PdII and PtII Complexes with Amphiphilic Ligands: Formation of Micelles and [5]Rotaxanes with α‐Cyclodextrin in Aqueous Solution |
| |
| Authors: | Toshiaki Taira Yuji Suzaki Dr. Kohtaro Osakada Prof. Dr. |
| |
| Affiliation: | Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagastuta, Midori‐ku, Yokohama 226‐8503, Japan, Fax: (+81)?45‐924‐5224 |
| |
| Abstract: | [3]Pseudorotaxanes [ 1 (α‐CD)2][X] (X=Cl, NO3), prepared from reaction of an N‐alkylbipyridinium [4,4′‐bpy‐N‐(CH2)10OC6H3‐3,5‐(OMe)2][X] ([ 1 ][X]) and α‐CD, react with M(NO3)2(en) (M=Pd, Pt; en=1,2‐ethylenediamine) in a 2:1 molar ratio to afford [5]rotaxanes [M{(4,4′‐bpy‐N‐(CH2)10OC6H3‐3,5‐(OMe)2)(α‐CD)2}2 (en)][NO3]4 ([ 2 (α‐CD)4][NO3]4, M=Pd; [ 3 (α‐CD)4][NO3]4, M=Pt). A similar reaction of [ 1 ][Cl] with [M(NO3)2(en)] (M=Pd, Pt) produces amphiphilic Pd and Pt complexes, [ 2 ][NO3]4 and [ 3 ][NO3]4. Complexes [ 2 ][NO3]4 and [ 3 ][NO3]4 form micelles in the presence of small amounts of dyes (Nile red and pyrene) in water. The critical micelle concentration (CMC) was determined by the absorption peak of the dye, which is encapsulated in the micelles in solution. Micelle formation is confirmed by dynamic light scattering measurement of the solution and TEM (transmission electron microscopy) images of the micelles deposited from the solution. Addition of α‐CD to the aqueous solution containing these amphiphilic complexes results in degradation of the micelle structure and the formation of [5]rotaxanes, [ 2 (α‐CD)4][NO3]4 and [ 3 (α‐CD)4][NO3]4. |
| |
| Keywords: | amphiphiles micelles palladium platinum rotaxanes |
|
|
