Synthesis, structure and decomposition of the digermane Ph₃GeGePh₂H

Article type: Research Article

Authors: Komanduri, Sangeetha P.^a | Schrick, Aaron C.^a | Daley, Christopher J.A.^b | Rheingold, Arnold L.^b | Weinert, Charles S.^{a; *}

Affiliations: [a] Department of Chemistry, Oklahoma State University, Stillwater, OK, USA | [b] Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA

Correspondence: [*] Corresponding author: Charles S. Weinert, Department of Chemistry, Oklahoma State University, 107 Physical Science, Stillwater, OK 74078, USA. Tel.: +1 405 744 6543; E-mail: Weinert@chem.okstate.edu.

Abstract: Reaction of Ge2Ph6 (1) with trichloroacetic acid at 95°C in toluene for 4 days yields a mixture of the two digermanes (Cl3CCOO)Ph2GeGePh2(OOCCCl3) (2) and Ph3GeGePh2(OOCCCl3) (3) that are converted to a mixture of ClPh2GeGePh2Cl (4) and Ph3GeGePh2Cl (5) using ethereal HCl. Treatment of the mixture of 4 and 5 with LiAlH4 affords the two digermanes HPh2GeGePh2H (6) and Ph3GeGePh2H (7). The digermane 7 was separated from 6 by crystallization and its X-ray crystal structure was determined. Digermane 7 crystallizes in two different morphologies, where one contains three independent molecules in the unit cell (7a) and the other contains only one independent molecule (7b). The Ge – Ge bond distances in these two structures are 2.4234(7) Å (average) in 7a and 2.4213(5) Å in 7b. Compound 7 is thermally unstable and releases Ph3GeH upon heating this material to 200°C in the solid state, with concomitant formation of the germylene Ph2Ge: that polymerizes.

Keywords: Germanium, organogermanium, oligogermanes, NMR spectroscopy, synthesis

DOI: 10.3233/MGC-170238

Journal: Main Group Chemistry, vol. 16, no. 3, pp. 217-225, 2017