Abstract
Conjugations with the recently developed [18F]ethenesulfonyl fluoride ([18F]ESF) were performed on 5-amino-1,10-phenanthroline, in its free form and coordinated to a rhenium(i) tricarbonyl complex, as a means of radiosynthesizing dual-modal optical and positron emission tomography (PET) tracers. The Michael-donating ability of the aromatic amine was noticeably perturbed on coordination with the rhenium(i) centre, resulting in decreased radiochemical yields from 34%, in the case of the free ligand, to 1%. We attribute the decreased nucleophilicity of the amine to metal deactivation from the electron-withdrawing feature of the rhenium(i) tricarbonyl centre, based on spectroscopic and computational evidence, thus highlighting this effect as a crucial parameter in designing late-stage metal coordination methods employing related aza-Michael additions. Photophysical analyses were also performed on the ESF-conjugated rhenium(i) complex, exhibiting a longer decay lifetime from the triplet metal-to-ligand charge transfer excited state when compared with the non-conjugated analogue.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
