Aarhus University Seal / Aarhus Universitets segl

Synthesis, crystal structures and thermal properties of ammine barium borohydrides

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

Standard

Synthesis, crystal structures and thermal properties of ammine barium borohydrides. / Grinderslev, Jakob B.; Amdisen, Mads B.; Jensen, Torben R.

I: Inorganics, Bind 8, Nr. 10, 57, 10.2020.

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

Harvard

APA

CBE

MLA

Vancouver

Author

Bibtex

@article{593113aef37b4d85a628cbdb94515bb3,
title = "Synthesis, crystal structures and thermal properties of ammine barium borohydrides",
abstract = "Ammine metal borohydrides show large compositional and structural diversity, and have been proposed as candidates for solid-state ammonia and hydrogen storage as well as fast cationic conductors. Here, we report the synthesis method of ammine barium borohydrides, Ba(BH4 )2·xNH3 (x = 1, 2). The two new compounds were investigated with time-resolved temperature-varied in situ synchrotron radiation powder X-ray diffraction, thermal analysis, infrared spectroscopy and photographic analysis. The compound Ba(BH4 )2·2NH3 crystallizes in an orthorhombic unit cell with space group symmetry Pnc2, and is isostructural to Sr(BH4 )2·2NH3, forming octahedral [Ba(NH3 )2 (BH4 )4 ] complexes, which are connected into a two-dimensional layered structure, where the layers are interconnected by dihydrogen bonds, N–Hδ+· · ·−δ H–B. A new structure type is observed for Ba(BH4 )2·NH3, which crystallizes in an orthorhombic unit cell with space group symmetry P21 21 21, forming a three-dimensional framework structure of [Ba(NH3 )(BH4 )6 ] complexes. The structure is built from distorted hexagonal chains, where NH3 groups form dihydrogen bonds to the nearby BH4−-groups within the chain. Ba(BH4 )2·2NH3 is unstable at room temperature and releases NH3 in two subsequent endothermic reactions with maxima at 49 and 117◦ C, eventually reforming Ba(BH4 )2 . We demonstrate that the thermal stability and composition of the gas release for the ammine alkaline earth metal borohydrides can be correlated to the charge density of the metal cation, but are also influenced by other effects.",
keywords = "Ammine metal borohydrides, Complex metal hydrides, Crystal structures",
author = "Grinderslev, {Jakob B.} and Amdisen, {Mads B.} and Jensen, {Torben R.}",
year = "2020",
month = oct,
doi = "10.3390/inorganics8100057",
language = "English",
volume = "8",
journal = "Inorganics",
issn = "2304-6740",
publisher = "MDPI",
number = "10",

}

RIS

TY - JOUR

T1 - Synthesis, crystal structures and thermal properties of ammine barium borohydrides

AU - Grinderslev, Jakob B.

AU - Amdisen, Mads B.

AU - Jensen, Torben R.

PY - 2020/10

Y1 - 2020/10

N2 - Ammine metal borohydrides show large compositional and structural diversity, and have been proposed as candidates for solid-state ammonia and hydrogen storage as well as fast cationic conductors. Here, we report the synthesis method of ammine barium borohydrides, Ba(BH4 )2·xNH3 (x = 1, 2). The two new compounds were investigated with time-resolved temperature-varied in situ synchrotron radiation powder X-ray diffraction, thermal analysis, infrared spectroscopy and photographic analysis. The compound Ba(BH4 )2·2NH3 crystallizes in an orthorhombic unit cell with space group symmetry Pnc2, and is isostructural to Sr(BH4 )2·2NH3, forming octahedral [Ba(NH3 )2 (BH4 )4 ] complexes, which are connected into a two-dimensional layered structure, where the layers are interconnected by dihydrogen bonds, N–Hδ+· · ·−δ H–B. A new structure type is observed for Ba(BH4 )2·NH3, which crystallizes in an orthorhombic unit cell with space group symmetry P21 21 21, forming a three-dimensional framework structure of [Ba(NH3 )(BH4 )6 ] complexes. The structure is built from distorted hexagonal chains, where NH3 groups form dihydrogen bonds to the nearby BH4−-groups within the chain. Ba(BH4 )2·2NH3 is unstable at room temperature and releases NH3 in two subsequent endothermic reactions with maxima at 49 and 117◦ C, eventually reforming Ba(BH4 )2 . We demonstrate that the thermal stability and composition of the gas release for the ammine alkaline earth metal borohydrides can be correlated to the charge density of the metal cation, but are also influenced by other effects.

AB - Ammine metal borohydrides show large compositional and structural diversity, and have been proposed as candidates for solid-state ammonia and hydrogen storage as well as fast cationic conductors. Here, we report the synthesis method of ammine barium borohydrides, Ba(BH4 )2·xNH3 (x = 1, 2). The two new compounds were investigated with time-resolved temperature-varied in situ synchrotron radiation powder X-ray diffraction, thermal analysis, infrared spectroscopy and photographic analysis. The compound Ba(BH4 )2·2NH3 crystallizes in an orthorhombic unit cell with space group symmetry Pnc2, and is isostructural to Sr(BH4 )2·2NH3, forming octahedral [Ba(NH3 )2 (BH4 )4 ] complexes, which are connected into a two-dimensional layered structure, where the layers are interconnected by dihydrogen bonds, N–Hδ+· · ·−δ H–B. A new structure type is observed for Ba(BH4 )2·NH3, which crystallizes in an orthorhombic unit cell with space group symmetry P21 21 21, forming a three-dimensional framework structure of [Ba(NH3 )(BH4 )6 ] complexes. The structure is built from distorted hexagonal chains, where NH3 groups form dihydrogen bonds to the nearby BH4−-groups within the chain. Ba(BH4 )2·2NH3 is unstable at room temperature and releases NH3 in two subsequent endothermic reactions with maxima at 49 and 117◦ C, eventually reforming Ba(BH4 )2 . We demonstrate that the thermal stability and composition of the gas release for the ammine alkaline earth metal borohydrides can be correlated to the charge density of the metal cation, but are also influenced by other effects.

KW - Ammine metal borohydrides

KW - Complex metal hydrides

KW - Crystal structures

UR - http://www.scopus.com/inward/record.url?scp=85094559801&partnerID=8YFLogxK

U2 - 10.3390/inorganics8100057

DO - 10.3390/inorganics8100057

M3 - Journal article

AN - SCOPUS:85094559801

VL - 8

JO - Inorganics

JF - Inorganics

SN - 2304-6740

IS - 10

M1 - 57

ER -