Treating diethynyl-substituted perylenediimides with ICI successfully induced an annulation reaction and generated a series of coronenediimide derivatives. Instead of the expected iodine-substituted cyclization product, chlorine-substituted analogues were produced. The mechanism of this annulation reaction thus necessarily involved a chlorine addition step prior to the aromatic substitution reaction. With facile subsequent transformations, various tetraaryl coronenediimides could be obtained via the annulated chloro-substituted coronenediimide.
A metal-insulator-metal vertical nanocavity is proposed to be integrated at the center of a plasmonic lens. Utilizing cavity resonance effect, the light intensity at the center of the integrated plasmonic lens gets enhancement up to 5500 times compared to that without the cavity, and the light field is tightly confined into a spot as small as 6.0 x 10(-3)lambda(2)(0). The Purcell factor of the cavity reaches up to 1400, ensuring greatly enhanced light-matter interaction inside the cavity. Moreover, the proposed structure takes advantage of linearly polarized light excitation and easy fabrication. (C) 2012 Optical Society of America