Langmuir-Blodgett Film and Second Harmonic Generation of C60(C4H8N2)

Amination of [60]Fullerene by Ammonia and by Primary and Secondary Aliphatic Amines—Preparation of Amino[60]fullerene Peroxides

Ammonia and aliphatic amines react readily in the oxygen-rich regions of the Cs symmetric fullerene peroxides C60(O)(OOtBu)4 (1) and C60(OH)(Br)(OOtBu)4 (2 c). Michael addition-type hydroamination of the 1,4-diene moiety on the central skew-pentagon was observed when 1 was treated with ammonia or with nonbulky primary amines, while sterically demanding primary amines opened the epoxy moiety to form vicinal aminohydroxy fullerene compounds with the amino group on the central pentagon. In 2 c the bromo group was replaced under similar conditions by ammonia and primary amines. Cyclic secondary amines showed different reaction patterns, forming hydrogenation products or aminoketal-fullerenes when treated with 1 and 2 c, respectively. Single-electron transfer (SET) is the key step in all the proposed mechanisms. The compounds were characterized by their spectroscopic data, and in addition, three single-crystal X-ray structures were obtained.

Langmuir-Blodgett Film Formation of a Fullerene Dicarboxylic Acid Derivative C60(HOOCCHNHCHCOOH) and its Photocurrent Generation

The Langmuir films of a fullerene dicarboxylic acid derivative I, C60(HOOCCHNH2CHCOOH)CF3SO3H (FDA), at the air/water interface have been investigated. FDA formed a stable monolayer on pure water when dilute solution (1.04 x 10(-5) mol/L) was used as the spreading solution. The monolayer formation on various subphases was investigated, including solutions containing different monovalent (Na+, Ag+) and divalent (Ca2+, Cd2+, Cu2+) cations. The introduction of these cations makes the monolayer more stable. The limiting molecular area is also dependent on the pH of the subphase. The surface pressure versus area isotherms at different temperature clearly indicate that FDA molecules easily aggregate at high temperature. The monolayer and multilayer LB films of FDA were deposited on quartz and glass substrates from Ca2+, Cd2+, Cu2+, or Cu2+/Phen solution subphase, and their UV-vis and XPS spectra were obtained. The data showed that for Cd2+ and Cu2+/Phen subphase the cation can be transferred onto the substrates together with FDA but not the other two. The photoelectrochemical behavior of FDA on an ITO electrode was investigated, which showed that the photocurrent is cathodic. Oxygen and negative bias are beneficial factors for the photocurrent generation. The external quantum yield is ca. 4%. Copyright 1998 Academic Press.