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DeCarlo S, Mayo DH, Tomlinson W, Hu J, Hooper J, Zavalij P, Bowen K, Schnöckel H, Eichhorn B. Synthesis, Structure, and Properties of Al((R)bpy)3 Complexes (R = t-Bu, Me): Homoleptic Main-Group Tris-bipyridyl Compounds. Inorg Chem 2016; 55:4344-53. [PMID: 27064350 DOI: 10.1021/acs.inorgchem.6b00034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The neutral homoleptic tris-bpy aluminum complexes Al((R)bpy)3, where R = tBu (1) or Me (2), have been synthesized from reactions between AlX precursors (X = Cl, Br) and neutral (R)bpy ligands through an aluminum disproportion process. The crystalline compounds have been characterized by single-crystal X-ray diffraction, electrochemical experiments, EPR, magnetic susceptibility, and density functional theory (DFT) studies. The collective data show that 1 and 2 contain Al(3+) metal centers coordinated by three bipyridine (bpy(•))(1-) monoanion radicals. Electrochemical studies show that six redox states are accessible from the neutral complexes, three oxidative and three reductive, that involve oxidation or reduction of the coordinated bpy ligands to give neutral (R)bpy or (R)bpy(2-) dianions, respectively. Magnetic susceptibility measurements (4-300 K) coupled with DFT studies show strong antiferromagnetic coupling of the three unpaired electrons located on the (R)bpy ligands to give S = (1)/2 ground states with low lying S = (3)/2 excited states that are populated above 110 K (1) and 80 K (2) in the solid-state. Complex 2 shows weak 3D magnetic interactions at 19 K, which is not observed in 1 or the related [Al(bpy)3] complex.
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Affiliation(s)
- Samantha DeCarlo
- Department of Chemistry and Biochemistry University of Maryland-College Park , College Park, Maryland 20742, United States
| | - Dennis H Mayo
- Department of Chemistry and Biochemistry University of Maryland-College Park , College Park, Maryland 20742, United States.,Research Department Naval Surface Warfare Center Indian Head EOD Tech Division, Indian Head, Maryland 20640, United States
| | - Warren Tomlinson
- Department of Physics, Naval Postgraduate School , Monterey, California 93943, United States
| | - Junkai Hu
- Department of Chemistry and Biochemistry University of Maryland-College Park , College Park, Maryland 20742, United States
| | - Joseph Hooper
- Department of Physics, Naval Postgraduate School , Monterey, California 93943, United States
| | - Peter Zavalij
- Department of Chemistry and Biochemistry University of Maryland-College Park , College Park, Maryland 20742, United States
| | - Kit Bowen
- Departments of Chemistry and Materials Science Johns Hopkins University , Baltimore, Maryland 21218, United States
| | - Hansgeorg Schnöckel
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT) , D-76128 Karlsruhe, Germany
| | - Bryan Eichhorn
- Department of Chemistry and Biochemistry University of Maryland-College Park , College Park, Maryland 20742, United States
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Gomes AC, Neves P, Figueiredo S, Fernandes JA, Valente AA, Almeida Paz FA, Pillinger M, Lopes AD, Gonçalves IS. Tris(pyrazolyl)methane molybdenum tricarbonyl complexes as catalyst precursors for olefin epoxidation. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcata.2012.12.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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