Compression for data archiving and backup revisited
Corneliu Constantinescu
SPIE Optical Engineering + Applications 2009
We report the on-surface synthesis of a nonbenzenoid triradical through dehydrogenation of truxene (C27H18) on coinage metal and insulator surfaces. Voltage pulses applied via the tip of a combined scanning tunneling microscope/atomic force microscope were used to cleave individual C-H bonds in truxene. The resultant final product truxene-5,10,15-triyl (1) was characterized at the single-molecule scale using a combination of atomic force microscopy, scanning tunneling microscopy, and scanning tunneling spectroscopy. Our analyses show that 1 retains its open-shell quartet ground state, predicted by density functional theory, on a two monolayer-thick NaCl layer on a Cu(111) surface. We image the frontier orbital densities of 1 and confirm that they correspond to spin-split singly occupied molecular orbitals. Through our synthetic strategy, we also isolate two reactive intermediates toward the synthesis of 1, derivatives of fluorenyl radical and indeno[1,2-a]fluorene, with predicted open-shell doublet and triplet ground states, respectively. Our results should have bearings on the synthesis of nonbenzenoid high-spin polycyclic frameworks with magnetism beyond Lieb’s theorem.
Corneliu Constantinescu
SPIE Optical Engineering + Applications 2009
R. Ghez, J.S. Lew
Journal of Crystal Growth
E. Babich, J. Paraszczak, et al.
Microelectronic Engineering
I.K. Pour, D.J. Krajnovich, et al.
SPIE Optical Materials for High Average Power Lasers 1992