Some New Hexacoordinated Aluminium(III) Complexes of Sterically Hindered Heterocyclic P-Diketones and N-Protected Amino Acids : Preparation And Structural Considerations Based Upon Spectral [IR And NMR (~1H, ~(13)C and ~(27)Al)] Studies

摘要

A number of new sterically hindered heterocyclic β-diketones and N-protected amino acids -modified Al(OPr~i)_3 products of composition either Al[RCOC:C(O)N(C_6H_5)N:CCH_3][O_2CCH(R')NC(O)C_6H_4(O)]_2 where R= -C_2H_5 and R'= -CH_2C_6H_5, -CH(CH_3)_2, -CH(CH_3)C_2H_5 ; R= -CH_3 and R'= -CH(CH_3)_2, -CH(CH_3)C_2H_5; R= -C_6H_5 and R'= -CH_2C_6H_5, -CH(CH_3)_2, or Al[RCOC:C(O)N(C_6H_5)N:CCH_3]_2[O_2CCH(R')NC(O)C_6H_4C(O)] where R= -C_2H_5 and R' = -CH(CH_3)_2, -CH(CH_3)C_2H_5 ; R= -CH_3 and R'= -CH_2C_6H_5, -CH(CH_3)C_2H_5 ; R= -C_6H_5 and R'= -CH_2C_6H_5, -CH(CH_3)_2, -CH(CH_3)C_2H_5, were prepared by the interaction of sterically hindered heterocyclic β-diketones and N-protected amino acids in 1 : 1 : 2 and 1:2:1 molar ratios in anhydrous refluxing benzene. The structures of these newly synthesized sterically hindered heterocyclicβ-diketones and N-protected amino acids -modified Al(OPr~i)_3 products were suggested on the basis of analytical data, molecular weight measurements and spectral studies. The ~(27)Al NMR spectral study of some of these complexes revealed the presence of hexacoordinated aluminium centres in these products.