Cyclopropanation of [2.2] Paracyclophanes

Facile Autoreduction of Iron Oxide/Carbon Nanotube Encapsulates

“…On the other hand, Haddon used π-orbital axis vector analysis to show that the chemistry of fullerene-type carbon relates directly to the strain of the graphitic network . Deviation from planarity causes the partial rehybridization from sp 2 to sp 3 and the pyramidalization of the carbon atoms in curved aromatic systems. − As a result, π-electron density is shifted from the concave inner to the convex outer surface, and this shift is enhanced as the CNT cross-section becomes smaller. ,, Therefore, the interaction between the electron-deficient concave surface of the nanotube and the anionic oxygen in Fe 2 O 3 could lead to weakened bonding strength of Fe 2 O 3 and hence lower the activation energy for the reduction in the bores. Thus, Fe could form at the very low temperature of 600 °C.…”

“…[12][13][14][15] As a result, π-electron density is shifted from the concave inner to the convex outer surface, and this shift is enhanced as the CNT cross-section becomes smaller. 12,14,15 Therefore, the interaction between the electron-deficient concave surface of the nanotube and the anionic oxygen in Fe 2 O 3 could lead to weakened bonding strength of Fe 2 O 3 and hence lower the activation energy for the reduction in the bores. Thus, Fe could form at the very low temperature of 600 °C.…”

Progressive and invasive functionalization of carbon nanotube sidewalls by diluted nitric acid under supercritical conditions

“…In a strained (curved) graphitic network, the partial rehybridization of carbon atoms shifts the p electron density from the concave surface to the convex surface, which reduces the chemical reactivity of the concave side, contrary to the increase in the reactivity of the convex side. [26][27][28] As a result of this, the straininduced reduction of the chemical reactivity might cause the lowering of the reaction rate in the innermost layers.…”

A Simple Route tocis- andtrans-Bis-σ-homobenzenes

“…The thermal stability of the stable bis-σ-homobenzenes 13 and 14 prepared by Menke and Hopf is certainly the result of the additional molecular bridges acting as rateretarding elements. [35] Here we report on a new synthetic route to substituted cis-bis-σ-homobenzene derivatives by an unexpected cycloaddition/cycloelimination sequence including a sigmatropic cyclopropane ring shift. [36] …”