Metal-Centered Deltahedral Zintl Ions: Synthesis of [Ni@Sn9]4鈥?/sup> by Direct Extraction from Intermetallic Precursors and of the Vertex-Fused Dimer [{Ni@Sn8(渭-Ge)1/2<

详细信息    查看全文

• 作者：Miriam M. Gillett-Kunnath ; Joseph I. Paik ; Sara M. Jensen ; Jacob D. Taylor ; Slavi C. Sevov
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：November 21, 2011
• 年：2011
• 卷：50
• 期：22
• 页码：11695-11701
• 全文大小：873K
• 年卷期：v.50,no.22(November 21, 2011)
• ISSN：1520-510X

文摘

Ni-centered deltahedral Sn₉ clusters with a charge of 4鈥? i.e., [Ni@Sn₉]^{4鈥?/sup>, were extracted in ethylenediamine in high yield directly from intermetallic precursors with the nominal composition 鈥淜₄Sn₉Ni₃鈥? The new endohedral clusters were crystallized and structurally characterized in K[K(18-crown-6)]₃[Ni@Sn₉]路3benzene (1a, triclinic, P1̅, a = 10.2754(5) 脜, b = 19.5442(9) 脜, and c = 20.5576(13) 脜, 伪 = 73.927(3)掳, 尾 = 79.838(4)掳, and 纬 = 84.389(3)掳, V = 3899.6(4) 脜3, Z = 2) and K[K(2,2,2-crypt)]₃[Ni@Sn₉] (1b, triclinic, P1̅, a = 15.8028(8) 脜, b = 16.21350(9) 脜, and c = 20.1760(12) 脜, 伪 = 98.71040(10)掳, 尾 = 104.4690(10)掳, and 纬 = 118.3890(10)掳, V = 4181.5(4) 脜3, Z = 2). The alternative method of a post-synthetic insertion of a Ni atom in empty Sn₉ clusters by a reaction with Ni(cod)₂ predominantly produces the more-oxidized clusters with a charge of 3鈥? i.e., the recently reported [Ni@Sn₉]3鈥?/sup>. Nonetheless, using substoichiometric amounts of 18-crown-6 as a cation sequestering agent, we also have been able to isolate the 4鈥?clusters as a minor phase from such reactions. They were structurally characterized in K[K(en)][K(18-crown-6)]₂[Ni@Sn₉]路0.5en (2, monoclinic, P2₁/n, a = 10.4153(5) 脜, b = 25.6788(11) 脜, and c = 20.6630(9) 脜, 尾 = 102.530(2)掳, V = 5394.7(4) 脜3, Z = 2). The ability of the Ni-centered clusters to exist with both 3鈥?and 4鈥?charges parallels the same ability of the empty clusters and is very promising for similarly rich chemistry involving electron transfer and flexible 鈥渙xidation states鈥? We also report the synthesis and characterization of the endohedral heteroatomic dimer [{Ni@Sn₈(渭-Ge)_1/2}₂]4鈥?/sup> composed of two [Ni@(Sn₈Ge)]-clusters fused at the Ge-vertex. The dimer was synthesized by reacting an ethylenediamine solution of a ternary precursor with the nominal composition 鈥淜₄Ge_4.5Sn_4.5鈥? which is known to produce heteroatomic Ge_9鈥?i>xSn_x clusters, with Ni(cod)₂. It is isostructural with the reported [{Ni@Sn₈(渭-Sn)_1/2}₂]4鈥?/sup> and is structurally characterized in [K-(2,2,2-crypt)]₄[{Ni@Sn₈(渭-Ge)_1/2}₂]路2en (3, monoclinic, C2/c, a = 30.636(2) 脜, b = 16.5548(12) 脜, and c = 28.872(2) 脜, 尾 = 121.2140(10)掳, V = 12523.5(15) 脜3, Z = 4).}