内含式化合物X@Al12P12的结构与稳定性研究

采用B3LYP／6—31G*方法,对内含式化合物X@Al12P12(X=Li^0/ ,Na^0/ ,K^0/2 ,Be^0/2 ,Mg^0/2 ,Ca^0/2 ,H和He)的不同对称性构型进行计算,讨论其最稳定构型的几何参数、布居分析、偶极矩、电离势、包含能、频率、HOMO—LUMO能隙和自旋密度．发现X@Al12P12化合物中,客体X=Na^0/ ,K^0/ ,Mg和He几乎处在笼的中心,Be和Ca^0/2 处在中心附近0．033nm的半径内,Li^0/ ,Be^2 ,Mg^2 和H很大程度上偏离笼的中心位置．大部分金属内含式化合物的C3对称性构型稳定．Li^0/ 。,Be^0/2 ,Mg^2 ,Ca^2 和H与其它离子相比更易嵌入笼内形成稳定的内含式化合物．     

内含式复合物X@(HAlNH)12 (X=Be,Mg, Ca,Zn, Al+, Ga+)的结构和稳定性

在研究闭式多面体(HAlNH)12簇合物几何构型及稳定性的基础上, 用DFT的B3LYP方法在6-31G(d)的水平上, 对其内含式复合物X@(HAlNH)12 (X= Be, Mg, Ca, Zn, Al+, Ga+)进行了构型优化和能量计算, 并讨论了稳定结构的几何构型、自然键轨道(NBO)、振动频率、能量参数及NMR数据与结构的关系. 用Gaussian 03的QST3方法确定了客体X通过笼面6-元环的迁移过渡态(TS)结构, 并用IRC方法对所得TS结构进行了验证. 最后得到内含式复合物X@(HAlNH)12结构在热力学和动力学上的稳定性信息, 其中复合物Ga+@(HAlNH)12的结构相对最稳定.     

内含式复合物X@(HAINH)12(X=Be,Mg,Ca,Zn,Al+,Ga+)的结构和稳定性

在研究闭式多面体(HA1NH)12簇合物几何构型及稳定性的基础上,用DFT的B3LYP方法在6-31G(d)的水平上,对其内含式复合物X@(HAINH)12(X=Be,Mg,Ca,Zn,Al ,Ga )进行了构型优化和能量计算,并讨论了稳定结构的几何构型、自然键轨道(NBO)、振动频率、能量参数及NMR数据与结构的关系.用Gaussian 03的QST3方法确定了客体X通过笼面6-元环的迁移过渡态(TS)结构,并用LRC方法对所得TS结构进行了验证.最后得到内含式复合物X@(HA1NH)12结构在热力学和动力学上的稳定性信息,其中复合物Ga @(HAINH)12的结构相对最稳定.     

X@(HAINH)_(12)和X(HAINH)_(12)(X=F~-,Cl~-,Br~-,O~(2-),S~(2-),Se~(2-))复合物的结构和稳定性

用DFT的B3LYP方法在6-31G(d)基组的水平上,对闭式多面体簇合物(HA1NH)12及其内含式X@(HA1NH)12外接式X(HA1NH)12(X=F-,Cl-,Br-,O2-,S2-,Se2-)复合物的结构进行了构型优化和能量计算,并讨论了几何构型、自然键轨道(NBO)、振动频率、能量参数及NMR数据与结构的关系,最后得到复合物结构的稳定性信息,具有Th对称性的X@(HA1NH)12(X=F-,Cl-,Br-,S2-,Se2-)复合物和具有C3对称性的O2-@(HA1NH)12复合物为内含式的基态结构,从能量角度分析,内含式复合物比外接式复合物的结构稳定.     

内含式化合物X@Al12P12的结构与稳定性研究

采用B3LYP/6-31G*方法, 对内含式化合物X@Al₁₂P₁₂ (X＝Li^0/＋, Na^0/＋, K^0/＋, Be^0/2＋, Mg^0/2＋, Ca^0/2＋, H和He)的不同对称性构型进行计算, 讨论其最稳定构型的几何参数、布居分析、偶极矩、电离势、包含能、频率、HOMO-LUMO能隙和自旋密度．发现X@Al₁₂P₁₂化合物中, 客体X＝Na^0/＋, K^0/＋, Mg和He几乎处在笼的中心, Be和Ca^0/2＋处在中心附近0.033 nm的半径内, Li^0/＋, Be^2＋, Mg^2＋和H很大程度上偏离笼的中心位置. 大部分金属内含式化合物的C₃对称性构型稳定．Li^0/＋, Be^0/2＋, Mg^2＋, Ca^2＋和H与其它离子相比更易嵌入笼内形成稳定的内含式化合物.     

X@（HAINH）12和X（HAINH）12（X=Fˉ，Clˉ，Brˉ，O2ˉ，S2ˉ，Se2ˉ）复合物的结构和稳定性

用DFT的B3LYP方法在6-31G(d)基组的水平上，对闭式多面体簇合物(HAlNH)12及其内含式X@(HAlNH)12和外接式X(HAINH)12(X=Fˉ，CIˉ，Brˉ，O2ˉ，S2ˉ，Se2ˉ)复合物的结构进行了构型优化和能量计算，并讨论了几何构型、自然键轨道(NBO)、振动频率、能量参数及NMR数据与结构的关系，最后得到复合物结构的稳定性信息，具有Th对称性的X@(HAINH)12(X=Fˉ，CIˉ，Brˉ，S2ˉ，Se2ˉ)复合物和具有C3对称性的O2ˉ@(HAINH)12复合物为内含式的基态结构，从能量角度分析，内含式复合物比外接式复合物的结构稳定．     

X@(HAlNH)12和X(HAlNH)12 (X＝F－, Cl－, Br－, O2－, S2－, Se2－)复合物的结构和稳定性

用DFT的B3LYP方法在6-31G(d)基组的水平上, 对闭式多面体簇合物(HAlNH)₁₂及其内含式X@(HAlNH)₁₂和外接式X(HAlNH)₁₂ (X＝F^－, Cl^－, Br^－, O^2－, S^2－, Se^2－)复合物的结构进行了构型优化和能量计算, 并讨论了几何构型、自然键轨道(NBO)、振动频率、能量参数及NMR数据与结构的关系, 最后得到复合物结构的稳定性信息, 具有T_h对称性的X@(HAlNH)₁₂ (X＝F^－, Cl^－, Br^－, S^2－, Se^2－)复合物和具有C₃对称性的O^2－@(HAlNH)₁₂复合物为内含式的基态结构, 从能量角度分析, 内含式复合物比外接式复合物的结构稳定.     

X@(HAlNH)12和X(HAlNH)12 (X＝F－, Cl－, Br－, O2－, S2－, Se2－)复合物的结构和稳定性

用DFT的B3LYP方法在6-31G(d)基组的水平上, 对闭式多面体簇合物(HAlNH)₁₂及其内含式X@(HAlNH)₁₂和外接式X(HAlNH)₁₂ (X＝F^－, Cl^－, Br^－, O^2－, S^2－, Se^2－)复合物的结构进行了构型优化和能量计算, 并讨论了几何构型、自然键轨道(NBO)、振动频率、能量参数及NMR数据与结构的关系, 最后得到复合物结构的稳定性信息, 具有T_h对称性的X@(HAlNH)₁₂ (X＝F^－, Cl^－, Br^－, S^2－, Se^2－)复合物和具有C₃对称性的O^2－@(HAlNH)₁₂复合物为内含式的基态结构, 从能量角度分析, 内含式复合物比外接式复合物的结构稳定.     

Structure and Stability of Endohedral Complexes X@（HBNH）12

Using quantum chemistry methods B3LYP/6-31＋＋G（d,p） to optimize endohedral complexes X@（HBNH）12 （X=Li^0/＋, Na^0/＋, K^0/＋, Be^0/2＋, Mg^0/2＋, Ca^0/2＋, H and He）, the geometries with the lowest energy were achieved. Inclusion energy, standard equilibrium constant, natural charge, spin density, ionization potentials, and HOMO-LUMO energy gap were also discussed. The calculation predicted that X=Na^0/＋, K^0/＋, Mg^0/2＋, Ca^0/2＋, H and He are nearly located at the center of （HBNH）12 cluster. Li^＋ lies in less than 0.021 nm departure from the center. Li and Be^0/2＋ dramatically deviate from the center. （HBNH）12 prefers to enclose Li^＋, Be^2＋, Mg^2＋, and Ca^2＋ in it than others. Moreover, M@（HBNH）12 （M=Li, Na, K） species are ＂superalkalis＂ in that they possess lower first ionization potentials than the Cs atom （3.9 eV）.     

内含式化合物X@(HBNH)12的结构与稳定性

采用B3LYP/6-31++G(d,p)方法，对内含式化合物X@(HBNH)₁₂ (X = Li^0/+, Na^0/+, K^0/+, Be^0/2+, Mg^0/2+, Ca^0/2+, H和He)的不同对称性构型进行计算，讨论其最稳定构型的几何参数、包含能、平衡常数、自然电荷、自旋密度、电离势和HOMO-LUMO能隙。发现在X@(HBNH)₁₂化合物中，客体Na^0/+, K^0/+, Mg^0/2+, Ca^0/2+, H和He几乎处在笼的中心，Li⁺处在中心附近0.021 nm的半径内，Li和Be^0/2+很大程度上偏离笼的中心位置。Li⁺, Be²⁺, Mg²⁺和Ca²⁺与其它离子相比，更易嵌入笼内形成稳定的内含式化合物。而且，M@(HBNH)₁₂ (M = Li, Na,K)的第一电离势比Cs(3.9 eV)原子小，是超碱金属。     

On the viability of small endohedral hydrocarbon cage complexes: X@C4H4, X@C8H8, X@C8H14, X@C10H16, X@C12H12, AND X@C16H16

Small hydrocarbon complexes (X@cage) incorporating cage-centered endohedral atoms and ions (X = H(+), H, He, Ne, Ar, Li(0,+), Be(0,+,2+), Na(0,+), Mg(0,+,2+)) have been studied at the B3LYP/6-31G(d) hybrid HF/DFT level of theory. No tetrahedrane (C(4)H(4), T(d)()) endohedral complexes are minima, not even with the very small hydrogen atom or beryllium dication. Cubane (C(8)H(8), O(h)()) and bicyclo[2.2.2]octane (C(8)H(14), D(3)(h)()) minima are limited to encapsulating species smaller than Ne and Na(+). Despite its intermediate size, adamantane (C(10)H(16), T(d)()) can enclose a wide variety of endohedral atoms and ions including H, He, Ne, Li(0,+), Be(0,+,2+), Na(0,+), and Mg(2+). In contrast, the truncated tetrahedrane (C(12)H(12), T(d)()) encapsulates fewer species, while the D(4)(d)() symmetric C(16)H(16) hydrocarbon cage (see Table of Contents graphic) encapsulates all but the larger Be, Mg, and Mg(+) species. The host cages have more compact geometries when metal atoms, rather than cations, are inside. This is due to electron donation from the endohedral metals into C-C bonding and C-H antibonding cage molecular orbitals. The relative stabilities of endohedral minima are evaluated by comparing their energies (E(endo)) to the sum of their isolated components (E(inc) = E(endo) - E(cage) - E(x)) and to their exohedral isomer energies (E(isom) = E(endo) - E(exo)). Although exohedral binding is preferred to endohedral encapsulation without exception (i.e., E(isom) is always exothermic), Be(2+)@C(10)H(16) (T(d)(); -235.5 kcal/mol), Li(+)@C(12)H(12) (T(d)(); 50.2 kcal/mol), Be(2+)@C(12)H(12) (T(d)(); -181.2 kcal/mol), Mg(2+)@C(12)H(12) (T(d)(); -45.0 kcal/mol), Li(+)@C(16)H(16) (D(4)(d)(); 13.3 kcal/mol), Be(+)@C(16)H(16) (C(4)(v)(); 31.8 kcal/mol), Be(2+)@C(16)H(16) (D(4)(d)(); -239.2 kcal/mol), and Mg(2+)@C(16)H(16) (D(4)(d)(); -37.7 kcal/mol) are relatively stable as compared to experimentally known He@C(20)H(20) (I(h)()), which has an E(inc) = 37.9 kcal/mol and E(isom) = -35.4 kcal/mol. Overall, endohedral cage complexes with low parent cage strain energies, large cage internal cavity volumes, and a small, highly charged guest species are the most viable synthetic targets.     

内含式化合物X@B12P12的结构与稳定性研究

采用B3LYP/6-31G*方法，对内含式化合物X@B₁₂P₁₂(X=Li^0/+、Na^0/+、K^0/+、Be^0/2+、Mg^0/2+、Ca^0/2+、H和He)的不同对称性构型进行了计算，讨论其最稳定构型的几何参数、布居分析、偶极矩、电离势、包含能、振动频率、能隙和自旋密度． 发现在X@B₁₂P₁₂化合物中，客体X=Li、Na^0/+、K^0/+、Mg^0/2+、Ca^0/2+和He处在偏离笼的中心0.006 nm的半径内． Be²⁺沿着C₃轴偏离中心点0.279 nm． 在Be@B₁₂P₁₂和H@B₁₂P₁₂的基态结构中，Be和H与笼上的B原子成键． 除Li@B₁₂P₁₂、 Be²⁺@B₁₂P₁₂和He@ B₁₂P₁₂外， 其余结构为C_s对称稳定构型．     

Exceptionally pyramidalized olefins: A theoretical study of the cyclopropenyl fused tricycles Tricyclo

RHF, MP2, and TCSCF ab initio theory and B3LYP, B3PW91, and SVWN density functional theory were used to study the series of cyclopropenyl-fused tricycles 9-12. In each of 9-12, the cyclopropenyl double bond is exceptionally pyramidalized (butterfly angle psi approximately 41-50 degrees ) with both endo and exo bent isomers. In the norbornyl systems (9 and 10), the endo bent isomers are more stable than the exo bent isomers, whereas in the bicyclo[2. 2.2]octadiene 12 the reverse is true with the exo bent isomer being the low energy form. The activation barriers for the endo/exo interconversions are calculated to be relatively low (DeltaH() approximately 6-13 kcal/mol).     

Theoretical Study on the Structure and Stability of Si5X （X = Li, Be, B, C, N, O, F, Na, Mg, Al, Si, P, S, Cl） Clusters

1 INTRODUCTION In the later 60s of last century, silicon substituted for germanium to present as mainstream in semicon- ductor. The semi-conductive devices made by silicon have many advantages, for example, refractory pro- perty, high radioresistance, simple and stable process- ing technic, high machinability and low cost. So it was widely used to manufacture large power appara- tuses, for instance, digit and linear integrated circuit, large scale integrated circuit (LSI), etc. Thus, th…     

Theoretical Study on the Structure and Stability of Si4X（X=Li, Be, B, C, N, O, F） Clusters

1 INTRODUCTION Silicon is an important kind of semiconductormaterial having been used to produce many sorts ofapparatus, digital and linear integrated circuit andLarge Scale Integrated circuit (LSI), and its clustershave drawn many scientists’ atten…     

Sandwich-like compounds based on the all-metal aromatic unit Al(4)2- and the main-group metals M (M=Li, Na, K, Be, Mg, Ca)

Inspired by the pioneering experimental characterisation of the all-metal aromatic unit Al(4)2- in the bimetallic molecules MAl4- (M=Li, Na, Cu) and by the very recent theoretical design of sandwich-type transition-metal complexes [Al4MAl4]q- (q=0-2; M=Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W), we used density functional theory (DFT) calculations (B3LYP/6-311+G(d) to design a series of novel non-transition-metal sandwich complexes based on the all-metal aromatic unit Al4(2-) and the main-group metals M (M=Li, Na, K, Be, Mg, Ca). The traditional homo-decked sandwich compounds [Al4MAl4]q- (without counterions) and (nM)q+[Al4MAl4]q- (with counterions M) (q=2-3, M=Li, Na, K, Be, Mg, Ca), although some of them are truly energy minima, have a much higher energy than many fused isomers. We thus concluded that it seems unlikely for Al4(2-) to sandwich the main-group metal atoms in the homo-decked sandwich form. Alternatively, we proposed a new type of sandwich complex, namely hetero-decked sandwich compounds [CpMAl4]q-, that are the ground-state structures for each M both with and without counterions. It was shown that with the rigid Cp- partner, the all-metal aromatic unit Al(4)2- might indeed act as a "superatom". These new types of all-metal aromatic unit-based sandwich complexes await future experimental verification.     

金属硼化物结构与稳定性的理论研究

用ＨＦ／３－２１Ｇａｂｉｎｉｔｉｏ法对金属硼化物ＭＢ２／ＭＢ２（Ｍ＝Ｌｉ，Ｎａ，Ｂｅ，Ｍｇ，Ａｌ）的７５个电子态结构进行能量梯度法优化，再用大基组二次且上互作用ＱＣＩＳＤ（Ｔ）／６－３１１Ｇ进行单点计算，得到了结构参数总能量，为了考察各原子簇的稳定性，还对２４个碎片的７０多个电子态，求得相应的ＱＣＩＳＤ（Ｔ）能量，在此基础上计算了原子化能、电离能、离解通道和碎片化能，得到了原子簇的稳定性规律。