216006-14-3Relevant academic research and scientific papers
O-(trifluoromethyl)aryl interactions and stabilization in hypervalent germanium compounds
Bender IV, John E.
, p. 5166 - 5171 (1998)
A series of o-(trifluoromethyl)phenyl-substituted germanes have been synthesized to study the potential for weak Ge-F bonding interactions. 1H-19F coupling constants in these compounds range between 2 and 5 Hz. These coupling magnitudes are consistent with previously reported literature examples in 19F and multinuclear NMR spectra for derivatives of the [2,4,6-(CF3)3C6H2]- ligand. Solid-state structural characterization of these germanes consistently reveals Ge-F contacts at 2.8-2.9 A?, midway between the longest single bond and the longest expected van der Waals contact. For the simple unsymmetrical catenate, [3,5-(CF3)2C6H3] 2Ge(H)Ge(H)[2,4,6-(CF3)3C6H 2]2 (4), there are close contacts to both germanium atoms from the ortho-CF3 groups. 4 is not otherwise sterically constrained to force distal, intramolecular contacts, and thus a weak Ge-F bonding interaction is invoked for the entire series of o-(trifluoromethyl)aryl-substituted tetravalent Ge compounds. The synthetic approaches to these germanes make extensive use of Ge(II) precursors, employing both catalytic hydrogenation and insertion reactions of germylenes.
