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

ABSTRACT

Two new sets of diethylgermanium(IV) complexes of the types Et₂GeA₂ and Et₂GeB₂ have been generated by the reactions of diethylgermanium(IV) dichloride with sodium salts of N-protected amino acids (AH) [where AH = , R = -CH(CH₃)C₂H₅: A₁H, R = -CH₂CH(CH₃)₂: A₂H, R = -CH(CH₃)₂: A₃H] and with sodium salts of sterically demanding heterocyclic β-diketones (BH) [where BH = , R’ = -C₆H₅: B₁H, R’ = -p-(Cl)C₆H₄: B₂H, R’ = -CH₃: B₃H, R = -C₂H₅: B₄H], 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 Et₂GeA₂ and Et₂GeB₂ 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.

GRAPHICAL ABSTRACT

KEYWORDS:

• Diethylgermanium(IV) complexes
• N-protected amino acids
• heterocyclic β-diketones
• antioxidant activity

Acknowledgment

Dr. Asha Jain and Karuna Maheshwari are thankful for financial support to UGC New Delhi, India.