Diaminooctanederivatised C60 Powder

Fullerene C60 pristine powder exhibits only one sharp and uniform weight loss between 500°C and 650°C (Fig. 20.2(b)). The derivatised C60 powder begins to lose the weight after 300°C (Fig. 20.2(a)). First the weight loss is relatively slow up to almost 500°C, then becomes sharper and straighter, and the material decomposes completely under further heating up to 650°C.

In the infrared absorption spectra of crystalline C60 powder reacted with 1,8-diaminooctane, we observed remarkable changes as compared to the spectrum of pristine C60 (Fig. 20.3(a)). The latter exhibits four characteristic bands at 526, 576, 1181 and 1427 cm-1 (Dresselhaus et al., 1993). The derivatisation product has a richer chemical structure, and in addition to the above four bands, it shows several intense broad peaks (Fig. 20.3(b)) near 715, 1096 (Vc-c), 1643 (Snh), 2855 and 2922 cm-1 (VCH). The region of 500-800 cm-1 is a 'fingerprint' region for fullerene derivatisation, and new IR features are observed when the C60 skeleton is partially broken (Iwasa et al. 1994), for example in the formation of cross-linked fullerene molecules as reported by Sun and Reed (2000). In our case one can also see that instead of only one band at 1425 cm-1 (C=C skeleton vibration), there is another sharp peak at 1383 cm-1. Peak position for this mode is known to be very sensitive to such modifications of C60 molecule as polymerisation (Sun and Reed, 2000).

100 Cp 80 60

0 200 400 600 800 1000

Temperature (°C)

Fig. 20.2. TGA curves for C60 derivatised with 1,8-diaminooctane (a) in comparison with pristine C60 powder (b)

Was this article helpful?

0 0
Brain Blaster

Brain Blaster

Have you ever been envious of people who seem to have no end of clever ideas, who are able to think quickly in any situation, or who seem to have flawless memories? Could it be that they're just born smarter or quicker than the rest of us? Or are there some secrets that they might know that we don't?

Get My Free Ebook

Post a comment