The irreversible photolytic axial to equatorial change (3ax–4ax→3eq–4eq) and the irreversible thermal equatorial to axial change (3eq–4eq→3ax–4ax) of the S–O configuration were first observed. Meanwhile, the shorter 1,9-bridged derivative (2ax) exhibited the interesting photolytic degradation, affording 1,9-dithiadibenzothiophene (5) by the elimination of SO and ethylene.