Access to metastable [GeH2]n materials via a molecular "bottom-up" approach. Issue 47 (22nd November 2021)

• Record Type: Journal Article
• Authors: Sinclair, Jocelyn; Medroa del Pino, William; Aku-Dominguez, Kwami; Minami, Yohei; Kiran, Anagha; Ferguson, Michael J.; Yasuda, Makoto; Rivard, Eric
• Is Part Of: Dalton transactions. Volume 50:Issue 47(2021)
• Page Start: 17688
• Page End: 17696
• Publication Date: 2021-11-22
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d1dt02850b
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : The molecular precursor Ge(O t Bu)2 was combined with soluble hydride sources to either yield metastable [GeH2 ] n materials (orange solids) or the deposition of nanoscale films of Ge from solution. Abstract : We describe the application of a mild, molecular-based, hydride metathesis protocol for the preparation of metastable germanium(ii ) dihydrides with compositions approaching [GeH2 ] n . The common starting material for this work [Ge(O t Bu)2 ] was prepared in a high yield and shown to undergo O t Bu/H exchange at Ge with the hydride sources pinacolborane (HBpin), catecholborane (HBcat), and diisobutylaluminum hydride (DIBAL-H) to give the [GeH2 ] n materials as yellow to orange solids. Heating one of these [GeH2 ] n materials to 200 °C affords a narrowing of the optical band gap (from 2.5 eV) and the generation of amorphous Ge. Reaction of [Ge(O t Bu)2 ] with excess H3 B·SMe2 in toluene at 70 °C provides a convenient route to thin films of amorphous Ge, including its deposition onto soft substrates, such as polyethyleneterephthalate (PET). Accompanying computations give insight into the energetics of O t Bu/H exchange at Ge, and reveal a general thermodynamic preference for branched structures of [GeH2 ] n oligomers over linear forms as the Ge chain becomes longer. We also show that [Ge(O t Bu)2 ] is a suitable pre-catalyst for the borylation of aldehydes.