in neat (no solvent, gas phase) byproducts: Si5CO, c-Si2(μ-O)(μCSi), c-Si2(.mu-O)(μ-CCO); (excess Ar) laser ablated Si atoms codeposited with CO onto CsI window cooled to 7 K for 1-2 h; annealed at 30, 34, 38 K; obtained Si5CO, Si2OCSi, Si2OCCO; detected by IR;