Aromatic C20F20 cage and its endohedral complexes X@C20F20 (X = H−, F−, Cl−, Br−, H, He)

Abstract

The structure and stability of endohedral X@C20F20 complexes (X = H-, F-, Cl-, Br-, H, He) have been computed at the B3LYP level of theory. All complexes in I (h) symmetry were found to be energy minimum structures. H-@C20F20 and F-@C20F20 complexes have negative inclusion energies, while other complexes have positive inclusion energies. Similarity between C20F20 and C20H20 has been found for X = H and He. On the basis of the computed nucleus independent chemical shift values at the cage center, both C20F20 and C20F20 are aromatic.

The synthesis and evaluation of flavone and isoflavone chimeras of novobiocin and derrubone

“…Hsp90 substrates function in a wide variety of cellular processes, including receptors, transcription factors, and protein kinase signaling pathways 9-14. Although many of these individual enzymes/proteins are individually sought-after anticancer targets,15 inhibition of Hsp90 affords simultaneous degradation of multiple clients through utilization of the ubiquitin-proteasome pathway 1,11,16-19. Consequently, inhibition of the Hsp90 protein folding machinery results in a combinatorial attack on numerous oncogenic pathways 16.…”

Refractive index enhancement in three-levelΛ-type atom with a saturation field: a dressed state analysis

“…RIE was also discovered in the two-level atom [13] and extended to the cascade atom [14]. Among these schemes, we find a common feature in RIE [13,19,22]: extremum of refractive index appears between the alternating points of emission and absorption peaks, and a maximum occurs when emission is on the left side while absorption is on the right side (following our definition of probe detuning), in agreement with the Kramers-Kronig relation [24]. In the above mentioned à scheme, the injection of atoms into the excited level leads to the alternation of emission and absorption, thus RIE appears.…”

“…RIE has been demonstrated in various atomic ensembles [6,9,13,[19][20][21][22][23]] . In the three-level Ã-type EIT media [3], by injecting atoms into the excited state, a large real part of susceptibility with vanishing absorption was obtained when the two-photon resonance is partially destroyed [6].…”

The evolutions of the structure stability, vibrational frequency, frontier orbital, and electronegativity of the unconventional exohedral fullerenes C64X4 (X=H, F, Cl, Br, and I): A density functional study

“…Commonly, hydrogen atom or halogen atoms can be all used to stabilize the fullerene cage, such as C 28 [9][10][11][12] and C 40 [13] and so on. In addition, the fluorination, chlorination, bromination, and iodination of fullerenes, under controlled conditions, can lead to the isolation of different stable compounds, such as C 20 F 20 [15], C 36 X n (X = F, Cl, and Br, n = 2, 4, 6, and 12) [16], C 50 X 10 (X = F, Cl, and Br) [8], C 60 F 24 [17], C 50 Cl 12 [18,19], C 60 X 24 (X = Br and I) [20], and C 70 I n (n = 2 and 17) [20]. Therefore, the conjecture of adsorbing four halogen atoms to the pentagon-pentagon vertex instead of hydrogen atoms to stabilize the unconventional C 64 is reasonable.…”