Nitrosonium complexes of 2,11-dithia-5,6,8,9-tetramethyl[32](1,4)cyclophane: a combined experimental and theoretical study.

¹H and ¹³C NMR studies and quantum chemical calculations show the interaction between 2,11-dithia-5,6,8,9-tetramethyl[3₂](1,4)cyclophane and nitrosonium cation to result in the formation of π- and n-complexes. According to DFT/B3LYP/6-31G(2d,p) calculations, formation of nitrosonium complexes is a strongly exothermic process both in gas phase and in SO₂. Affinity of single-charged complexes to NO⁺ is usually larger than that of double-charged and triple-charged complexes, affinity of all the charged complexes to nitrosonium cation in SO₂ being larger than that in gas phase. The π-complex with nitrosonium cation coordinated to the methylated aromatic ring is the most stable with structural characteristics being close to those obtained by X-ray diffraction for nitrosonium π-complexes of hexamethylbenzene and other arenes. The N-O bond lengths in all the complexes are quite close to each other and larger than that in NO⁺ cation. The S-N bond length increases upon transition from single-charged to double-charged and polycharged complexes. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]