title: Synthesis and characterization of di- and trivalent pyrazolylborate β-diketonates and cyanometalates.
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.
authors.affiliation: Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA.
authors.forename: Minao
authors.initials: M
authors.lastname: Tang
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Li
authors.forename: Uma Prasad
authors.initials: UP
authors.lastname: Mallik
authors.forename: Yuan-Zhu
authors.initials: YZ
authors.lastname: Zhang
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Clérac
authors.forename: Gordon T
authors.initials: GT
authors.lastname: Yee
authors.forename: Myung-Hwan
authors.initials: MH
authors.lastname: Whangbo
authors.forename: Amshumali
authors.initials: A
authors.lastname: Mungalimane
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Holmes
mesh_terms: D018360:Crystallography, X-Ray; D007659:Ketones / Q000737:chemistry*; D008280:Magnetics; D008345:Manganese / Q000737:chemistry*; D008958:Models, Molecular; D009570:Nitriles / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry*
chemical_list: D007659:Ketones; D009570:Nitriles; D009942:Organometallic Compounds; D011720:Pyrazoles; D008345:Manganese