Partial Insertion of the 9-BBN Unit into the nido-B10 Framework: Preparation and Structural Characterization of (9-BBN)B10H13 and [(9-BBN)B10H12

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• 作者：Adam N. Bridges ; Jianping Liu ; Roman G. Kultyshev ; Donald F. Gaines ; and Sheldon G. Shore
• 刊名：Inorganic Chemistry
• 出版年：1998
• 出版时间：June 29, 1998
• 年：1998
• 卷：37
• 期：13
• 页码：3276 - 3283
• 全文大小：199K
• 年卷期：v.37,no.13(June 29, 1998)
• ISSN：1520-510X

文摘

Na[B₁₀H₁₃] reacts with 9-Br-BBN(9-BBN = 9-bora[3.3.1]bicyclononane) inCH₂Cl₂ to produce(9-BBN)B₁₀H₁₃,1, in high yield. Single-crystal X-ray diffractionanalysis shows that the boron atom of the 9-BBN unit in 1ispartially inserted into the nido-B₁₀ structurethrough a highly asymmetric bridge between B(5) and B(6) ontheB₁₀ cluster with distances of B(BBN)-B(5) =1.740(6) Å and B(BBN)-B(6) = 2.079(6) Å. There isalso anagostic interaction of the terminal H(5b) on B(5) withB(BBN). NMR studies confirm that this interaction ismaintained in solution. Compound 1 is unstable incoordinating solvents, resulting in some cases in thecleavageof the 9-BBN unit from the decaborane skeleton. When 1is placed in Et₂O, NMR spectra suggest that(Et₂O)(9-BBN)B₁₀H₁₃, 2, is formed inwhich an Et₂O molecule associates with the boron B(BBN) ofthe 9-BBN unitwhile the interactions of that boron with B(6) and with H(5b) areeliminated, leaving only a direct bond betweenB(BBN) and B(5). Reaction of 1 with "ProtonSponge", 1,8-bis(dimethylamino)naphthalene, inCH₂Cl₂ gives[PSH][(9-BBN)B₁₀H₁₂],3, (PSH = protonated "Proton Sponge").Single-crystal X-ray diffraction analysis of3indicates a structure similar to that ofnido-[B₁₁H₁₄]^-, withthe boron of the 9-BBN unit approximately occupyinga vertex site of the pentagonal face of anido-B₁₁ cluster. The B(BBN) boron isinserted into a bridging sitebetween B(5) and its crystallographically imposed mirror equivalentB(10') of the decaborane cluster with B(BBN)-B(5)/B(BBN)-B(10') distances of 1.884(4) Å and a B(5)-B(10')distance of 1.823(5) Å. On the other hand thedistance of the B(BBN) boron to B(6) and to the mirror equivalent B(9')is an abnormally long 2.142(4) Å, whichindicates that the B(BBN) boron is not fully accommodated in theformation of anido-[B₁₁H₁₄]^-analogue. Thenovel interaction of the 9-BBN fragment with the decaborane cluster in1 and the partial insertion of the 9-BBNmoiety into the nido-B₁₀ unit observed in3 are the first examples of such interactions observedbetween amonoboron unit and a decaborane cluster. Crystal data:1, Pbca (No. 61), a = 11.924(3)Å, b = 13.205(6) Å,c = 19.655(5) Å, Z = 8; 3,Pnma (No. 62), a = 15.359(3) Å,b = 13.932(3) Å, c = 12.565(4) Å,Z = 4.