Deuterium NMR spectroscopy has been used to probe the dynamics of two samples, 2,2-d(2)-hexadecanoate (HDCA) and perdeuterated HDCA monolayers on nonporous ZrO2 powder (surface area similar to 40 m(2)/g) over the temperature range of 180 K to room temperature. The data indicate the presence of a considerable motional gradient in the tethered chain. Line shape simulations were performed on the spectra of 2,2-d(2)-HDCA to extract detailed information on the dynamic processes involved. These quantitative line shape analyses clearly show that, over the whole temperature range studied, the C2-D bonds have substantial motional freedom with respect to the characteristic H-2 NMR time scale. In addition, at each temperature, a weighted superposition of several simulated line shapes with different rates and site populations is required to account for the observed spectral features, indicating the presence of considerable motional heterogeneity within the hexadecanoate monolayers. The results will be compared with dynamic behaviors of other self-assembled monolayers (SAMs), particularly those of alkylthiolate SAMs on gold nanoparticles and phosphonate SAMs on ZrO2 powder. Attempts will be made to delineate the effects of various factors on the alkyl chain dynamics.