The halogen bonding and the pi...pi stacking interactions induce the noncovalent self-assembly of modules into photoreactive supramolecular architecture. The pi...pi interaction pre-organizes the template, and the halogen bonding aligns the olefins to conform to the topochemical principle for photoreaction. The UV irradiation of the crystal resulted in a cyclization product with quantitative yield and stereospecificity.

The crystal matrix of N-methyl-3,5-dibromopyridinium iodide is constituted of infinite helices where the cation and the anion alternate and are bound by the second shortest reported C-BrÁ Á ÁI halogen bonding. The electron poor pyridinium scaffold is particularly effective in boosting the electron acceptor ability of bromine substituents.

Whether it is prolonged strike action, a protest movement or a global viral outbreak, the disruptions triggered in higher education are profound. In a STEM subject, laboratory classes are vital to teaching and learning. Chemistry educators had to transport laboratory skills-based teaching and assessment courses to the virtual world at short notice, whilst adhering to evolving university policies.Analysis of the situation from the perspective of the lecturer and the student revealed for a laboratory class setting that student engagement did not significantly change throughout the semester and was relatively high compared to other teaching activities. During the lockdown students embraced traditional pathways for seeking support and reluctantly adopted new opportunities presented to staff and students alike at the start of the closure period. More active and interactive formats failed to take proper hold mainly due to a combination of technology (restrictions in available bandwidth and hardware) and anxiety issues. Undergraduate students, however, do wish to engage with their studies and if the difficulties identified herein can be addressed adequately, the scene can be set for a successful and supportive teaching and learning environment in a socially distanced lab class combined with improved online support. It would include a structured and prescribed participation in partly online, partly live teaching sessions that are summatively assessed. This must be supported by a formal induction to the available IT infrastructure as well as assurances that learning in open fora enriches the learning experience and should not cause nervousness. Sticking to the published timetable for synchronous delivery and additional asynchronous support opportunities will assisted students in planning and undertaking a balanced workload, and the social aspects and value of faceto-face time in a blended teaching approach must be emphasised.