本實驗以核磁共振的方法， 測量 1-butyl-3-methylimidazole
tetrafluoroborate (BMIBF4) 、1-butyl-3-methylimidazolium tetrafluoroborate
(BMIPF6) ，分別加入溶劑 polyethyleneglycol ( PEG )，
分子量200、300、400 與 polyehtyleneimine( PEI )，分子量423 後，
溶劑含量 ( 莫爾分率x=0.05、0.1、0.2、0.3、0.4、0.5 ) 及溫度的改
變 ( 300 - 338 K ) 對於擴散係數、化學位移及二維光譜之影響。本實
驗同時也測量混合液之黏度、密度與導電度，以進一步研究離子液體
的分子動態行為及結構影響。
結果顯示，溶劑 PEG 會利用其孤立電子對與陽離子 BMI+ 環上
之H 原子產生氫鍵，其1H 化學位移的變化與陰、陽離子間的相對距
離有關。由HOESY 光譜上也發現溶劑 PEG 會利用其環上的烷基氫
與 BF4
- PF6
- 之F 原子產生氫鍵。當溶劑 PEG 含量增加時，離子液
體BMIPF6、BMIBF4 的陰陽離子擴散速率增加，溶液黏度及導電度
均隨之下降。
經由擴散半徑變大、結合程度變大、Tansport number 減小，驗證
溶劑PEG 加入到離子液體 BMIBF4 BMIPF6 後，會與陽離子 BMI+
有氫鍵作用，而將陽離子包覆起來，但是溶劑 PEG 並沒有將陰陽離
子對拆開，只是將陰陽離子之間的距離拉開，形成所謂的離子團簇物
II
（cluster）。而且當溶劑 PEG 分子量越高和濃度越高，包覆情形就更
明顯，就會形成更大的 cluster ， 而在 BMIBF4/PEG 系統比在
BMIPF6/PEG 系統越容易形成cluster ，且溶液中有更小的分子群
聚。但不管加入哪一種 PEG 至何種離子液體，皆可以讓純的離子液
體中大分子群聚變成較小的分子群聚。溶劑 PEI 本身結構較剛性與
BMIPF6 作用力較不好，所以不容易與BMIPF6 產生離子團簇。

1-butyl-3-methylimidazole tetrafluoroborate (BMIBF4) and 1-butyl-
3-methylimidazole tetra-fluoroborate(BMIPF6) was respectively mixed
firstly with various diluents such as polyethyleneglycol(PEG MW=
200、300、400 ) and polyehtyleneimine (PEI MW=423)
Nuclear Magnetic resonance techniques were then applied to
investigate the influences of solvent content(x=0.05、0.1、0.2、0.3、0.4、
0.5)and temperature variations (303-338 K) on the chemical shift,
diffusion coefficient. The physical properties, like viscosity, density and
conductivity of the mixture were also measured to understand further the
dynamics and structure of mixed solutions.
The results showed that intermolecular hydrogen-bonding forms
between the O lone-pair electrons of solvent PEG and the H’s in BMI+
ring. The 1H chemical shift difference is closely related to the distance
between BMI+ and BF4
- or PF6
- ions. It’s also found from the HOESY
spectra that hydrogen bond is also formed between the alkyl hydrogen of
the solvent and the 19F atom of BF4
- and PF6
-. As solvent content
increases, the viscosity and conductivity of solution falls, the movement
of the anions increase and that of the cations decrease thereupon from the
diffudion coefficient measurements.
We found that the Hydrodynamic radius and the Aggregation
became larger and the Transport number of BMI+ became smaller, which
indicate that when the PEG mix with the BMIBF4 、BMIPF6, the PEG
utilizes its lone electron pairs to form hydrogen bond with the H atom of
IV
BMI+ ring and cove BMI+. However, the added PEG just makes the
average distance between BMI+ and F- larger and produces cluster
without dissociating BMI+ and its counter anion by simultaneously
H-bonds with BMI+ and its counter anion. When the molecular weight
and the consistency of PEG are getting larger, the obvious effect of
coving will generate larger clusters involving PEG, BMI+ and its counter
anion. Besides, the BMIBF4/PEG system has an even smaller group of
BF4
- in comparison with PF6
- and is easier to generate clusters than the
BMIPF6/PEG system. No matter which PEG solvent could induce the
shift in aggregation from big cluster for pure ionic liquid to smaller
cluster without dissociation of ion pairs. In addition, since the structure of
PEI is rigid, it does not have a good interaction with BMIPF6, and is
difficult to generate clusters with BMIPF6 via coving.

1. Walden P., Bull. Acad. Imper. Sci.(St. Petersburg), 1914, 1800.
2. Hurley F. H.; Wier T. P., J. Electrochem. Soc., 1951, 98, 203.
3. Carpio R. A.; King L. A.; Lindstrom R. E.; Nardi J. C.; Hussy C. L.,
J. Electrochem. Soc., 1979, 126, 1644.
4. Wilkes J. S.; Levisky J. A.; Wilson R. A.; Hussey C. L., Inorg. Chem.,
1982, 21, 1263.
5. Wilkes J. S.; Zaworotko M. J., J. Chem.Soc. Chem. Commun., 1992,
965.
6. Fuller J.; Carlin R. T., Osteryoung, R. A., J. Electrochem. Soc., 1997,
144, 3881.
7. Suarez P. A. Z.; Dullius J. E. L.; Einloft S.; Souza R. F. De; Dupont J.,
Polyhedron, 1996, 15 1217.
8. Bonhote P.; Dias A. P.; Papageorgiou N.; Kalyanasundaram K. S.;
Gratzel M., Inorg. Chem., 1996, 35, 1168.
9. Headley A. D.; Jackson N. M., J. Phys. Org. Chem., 2002, 15, 52.
10. Nishida T.; Tashiro Y.; Yamamoto M.; J. Fluorine Chem, 2003, 120,
135.
11. Su B. M.; Zhang S.; Zhang Z. C., J. Phys. Chem. B, 2004, 108,
19510.
12. Purcell E. M.; Torrey H. C.; Pound R. V., Phys. Rev. 1946, 69, 37
13. Block F.; Hansen W.; Packard W., Phys. Rev. 1946, 69, 127
139
14. 甘魯生,電子月刊,1998, 36, 55.
15. Arnold J. T.; Dharmatti S. S.; Packard M. E., J. Chem. Phys. 1951,
19, 507.
16. 黃紹光, 天下遠見, 1999.
17. Yang D.; Konrat R.; Kay L. E.; J. Am. Chem. Soc. 1997, 119, 11938.
18. Yang D.; Kay L. E., J. Am. Chem. Soc. 1999, 121, 2571.
19. Klabunde K. J.; D. J. Burton, J. Am. Chem. Soc., 1972, 94, 5985.
20. Cluster E. L., Diffusion-Mass Transfer in Fluid Systems, Cambridge
Univeristy Press, Cambridge, 1984
21. Umecky T., Fluid Phase Equilibria, 2005, 228-229
22. Watanabe M., J. Chem. Phy. B, 2004, 108, 16593-16600