含螯合硝酰氮氧自由基的镍（II）配合物的核磁共振光谱和磁交换相互作用

NMR Spectra and Magnetic Exchange Interactions in Nickel(II) Complexes with a Chelated Nitronyl Nitroxide Radical.

作者信息

Yoshida Takafumi, Kaizaki Sumio

机构信息

Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560 Japan.

出版信息

Inorg Chem. 1999 Mar 22;38(6):1054-1058. doi: 10.1021/ic9805426.

DOI:10.1021/ic9805426

PMID:11670885

Abstract

1H or (2)H NMR contact shifts of the beta-diketonate methine in the radical complexes [Ni(beta-diketonato)(2)(NIT2-py)] and Ni(beta-diketonato)(tmen)(NIT2-py) (NIT2-py = 2-(2'-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-3-oxide-1-oxyl and tmen = N,N,N',N'-tetramethylethylenediamine) were found to correlate to a product of the respective (1)H or (2)H NMR contact shifts of the methine in the nonradical complexes [Ni(beta-diketonato)(2)(tmen)] and the fractional contribution to the Ni(II) moiety arising from the magnetic interaction between nickel(II) ion and NIT2-py radical, proposing a new method to estimate the exchange coupling constant J value from the NMR contact shifts. Variable temperature (2)H NMR measurements of the C-D signals in [Ni(acac-d)(2)(NIT2-py)], Ni(acac-d)(tmen)(NIT2-py), and [Ni(acac-d)(2)(tmen)] suggested the topological discrimination of the acetylacetonates.

摘要

在自由基配合物[Ni(β - 二酮腙)(2)(NIT2 - py)]和[Ni(β - 二酮腙)(tmen)(NIT2 - py)]⁺（NIT2 - py = 2 - (2'-吡啶基)-4,4,5,5 - 四甲基 - 4,5 - 二氢 - 1H - 咪唑基 - 3 - 氧化物 - 1 - 氧基，tmen = N,N,N',N' - 四甲基乙二胺）中，β - 二酮腙次甲基的¹H或²H NMR接触位移被发现与非自由基配合物[Ni(β - 二酮腙)(2)(tmen)]中次甲基各自的¹H或²H NMR接触位移以及镍(II)离子与NIT2 - py自由基之间磁相互作用对Ni(II)部分的分数贡献的乘积相关，这提出了一种从NMR接触位移估计交换耦合常数J值的新方法。对[Ni(acac - d)(2)(NIT2 - py)]、[Ni(acac - d)(tmen)(NIT2 - py)]⁺和[Ni(acac - d)(2)(tmen)]中C - D信号进行的变温²H NMR测量表明了乙酰丙酮化物的拓扑区分。