Monolayers of H-2 On NaCl(100) at 5.2 K have been prepared from both normal and pam-enriched hydrogen and examined by polarized infrared spectroscopy. Vibrational features associated with J=0 and J=1 molecules are distinguished. The spectroscopic data are consistent with hydrogen adsorbed to two distinct sites: surface Na+ ions and Cl- ions. For the pam-enriched sample a two-dimensional crystal structure is proposed in which J=0 molecules reside on Nat ions and J =1 molecules cover Cl-sites. The polarization measurements show that all transition dipoles are perpendicular to the NaCl(100) surface. The mechanism for the infrared absorption is through electric field induced transition dipoles.