From Saturated BN Compounds to Isoelectronic BN/CC Counterparts: An Insight from Computational Perspective. Issue 43 (4th September 2015)

• Record Type: Journal Article
• Authors: Sagan, Filip; Piękoś, Łukasz; Andrzejak, Marcin; Mitoraj, Mariusz Paweł
• Is Part Of: Chemistry. Volume 21:Issue 43(2015)
• Page Start: 15299
• Page End: 15307
• Publication Date: 2015-09-04
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201502629
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>In the present study, the inorganic analogues of alkanes as well as their isoelectronic BN/CC counterparts that bridge the gap between organic and inorganic chemistry are comparatively studied on the grounds of static DFT and Car–Parrinello molecular dynamics simulations. The BN/CC butanes CH<sub>3</sub>CH<sub>2</sub>BH<sub>2</sub>NH<sub>3</sub>, BH<sub>3</sub>CH<sub>2</sub>NH<sub>2</sub>CH<sub>3</sub>, and NH<sub>3</sub>CH<sub>2</sub>BH<sub>2</sub>CH<sub>3</sub> were considered and compared with their isoelectronic counterparts NH<sub>3</sub>BH<sub>2</sub>NH<sub>2</sub>BH<sub>3</sub> and CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>CH<sub>3</sub>. In addition, systematical replacement of the NH<sub>2</sub>BH<sub>2</sub> fragment by the isoelectronic CH<sub>2</sub>CH<sub>2</sub> moiety is studied in the molecules H<sub>3</sub>N(NH<sub>2</sub>BH<sub>2</sub>)<sub>3–<italic>m</italic></sub>(CH<sub>2</sub>CH<sub>2</sub>)<sub><italic>m</italic></sub>BH<sub>3</sub> (for <italic>m</italic>=0, 1, 2, or 3) and H<sub>3</sub>N(NH<sub>2</sub>BH<sub>2</sub>)<sub>2–<italic>m</italic></sub>(CH<sub>2</sub>CH<sub>2</sub>)<sub><italic>m</italic></sub>BH<sub>3</sub> (for <italic>m</italic>=0, 1, or 2). The DFT and Car–Parrinello simulations show that the isosteres of the BN/CC butanes CH<sub>3</sub>CH<sub>2</sub>BH<sub>2</sub>NH<sub>3</sub>, BH<sub>3</sub>CH<sub>2</sub>NH<sub>2</sub>CH<sub>3</sub>, and NH<sub>3</sub>CH<sub>2</sub>BH<sub>2</sub>CH<sub>3</sub> and of larger oligomers of the type (BN)<sub><italic>k</italic></sub>(CC)<sub><italic>l</italic></sub> where <italic>k</italic>≥<italic>l</italic> are stable compounds. The BN/CC butane H<sub>3</sub>NCH<sub>2</sub>CH<sub>2</sub>BH<sub>3</sub> spontaneously produces molecular hydrogen at room temperature. The reaction, prompted by very strong dihydrogen bonding NH⋅⋅⋅HB, undergoes through the neutral, hypervalent, pentacoordinated boron dihydrogen complex RBH<sub>2</sub>(H<sub>2</sub>) [R=(CH<sub>2</sub>CH<sub>2</sub>)<sub><italic>n</italic></sub>NH<sub>2</sub>]. The calculations suggest that such intermediate and the other BN/CC butanes CH<sub>3</sub>CH<sub>2</sub>BH<sub>2</sub>NH<sub>3</sub>, BH<sub>3</sub>CH<sub>2</sub>NH<sub>2</sub>CH<sub>3</sub>, and NH<sub>3</sub>CH<sub>2</sub>BH<sub>2</sub>CH<sub>3</sub> as well as larger BN/CC oligomers are viable experimentally. A simple recipe for the synthesis of CH<sub>3</sub>CH<sub>2</sub>BH<sub>2</sub>NH<sub>3</sub> is proposed. The strength of the dihydrogen bonding appeared to be crucial for the overall stability of the saturated BN/CC derivatives.</p> </abstract>