Corrosion-inhibiting coating materials comprise a sol-gel and a corrosion-inhibiting compound with at least one disulfide group. The corrosion-inhibiting compound is contained within the sol-gel. Coated and/or laminated structures may include the corrosion-inhibiting coating materials on a metal substrate, and may include a secondary layer (e.g., a paint, etc.) adhered to the coating material opposite the metal substrate. Methods of forming a corrosion-inhibiting sol-gel comprise mixing organo-metallic compounds and the corrosion-inhibiting compound into a sol solution and incubating (e.g., reacting) the sol solution to form the corrosion-inhibiting sol-gel with the corrosion-inhibiting compound contained within the sol-gel. Generally, corrosion-inhibiting coating materials are hexavalent chromium free.