These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
A 5,15-bis(1,1’-biphenyl)porphyrin-based molecular clip covalently-linked to a stiff
phenanthrene appended moiety yields a porphyrin-based macrocycle with a well-defined and
relatively small cavity in the solid-state and in solution. Introduction of a Ru(II) ion into the
porphyrin moiety followed by axial coordination of the inert and bulky diphenylcarbene ligand
exo-to the macrocycle’s cavity affords a Ru(II)porphyrinate-based macrocycle able to promote
the active-metal template rotaxane synthesis in quantitative yield through the challenging
single N–H bond carbenoid insertion. A detailed structural investigation of the
Ru(II)porphyrinate-based macrocycle and the resulting asymmetrical rotaxanes reveals that
the synergy between the steric shielding provided by the hollow macrocyclic structure and the kinetic stabilization of otherwise labile coordinative bonds, warranted by the mechanical bond,
can be used as principles for the design of molecular nanoreactors.