The effect of temperature variation on the amplitudes of vibration and shrinkage effects in carbon suboxide studied by gas electron diffraction

C3O2 has been studied in the gas phase by electron diffraction at the nozzle temperatures 237 degrees K and 508 degrees K. Preliminary results for the structure parameters are given. The shrinkage effects for three of the non- bonded distances ( the O center dot center dot center dot O-center dot the longest C center dot center dot center dot O-center dot and the C center dot center dot center dot C distance) are very large and show a significant variation with the temperatures. The root-mean-square amplitudes of vibration for the same distances are also very different for the two temperatures. The potential for the C=C=C bending vibration. and the possibility of determining the "temperature" corresponding to the actual population of the vibrational levels for this vibration. are discussed.