- 作者: 吳憲明; 陳壽安
- 作者服務機構: 國立清華大學化學工程研究所
- 中文摘要: 將六氯化鎢(WCl6)及五氯化銅(Mocl5)摻雜於聚乙炔(PA)後,以中子活化分析方法分析摻雜1~4小時後之聚乙炔得知原子比值〔C1〕∕[W]及[C1] / [Mo]接近2。以XPS(X一射線光電子分光儀)分析C12p之束縛能,它由原來聚乙炔之283.7 ev降到282.9 ev,此與碘(I2)及五氟化砷(AsF5)之摻雜結果相反。同時XPS分析W4f, MO3d及C12p之結果都顯出出其束縛能比原來WC16及MOC15中W4f,MO3d及C12p之束縛能低,此種束縛能之降低表示摻雜後W, Mo及C1之外層電子增加。此是由於金屬離子能自聚乙炔之乙烯基π鍵結上拉走電子,並自它們的d軌道上回供(backdonation)電子到乙烯基Pπ*軌道才造成C1s, W4f及MO3d束縛能降低之現象,同時金屬離子亦可由d軌道回供電子到C1一空的d軌道,而造成另一種(d-d)π回供鍵結。由於金屬原子可以同時接上好幾個不同聚乙炔鏈中之乙烯某,故電子可經由此金屬原子傳遞至另一聚乙炔鏈。
- 英文摘要: Polyacetylen (PA) is doped with WCl6 and MoCl5.The doping levels determined using the methodof neutron activation analysis indicate that the atom ratios [Cl]∕[W] and [Cl]∕[MO】after 2~4 hrs dopingreach a value of about 2. The C1s XPS (X-ray photoelectron spectroscopy) of WCl6- and MoCl5-dopedPA show a decrease in binding energy (BE) from 283.7 ev of the pristine PA to about 282.9 ev for 1~4 hrsdoping, opposite to that of I2一and AsF5-doped PA. W4f and Mo3d BE also decrease. C12p3/2 BE shows adecrease of 3.2 ev for both cases. The BE lowering means that the outer shell electron densities of carbon,W, Mo and chlorine increase after the doping. These observations imply that the pπ* orbital of the olefins,and that the electrons in the d orbital of the metal atom can also backdonate to the Cl- ligand. Severalolefins from more than one PA chains can interact with one metal atom, allowing electron transfer fromone PA chain to another.
- 中文關鍵字: polyacetylene; doping; tungsten chloride; molybdenum chloride
- 英文關鍵字: --