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Synthesis and Characterization of Di- And Trivalent Pyrazolylborate β-diketonates and Cyanometalates

Minao Tang, Dongfeng Li, Uma Prasad Mallik, Yuan-Zhu Zhang, Rodolphe Clérac, Gordon T Yee, Myung-Hwan Whangbo, Amshumali Mungalimane, Stephen M Holmes

Inorg Chem. 2011 Jun 6;50(11):5153-64.

PMID: 21520919

Abstract:

The syntheses, structures, and magnetic properties of a series of di- and trivalent hydridotris(3,5-dimethylpyrazol-1-yl)borate (Tp*) cyanomanganates are described. Treatment of tris(acetylacetonate)manganese(III) [Mn(acac)(3)] with KTp* and tetra(ethyl)ammonium cyanide affords [NEt(4)][(Tp*)Mn(II)(κ(2)-acac)(CN)] (1), as the first monocyanomanganate(II) complex; attempted oxidation of 1 with iodine affords {(Tp*)Mn(II)(κ(2)-acac(3-CN))}(n) (2) as a one-dimensional chain and bimetallic {[NEt(4)][(Tp*)Mn(II)(κ(2)-acac(3-CN))](2)(μ-CN) (3) as the major and minor products, respectively. A fourth complex, [NEt(4)][(Tp*)Mn(II)(η(2)-acac(3-CN))(η(1)-NC-acac)] (4), is obtained via treatment of Mn(acac(3-CN))(3) with KTp* and [NEt(4)]CN, while [NEt(4)](2)[Mn(II)(CN)(4)] (5) was prepared from manganese(II) trifluoromethanesulfonate and excess [NEt(4)]CN. Tricyanomanganate(III) complexes, [cat][(Tp*)Mn(III)(CN)(3)] [cat = NEt(4)(+), 7; PPN(+), 8], are prepared via sequential treatment of Mn(acac(3-CN))(3) with KTp*, followed by [NEt(4)]CN, or [cat](3)[Mn(III)(CN)(6)] with (Tp*)SnBu(2)Cl. Magnetic measurements indicate that 1, 2, and 4 contain isotropic Mn(II) (S = (5)/(2); g = 2.00) centers, and no long-range magnetic ordering is found above 1.8 K. Compounds 7 and 8 contain S = 1 Mn(III) centers that adopt singly degenerate spin ground states without orbital contributions to their magnetic moments.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP14024589 Manganese(II) acetylacetonate Manganese(II) acetylacetonate 14024-58-9 Price
AP35895693 Tetraethylammonium trifluoromethanesulfonate Tetraethylammonium trifluoromethanesulfonate 35895-69-3 Price
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