Here we review our most recent results on the vibrational spectroscopy of the MX chain solids [Pt(en) 2][Pt(en) 2X 2](ClO 4) 4, (X=Cl, Br or I, and en = C 2H 8N 2), referred to as PtX. Isotopic substitutions are used to clarify the nature of various vibrational modes. For Raman spectroscopy, fundamental photon frequencies are determined, when possible, by excitation far below the band edge using a Ti:Sapphire laser, thus avoiding defect production, while photo-induced defects are studied specifically after intentional production.