Salicyclaldimines (5-9) and naphthaldimines (10-13) derived from condensation reactions of N 2 O 2 donor type bifunctional aminopodands (1-4), [(H 2 NPhO) 2 R, where R = CH 2 CH 2 , CH 2 CH 2 CH 2 and CH 2 PhCH 2 ], and hydrazine monohydrate with salicylaldehyde and 2-hydroxy-1-naphthaldehyde, respectively, have been prepared (scheme 1) and characterized by elemental analyses, UV-vis, FTIR, NMR and MS. NMR assignments were made using 1 H, 13 C NMR, DEPT and aided by 2D HETCOR and HMBC heteronuclear correlation techniques. The UV-vis spectra of the Schiff bases have been systematically studied in organic solvents of different polarity, acidic and basic media and found useful in understanding of tautomeric equilibria (phenol-imine, O-H...N and keto-amine, O...H-N forms) in this series. The molecular structure of 8 has been determined crystallographically, and observed that the compound is in the form of phenol-imine, defined by the strong intramolecular [O-H...N = 1⋅72(3), 1⋅81(2) Å] hydrogen bonds. Compound 8 crystallizes in the monoclinic space group P2 1 /a with a = 8⋅4675(7), b = 38⋅448(3), c = 9⋅3875(7) Å, β = 103⋅0780(10)°, V = 2976⋅9(4) Å 3 , Z = 4 and D x = 1⋅271 Mg m -3 , and contains acetonitrile molecule in the crystal lattice.

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