TY - JOUR
T1 - The synthesis of a bis(Thiosemicarbazone) macrocyclic ligand and the Mn(II), Co(II), Zn(II) and 68Ga(III) complexes
AU - Grieve, Melyssa L.
AU - Davey, Patrick R.W.J.
AU - Forsyth, Craig M.
AU - Paterson, Brett M.
N1 - Funding Information:
This research was funded by the Australian Research Council, grant number DE170100540 and a National Imaging Facility Fellowship (B.M.P.). M.L.G. and P.R.W.J.D. were supported by the Australian Government with a Research Training Program Stipend.
Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/6/2
Y1 - 2021/6/2
N2 - A 1,4,7,10-tetraazacyclododecane (cyclen) variant bearing two thiosemicarbazone pen-dant groups has been prepared. The ligand forms complexes with Mn2+, Co2+ and Zn2+. X-ray crystallography of the Mn2+, Co2+ and Zn2+ complexes showed that the ligand provides a six-coordinate environment for the metal ions. The Mn2+ and Zn2+ complexes exist in the solid state as racemic mixtures of the Δ(δ,δ,δ,δ)/Λ(λ,λ,λ,λ) and Δ(λ,λ,λ,λ)/Λ(δ,δ,δ,δ) diastereomers, and the Co2+ complex exists as the Δ(δ,δ,δ,δ)/Λ(λ,λ,λ,λ) and Δ(λ,λ,λ,δ)/Λ(δ,δ,δ,λ) diastereomers. Density functional theory calculations indicated that the relative energies of the diastereomers are within 10 kJ mol−1. Magnetic susceptibility of the complexes indicated that both the Mn2+ and Co2+ ions are high spin. The ligand was radiolabelled with gallium-68, in the interest of developing new positron emission tomography imaging agents, which produced a single species in high radiochemical purity (>95%) at 90 °C for 10 min.
AB - A 1,4,7,10-tetraazacyclododecane (cyclen) variant bearing two thiosemicarbazone pen-dant groups has been prepared. The ligand forms complexes with Mn2+, Co2+ and Zn2+. X-ray crystallography of the Mn2+, Co2+ and Zn2+ complexes showed that the ligand provides a six-coordinate environment for the metal ions. The Mn2+ and Zn2+ complexes exist in the solid state as racemic mixtures of the Δ(δ,δ,δ,δ)/Λ(λ,λ,λ,λ) and Δ(λ,λ,λ,λ)/Λ(δ,δ,δ,δ) diastereomers, and the Co2+ complex exists as the Δ(δ,δ,δ,δ)/Λ(λ,λ,λ,λ) and Δ(λ,λ,λ,δ)/Λ(δ,δ,δ,λ) diastereomers. Density functional theory calculations indicated that the relative energies of the diastereomers are within 10 kJ mol−1. Magnetic susceptibility of the complexes indicated that both the Mn2+ and Co2+ ions are high spin. The ligand was radiolabelled with gallium-68, in the interest of developing new positron emission tomography imaging agents, which produced a single species in high radiochemical purity (>95%) at 90 °C for 10 min.
KW - Coordination chemistry
KW - Cyclen
KW - Gallium-68
KW - Macrocycle
KW - Radiochemistry
KW - Thiosemicarbazone
KW - Transition metal
UR - http://www.scopus.com/inward/record.url?scp=85108812454&partnerID=8YFLogxK
U2 - 10.3390/molecules26123646
DO - 10.3390/molecules26123646
M3 - Article
C2 - 34203751
AN - SCOPUS:85108812454
SN - 1420-3049
VL - 26
JO - Molecules
JF - Molecules
IS - 12
M1 - 3646
ER -