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DFT computations (ωB97X-D/6-31G(d)) of eight different cycloparaphenylenes that have three internal linking groups are shown to have two different conformations that express interesting Möbius topologies. The D3 conformers have linking numbers Lk of 3 (three half-twists as a trefoil), and the much more stable C2 conformers have a single half-twist, Lk = 1. [ABSTRACT FROM AUTHOR]

Nano-Saturn complexes with a planar horizontal ring can be constructed by selective nitrogen substitution into the ortho-positions in polyaryl macrocycles. A number of intriguing supermolecular complexes can be created with these planar or ribbon macrocycles, including nano-Saturns with a flat ring, nano-Saturns with an encircling belt, and nanotubes encircled by belts or rings. These systems are investigated using DFT (B3LYP-D3/6-31G(d)), which predicts their structures and finds them to have significant binding enthalpies. [ABSTRACT FROM AUTHOR]

MP2/aug-cc-pVDZ and B3LYP/cc-pVDZ calculations of the reactions of CH3SSR (R = H or CH3) with fluoride, hydroxide or allyl anion in the gas-phase were performed to determine the mechanism for both elimination and substitution reactions. The elimination reactions were shown to follow the E2 mechanism. The substitution reactions with hydroxide and fluoride proceed by the addition-elimination mechanism, but those with allyl anion proceed by the SN2 mechanism. The elimination reactions with F- and HO- are preferred to the substitution reactions, while allyl anion prefers the substitution route.