We have synthesised the series of lanthanide complexes Ln(trensal-thiophene), where Ln = Er, Dy, Yb and H3trensal = 2,2,2-tris(salicylideneimino)trimethylamine. These complexes are functionalised with thiphene groups which make them suitable for graftiong on gold surfaces by specific S - Au interactions. We would like to study the INS spectra of these complexes, in concern with other spectroscopic techniques, to ununmiguously determine their energy spectrum. This information will help us rationalise the static and dynamic magnetic properties of these complexes.