Infrared and Raman spectra for metal-string complexes M-3(dpa)(4)X-2 ( M = Ni, Co, dpa = di(2-pyridyl) amido, and X = Cl, NCS) are studied. We assign the Ni-3 asymmetric stretching vibration to infrared lines at 304 and 311 cm (1) for Ni-3(dpa)(2)Cl-2 and Ni-3(dpa)(2)(NCS)(2), respectively. A Raman shift at 242 cm (1) is assigned to the Ni3 symmetric stretching mode. For Co-3 complexes a line for the Co-3 asymmetric stretching mode appears at 313 and 331 cm (1) for Co-3(dpa)(2)Cl-2 and Co-3(dpa)(2)(NCS)(2), respectively. (c) 2008 Elsevier B. V. All rights reserved.