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Abstract Macrocyclic Co(II) complexes with appended amide‐glycinate groups were prepared to develop paramagnetic Co(II) chemical exchange saturation transfer (CEST) agents of reduced overall charge. Complexes with reduced charge and lowered osmolarity are important for their loading into liposomes and to provide complexes that are highly water soluble and well tolerated in animals. Co(L1) has two non‐coordinating benzyl groups and two amide‐glycinate pendants, whereas Co(L2) has two unsubstituted amide pendants and two amide‐glycinate pendants on cyclam (1,4,8,11‐tetraazacyclododecane). The¹H NMR spectrum of Co(L1) is consistent with a singlecis‐pendant isomer with both amide protons in thetrans‐configuration, as supported by an X‐ray crystal structure. Co(L2) has a mixture of different isomers in solution, including thetrans‐1,4 and 1,8 pendant isomers. The Z‐spectrum of Co(L1) shows one highly‐shifted CEST peak, whereas Co(L2) exhibits six CEST peaks. Encapsulation of 40 mM Co(L1) in a liposome with osmotically‐induced shrinking at 300 mOsm/L produces a liposomal CEST agent with saturation frequency offset of 3 ppm. Addition of the amphiphilic 1,4,7‐triazacyclononane‐based complex Co(L5) to the liposomal bilayer at 18 mM with Co(L1) encapsulated in the liposome at 50 mM changes the sign and increases the magnitude of the saturation frequency offset to −7.5 ppm at 300 mOsm/L. 

Actinide doping enhances redox chemistry of polyoxomolybdate-alkoxide clusters; the first isolable U(v) polyoxometalate cluster is reported. 

Fe(iii) macrocyclic complexes with mixed oxygen donor pendants are studied as T₁MRI probes. Complexes with a phenolate pendant are among the most promising and produce pH dependent relaxivity profiles consistent with proton exchange pathways.