Intriguing E...E' bonding in [Nap(EPh)(E'Ph)](center dot+) (E, E'=O, S, Se, Te)

摘要

The nature of E center dot center dot center dot E' bonding in homonuclear (E=E') and heteronuclear (E not equivalent to E') [Nap(EPh)(E'Ph)](center dot+) (E, E'=O, S, Se, and Te) radical cations has been investigated by quantum chemistry and the topological analysis of electron density. The calculation results show that the EE' bonding in the title compounds occurs through attractive interactions; O center dot center dot center dot E' (E'=O, S, Se, and Te) bonding are electrostatic interactions, and the others have a partial covalent character. The nature of E center dot center dot center dot E' bonding varies periodically, with the changes of E' atoms going from the lighter to the heavier (O, S, Se, and Te). Both in homonuclear and heteronuclear [Nap(EPh)(E'Ph)](center dot+), for the same E atom, a heavier E' atom means stronger E center dot center dot center dot E/E' bonding, a more covalent character of the E center dot center dot center dot E' bond, and more spin electron density transfers from benzene rings to the E center dot center dot center dot E' group. (c) 2016 Wiley Periodicals, Inc.