Single OCS molecules have been embedded in large He-4 droplets ((N) over bar = 1 x 10(3)-8 x 10(3) atoms) and their infrared spectra in the vicinity of the nu(3)-fundamental at 2062 cm(-1) have been studied using coaxial laser depletion spectroscopy. Sharp lines corresponding to the P- and R-branches with a linewidth of 160 MHz or greater are observed. From the line intensities a droplet temperature of 0.37 +/- 0.02 K is obtained and from the line positions the rotational constants B for the ground and excited states and an average centrifugal distortion constant D are determined. The former are about a factor of 2.8 smaller and the latter four orders-of-magnitude larger than for the free molecule. The decrease in B is attributed to an attached nonsuperfluid component which has the same effect as a ring of about six He-4 atoms in an equatorial plane around the waist of the OCS molecule, which is carried along in the end-over-end rotation. The widths of the individual lines show an interesting asymmetry which is oppositely sloped for the P- and R-branches and increases with the rotational quantum number. Several possible explanations for the line shapes and widths are presented. (C) 2000 American Institute of Physics. [S0021-9606(00)00801-1].