物理化学学报
物理化學學報
물이화학학보
ACTA PHYSICO-CHIMICA SINICA
2014年
3期
423-430
,共8页
[n.n.n]螺桨烷%BX(CH2)n3%BX(CH2)CH(CH2)nCH%稳定性%化学键%电子光谱
[n.n.n]螺槳烷%BX(CH2)n3%BX(CH2)CH(CH2)nCH%穩定性%化學鍵%電子光譜
[n.n.n]라장완%BX(CH2)n3%BX(CH2)CH(CH2)nCH%은정성%화학건%전자광보
[n.n.n]propel ane%BX[(CH2)n]3%BX(CH2)[CH(CH2)nCH]%Stability%Chemical bond%Electronic spectrum
采用密度泛函理论(DFT)研究了螺桨烷型分子BX[(CH2)n]3和BX(CH2)[CH(CH2)nCH](X=N, P；n=1-6)的结构、稳定性、化学键和电子光谱性质.计算结果表明这些分子都是稳定的. BX[(CH2)n]3(X=N, P；n=1-6)的最高占据分子轨道(HOMO)和最低空分子轨道(LUMO)之间的能隙均大于5.20 eV,其中BN[CH2]3和BP[CH2]3的能隙超过7.0 eV,与C5H6的能隙(7.27 eV)很接近, BX(CH2)[CH(CH2)nCH](X=N, P；n=1-6)的能隙在6.80 eV左右.所研究分子能量的二阶差分表明BN[(CH2)3]3、BP[(CH2)4]3及BX(CH2)[CH(CH2)2CH](X=N, P)是最稳定的. BX[(CH2)n]3的Wiberg键级表明除了BN[(CH2)n]3(n=2和6)中不存在B-N键,其它化合物中B和N均形成了化学键, BP[(CH2)n]3中除了BP[(CH2)2]3不存在B-P键,其它的均存在.电子密度的拓扑分析表明N-B键属于离子键,而P-B键具有共价键特征. BX[(CH2)n]3(X=N, P)的第一垂直激发能分别在191.1-284.8 nm和191.8-270.1 nm之间, BX(CH2)[CH(CH2)nCH](X=N, P)的第一垂直激发能分别在190.5-199.7 nm和209.0-221.3 nm之间.
採用密度汎函理論(DFT)研究瞭螺槳烷型分子BX[(CH2)n]3和BX(CH2)[CH(CH2)nCH](X=N, P；n=1-6)的結構、穩定性、化學鍵和電子光譜性質.計算結果錶明這些分子都是穩定的. BX[(CH2)n]3(X=N, P；n=1-6)的最高佔據分子軌道(HOMO)和最低空分子軌道(LUMO)之間的能隙均大于5.20 eV,其中BN[CH2]3和BP[CH2]3的能隙超過7.0 eV,與C5H6的能隙(7.27 eV)很接近, BX(CH2)[CH(CH2)nCH](X=N, P；n=1-6)的能隙在6.80 eV左右.所研究分子能量的二階差分錶明BN[(CH2)3]3、BP[(CH2)4]3及BX(CH2)[CH(CH2)2CH](X=N, P)是最穩定的. BX[(CH2)n]3的Wiberg鍵級錶明除瞭BN[(CH2)n]3(n=2和6)中不存在B-N鍵,其它化閤物中B和N均形成瞭化學鍵, BP[(CH2)n]3中除瞭BP[(CH2)2]3不存在B-P鍵,其它的均存在.電子密度的拓撲分析錶明N-B鍵屬于離子鍵,而P-B鍵具有共價鍵特徵. BX[(CH2)n]3(X=N, P)的第一垂直激髮能分彆在191.1-284.8 nm和191.8-270.1 nm之間, BX(CH2)[CH(CH2)nCH](X=N, P)的第一垂直激髮能分彆在190.5-199.7 nm和209.0-221.3 nm之間.
채용밀도범함이론(DFT)연구료라장완형분자BX[(CH2)n]3화BX(CH2)[CH(CH2)nCH](X=N, P；n=1-6)적결구、은정성、화학건화전자광보성질.계산결과표명저사분자도시은정적. BX[(CH2)n]3(X=N, P；n=1-6)적최고점거분자궤도(HOMO)화최저공분자궤도(LUMO)지간적능극균대우5.20 eV,기중BN[CH2]3화BP[CH2]3적능극초과7.0 eV,여C5H6적능극(7.27 eV)흔접근, BX(CH2)[CH(CH2)nCH](X=N, P；n=1-6)적능극재6.80 eV좌우.소연구분자능량적이계차분표명BN[(CH2)3]3、BP[(CH2)4]3급BX(CH2)[CH(CH2)2CH](X=N, P)시최은정적. BX[(CH2)n]3적Wiberg건급표명제료BN[(CH2)n]3(n=2화6)중불존재B-N건,기타화합물중B화N균형성료화학건, BP[(CH2)n]3중제료BP[(CH2)2]3불존재B-P건,기타적균존재.전자밀도적탁복분석표명N-B건속우리자건,이P-B건구유공개건특정. BX[(CH2)n]3(X=N, P)적제일수직격발능분별재191.1-284.8 nm화191.8-270.1 nm지간, BX(CH2)[CH(CH2)nCH](X=N, P)적제일수직격발능분별재190.5-199.7 nm화209.0-221.3 nm지간.
We have designed a family of novel molecules BX[(CH2)n]3 and BX(CH2)[CH(CH2)nCH] (X=N, P) with the [n.n.n]propel ane configuration (n=1-6). The structures, stabilities, chemical bonds, and electronic spectra of these structures were investigated using density functional theory (DFT). The calculated results indicate that al of these compounds are situated at minima on the potential energy surfaces. The energy gaps between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of BN[(CH2)n]3 and BP[(CH2)n]3 (n=1-6) were in the range of 5.24-7.07 eV and 5.47-7.33 eV, respectively, and the energy gap of BX[CH2]3 is close to that of C5H6. In addition, the energy gaps of BN(CH2) [CH(CH2)nCH] and BP(CH2) [CH(CH2)nCH] (n=1-6) are around 6.80 eV. To compare the relative stabilities of these compounds, we investigated the second-order differences of energies. The results indicate that BN[(CH2)3]3, BP[(CH2)4]3, and BX(CH2)[CH(CH2)2CH] (X=N, P) are more stable than the other structures. Moreover, based on the bond lengths, Wiberg bond indices, and charges of the two“inverted”atoms, it can be concluded that the bridgehead B and N(P) atoms in BN[(CH2)n]3 (n=2, 6) and BP[(CH2)2]3 do not form chemical bonds, while the two bridgehead atoms in the other compounds studied formed chemical bonds. Additionally, topological analysis of the electron density using the theory of atoms-in-molecules shows that the inverted N-B bonds in BN[(CH2)n]3 (n=3-5) are ionic bonds whereas the B-P bonds in BP[(CH2)n]3 (n=3-6) have covalent character. The vertical transition energies of BN[(CH2)n]3, BP[(CH2)n]3, BN(CH2) [CH(CH2)nCH], and BP(CH2) [CH(CH2)nCH] (n=1-6) range from 191.1 to 284.8 nm, 191.8 to 270.1 nm, 190.5 to 199.7 nm, and 209.0 to 221.3 nm, respectively.
