title: Sigma-aromaticity and sigma-antiaromaticity in saturated inorganic rings.
abstract: The magnetic properties of a series of inorganic saturated rings, (SiH2)n, (GeH2)n, (NH)n, (PH)n, (AsH)n, On, Sn, and Sen (n = 3-6), exhibit zigzag behavior with ring size resembling that of aromatic and antiaromatic Hückel pi-systems and (CH2)n rings. Computed GIAO-SCF nucleus-independent chemical shifts (NICS) and localized (LMO) NICS analysis indicate that the sigma-ring electrons are chiefly responsible for this zigzag behavior. This evidence for sigma-aromaticity is further supported by theoretical strain energy (TSE). The Hückel 4n + 2/4n aromaticity/antiaromaticity rule for pi-electron systems applies well to the smaller saturated rings.
authors.affiliation: Center for Theoretical Chemical Physics, Laboratory of Molecular Catalysis & Innovative Material Department of Chemistry, Fudan University, Shanghai 200433, China.
authors.forename: Zhen-Hua
authors.initials: ZH
authors.lastname: Li
authors.forename: Damian
authors.initials: D
authors.lastname: Moran
authors.forename: Kang-Nian
authors.initials: KN
authors.lastname: Fan
authors.forename: Paul von Ragué
authors.initials: Pv
authors.lastname: Schleyer