In:
Chemistry – A European Journal, Wiley, Vol. 23, No. 64 ( 2017-11-16), p. 16274-16282
Abstract:
For the first time, in situ monitoring of uninterrupted mechanochemical synthesis of two bimetallic amidoboranes, M 2 Mg(NH 2 BH 3 ) 4 (M=Li, Na), by means of Raman spectroscopy, has been applied. This approach allowed real‐time observation of key intermediate phases, and a straightforward follow‐up of the reaction course. Detailed analysis of time‐dependent spectra revealed a two‐step mechanism through MNH 2 BH 3 ⋅ NH 3 BH 3 adducts as key intermediate phases which further reacted with MgH 2 , giving M 2 Mg(NH 2 BH 3 ) 4 as final products. The intermediates partially take a competitive pathway toward the oligomeric M(BH 3 NH 2 BH 2 NH 2 BH 3 ) phases. The crystal structure of the novel bimetallic amidoborane Li 2 Mg(NH 2 BH 3 ) 4 was solved from high‐resolution powder diffraction data and showed an analogous metal coordination to Na 2 Mg(NH 2 BH 3 ) 4 , but a significantly different crystal packing. Li 2 Mg(NH 2 BH 3 ) 4 thermally dehydrogenates releasing highly pure H 2 in the amount of 7 wt.%, and at a lower temperature then its sodium analogue, making it significantly more viable for practical applications.
Type of Medium:
Online Resource
ISSN:
0947-6539
,
1521-3765
DOI:
10.1002/chem.201702665
Language:
English
Publisher:
Wiley
Publication Date:
2017
detail.hit.zdb_id:
1478547-X
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