화학공학소재연구정보센터
Langmuir, Vol.24, No.19, 10865-10873, 2008
Synthesis and surface self-assembly of [3]rotaxane-porphyrin conjugates: Toward the development of a supramolecular surface tweezer for C-60
Surface immobilization of pristine C-60 by supramolecular interactions is an attractive way to introduce C-60 on surfaces since the pi-electron network and the electronic properties Of C-60 remain intact. Several hosts have been developed for surface complexation of C-60. With few exceptions, the hosts reported to date are "electronically inert", limiting the potential applications of pristine C-60-based devices. In this study, we present the synthesis and self-assembly of a potential tweezer-like host for C-60 having a light-harvesting moiety and an electron-donating unit. More precisely, an azide-containing [3]rotaxane scaffold having ferrocene moieties as blocking group and thioctic acid as anchoring group for a gold surface has been synthesized. This [3]rotaxane has been self-assembled on gold in its protonated (NH2+) (1p) and neutral (NH) (1n) forms and characterized using electrochemistry, XPS, and contact angle measurements. The SAMs were functionalized with free-base and zinc porphyrin using copper-catalyzed 1,3-dipolar cycloaddition in optimized conditions. In combination with C-60, this new host is expected to form a triad that could potentially be used as active building block in the preparation of nanostructured electrodes for photoelectrochemical application.