Vibrational study of the interaction of dinaphthalenic Ni(II) and Cu(II) azamacrocycle complexes methyl and phenyl substituted with different metal surfaces

Abstract

The FT-IR and Raman spectra in the solid state, the reflection-absorption IR spectra (RAIRS) and the surface enhanced IR (SEIR) and surface enhanced Raman spectra (SERS) of the Ni(II) (trans-7,14-dimethyl-5,12,-diphenyl-1,4,8,11-tetra-aza-2,3-9,10-dinaphthyl- cyclotetradeca-5,7,12,14-tetraene) and Cu(II) (5,7,12,14-tetramethyl-1,4,8,11-tetra-aza-2,3-9,10-dinaphthyl- cyclotetradeca-5,7,12,14-tetraene) are reported. The RAIRS analysis and differences observed in the relative intensities of complexes deposited onto KBr and Cu surfaces suggest that the organisation of each macrocycle is different on both surfaces. SERS data allow to propose for both complexes an adsorbate-substrate interaction between the complex and the colloidal Ag surface. Complexes are oriented face-on to the surface being the number of Cu macrocycles oriented face-on to the surface larger than that of the Ni macrocycles. The organisation of the complexes on Au film is different to that found on Ag colloids and rather random. The phenyl groups avoid a better organisation of the Ni complex on the surface. SEIR data analysis of samples deposited on Au film suggests that the Ni complex is less organised than the Cu complex. The dynamic and energetic of the adsorbate-substrate interaction is interpreted by using a simple molecular model and INDO/1 calculations