Enhancing the Stability of Nicotine via Crystallization Using Enantiopure Tartaric Acid Salt Formers.

Crystallization of nicotine, an oil prone to degradation at room temperature, has been demonstrated to be an effective means of creating nicotine-based materials with tunable thermal properties and improved resistance to photo-induced degradation. Herein, we show that both isomers of enantiomerically pure tartaric acid are highly effective salt formers when combined with nicotine. Both salts exhibit enhanced photostability, and with a melting point of 143.

1,2-Bis(pyridin-4-yl)ethene-4-hy-droxy-3-meth-oxy-benzoic acid (1/1).

In the title 1:1 co-crystal [alternatively called bi-pyridine ethyl-ene--vanillic acid (1/1)], CHN·CHO, the dihedral angle between the pyridine rings is 59.51 (5)°. In the crystal, the mol-ecules are linked by O-H⋯N hydrogen bonds, generating [401] chains of alternating CHN and CHO mol-ecules.

4,4'-(Ethene-1,2-diyl)dipyridinium bis(2-hy-droxy-3-meth-oxy-benzoate).

In the title double proton-transfer salt, CHN ·2CHO , consisting of a 1:2 ratio of 4,4'-(ethene-1,2-diyl)dipyridinium cations ( bipyridinium ethyl-ene) to 2-hy-droxy-3-meth-oxy-benzoate anions (-vanillate), the complete cation is generated by crystallographic inversion symmetry and it is linked to adjacent -vanillate anions by N-H⋯O hydrogen bonds, forming trimolecular assemblies. The trimers are linked by C-H⋯O hydrogen bonds as well as aromatic π-π stacking inter-actions into a three-dimensional network. The anion features an intra-molecular O-H⋯O hydrogen bond.

Enhancing the Photo and Thermal Stability of Nicotine through Crystal Engineering with Gentisic Acid.

The use of crystal engineering to convert liquids into crystalline solids remains a powerful method for inhibiting undesired degradation pathways. When nicotine, a liquid sensitive to both light and air, is combined with the GRAS-listed compound, gentisic acid, the resulting crystalline solid, exhibits enhanced photo and thermal stability. Despite a modest ΔT of 42.