The thermodynamic phase behaviors, dissociation enthalpies, and Raman spectra of N-2 tetra-n-butyl ammonium chloride (TBAC) + water systems were measured in order to investigate the enclathration of N-2 in TBAC semiclathrates. The three-phase(H-L-W-V) equilibria of the N-2 + TBAC (1.0, 3.3, and 5.0 mol%) semiclathrates measured using a high pressure vessel as well as a high pressure micro-differential scanning calorimeter (HP mu-DSC) indicated that the N-2 TBAC semiclathrates have significant stability in the thermodynamic equilibrium compared with the N-2 gas hydrate and that they also exhibit maximum thermodynamic stability at 3.3 mol%, which corresponds to the stoichiometric concentration of TBAC center dot 29.7H(2)O. The dissociation enthalpies of the N-2 TBAC semiclathrates were determined from the endothermic dissociation thermograms of a HP mu-DSC under pressure. The Raman spectroscopic results clearly demonstrated that N-2 molecules are enclathrated in the cages of the TBAC semiclathrate. From the overall experimental results, TBAC is expected to be an effective semiclathrate former that can reduce the equilibrium dissociation pressure or enhance the equilibrium dissociation temperature for enclosing N-2 molecules as a guest in the vacant cages of TBAC semiclathrates. (C) 2015 Elsevier B.V. All rights reserved.