Synthesis, structural studies, and oxidation catalysis of the manganese(II), iron(II), and copper(II) complexes of a 2-pyridylmethyl pendant armed side-bridged cyclam.
The first 2-pyridylmethyl pendant armed structurally reinforced cyclam ligand has been synthesized and successfully complexed to Mn2+, Fe2+, and Cu2+cations. X-ray crystal structures were obtained for the diprotonated ligand and its Cu2+complex demonstrating pentadentate binding of the ligand withtrans-IIconfiguration of the side-bridged cyclam ring, leaving a potential labile binding sitecisto the pyridine donor for interaction of the complex with oxidants and/or substrates. The electronic properties of these complexes were determined by means of solid state magnetic moment, with a low value of μ = 3.10 μBfor the Fe2+complex suggesting it has a trigonal bipyramidal coordination geometry, matching the crystal structure of the Cu2+complex, while the μ = 5.52 μBvalue for the Mn2+complex suggests it is high spin octahedral. Cyclic voltammetry in acetonitrile revealed reversible redox processes in all three complexes, suggesting catalytic reactivity involving electron transfer processes are possible for these complexes. Screening for oxidation catalysis using hydrogen peroxide as the terminal oxidant identified the Fe2+complex as the oxidation catalysts most worthy of continued development.
Department of Chemistry and Physics, Southwestern Oklahoma State University, 100 Campus Drive, Weatherford, OK 73096.
Anthony D
AD
Shircliff
Department of Chemistry and Physics, Southwestern Oklahoma State University, 100 Campus Drive, Weatherford, OK 73096.
Kevin R
KR
Wilson
Department of Chemistry and Physics, Southwestern Oklahoma State University, 100 Campus Drive, Weatherford, OK 73096.
Desiray J
DJ
Cannon
Department of Chemistry and Physics, Southwestern Oklahoma State University, 100 Campus Drive, Weatherford, OK 73096.
Donald G
DG
Jones
Key Laboratory for Large-Format Battery Materials and System, Ministry of Education, School of Chemistry and Chemical Engineering, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China.
Zhan
Z
Zhang
Key Laboratory for Large-Format Battery Materials and System, Ministry of Education, School of Chemistry and Chemical Engineering, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China.
Zhuqi
Z
Chen
Key Laboratory for Large-Format Battery Materials and System, Ministry of Education, School of Chemistry and Chemical Engineering, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China.
Guochuan
G
Yin
Department of Chemistry, The University of Hull, Cottingham Road, Hull, UK, HU6 7RX.
Timothy J
TJ
Prior
Department of Chemistry and Physics, Southwestern Oklahoma State University, 100 Campus Drive, Weatherford, OK 73096.
Timothy J
TJ
Hubin
2-pyridylmethyl; oxidation catalysis; pendant-arm macrocycle; side-bridged cyclam; structurally reinforced cyclam