hafnium borohydride

• 分子结构分类: 无机化合物 - 混合金属/非金属化合物 - 各种混合金属/非金属
• 英文名称: hafnium borohydride
• 英文别名: Hf(BH4)4；boranuide;hafnium(4+)
• 化学式: 4BH₄*Hf
• 分子量: 237.861
• InChiKey: RZRSHKQYNYDLGI-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -1.45
• 重原子数：
  2.0
• 可旋转键数：
  0.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  0.0
• 氢给体数：
  0.0
• 氢受体数：
  0.0

反应信息

• 作为反应物：
  描述：

  hafnium borohydride 以 neat (no solvent) 为溶剂， 生成 hafnium diboride
  参考文献：
  名称：

  用于硅上光电集成的外延半金属 HfxZr1−xB2 模板

  摘要：

  高质量的异质外延 HfxZr1-xB2 (x=0-1) 缓冲液直接生长在 Si(111) 上。薄膜结构的成分依赖性和从头算弹性常数用于表明六方 HfxZr1-xB2 在生长时具有拉伸面内应变 (0.5%)。高质量的 HfB2 薄膜也在应变补偿 ZrB2 缓冲的 Si(111) 上生长。厚 ZrB2 薄膜的初始反射率测量与第一性原理计算一致，该计算预测 HfB2 的反射率在 2-8eV 范围内相对于 ZrB2 增加 20%。这些可调的结构、热弹性和光学特性表明 HfxZr1-xB2 模板应该适用于 III 族氮化物与 Si 的广泛集成。

  DOI：

  10.1063/1.2403189
• 作为产物：
  描述：

  锂硼氢 、 氯化铪 以 乙醚 为溶剂， 生成 hafnium borohydride
  参考文献：
  名称：

  Zirconium and hafnium polyhydrides. Preparation and characterization of M2H3(BH4)5(PMe3)2, MH(BH4)3(dmpe), and MH2(BH4)2(dmpe)2

  摘要：

  Treatment of the zirconium and hafnium tetrahydroborate complexes M(BH4)4 with trimethylphosphine yields amber (M = Zr) or colorless (M = Hf) crystals of the new polyhydride complexes Zr2H3(BH4)5(PMe3)2 and Hf2H3(BH4)5(PMe3)2. These d0 complexes exhibit triplets (J(PH) almost-equal-to 13 Hz) for the hydride ligands in their H-1 NMR spectra at delta-3.96 (Zr) and 8.53 (Hf). The H-1, B-11{H-1}, and P-31{H-1} NMR spectra show that there is only one phosphine environment but two BH4- environments in a 2:3 ratio. Single-crystal X-ray diffraction studies of the two complexes in each case reveal a distinctly asymmetric dinuclear structure bridged by three hydrogen atoms. One metal center is ligated by three terminal tridentate BH4- groups, while the other is ligated by the two phosphines and by one tridentate and one bidentate BH4- group. All the metal-ligand distances in the zirconium complex are slightly longer than those in the hafnium complex, as expected from the relative ionic radii: Zr...Zr = 3.124 (1) angstrom, Zr-H(b) = 1.92 (4) angstrom, Zr-P = 2.750 (1) angstrom, Zr-B = 2.346 (8) angstrom (eta-3-BH4), Zr-B = 2.604 (8) angstrom (eta-2-BH4), Zr-H-Zr = 109 (3)degrees; Hf...Hf = 3.076 (1) angstrom, Hf-P = 2.725 (6) angstrom, Hf-B = 2.34 (3) angstrom (eta-3-BH4), and Hf-B = 2.53 (3) angstrom (eta-2-BH4). Treatment of the M(BH4)4 complexes with the bidentate phosphine 1,2-bis(dimethylphosphino)ethane gives mononuclear hydrides of stoichiometry MH(BH4)3(dmpe) or MH2(BH4)2(dmpe)2, depending on the conditions. The monohydride complexes MH(BH4)3(dmpe) contain both bidentate and tridentate BH4- groups as judged by IR spectroscopy. The H-1 NMR spectra show a triplet for the terminal hydride groups at delta-6.08 (J(PH) = 56 Hz) for M = Zr and 10.99 (J(PH) = 45 Hz) for M = Hf. The H-1 NMR spectra also show that there are two PMe2 environments, while the B-11{H-1} and P-31{H-1} NMR spectra show that there is a single BH4- and a single phosphorus environment. These data are consistent with a pseudooctahedral structure in which the three mutually fac BH4- groups are exchanging with each other. The BH4- groups in the dihydride complexes MH2(BH4)2(dmpe)2 are bidentate by IR spectroscopy. The H-1 NMR spectra show that there is one hydride environment and one BH4- environment but that the two ends of each dmpe ligand are inequivalent. The terminal hydride resonances at delta-3.38 (Zr) and 6.65 (Hf) are complex multiplets arising from the X part of XX'AA'BB' spin systems. Simulation of the resonances suggests that the coupling constant between the two hydride ligands may be unusually large at ca. 30 Hz. The possibility that nuclear exchange processes are responsible for this large coupling constant was ruled out on the basis of deuteration studies. Interestingly, these MH2(BH4)2(dmpe)2 molecules are nonfluxional at room temperature, despite the high coordination numbers (8 or 10, depending on how the BH4- groups are counted). Variable-temperature NMR spectroscopy shows that the molecules undergo an intramolecular fluxional process with an activation energy of 15.6 kcal mol-1; this value is unusually high for a molecule with such a high coordination number. Crystal data for Zr2C6H41B5P2 at -75-degrees-C are as follows: orthorhombic; P2(1)2(1)2(1); a = 10.921 (2) angstrom, b = 12.255 (3) angstrom, c = 16.524 (6) angstrom, V = 2212 (1) angstrom3, Z = 4, R(f) = 0.031, R(wf) = 0.029 for 301 variables and 2821 data for which I > 2.58-sigma(I). Crystal data for Hf2C6H41B5P2 at -75-degrees-C are as follows orthorhombic; P2(1)2(1)2(1); a = 10.860 (7) angstrom, b = 12.248 (7) angstrom, c = 16.490 (4) angstrom, V = 2193 (3) angstrom3, Z = 4, R(f) = 0.042, R(wf) = 0.051 for 112 variables and 1634 data for which I > 2.58-sigma(I).

  DOI：

  10.1021/ja00010a027

文献信息

• Low‐temperature deposition of zirconium and hafnium boride films by thermal decomposition of the metal borohydrides (<i>M</i>[BH₄]₄)
  作者：A. L. Wayda、L. F. Schneemeyer、R. L. Opila

  DOI：10.1063/1.100603

  日期：1988.8

  zirconium and hafnium borides have been deposited on various substrates by the low‐temperature (100–270 °C) thermal decomposition of Zr[BH4]4 and Hf[BH4]4. Auger electron spectroscopy of these films shows that their composition is ZrB2 and HfB2. The film surfaces are oxidized and slightly carbon contaminated. However, the bulk contains less than 1 at. % C or O. This synthesis is by far the lowest temperature

  通过 Zr[BH4]4 和 Hf[BH4]4 的低温（100-270°C）热分解，锆和铪硼化物的导电（150 μΩ cm）粘附膜已沉积在各种基材上。这些薄膜的俄歇电子能谱表明它们的成分是 ZrB2 和 HfB2。薄膜表面被氧化，并有轻微的碳污染。然而，散装包含少于 1 at。% C 或 O。这种合成是迄今为止这些材料的最低温度制备（TiB2 的等离子体增强化学气相沉积需要 480-600°C），并且对于这些材料在电子应用中的使用具有广阔的前景。
• Epitaxial semimetallic HfxZr1−xB2 templates for optoelectronic integration on silicon
  作者：Radek Roucka、YuJin An、Andrew V. G. Chizmeshya、John Tolle、John Kouvetakis、Vijay R. D'Costa、José Menéndez、Peter Crozier

  DOI：10.1063/1.2403189

  日期：2006.12.11

  High quality heteroepitaxial HfxZr1−xB2 (x=0–1) buffers were grown directly on Si(111). The compositional dependence of the film structure and ab initio elastic constants were used to show that hexagonal HfxZr1−xB2 possess tensile in-plane strain (0.5%) as grown. High quality HfB2 films were also grown on strain compensating ZrB2-buffered Si(111). Initial reflectivity measurements of thick ZrB2 films

  高质量的异质外延 HfxZr1-xB2 (x=0-1) 缓冲液直接生长在 Si(111) 上。薄膜结构的成分依赖性和从头算弹性常数用于表明六方 HfxZr1-xB2 在生长时具有拉伸面内应变 (0.5%)。高质量的 HfB2 薄膜也在应变补偿 ZrB2 缓冲的 Si(111) 上生长。厚 ZrB2 薄膜的初始反射率测量与第一性原理计算一致，该计算预测 HfB2 的反射率在 2-8eV 范围内相对于 ZrB2 增加 20%。这些可调的结构、热弹性和光学特性表明 HfxZr1-xB2 模板应该适用于 III 族氮化物与 Si 的广泛集成。
• Petrova, L. A.; Borisov, A. P.; Makhaev, V. D., Koordinatsionnaya Khimiya, 1992, vol. 18, p. 425 - 428
  作者：Petrova, L. A.、Borisov, A. P.、Makhaev, V. D.

  DOI：——

  日期：——
• The Preparation and Properties of the Group IV-B Metal Borohydrides
  作者：H. R. Hoekstra、J. J. Katz

  DOI：10.1021/ja01175a073

  日期：1949.7
• Gmelin Handbuch der Anorganischen Chemie, Gmelin Handbook: Hf: SVol., 7, page 22 - 23
  作者：

  DOI：——

  日期：——