ceeds the size of the nanoparticles and therefore cannot be formed. Further experiments at lower temperatures and with higher spectral resolution are necessary to refine the results, but as the excitation data show, the existence of quantum confined GaN inside the pores of MCM-41 seems to be unquestionable.
Experimental
Boron-containing MCM-41 was synthesized according to literature [9]. The synthesis of triazido(trimethylamine)gallium 1 was performed according to the literature [7d].
Preparation of the Composites (GaN@MCM-41): 0.5 g of MCM-41 was dried in vacuum at 300 C for 24 h. The powder was combined with a solution of 0.5 g triazido(trimethylamine)gallium 1 in 30 mL of toluene (dried by standard methods and freshly distilled under argon) and stirred overnight. After filtration the product was dried in vacuum at room temperature (composite 1) or was washed twice with toluene before drying (composite 2). After heating at a rate of 2 C/min from room temperature to 300 C and then keeping at that temperature for 1 h under flowing ammonia, the powder was again heated with 2 C/min to 500 C and kept at that temperature for 10 h. The unused ammonia was sucked off the pale-gray powder after cooling to room temperature.