Synthesis, Structures and Dehydrogenation Properties of Zinc Borohydride Ethylenediamine Complexes. Issue 4 (6th April 2016)

• Record Type: Journal Article
• Authors: Roedern, Elsa; Jensen, Torben R.
• Is Part Of: ChemistrySelect. Volume 1:Issue 4(2016)
• Page Start: 752
• Page End: 755
• Publication Date: 2016-04-06
• Subjects: Synthesis (inorg.) -- Transition-met. (late) compl -- Hydrides -- Hybrid materials -- Crystal-structure determination -- Thermal analysis; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201600077
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Zinc borohydride–ethylenediamine composites with high hydrogen content and moderate decomposition temperatures were synthesized by a solvent based approach in diethyl ether. The complexation with ethylenediamine allows to stabilize zinc borohydride, Zn(BH4 )2, which otherwise decomposes at temperatures below RT. The crystal structures of Zn(en)n (BH4 )2, n=3 or 4, were determined from synchrotron radiation powder X‐ray diffraction data (SR‐PXD). The decomposition mechanism of the compounds was analyzed by in situ SR‐PXD and thermal analysis. Zn(en)n (BH4 )2, n=3 or 4, release ethylenediamine during heating, while the composites Zn(BH4 )2 ‐en 1:2 and 1:1 release 8 or 5 wt% of hydrogen at 135 and 110 °C, respectively, in contrast to e. g. alkali metal zinc borohydrides, which release a mix of diborane and hydrogen. Abstract : In a solvent based synthesis approach, the highly reactive zinc borohydride is stabilized by complexation with ethylenediamine. The crystal structure of two novel complexes is solved from X‐ray powder diffraction data, and thermal analysis reveals release of up to 8 wt% hydrogen at moderate temperatures.