(1)聯砒啶的錸錯合物與(2)含高μβ值發色團的聚胺甲酸酯其合成與二次非線性光學活性之研究

Abstract

(1)合成一系列含有多羰基聯砒啶的錸(I)錯合物，fac-[Re(4,4'-X2- bipy)(CO)3Cl] (X=NEt2，OCH3，CH3，H，Cl，NO2)，其取代基的特性可 由推電子基如(NEt2，OCH3，CH3)轉變為拉電子基如(Cl，NO2)。當配位基 上的取代基由推電子基轉變為拉電子基時，錯合物在電子吸收光譜上，可 見金屬對配位基的電子轉移(MLCT)吸收峰往低能量偏移。而媒合顯色( solvatochromism)對於金屬對配位基的電子轉移吸收帶為一負值。由此現 像顯示，在電子激發態其電偶極為遞減的，且ClRe(CO)3扮演了在基態為 受體而在激態為施體的角色。應用電場誘導二次諧波 (EFISH)的技術，測 量此錸(I)聯砒啶錯合物的二次非線性光學係數。 (2)我們將已知具有高 β值的非線性光學發色團分子N,N'-dimethyl- amino-p-[4-( tricyanovinyl)-2-thienylvinyl]benzene做一適當的改變，使其為具有 兩個-OH官能基的單體，而能與另一單體isophorone diisocyanate進行逐 步聚合的反應。所形成的聚胺甲酸酯，其玻璃轉移溫度為162.5℃，在側 鏈上的發色團包含一強的拉電子基三氰乙烯 (tricyanovinyl)官能基而擁 有相當大的分子極化度。 Part(1) A series polypyridyl complex of Rhenium(I)，fac- [Re(4,4'-X2-bipy)(CO)3Cl] (X=NEt2，OCH3，CH3，H，Cl，NO2) has been synthesized. As the properties of the substituents are varied from electron donating (NEt2，OCH3，CH3) to electron withdrawing (Cl，NO2)，the maximum in MLCT absorption band shift to lower energy. The solvatochromism for the MLCT absorption band is negative. This reveals that upon electronic excitation the dipole moment is reduced and that the ClRe(CO)3 group appear to be those of an ground-state acceptor and excited-state donor.The evaluation of the second-order hyper- polarizability of the Re-bipyridine complexes is currently under study via EFISH technique. Part(2) The synthetic method of a diol compound containing a thiophene conjugating unit and a tricyanovinyl acceptor is developed. Polycondensation of the diol monomer with isophorone diisocyanate produces a polyurethane having highly efficient second-order nonlinear optical chromophores as pendant side- chian.The glass transition temperature (Tg) of the polyurethane is 162.5℃ which is sufficiently for device application.