| 摘要註: |
以N,N,N三芽螯合的配位基1,8-bis(phenylimino)-3,6-di-tert-butyl-9H-carbazole (3) 及1,8-bis(n-hexylimino)-3,6-di-tert-butyl-9H-carbazole (4) 為基礎，加入三乙基鋁進行金屬錯化反應可形成甲基丙烯酸甲酯聚合的預催化劑-二乙基鋁錯化合物[1,8-bis(phenylimino)-3,6-di-tert-butylcarbazolide]-Al(CH2CH3)2 (3a) 和[1,8-bis(n-hexylimino)-3,6-di-tert-butylcarbazolide]-Al(CH2CH3)2 (4a)。此鋁錯化合物與約一當量的三氯化鋁形成二氯鋁錯化合物[1,8-bis(phenylimino)-3,6-di-tert-butylcarbazolide]-AlCl2 (3b) 和[1,8-bis(n-hexylimino)-3,6-di-tert-butylcarbazolide]-AlCl2 (4b)。由X-ray單晶繞射分析發現3b和4b之固態結構是以鋁金屬原子為中心，結合周圍氮與氯取代基環境而構成雙三角錐的幾何型態，其中兩個氯原子皆位於赤道位向。 配位基3和4也可與二甲基鋅試劑反應得鋅金屬中心之甲基鋅錯化合物[1,8-bis(phenylimino)-3,6-di-tert-butylcarbazolide]-Zn(CH3) (3c) 和[1,8-bis(n-hexylimino)-3,6-di-tert-butylcarbazolide]-Zn(CH3) (4c)。由X-ray單晶繞射分析發現取代基會影響其固態結構，3c以單核鋅金屬型式存在，而4c卻是一個雙核鋅原子構造。之後將此二錯合物測試其聚合丙交酯的反應性，也發現3c與4c具有不同的催化表現。另外合成一系列以吡啶為骨架含氧之吡啶-醇與含氟吡啶-醇配位基，並與二甲基鋅進行錯化反應而形成金屬化合物。其中連結吡啶與氧之烷鏈會因引入不同的取代基，二甲基、二苯基和芴基而使得吡啶上之氮、醇上之氧、烷鏈與鋅金屬所形成環的角度與張力不同而影響此類錯化合物的固態結構，同時也發現錯化合物的固態結構與配位基上之氧數目也有極大關係。X-ray單晶繞射分析說明吡啶-醇鋅化合物具有二、四和六等金屬中心核的穩定結構。 The N,N,N-pincer type ligands such as 1,8-bis(phenylimino)-3,6-di-tert-butyl-9H-carbazole (3) and 1,8-bis(n-hexylimino)-3,6-di-tert-butyl-9H-carbazole (4) were reacted with triethyl aluminum to yield the pre-catlysts, [1,8-bis(phenylimino)-3,6-di-tert-butylcarbazolide]-Al(CH2CH3)2 (3a) and [1,8-bis(n-hexylimino)-3,6-di-tert-butyl-carbazolide]-Al(CH2CH3)2 (4a) that are able to polymerize methyl methacrylate (MMA) while combined with aluminum chloride as cocatalyst. The reaction of 3a and 4a with about 1 equivalent of AlCl3 to form aluminum complexes, [1,8-bis(phenylimino)-3,6-di-tert-butylcarbazolide]-AlCl2 (3b) and [1,8-bis(n-hexylimino)-3,6-di-tert-butylcarbazolide]-AlCl2 (4b). X-ray diffraction crystallography revealed that both of 3b and 4b exhibit a trigonal bipyrimidal geometry consisted of the Al metal center surround by nitrogen and chloride atoms of the ligands in their solid state, in which two chloride atoms are in the equatorial position. Complexation of dimethyl zinc and the N,N,N tridentate ligands 3 and 4 gives [1,8-bis(phenylimino)-3,6-di-tert-butylcarbazolide]-Zn(CH3) (3c) and [1,8-bis(n-hexylimino)-3,6-di-tert-butylcarbazolide]-Zn(CH3) (4c). By X-ray diffraction crystallography, 3c has a monomeric structure, but 4c has a dimeric structure in solid state, that might result from the difference of the substituents phenyl & n-hexyl groups. The preliminary study of polymerization of L-lactide by 3c & 4c also shows the different results.Moreover, we synthesized a series of pyridine-oxo and 2-fluoro-oxo (F-pyridine-oxo) ligands, which reacted with dimethyl zinc to yield pyridine-oxo-based zinc complexes. We find that the zinc complexes have different solid state structures probably due to the difference of ring strain resulted from substituent groups, such as dimethyl, diphenyl or fluorenyl moieties. For examples, they exist in dimeric, tetrameric, and hexameric forms. |