There is little systematic understanding of pore surfaces in layered microporous metal(IV) phosphate-phosphonate materials and their interactions with guest molecules. In this paper, we show how to probe the mobility of guest molecules in such poorly crystalline systems using multinuclear solid-state NMR and relaxation time measurements. Anisotropic motions of benzene-d(6) molecules absorbed on the pore walls of material Sn(O3PC6H4PO3)(0.85)(O3POH)(0.33) (1) have been recognized as the fast in-plane C-6 rotation due to metal-pi interactions with pore walls. The benzene-d(6) absorption enthalpy due to Sn center dot center dot center dot pi interactions has been determined as -Delta H = 5.9 kcal/mol. Specific interactions between pyridine and the pore walls of 1 have been observed as immobile pyridine, the population of which grows strongly at low temperatures to show thermodynamic parameters -Delta H of 5.0 kcal/mol and Delta S of -11.0 e.u. It has been suggested that these parameters characterize N center dot center dot center dot H-OP hydrogen bonding as a driving force for accumulation of immobile pyridine molecules in pores of compound 1.