Cross-Linking of C₆₀ Films with 1,8-Diaminooctane and Further Decoration with Silver Nanoparticles

We applied the direct solvent-free functionalization of fullerene C₆₀ with aliphatic bifunctional amine, 1,8-diaminooctane, to prepare chemically cross-linked C₆₀ thin films capable of binding silver nanoparticles. The gas-phase diamine treatment of C₆₀ reduced dramatically the fullerene solubility in toluene, indicating the transformation of pristine C₆₀ into a different solid phase with cross-linked fullerene molecules. Compared to the spectra of pristine C₆₀ film and powder samples, Fourier-transform infrared, UV-Visible, Raman, and ¹³C nucleic magnetic resonance spectra of the functionalization products exhibited new features, which point to a breakingof C₆₀ ideal structure during the formation of new covalent bonds and to the appearance of sp ³ hibridization. The covalent functionalization with 1,8-diaminooctane allowed for a stable and homogeneous deposition of silver nanoparticles of ca. 5-nm diameter onto the functionalized films through the coordination bonding between metal atoms and nitrogen donor atoms of the fullerene derivatives. The proposed mechanism of Ag nanoparticle binding was supported by density functional theory calculations using the hybrid BLYP functional in conjunction with the double numerical basis set DND.