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oai:figshare.com:article/34025350 2026-09-29T17:16:20Z category_1 category_4 category_915 category_12 category_21 category_272 category_873 category_45 portal_63 item_type_6 month_year_09_2026

Picolinate- and Phosphonated Pyridyl-TACN Ligands for Highly Stable and Inert Cu(II) Complexes for Radiochemical Applications Tarek El Sayed (12846491) Monika Rana (5558099) Saumitra Bhowmik (12269438) Iwona T. Dobrucki (10315936) Lawrence W. Dobrucki (1910665) Liviu M. Mirica (1341486) Biophysics Biochemistry Physical Sciences not elsewhere classified Cell Biology Biotechnology Environmental Sciences not elsewhere classified Chemical Sciences not elsewhere classified Sociology positron emission tomography partial liver excretion electron paramagnetic resonance excretion pathway due two phosphonated pyridine tacn analogue exhibited 64 </ sup cu radiolabeling studies cu pet imaging ligands contain picolinate imaging studies vivo </ renal pathway phosphonated pyridyl phosphonated pyridines inert cu vis spectroscopy tacn ligands solution chemistry radiochemical applications optimal five lipophilic nature ligand platform highly stable excreted via epr ), cyclic voltammetry cv ). coordinate geometry In this study, three novel chelators based on the 1,4,7-triazacyclononane (TACN) ligand platform were introduced. The ligands contain picolinate and phosphonated pyridine chelating arms to provide an optimal five-coordinate geometry for Cu(II). The solution chemistry of these complexes was systematically investigated using spectrophotometric titrations, UV-vis spectroscopy, electron paramagnetic resonance (EPR), and cyclic voltammetry (CV). Then, these ligands were employed in ⁶⁴Cu radiolabeling studies and subsequent <i>in vivo</i> positron emission tomography (PET) imaging studies to reveal that the ⁶⁴Cu complexes of the two phosphonated pyridine-TACN ligands were excreted via the renal pathway, while the picolinate-TACN analogue exhibited a shift in the excretion pathway due to its lipophilic nature, resulting in partial liver excretion. To our knowledge, the use of phosphonated pyridines as chelators in ⁶⁴Cu PET imaging is uncommon, which underscores the significance of this study. 2026-09-29T00:00:00Z Text Journal contribution 10.1021/acs.inorgchem.6c03664.s001 https://figshare.com/articles/journal_contribution/Picolinate-_and_Phosphonated_Pyridyl-TACN_Ligands_for_Highly_Stable_and_Inert_Cu_II_Complexes_for_Radiochemical_Applications/34025350 CC BY-NC 4.0