The subpicosecond ultraviolet observation of a sulfur−sulfur bond making (2σ/1σ* bond) is carried out in pure liquid dimethyl sulfide at 294 K. The early stages of a disulfide bonded radical formation (CH3S∴SCH3 -) are characterized by a nonlinear λ max red shift of the absorption spectrum. In the temporal range 0−1600 fs, the red shift of 0.31 ± 0.1 eV is analyzed in the framework of a change of the 2σ/1σ* transition due to a lowering of the 2c,3e S−S bond strength and/or a destabilization of the σ lone pair during the demethylation process.