Molecular intercalation of ammonia into zirconium disulfide

The intercalation and deintercalation of NH3 into ZrS2 has been investigate d by evolved gas analysis, thermogravimetric analysis, differential scannin g calorimetry, vapor pressure measurements, SQID magnetometry, and X-ray po wder diffraction. Ammonia intercalation of ZrS2, in contrast to other trans ition metal disulfides (TS2), is predominately a molecular insertion reacti on. Only a small amount of NH4+ (less than or equal to 1%) is insertion rea ction. Only a small amount of NH4+ (less than or equal to 1%) is present in the intercalate, which mag be required for intercalation to occur, The sma ll degree of charge transfer can be understood qualitatively within the rig id-band model. The equilibrium intercalate, (NH3)(0.92)ZrS2, can be indexed to a 3R, stage-1 structure having an occupied layer expansion (3.17 Angstr om) in good agreement with other NH3-TS2 intercalation compounds, The guest -guest and guest-host interactions that stabilize the intercalate apparentl y involve H2N-H ... NH3 and H2N-H ... S hydrogen bonding, respectively. Bas ed on this study, ammoniated ZrS2 offers an excellent model system for prob ing the structure and properties of molecular guest species in lamellar mat erials, (C) 1999 Academic Press.