Controlling Catenation in Germanium(I) Chemistry through Hemilability.

ABSTRACT: We present a novel approach for constructing chains of Group 14 metal atoms linked by unsupported metal-metal bonds that exploits hemilabile ligands to generate unsaturated metal sites. The formation/nature of catenated species (oligo-dimetallynes) can be controlled by the use of (acidic/basic) "protecting groups" and through variation of the ligand scaffold. Reduction of Ar^NiPr2 GeCl (Ar^NiPr2 =2,6-(ⁱ Pr₂ NCH₂ )₂ C₆ H₃ )-featuring hemilabile Nⁱ Pr₂ donors-yields (Ar^NiPr2 Ge)₄ (2), which contains a tetrameric Ge₄ chain. 2 represents a novel type of a linear homo-catenated Ge^I compound featuring unsupported E-E bonds. Trapping experiments reveal that a key structural component is the central two-way Ge=Ge donor-acceptor bond: reactions with IMe₄ and W(CO)₅ (NMe₃ ) give the base- or acid-stabilized digermynes (Ar^NiPr2 Ge(IMe₄ ))₂ (4) and (Ar^NiPr2 Ge{W(CO)₅ })₂ (5), respectively. The use of smaller N-donors leads to stronger Ge-N interactions and quenching of catenation behaviour: reduction of Ar^NEt2 GeCl gives the digermyne (Ar^NEt2 Ge)₂ , while the unsymmetrical system Ar^NEt2 GeGeAr^NiPr2 dimerizes to give tetranuclear (Ar^NEt2 GeGeAr^NiPr2 )₂ through aggregation at the Nⁱ Pr₂ -ligated Ge^I centres.

SUBMITTER: Caise A 

PROVIDER: S-EPMC8362110 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature