- Ground triplet pyrimidine-4,6-diyl bis(tert-butyl nitroxide) as a paramagnetic building block for metal-organic frameworks
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We synthesized pyrimidine-4,6-diyl bis(tert-butyl nitroxide) (pmbNO), and characterized as a biradical by means of ESR spectroscopy. The zero-field splitting parameters were |D|/hc = 2.52 × 10-2 cm-1 and |E|/hc = 2.34 × 10-3 cm-1 in frozen toluene at 100 K. Magnetic study clarified the presence of intramolecular ferromagnetic coupling with 2J/kB = +18.5(5) K in frozen toluene-ethanol. DFT calculation supports the ground triplet state of pmbNO. The reaction of pmbNO with Cu(hfac)2 gave [Cu3(pmbNO)2(hfac) 4], and the structure was determined by X-ray crystallographic analysis. Though the ligand was reduced to be an anion radical, pmbNO is confirmed to work as a rigid bridge, and the nitroxide oxygen atoms can ligate the metal ions.
- Homma, Yuta,Okazawa, Atsushi,Ishida, Takayuki
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- Arylation of halogenated pyrimidines via a suzuki coupling reaction
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The Suzuki coupling reaction has been used extensively for the synthesis of a wide variety of unsymmetrical biaryl compounds. We have extended this reaction to demonstrate the utility of preparing monophenyl-, diphenyl-, or triphenylpyrimidine depending on the reaction conditions. Further, it has been shown that chloropyrimidine substrates are preferable over iodo-, bromo-, or fluoropyrimidines.
- Schomaker,Delia
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p. 7125 - 7128
(2007/10/03)
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