Thermodynamic study of tetramethyltin, Sn(CH3)4, adsorbed on (0001) graphite planes

Abstract

Vapour adsorption isotherms of Sn(CH₃)₄ on graphite have been determined between 230 and 296 K. All the data are interpreted in terms of two-dimensional mobile adsorption. Cross-sectional adsorption areas of different Sn(CH₃)₄ arrangements are discussed and comparison is made with X-ray diffraction results. Various thermodynamic quantities relating to adsorption are given as a function of surface coverage. Calculated isosteric heats of adsorption are compatible with those obtained from low-temperature Mössbauer binding-energy data at the same coverage. The two-dimensional critical temperature of the first monolayer of Sn(CH₃)₄ has been determined.