Ih对称性硼、碳原子簇化合物的从头计算(I)──B32、C2B30及B32H322-的构型及稳定性

本文用从头计算方法研究了含32个顶点的硼烷B₃₂H₃₂^2-及裸原子簇B₃₂与C₂B₃₀的构型、稳定性及反应活性。B₃₂的优化计算结果表明,12个5配位与20个6配位两类硼原子不在同一球面时最稳定,而且所含两种B-B核间距离(R₅₆R₆₆)的优化值验证了Lipscomb的经验数值。B₃₂、B₃₂H₃₂^2-电子结构及原子布居的计算表明骨架成键轨道满足Wade规则。相应的计算还表明,中性BB₃₂H₃₂可能稳定存在,但构型的对称性将低于I_h对称,另外。对C₂B₃₀结合能的计算及前线轨道性质的分析表明,C₂B₃₀热稳定性较高,并且有较强的得电子反应活性。     

过渡金属杂硼烷结构规则的量子化学计算

用EHMO量子化学计算方法,计算了过渡金属杂硼烷骨架Fe_{nB6-n(n=0,1,…,6),验证和讨论了过渡金属杂硼烷的价成键和价非键轨道数BMO+NBMO=4n1+9n2-F。其中n1、n2和F都只与骨架的几何性质有关。}     

碳十硼烷及其衍生物的反应性及应用

碳十硼烷(C₂B₁₀H₁₂)是由2个C原子和10个B原子组成的二十面体笼状结构大分子,有邻位、间位和对位三种异构体。碳十硼烷庞大的体积以及类芳香族三维刚性结构使它具有优异的高温稳定性和化学稳定性,良好的溶解性使其具有广泛而灵活的应用。本文总结了近年来碳十硼烷和碳十硼烷衍生物在C原子、B原子上的化学反应性以及在环加成和金属络合方面的研究。另外,由于碳十硼烷衍生物特殊的立体结构,优异的耐高温性、热氧化性及高硼含量,本文综述了碳十硼烷衍生物近年来在功能材料、催化剂及生物医药等多个领域的应用进展。     

14顶点双取代碳硼烷和金属硼烷极化率和二阶超极化率的DFT研究

采用量子化学密度泛函理论(DFT) B3LYP/6-31G(d)方法对14顶点双取代碳硼烷和金属硼烷几何构型进行优化, 结合有限场(FF)方法计算了各体系的极化率和二阶超极化率. 同时金属硼烷中金属原子采用赝势基组进行计算, 讨论基组对计算结果的影响. 结果表明, 14顶点碳硼烷和金属硼烷中碳和金属元素的成键方式不同, 金属硼烷中各原子间距离比碳硼烷中大, 平面偏移角增大. 金属原子的引入有效增加分子的NLO系数, 同时金属硼烷的前线分子轨道能级差比碳硼烷小很多, 金属硼烷材料有可能表现出半导体甚至导体特性, 金属原子采用不同基组对计算结果影响不大.     

含邻位-碳硼烷与二茂铁基的新型半夹心式钌化合物的合成

以邻位-碳硼烷、正丁基锂、硫粉和[(p-cymene)RuCl₂]₂为原料,参考文献方法制得化合物(p-cymene)Ru(S₂C₂B₁₀H₁₀)(1)和(p-cymene)Ru₂(μ-S₂)(S₂C₂B₁₀H₁₀)₂(2)(p-cymene=对甲基异丙基苯基); HC≡CC(O)Fc(Fc=二茂铁基)分别与1和2反应合成了新化合物(p-cymene)Ru(S₂C₂B₁₀H₉)(H₂C=CC(O)Fc)(3)和(p-cymene)Ru₂(μ-S₂)(S₂C₂B₁₀H₁₀)₂(R¹C=CR₂)[R¹=FcCO, R²=H(4); R1=H, R2=FcCO(〖STHZ〗5〖STBZ〗)\],其结构经¹H NMR, ¹³C NMR, ¹¹B{¹H} NMR, IR, MALDI-TOF-MS和元素分析表征。     

硼烷结构规则的量子化学计算

利用EHMO方法,对n=5～12的完整多面体硼烷骨架、缺一个和两个顶点以及戴一个和两个帽原子的各种异构体进行了量子化学计算。直接对硼烷的价成键轨道数公式BMO=4n-[f+3(s+1)]进行了验证。在对计算结果讨论的基础上,进一步探讨了骨架几何结构与成键轨道数之间的关系。     

多面体碳烷的分子轨道方法研究

利用INDO自洽场方法和Edmiston-Ruedenberg定域化方法,计算了多面体碳烷C_2nH_2n(n=2,3,4,5和10)及其骨架C_2n,讨论了它们的电子结构、稳定性和化学键性质。     

碳和硼的笼状原子簇及其关系

碳笼烯C_(60)的发现及碳笼烷C-(60)H_(60)的制备,激励人们去探索合成新的碳元素类似物和其它元素的类似物。本文利用碳和硼的笼型烷烃的化学键和几何特征,讨论碳和硼的笼状原子簇骨架的共轭关系,推导其中一些高对称化合物的原子数和几何结构,并讨论其稳定性。 1 碳和硼的笼状原子簇骨架的共轭关系     

利用邻-碳硼烷可变的C-C键实现发光分子从ACQ到AIE转变

利用邻-碳硼烷骨架中可变的C-C键,将在聚集态会发生猝灭（ACQ）的传统发光分子和具有振动自由度的碳硼烷基团连接起来,合成了带有聚集诱导发光（AIE）效应的邻-碳硼烷基发光分子。通过紫外可见吸收光谱、DFT计算、发射光谱及晶体结构测定等手段,研究了邻-碳硼烷可变的C-C键对化合物性质的影响。结果表明,在邻-碳硼烷骨架的碳原子上引入不同的取代基可以改变C-C键的振动特性,从而能够调控化合物的发光性质,并有效实现从ACQ到AIE的转变。     

过渡金属卡宾配合物V.铼的阳离子卡拜配合物与邻-碳硼烷双锂盐的反应及其产物π-环戊二烯基二羰基[(1-碳硼烷基)(苯基)卡宾]铼的晶体结构

铼的阳离子卡拜配合物,[π-C5H5(CO)2ReCC6H5]BBr4(1),在THF中低温下与1,2-碳硼烷双锂盐反应,生成π-环戊二烯基二羰基[(1-碳硼烷基)(苯基)卡宾]铼[π-C5H5(CO)2ReC(C2HB10H10)-C6H5](2)及π-环戊二烯羧基[(1-碳硼烷基甲酰基)(苯基卡拜)铼[π-C5H5(CO)(COC2HB10H10)-ReCC6H5](3),和1与邻-碳硼烷单锂盐反应所生成的产物完全相同.2的分子结构已由单晶X-射线结构分析证实.属于单斜晶系,空间群为P21/n,晶胞参数:a=14.043(8)埃,b=8.302(6)埃,c=17.926(11)埃,β=93.96(5).晶胞中有四个分子.其结构已用重原子法解出并用块矩阵最小二乘法修正,最后的偏离因子R=0.076.同时也讨论了可能的反应机制.     

A density functional theoretical studies on the structures and aromaticities of （CH）n（BCO）6-n （n =0-6）

Density functional theoretical calculations have been made on the electronic structure of （CH）n（BCO）6-n（n = 0-6） at B3LYP/6- 311 ＋ G（d） level. The nuclear-independent chemical shifts （NICS） values calculated using the gauge-including atomic orbitals （GIAO） method were used to assess on the aromaticities of these molecules. The results shows that （CH）n（BCO）6n（n = 0-6） species are aromatic.     

包含两个平面五配位碳原子C_(2+n)B_(10-n)(n=0～10)团簇的结构的理论研究

采用B3LYP/6-311+G**方法,我们优化了初始构型中包含两个平面五配位碳原子(ppCs)的C2+nB10-n(n=0～10)团簇的结构并计算了它们的振动频率.计算结果表明,C2+nB10-n(n=0～2)团簇是稳定的,而且这三个结构中ppC—B键的Wiberg键级介于0.511～0.909之间,ppC—C键的Wiberg键级为0.2254(n=1)和0.8586(n=2),ppC的键级介于3.778到3.879之间,即这三个结构中存在两个ppCs,而且ppC遵循八隅规则;C2+nB10-n(n=3～6)团簇的最稳定结构包含一个ppC;C2+nB10-n(n6)团簇能量最低结构中不存在ppC.而且只有团簇C2+nB10-n(n=0～2)中没有悬键,它们的π电子数分别为:6,7和8,计算它们的NICS(0)值表明强芳香性一般位于局部的三元环中心,表明局部离域有利于平面结构的形成.C2+nB10-n(n=0～2)团簇的第一垂直激发能分别为:1.91,0.56和3.12eV.     

Coordination of ScO+ and YO+ by multiple Ar, Kr, and Xe atoms in noble gas matrixes: a matrix isolation infrared spectroscopic and theoretical study

The combination of matrix isolation infrared spectroscopic and quantum chemical calculation results provide strong evidence that scandium and yttrium monoxide cations, ScO+ and YO+, coordinate multiple noble gas atoms in forming noble gas complexes. The results showed that ScO+ coordinates five Ar, Kr, or Xe atoms, and YO+ coordinates six Ar or Kr and five Xe atoms in solid noble gas matrixes. Hence, the ScO+ and YO+ cations trapped in solid noble gas matrixes should be regarded as the [ScO(Ng)5]+ (Ng = Ar, Kr, or Xe), [YO(Ng)6]+ (Ng = Ar or Kr) or [YO(Xe)5]+ complexes. Experiments with dilute krypton or xenon in argon or krypton in xenon produced new IR bands, which are due to the stepwise formation of the [ScO(Ar)(5-n)(Kr)n]+, [ScO(Kr)(5-n)(Xe)n]+ (n = 1-5), [YO(Ar)(6-n)(Kr)n]+ (n = 1-6), and [YO(Ar)(6-n)(Xe)n]+ (n = 1-4) complexes.     

NMR shielding calculations across the periodic table: diamagnetic uranium compounds. 2. Ligand and metal NMR

In this and a previous article (J. Phys. Chem. A 2000, 104, 8244), the range of application for relativistic density functional theory (DFT) is extended to the calculation of nuclear magnetic resonance (NMR) shieldings and chemical shifts in diamagnetic actinide compounds. Two relativistic DFT methods are used, ZORA ("zeroth-order regular approximation") and the quasirelativistic (QR) method. In the given second paper, NMR shieldings and chemical shifts are calculated and discussed for a wide range of compounds. The molecules studied comprise uranyl complexes, [UO(2)L(n)](+/-)(q); UF(6); inorganic UF(6) derivatives, UF(6-n)Cl(n), n = 0-6; and organometallic UF(6) derivatives, UF(6-n)(OCH(3))(n), n = 0-5. Uranyl complexes include [UO(2)F(4)](2-), [UO(2)Cl(4)](2-), [UO(2)(OH)(4)](2-), [UO(2)(CO(3))(3)](4-), and [UO(2)(H(2)O)(5)](2+). For the ligand NMR, moderate (e.g., (19)F NMR chemical shifts in UF(6-n)Cl(n)) to excellent agreement [e.g., (19)F chemical shift tensor in UF(6) or (1)H NMR in UF(6-n)(OCH(3))(n)] has been found between theory and experiment. The methods have been used to calculate the experimentally unknown (235)U NMR chemical shifts. A large chemical shift range of at least 21,000 ppm has been predicted for the (235)U nucleus. ZORA spin-orbit appears to be the most accurate method for predicting actinide metal chemical shifts. Trends in the (235)U NMR chemical shifts of UF(6-n)L(n) molecules are analyzed and explained in terms of the calculated electronic structure. It is argued that the energy separation and interaction between occupied and virtual orbitals with f-character are the determining factors.     

Synthesis, molecular structure and properties of the [H6-nNi30C4(CO)34(CdCl)2]n- (n=3-6) bimetallic carbide carbonyl cluster: a model for the growth of noncompact interstitial metal carbides

Reaction of the [Ni(9)C(CO)(17)](2-) dianion with CdCl(2)2.5 H(2)O in THF affords the novel bimetallic Ni--Cd carbide carbonyl clusters [H(6-n)Ni(30)C(4)(CO)(34)(micro(5)-CdCl)(2)](n-) (n=3-6), which undergo several protonation-deprotonation equilibria in solution depending on the basicity of the solvent or upon addition of acids or bases. Although the occurrence in solution of these equilibria complicates the pertinent electrochemical studies on their electron-transfer activity, they clearly indicate that the clusters [H(6-n)Ni(30)C(4)(CO)(34)(micro(5)-CdCl)(2)](n-) (n=3-6), as well as the structurally related [H(6-n)Ni(34)C(4)(CO)(38)](n-) (n=4-6), undergo reversible or partially reversible redox processes and provide circumstantial and unambiguous evidence for the presence of hydrides for n=3, 4 and 5. Three of the [H(6-n)Ni(30)C(4)(CO)(34)(micro(5)-CdCl)(2)](n-) anions (n=4-6) have been structurally characterized in their [NMe(3)(CH(2)Ph)](4)[H(2)Ni(30)C(4)(CO)(34)(CdCl)(2)]2 COMe(2), [NEt(4)](5)[HNi(30)C(4)(CO)(34)(CdCl)(2)]2 MeCN and [NMe(4)](6)[Ni(30)C(4)(CO)(34)(CdCl)(2)]6 MeCN salts, respectively. All three anions display almost identical geometries and bonding parameters, probably because charge effects are minimized by delocalization over such a large metal carbonyl anion. Moreover, the Ni(30)C(4) core in these Ni-Cd carbide clusters is identical within experimental error to those present in the [HNi(34)C(4)(CO)(38)](5-) and [Ni(35)C(4)(CO)(39)](6-) species, suggesting that the stepwise assembly of their nickel carbide cores may represent a general pathway of growth of nickel polycarbide clusters. The fact that the [H(6-n)Ni(30)C(4)(CO)(34)(micro(5)-CdCl)(2)](n-)(n=4-6) anions display two valence electrons more than the structurally related [H(6-n)Ni(34)C(4)(CO)(38)](n-) (n=4-6) species has been rationalized by extended Hückel molecular orbital (EHMO) analysis.     

金镍六原子团簇吸附CO的密度泛函研究

在UBP86/LAN2DZ水平上计算了金镍二元团簇(AunNi6-n,n=0～6)吸附CO的稳定构型和相关性质.计算结果表明,AunNi6-nCO团簇的最低能量结构是在AunNi6-n团簇最低能量结构或亚稳态结构基础上吸附CO分子而形成.优化结构中C-O键长表明,吸附后的CO没有解离,即CO分子在AunNi6-n团簇表...     

Lindqvist型[M6-nMonO19]p-阴离子（M=W,Nb,Ta）电子性质的密度泛函理论研究

采用密度泛函理论方法探讨了取代Mo原子对[W6-nMonO19]2-,[Nb6-nMonO19]p-和[Ta6-nMonO19]p-体系的M—Ot(M=W,Nb,Ta)键的活化作用.计算结果表明,随着取代Mo原子数的增多,[M6-nMonO19]2-(M=W,Nb,Ta)中M—Ot键的键能逐渐减小,因此Mo原子的引入使M—Ot键活化.在[W6-nMonO19]2-中,Mo—Ot键的键能小于W—Ot键的键能,因此,Mo—Ot键比W—Ot键易断裂,与实验结果一致.而在[Nb6-nMonO19]p-和[Ta6-nMonO19]p-体系中,Mo—Ot键的键能大于M—Ot(M=Nb,Ta)键的键能.Nb和Ta原子的端氧Ot的电荷大于Mo原子的端氧Ot的电荷,初步预测,当[Nb6-nMonO19]p-和[Ta6-nMonO19]p-与有机胺反应时,Nb—Ot和Ta—Ot键优先断裂,易与有机胺的氮原子成键.     

二(三)丁基锡烯基(炔基)膦酸酯的合成与表征

合成了12个新的二(三)丁基锡烯基(炔基)膦酸酯[(n-C4H9)nSn]n-1O2P(0)R,并用元素分析,红外光谱,核磁共振氢谱和TG-DTA对其组成和结构进行了表征,初步生物活性测试表明,有些化合物具有较强的杀螨和杀菌活性。     

Co-ETS-10 and Co-AM-6 as active catalysts for the oxidation of styrene to styrene oxide and benzaldehyde using molecular oxygen

Pristine ETS-10 and AM-6 and their Co2+-exchanged forms were prepared, and their catalytic activi-ties toward the oxidation of styrene in oxygen atmosphere were studied in dimethylformamide. The catalysts were denoted as Co-E10-n (n=0, 9, 26, 68, 81) and Co-A6-m (m=0, 8, 23, 63, 79), where n and m denote the degree of Co2+exchange. The products of the oxidation process were identified as styrene epoxide (E) and benzaldehyde (B). Both the pristine forms, ETS-10 (Co-E10-0) and AM-6 (Co-A6-0), and Co2+-exchanged forms displayed catalytic activities. With increasing n or m, the con-version, and hence the rate, increased. Specifically, the rates varied from 6.1 to 12.5 mmol·g?1·h?1 with increasing n (Co-E10-n catalysts) and from 5.4 to 12.4 mmol·g?1·h?1 with increasing m (Co-A6-m catalysts). In contrast, the E/B ratio decreased with increasing n or m. More specifically, the E/B ratio decreased from 2.1 to 0.1 with increasing n from 0 to 81 (Co-E10-n catalysts) and from 1.3 to 0.1 with increasing m from 0 to 79 (Co-A6-m catalysts). Co-E10-9 displayed the highest E yield and Co-A6-79 generated the highest B yield. The highest turnover frequency obtained was 36.3 Co?1·h?1, which was the highest one obtained among those obtained for the Co2+-exchanged zeolites and mesoporous silica reference materials studied in this work.