Synthesis and vibrational spectroscopy of new palladium(II) complexes with 2-hydrazino-2-imidazoline. Band assignment based on isotope substitution and density functional calculations

The novel complexes of formula [Pd(hi)X2] (hi—2-hydrazino-2-imidazoline; X—Cl, Br) were investigated by vibrational spectroscopy and quantum-mechanical methods. The experimental band assignment was supported by measured metal isotope shifts and deuteration effects. Both experiments were reproduced in DFT calculations and used as additional criteria verifying the computed data. All normal vibrations were characterized in terms of potential energy distribution. The stretching vibration of Pd(II)–imidazoline bond was observed at about 220 cm21. The vibrational coupling of most metal coordination sphere modes and ligand vibrations was found. q 2004 Elsevier B.V. All rights reserved.