Crystalline molecular framework:small molecule compounds. The molecular framework is formed from guanidinium cations and organosulfonate anions and the guanidinium cations and organosulfonate anions are associated via one or more hydrogen bond. The small molecule(s) is/are encapsulated by the molecular framework. Methods for making crystalline molecular framework:small molecule compounds may include combining guanidinium cations, organosulfonate anions, and small molecules in a single step. The crystalline molecular framework:small molecule compounds can be used to determine the structure of the small molecule(s).