-Pinene is a major component of natural turpentine and its polymer is nontoxic and used in a...

β-Pinene is a major component of natural turpentine and its polymer is nontoxic and used in a wide variety of industrial applications such as adhesives, varnishes, food packaging and chewing gum. Novel catalysts for the polymerization of β-pinene have been produced based on niobium and tantalum pentahalides (M. Hayatifar et al., Catal. Today, 2012, 192, 177). Which catalyst was the most effective for the polymerization and why are the reaction conditions so attractive? Describe the nature of the catalyst–β-pinene interaction.