Complexes of linear carbon clusters with water

The complexes of linear C-n (n = 4-9) carbon clusters with water have been formed in argon matrices and studied via FTIR spectroscopy. In most complex es, the CC stretching mode bands are shifted to the blue from the respectiv e C-n carbon cluster bands, and the OH stretching frequencies are shifted t o the red. The observed shifts compare well with displacements predicted by density functional theory calculations. Isotopic C-12/C-13 substitution ha s been used to confirm the vibrational assignments of the C-5. H2O and C-6. H2O complexes, With higher water concentrations in the matrix, bands appea r that are assigned to complexes with more than one water molecule, such as H2O . C-3. H2O, C-3.(H2O)(2), and H2O . C-3.(H2O)(2). Photolysis of the co mplexes leads to a number of CnO species, such as C5O, C7O, and C9O, for wh ich band assignments are proposed. The implications of these results for th e production of molecules on grains in the interstellar medium are discusse d.