The densities, viscosities, and electrical conductivities of the ionic liquid N-methoxymethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)amide, [Pyr(1,1O1)][Tf2N] have been measured with expanded uncertainties of +/- 0.05 kg m(-3), +/- 2%, and +/- 2% over a wide temperature range between 273.15 and 363.15 K at atmospheric pressure. The temperature dependence of the viscosity and conductivity was analyzed by the Litovitz and Vogel-Fulcher-Tammann equations. The effect of the methoxymethyl group instead of the propyl one on such physicochemical properties is discussed in comparison with the similar analogue, N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)amide, [PYr1,3][Tf2N]. (C) 2010 Elsevier B.V. All rights reserved.