Total fragmentation of SbCl3 by multiphoton dissociation in the UV

UV-multiphoton dissociation of SbCl3 in the gas phase is studied by monitor ing the emission spectra of the resulting excited atomic fragment Sb by mea ns of an optical multichannel analyzer (OMA). The relative fluorescence int ensities arising from different atomic states allow us to calculate the pop ulation of a subensemble of Sb* states produced upon photodissociation by a frequency doubled tuneable pulsed dye laser. For the range of 206-240 nm o f the dissociation wavelength the spectral analysis shows that the photodis sociation is a three-photon process and that the population of excited Sb s tates (43 000-50 000 cm(-1)) follows a Boltzmann distribution with temperat ures from 1100 to 2000 K increasing monotonically with increasing photon en ergy for dissociation. This result on SbCl3 confirms earlier observations f or SbBr3 where such behaviour was found for two- and three-photon dissociat ion in the same UV range. (C) 1999 Elsevier Science B.V. All rights reserve d.