Abstract
Redox-related changes in biological properties of copper bis(thiosemicarbazone) radiopharmaceuticals are induced by backbone alkylation. To determine whether these changes are mediated by changes in core structural parameters, eight X-ray structures of variously alkylated complexes were determined. The complexes include the hypoxia tracer diacetylbis(4-methyl-3-thiosemicarbazonato)copper(II) (CuATSM). The structures of the nickel analogue NiATSM and the corresponding free ligand ATSMH2 were also included. Distortions from planarity were slight and only present when there were significant intermolecular interactions (mainly pairs of N–H–N and N–H–S hydrogen bonds). These give rise to cross-linked flat or helical ribbons of complexes. Alkylation at the terminal nitrogen atoms interrupts hydrogen bonding, allowing complexes to become planar, but does not otherwise affect the coordination sphere. Alkylation at the backbone carbon atoms increases the backbone C–C bond length, allowing the metal to fit better into the ligand cavity with shorter Cu–S bonds.
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.
