**硼氢化铀(IV)**是一种无机化合物，化学式为U(BH4)4，是一种绿色易挥发的固体，有放射性。

制备
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1952年，Hermann I. Schlesinger等人采用铀的四卤化物（UCl4、UF4）和碱金属硼氢化物为原料（如LiBH4）为原料，在无水的液体介质中反应，生成硼氢化铀(IV)：

UCl4 + 4 LiBH4 → U(BH4)4 + 4 LiCl
Hermann I. Schlesinger等人还用硼氢化铝和铀的四卤化物反应制备U(BH4)4：

UF4 + 2 Al(BH4)3 → U(BH4)4 + 2 Al(BH4)F2
但硼氢化铝法存在严重的不足，当硼氢化铝遇到微量潮湿的空气时，便会自发性产生猛烈的爆炸。  

在Hermann I. Schlesinger之后，В. В. Волков等人用固相的合成方法将四氯化铀在磨球机中粉碎，得到硼氢化铀(IV)，化学反应方程式如下：

UCl4 + 4 LiBH4 → U(BH4)4 + 4 LiCl

物理性质
----

硼氢化铀(IV)为绿色、易挥发的固体（尤其超过30℃时显著挥发），固态时为聚合物。硼氢化铀(IV)微溶于正庚烷和高纯苯。硼氢化铀(IV)有两种晶型。第一种为黄绿色的，第二种为翠绿色的。第二种晶型为正交晶系。溶液中的U(BH4)4会发生离解：

3 U(BH4)4 → U(BH4)62- + 2 U(BH4)3+

硼氢化铀在不同温度下的蒸汽压| 温度/℃ | 蒸汽压/mmHg |
| --- | --- |
| 34.2 | 0.30 |
| 40.2 | 0.56 |
| 48.25 | 1.23 |
| 54.3 | 2.15 |
| 61.3 | 4.00 |

化学性质
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硼氢化铀(IV)和水、醇反应生成氢气。与乙醚反应形成包含硼氢化铀分子的乙醚络合物，该化合物在-80℃比较稳定。硼氢化铀(IV)是活泼的，在空气中缓慢发生反应生成黄色或白色的不挥发性物质。  
硼氢化铀(IV)在100℃分解，生成一种不挥发的物质，可自燃，可能是硼氢化铀(III)，并在150℃进一步分解，产生UB4和氢气。

应用
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硼氢化铀(IV)可以用于铀的同位素的分离。

硼氢化铀在频率I的光的照射下，含235U的化合物会被激发，而含238的不会被激发。同时，用频率II的光照射它们，含有235U的会发生化学分解，而含有238U的不会分解。然后再加热它们，使未分解的升华，238U(BF4)4会挥发，而235U(BF4)4在同样的温度下不会挥发。由上述方法可以实现铀的同位素的分离。

硼氢化铀(III)
---------

硼氢化铀(III)是一种无机化合物，化学式为U(BH4)3，在溶液中会发生离解：

3 U(BH4)3 → U(BH4)52- + 2 U(BH4)2+
硼氢化铀(III)可以在100℃下热分解硼氢化铀(IV)得到：

2 U(BH4)4 → 2 U(BH4)3 + B2H6 + H2

参考资料
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1. 1 2 3 4 5 6 7 8  《硼氢化合物》.郑学家 主编.化学工业出版社. ISBN 978-7-122-11506-5.第五章 其他硼氢化物
2. 1 2  Ephritikhine, M.. Chemical Reviews. 1997, **97** (6): 2193–2242. PMID 11848899. doi:10.1021/cr960366n.
3. ↑  Ibid. 75, 209(1953)
4. ↑   В. В. Волков И.Т.Д. Ра∂цохцмця, 18, 512(1976)
5. 1 2  《无机化学丛书》.张青莲 主编.第一卷.P259.*5.2.3 硼氢化铀和硼氢化钍*
6. ↑  《硼氢化铀的一种简易制备方法》.作者 严家氵甡 严亦君.中国科学院上海有机化学研究所
7. ↑  《无机化学丛书》.张青莲 主编.第一卷.P243.**5.2 金属硼氢化物MBH4**

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| * 
* 论
* 编
**硼氢化物** |
| --- |
|  |
| 

|  |  |  |  |  |
| --- | --- | --- | --- | --- |
| HBH4 |  |  |  | He |
| LiBH4LiBH(CH2CH3)3LiBH(CHCH3C2H5)3 | Be(BH4)2 | B(BH4)−2 | C | NH4BH4 | O | F | Ne |
| NaBH4NaBH3CNNaBH(CH3COO)3 | Mg(BH4)2 | Al(BH4)3 | Si | P | S | Cl | Ar |
| KBH4 | Ca | Sc | Ti(BH4)3 | V | Cr | Mn(BH4)2 | Fe(BH4)2 | Co | Ni | CuBH4((C6H5)3P)2CuBH4 | Zn(BH4)2 | Ga | Ge | As | Se | Br | Kr |
| RbBH4 | Sr | Y(BH4)3 | Zr(BH4)4 | Nb | Mo | Tc | Ru | Rh | Pd | Ag | Cd | In | Sn | Sb | Te | I | Xe |
| CsBH4 | Ba | 镧系 | Hf(BH4)4 | Ta | W | Re | Os | Ir | Pt | Au | Hg | Tl | Pb | Bi | Po | At | Rn |
| Fr | Ra | 锕系 | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og |
|  |  | ↓ |  |  |
| 镧系 | La | Ce | Pr | Nd | Pm | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu |
| 锕系 | Ac | Th(BH4)4 | Pa | U(BH4)4 | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr |

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| 

| * 
* 论
* 编
铀化合物 |
| --- |
|  |
| 铀(II) | 
* UB2
* UO
* US

 |
|  |
| 铀(III) | 
* UCl3
* UI3
* UP
* U2(SO4)3
* UH3
* UN
* U(HCOO)3

|  |  |
| --- | --- |
| 有机铀(III)化合物 | 
* U(C5H5)3

 |

 |
|  |
| 铀(IV) | 
* U(BH4)4
* UF4
* UCl4
* UBr4
* UI4
* UO2
* US2
* USe2
* U(SO4)2
* USi2
* U(HCOO)4
* U(CH3COO)4

|  |  |
| --- | --- |
| 有机铀(IV)化合物 | 
* U(C8H8)2
* U(C5H5)4
* U(C5H5)3Cl

 |

 |
|  |
| 铀(IV,V) | 
* U2N3

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|  |
| 铀(V) | 
* UF5
* UCl5
* UBr5
* U2O5

 |
|  |
| 铀(V,VI) | 
* U3O8

 |
|  |
| 铀(VI) | 
* (NH4)2U2O7
* Na2O(UO3)2
* Na2U2O7
* UCl6
* UClF5
* UF6
* U(PO4)2
* UO3
* UO4
* UN2
* UO22+

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|  |
| 铀(XII) | 
* *UO6（假想）*

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