The photoinduced O-bound coordination mode in RuSO2 complexes, previously observed only at 13 K, has been generated at 100 K in tetraammineaqua(sulfur dioxide)nithenium(II) (+/-)-camphorsulfonate. This coordination state, often denoted MS1, decays to the eta(2)-bound MS2 state, with an estimated half-life of 3.4(8) h and a long-lived population of 2.9(4)% at 120 K.