Generation, spectroscopic characterization and antioxidant activity of tetracoordinate and hexacoordinate complexes of diethylgermanium(IV) of relatively sterically undemanding N-protected amino acids and sterically demanding heterocyclic β-diketones containing radical sensitive Ge-O bond

<p>Two new sets of diethylgermanium(IV) complexes of the types Et<sub>2</sub>GeA<sub>2</sub> and Et<sub>2</sub>GeB<sub>2</sub> have been generated by the reactions of diethylgermanium(IV) dichloride with sodium salts of N-protected amino acids (AH) [where AH = , R = -CH(CH<sub>3</sub>)C<sub>2</sub>H<sub>5</sub>: A<sub>1</sub>H, R = -CH<sub>2</sub>CH(CH<sub>3</sub>)<sub>2</sub>: A<sub>2</sub>H, R = -CH(CH<sub>3</sub>)<sub>2</sub>: A<sub>3</sub>H] and with sodium salts of sterically demanding heterocyclic β-diketones (BH) [where BH = , R’ = -C<sub>6</sub>H<sub>5</sub>: B<sub>1</sub>H, R’ = -p-(Cl)C<sub>6</sub>H<sub>4</sub>: B<sub>2</sub>H, R’ = -CH<sub>3</sub>: B<sub>3</sub>H, R = -C<sub>2</sub>H<sub>5</sub>: B<sub>4</sub>H], respectively in 1:2 molar ratios in refluxing dry benzene. Plausible structures of these complexes were suggested on the basis of physico-chemical and spectroscopic studies. It is suggested that the complexes of the types Et<sub>2</sub>GeA<sub>2</sub> and Et<sub>2</sub>GeB<sub>2</sub> contain four coordinated and six coordinated germanium centers, respectively. The ligands and organogermanium(IV) complexes were evaluated for their free radical scavenging activity by DPPH method. These compounds/complexes demonstrate potential antioxidant activity.</p> <p></p>