The document describes a photoactivated 1,3-dipolar cycloaddition reaction, also known as a photoclick reaction. Ultraviolet light triggers a cycloaddition reaction between a nitrile-imine dipole and an alkyne, forming a fluorescent pyrazole or pyrazoline cycloadduct. Nitrogen is released during the reaction. The reaction staples together two aryl groups with a pyrazole or pyrazoline ring when triggered by UV lamp irradiation.