The FT-Raman spectra of Se(tu)(2)Cl-2 and Se(tu)(2)Br-2 complexes are repor
ted for the first time. The important modifications observed in the Raman a
ctive modes of thiourea molecules demonstrate a very strong interaction bet
ween the Se(II) ion and the sulfur atom of the ligand. As a result of this
coordination, and through a "resonance-assisted" mechanism, an intense hydr
ogen-bonded network is present in the crystal structure of the complexes wi
th notable vibrational effects. (C) 1999 Elsevier Science B.V. All rights r
eserved.