1、第5章 非金屬原子簇化合物 離子 足電子 富電子缺電子12LiNH2BH3 and NaNH2BH3nature materials VOL 7 FEBRUARY 20083B(s) + Ca(l) CaB6CaB6的結構，B62- 原子簇金屬硼化物 MB6, MB12 存在硼原子簇（cluster)4一. 硼烷和碳硼烷 二. 富勒烯, 碳納米管, 石墨烯, 石墨炔固體單質 硼的結構單元，B12 Ih點群（20面體）30條邊 價電子數(shù) = 123 = 36 成鍵缺電子！5William Lipscomb (1919-)1976年Nobel 化學獎the structure of boranes

2、 illuminating problems of chemical bonding 6 BnHn+m B2H6, B4H10, B5H9, B5H11, B6H10, B10H14 缺電子的硼氫簇合物 B2H6 和 C2H4 為等電子體B和橋H的化學鍵是什么鍵？橋H的原子軌道？一. 硼烷(Borane)的組成7閉式BnHn2 巢式(開式) BnHn+4 蛛網(wǎng)式 BnHn+6 8B4H10 四硼烷(10) B4H4+6B5H9 五硼烷(9) B5H5+4B5H11 五硼烷(11) B5H5+6B6H10 六硼烷(10) B6H6+4 B6H12 六硼烷(12) B6H6+6B12H122 十二

3、硼烷陰離子 ( B12H12+2 )m = 2 閉式（closo)m = 4 巢（開）式 (nido)m = 6 （蛛）網(wǎng)式 (arachno)通式：BnHn+m9二. 硼烷中的化學鍵 (定域)Lipscomb用單晶X衍射得出硼烷結構，提出: 3c-2e (三中心兩電子)鍵 3c-2e BBB鍵 3c-2e BHB鍵 10nido BnHn+44個BHB 8e1個BBB 2e2個BB 4e0 個BH2 0e5個BH 10e總電子: 24eB5H9 （4120）styx 表示 s BHB 鍵個數(shù)t BBB 鍵個數(shù)y BB 鍵個數(shù)x BH2 鍵個數(shù)11arachno BnHn+63個BHB 6e2

4、個BBB 4e0個BB 03個BH2 6e5個BH 10e總電子: 26estyx表示: (3203)12三種硼烷之間的關系 BH +4H BH +2H B6H62- B5H9 B4H10 m=2 m=4 m=6BnHn+m13斜線方向: BH, +2H水平方向: +2H垂直方向： BH14n+1 n+2 n+3 (Wade 規(guī)則）15三. 硼烷的骨架電子對規(guī)則(Wades rule)Wade規(guī)則: 骨架電子數(shù), 化學式和分子形狀之間的關系.把硼烷中的所有化學鍵作為整體處理骨架電子對數(shù) = 成鍵分子軌道數(shù)由英國化學家Kenneth Wade 在1970s提出. 主要用于三角形多面體(delta

5、hedra)類型的化合物中. 骨架電子: 除每個B-H鍵以外的所有電子B4H10 4個(B-H)鍵2 4 = 8個電子為非骨架電子, 其余電子為骨架電子 4 2 + 6 = 1416例如: B6H62 18+6+2=26e 6個 B-H 12e剩余 6 2 + 2=14e , 骨架電子數(shù)為14骨架電子對 = 6+1 = 7 （n+1, n為硼原子數(shù)）B5H9 即 B5H5+4 骨架電子數(shù)= 5 2 +4 = 14骨架電子對 = 5+2 = 7 （n+2, n為硼原子數(shù)）B5H11 即 B5H5+6 骨架電子數(shù)= 5 2 +6 = 16骨架電子對 = 5+3 = 8 （n+3, n為硼原子數(shù)）1

6、7結構化學式骨架電子對實例閉式(closo)BnHn2n +1B12H122巢式(nido)BnHn+4n +2B5H9蛛網(wǎng)式(arachno)BnHn+6n +3B5H11敞網(wǎng)式(hypho)BnHn+8n +4無簡單硼烷硼烷結構和骨架電子對數(shù)的關系18Wade 規(guī)則的應用： 骨架電子對 分子構形 B2H6 B2H2+4 2 + 2 巢式 B4H10 B4H4+6 4 + 3 蛛網(wǎng) B5H9 B5H5+4 5 + 2 巢式 B5H11 B5H5+6 5 + 3 蛛網(wǎng) B6H10 B6H6+4 6 + 2 巢式 B10H14 B10H10+4 10 + 2 巢式 B12H122 B12H12+

7、2 12 +1 閉式19B11H14- 的11B-NMR譜 BnHn+4 (nido結構), （缺頂二十面體）5KB9H14+ 2B5H9 5KB11H14 + 9H220硼烷的性質 熱穩(wěn)定性差, fGm和 fHm為正值, 吸熱化合物化學穩(wěn)定性差(自燃, 水解)燃燒值大(G小) BnHm+O2 B2O3+H2O Hf (B2O3)= -1273 kJ.mol-1毒性大四. 硼烷的性質和制備Alfred Stock (July 16, 1876 August 12, 1946) was a German inorganic chemist. He did pioneering research

8、on the hydrides of boron and silicon, coordination chemistry, mercury, and mercury poisoning.Due to their extreme reactivity and flammability in air, boron hydrides could not be purified until his development of methods for separation using high-vacuum manifolds around 1912.21硼烷的制備: BF3+ NaBH4 B2H6B

9、2O3+H2+Al B2H6B2H6作起始物 (用BF3制備 B2H6 ) B2H6(g) 2BH3(g) B2H6(g) + BH3(g) B3H7(g)+H2(g)B3H7(g)+ BH3(g) B4H10(g)穩(wěn)定的B化合物和氫化物或者與還原劑反應Herbert Charles Brown (May 22, 1912 December 19, 2004) was a chemist and Nobel Prize in Chemistry (1979)laureate for his work with organoboranes.22五. 碳硼烷及金屬硼烷衍生物B5H9 1,5- C2

10、B3H51,6- C2B4H62,4- C2B5H7C BH 等電子, 分子結構中C 取代 BH C BH， P BH (或BH2), S BH2 (或BH3) 231,2- C2B10H12 ( B12H122 )1-SB9H9 （B10H102）1-SB11H11 （B12H122）1,2-CPB10H11 （B12H122）結構？24Closo-B11H11AlCH32的金屬硼烷陰離子結構B11H132-+Al2(CH3)6 2B11H11AlCH32+4CH425Arachno和nido金屬取代硼烷Closo的C衍生物取代硼烷26C2B10H12 C2B9H112-盆狀二碳硼烷金屬配合

11、物27Inorganic Chemistry2001, coverSalute to Fred HawthorneIcosahedral B12H12240 years28Sn94-骨架電子對= 9+2Pb52-骨架電子對=5+129Bi42-，Se42+骨架電子對= 4+3C8H8（立方烷）非三角面結構不符合wade規(guī)則B4H4+630Tetrasulfur tetranitride, S4N4, P4其他重要的無機原子簇作為Lewis堿的反應S4N4 + SbCl5 S4N4.SbCl5 S4N4 + SO3 S4N4.SO331六. 富勒烯(Fullerenes)化學 C60 Ih C7

12、0 D5d如何確認C60 的結構？32 13C NMR spectrum of the purified C60 , reported by Kroto et al. (Taylor, 1990). The NMR spectrum contained a single peak at 142.7, as expected for the highly symmetrical truncated icosahedron structure in which all carbons are identical 33Using mass spectrometry, discrete peaks a

13、ppeared corresponding to molecules with the exact mass of sixty or seventy or more carbon atoms. In 1985, Harold Kroto (then of the University of Sussex), James R. Heath, Sean OBrien, Robert Curl and Richard Smalley, from Rice University, discovered C60, and shortly thereafter came to discover the f

14、ullerenes. Kroto, Curl, and Smalley were awarded the 1996 Nobel Prize in Chemistry for their roles in the discovery of this class of molecules. C60 and other fullerenes were later noticed occurring outside the laboratory (e.g., in normal candle soot). 34 Definitive proof for the structure of C60 cam

15、e in 1991 when Joel Hawkins (Univ. of California-Berkeley) synthesized and crystallized an osmium derivative of (C60)OsO4 (4-tert-butylpyridine)2. Single crystal X-ray analysis of this compound yielded the first atomic-resolution picture of the carbon framework of C60 (C 60 )OsO4 (4-叔丁基吡啶)235s0.9p2.

16、28雜化，30個6/6雙鍵，截頂20面體（B12）熱力學穩(wěn)定性比石墨差可被還原和自由基、親核試劑加成和化學修飾3637制備富勒烯的電弧爐38不同條件下合成的富勒烯的質譜圖(He的壓力不同和反應時間不同）39富勒烯及碳納米管的主要研究方面1. 制備和分離理論計算化學修飾 a. 富勒烯的超導化合物 b. 環(huán)加成反應(有機反應), C60與氨基酸酯的加成 c. 富勒烯配合物 d. 富勒烯包合物的研究4. 碳納米管的制備40153 K. C60 crystallizes in a face centered cubic， space group Pa3. 41富勒烯的金屬化合物, K3C60 , Rb

17、3C60, Cs3C60 , KxC60 超導溫度18KC60以面心立方密堆積, K, Rb, Cs 填充全部八面體和四面體空隙富勒烯的衍生物42Polymeric fullerene chains in RbC60 432. 金屬富勒烯包合物（EMF, endohedral metallofullerenes)單金屬: La82雙金屬: Sc282三金屬: Sc382雜原子: Sc3N80443. 富勒烯的金屬配合物 Os(O)4(py)2(C60)45(eta2-C70-Fullerene)-carbonyl-chloro-bis(triphenylphosphine)-iridium (

18、2-C70)-Ir(CO)Cl(PPh3)246七. 碳納米管( carbon nanotube)單層碳納米管 SWCN(Single-wall carbon nanotube)多層碳納米管 MWCN(Multi- wall carbon nanotube)石墨卷曲成長度: 幾十m直徑: 1100nm47The smallest carbon nanotube High-resolution electron microscope image of a 4 tubule (side walls are marked by lines) confined inside an 18-shell carbon nanotubeSumio Iijima et alNature 408, 50 (2000) 48Coalescence of C60 Molecules Assisted by Doped Iodine Inside Carbon NanotubesLunhui Guan, Kazu Su