Investigation of the Magnetic Moments of S2, Se2, Te2, Se6, and Se5 by the Stern–Gerlach Magnetic Deflection Method

An apparatus consisting of a Knudsen effusion cell, collimator, inhomogeneous-field magnet, and quadrupole mass spectrometer has been applied to investigation of the fraction of S2, Se2, Te2, Se6, and Se5 molecules that show a magnetic moment. The expected high concentration of paramagnetic S2 molecules was found, but the concentration of paramagnetic Se2 and Te2 molecules at 1000°K was less than the 10% detection limit. The concentration of paramagnetic Se6 and Se5 at 500°K was unmeasurably low. The results indicate that Se6 and Se5 are not diradicals and that the splittings between the 0g+ ground state and the 1g paramagnetic state of Se2 and Te2 exceed 2000 K. The Se2 data support the conclusion that the dissociation energy of Se2 is 78.63 kcal/mole.