīng)合成了許多結(jié)構(gòu)各異的分子基磁性材料,表現(xiàn)出多種不同的磁性:反鐵磁性、亞鐵磁性、鐵磁性、自旋翻轉(zhuǎn)、自旋玻璃、自旋傾斜、自旋交叉等。但是如何通過(guò)有效的制備方法獲得具有預(yù)期結(jié)構(gòu)的晶體,并在分子層面上調(diào)節(jié)其磁性,從而得到具有目標(biāo)磁性的分子基磁性材料仍然是一個(gè)挑戰(zhàn)。本論文中,我們選擇2-羥甲基吡啶(Hhmp)和甲酸為配體合成了八個(gè)化合物,并對(duì)其結(jié)構(gòu)-磁性的相互關(guān)系進(jìn)行了系統(tǒng)地研究:(1)利用Hhmp、甲酸和來(lái)自空氣中的CO_2形成的碳酸作為橋聯(lián)配體成功合成了兩個(gè)九核鈷配合物[Co9(hmp)6(CHOO)6(CO3)2(H2O)6](Cl O4)2·11H2O(1)和[Co9(hmp)6(CHOO)7(CO3)2(H2O)5]ClO4·CH3CN·12H2O(2)。用一個(gè)甲酸配體替換化合物1中的一個(gè)水分子配體,使化合物1中的{Co9}2+簇轉(zhuǎn)變?yōu)榛衔?中的{Co9}+簇,導(dǎo)致化合物1和2的晶體堆積模式不同。核簇電荷的改變使分子間相互作用發(fā)生變化,表現(xiàn)為:化合物1顯示反鐵磁行為,而化合物2表現(xiàn)自旋玻璃行為。(2)以Hhmp為配體,通過(guò)溶劑誘導(dǎo)合成了三個(gè)立方烷型銅配合物:[Cu4(hmp)4(CHOO)2(H2O)2](ClO4)2·2H2O(3),[Cu8(hmp)8(CHOO)4(CH3CN)2(H2O)4](Cl O4)4·2CH3CN(4),{[Cu2(hmp)2(CHOO)(H2O)]ClO4·H2O}n(5)。通過(guò)改變?nèi)軇┍壤?可將單立方烷四核銅簇3成功轉(zhuǎn)變?yōu)榫哂须p立方烷結(jié)構(gòu)的八核銅簇4,通過(guò)甲酸橋聯(lián)配體的進(jìn)一步延伸得到多立方烷鏈5。單立方烷化合物3和雙立方烷化合物4均具有反鐵磁相互作用,多立方烷化合物5表現(xiàn)出鐵磁相互作用。(3)通過(guò)改變中心金屬和溶劑比例,成功合成了三個(gè)以Hhmp和甲酸為配體的立方烷型配合物:[Ni4(hmp)4(CHOO)2(H2O)4](ClO4)2(6),[Ni4(hmp)4(CHOO)4(H2O)2]·5.5H2O(7),[Co4(hmp)6(H2O)2(CH3CN)2](ClO4)4·4CH3CN(8)。四核鎳化合物6和7具有相似的立方烷結(jié)構(gòu),不同的金屬配位環(huán)境,均表現(xiàn)反鐵磁相互作用。四核鈷化合物8具有缺立方烷結(jié)構(gòu),表現(xiàn)長(zhǎng)程有序行為。
[Abstract]:Molecular based magnetic materials have the advantages of adjustable structure, low magnetic loss, good solubility and light texture, so they have great application prospects in high density information storage, molecular switch and other fields. At present, many molecular based magnetic materials with different structures have been synthesized, showing various magnetic properties, such as antiferromagnetism, ferromagnetism, spin flip, spin glass, spin tilt, spin cross and so on. However, it is still a challenge to obtain the desired structure of crystals by effective preparation and adjust their magnetic properties at the molecular level to obtain the molecular based magnetic materials with target magnetic properties. In this thesis, we selected 2-hydroxymethylpyridine (Hhmp) and formic acid as ligands to synthesize eight compounds. The relationship between structure and magnetism was systematically studied. (1) two Co9 (hmp) 6 (CHOO) 6 (CO3) 2 (H 2O) 6 (CLO 4) 2 11H2O (1) and [Co9 (hmp) 6 (CHOO) 7 (CO3) 2 (H 2O) 5] ClO4 CH3CN 12H2O (2) complexes were successfully synthesized by using HHMP, formic acid and carbonic acid formed from air as bridging ligands in the presence of [Co9 (hmp) 6 (CHOO) 6 (CO3) 2 (H 2O) 6] (CLO 4) 2 11H2O (1) and [Co9 (hmp) 6 (CHOO) 7 (CO3) 2 (H 2O) 5] ClO4 CH3CN 12H2O (2). The {Co9} 2 cluster in compound 1 is transformed into {Co9} cluster in compound 2 by replacing an aqueous ligand in compound 1 with a formic acid ligand. The crystal stacking modes of compound 1 and 2 are different. 鏍哥皣鐢?shù)鑽风殑鏀瑰彉?shù)嬌鍒嗗瓙闂寸浉浜掍綔鐢ㄥ彂鐢熷彉鍖?zhuān)?

本文編號(hào)：2147867