Design of the N<subscript>n</subscript>H<subscript>3n+1</subscript><superscript>+</superscript> series of “non-metallic” superalkali cations.
In: New Journal of Chemistry, Jg. 43 (2019-03-28), Heft 12, S. 4959-4964
Online
academicJournal
Zugriff:
Species with a lower ionization energy than alkali atoms are referred to as superalkalis. Typical superalkalis include a central electronegative core with excess metal ligands. We propose a new series of “non-metallic” N n H 3n+1 + superalkali cations based on the results of the MP2/6-311++G(d,p) computations. These cations are designed by successive replacement of H-ligands of ammonium cations (NH 4 + ) by ammonium (NH 4 ) moieties. The resulting N n H 3n+1 + cations, which can be expressed in the form of [NH 4 …(n− 1)NH 3 ] + complexes, possess a number of unusual N–H…N type of partially covalent H-bonds, with the interaction energy in the range of 7.8–24.3 kcal mol −1 . These cations are stable against loss of a proton (N n H 3n + H + ) and loss of ammonia [(n− 1)NH 3 + NH 4 + ]. The vertical electron attachment energies (EA v s) of N n H 3n+1 + decrease monotonically from 4.39 eV for n = 1 to 2.39 eV for n = 5, which suggests their superalkali nature. This can be explained on the basis of electron localization on the core (central) N-atom (Q c ), as the EA v correlates linearly with Q c . We have also demonstrated that this series may be continued to obtain new superalkali cations with even lower EA v , by exemplifying N 9 H 28 + with an EA v of 1.84 eV. N 9 H 28 + is stabilized by four partially covalent H-bonds (8.5 kcal mol −1 each) and four electrostatic H-bonds (0.4 kcal mol −1 each). This led to an exponential relation between EA v and n, which may provide an approximate EA v for any value of n in the N n H 3n+1 + series. [ABSTRACT FROM AUTHOR]
Copyright of New Journal of Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Titel: |
Design of the N<subscript>n</subscript>H<subscript>3n+1</subscript><superscript>+</superscript> series of “non-metallic” superalkali cations.
|
---|---|
Autor/in / Beteiligte Person: | Srivastava, Ambrish Kumar |
Link: | |
Zeitschrift: | New Journal of Chemistry, Jg. 43 (2019-03-28), Heft 12, S. 4959-4964 |
Veröffentlichung: | 2019 |
Medientyp: | academicJournal |
ISSN: | 1144-0546 (print) |
DOI: | 10.1039/c8nj06126b |
Schlagwort: |
|
Sonstiges: |
|