Production of N,H, and NH active species in N2-H2 dc flowing discharges

Densities of N, H, and NH active species have been detected by laser-induced fluorescence (LIF) in N₂-xH₂ dc flowing discharges. A peak value of N atom densities far x = 0.2–0.5% and a plateau value of H atom densities between x = 1% and 90% in post-discharge conditions (0.05 sec, p = 2 torr) has been found. Comparison between LIF measurements of N atoms and the trend of the N₂(B, v = II) population shows that the emission from this state can be used for monitoring N atoms. The NH radical has only been detected inside the discharge region.On leave from Instituto Tecnológico de Aeronáutica, CNPq, Brazil.     

Effect of Ni and Pd on the geometry, electronic properties, and active sites of copper clusters

The geometry, electronic properties, and active sites of copper clusters doped with Ni or Pd atoms, Cu(n)()(-)(1)M (n = 2-6; M = Ni, Pd) have been investigated using first-principles methods. Planar structures are energetically favorable in Cu(n)()(-)(1)Ni (n = 2-6). However, for Pd-doped clusters, three-dimensional structures are competitive in energy, and for n = 6, the most stable structure is not planar. Several properties of doped copper clusters present odd-even oscillations as the number of copper atoms grow. The different atomic ground-state configuration of Ni and Pd determines the bonding and electronic properties of doped copper clusters. The interaction between impurities and copper atoms can modify the chemical hardness and active sites of doped copper clusters markedly inducing directionality in the reactivity. This effect is relevant to the behavior of catalysts as well as in the growth of metallic films.     

Self-assembly of diorganotin(IV) moieties and 2-pyrazinecarboxylic acid: syntheses, characterizations and crystal structures of monomeric, polymeric or trinuclear macrocyclic compounds

A series of diorganotin(IV) compounds of the type [R(2)Sn(pca)Cl](3)(R = CH(3); (n)Bu; C(6)H(5); C(6)H(5)CH(2); Hpca = 2-pyrazinecarboxylic acid), R(2)Sn(pca)(2)(mH(2)O)xnH(2)O (m= 1: R = CH(3), n= 2, R =(n)Bu, n= 0; m= 0, n= 0: R =(n)Bu, C(6)H(5), C(6)H(5)CH(2)) and (Et(3)NH)(+)[R(2)Sn(pca)(2)Cl](-)xmH(2)O (m= 0: R = CH(3), (n)Bu, C(6)H(5)CH(2); m= 1: R = C(6)H(5)) have been obtained by reactions of 2-pyrazinecarboxylic acid with diorganotin(iv) dichloride in the presence of sodium ethoxide or triethylamine. All compounds were characterized by elemental, IR and NMR spectra analyses. Except for compounds, and, the others were also characterized by X-ray crystallography diffraction analyses, which revealed that compounds and were trinuclear macrocyclic structures with six-coordinate tin(IV) atoms, compounds and were monomeric structures with seven-coordinate tin(IV) atoms, compounds and were polymeric chain structures with seven-coordinate tin(IV) atoms and compounds and were stannate with seven-coordinate tin(IV) atoms.     

Synthesis, Reactivity, and Structural Characterization of the Nonclassical [MTe(7)](n)()(-) Anions (M = Ag, Au, n = 3; M = Hg, n = 2)

Several tellurometalates of the general formula [MTe(7)](n)()(-) (n = 2, 3) have been isolated as salts of organic cations by reaction of suitable metal sources with polytelluride solutions in DMF. The [HgTe(7)](2)(-) anion has the same structure in both the NEt(4)(+) and the PPh(4)(+) salts except for a minor change in the ligand conformation. The [AgTe(7)](3)(-) and [HgTe(7)](2)(-) anions contain metal atoms coordinated in trigonal-planar fashion to eta(3)-Te(7)(4)(-) ligands. The central Te atom of an eta(3)-Te(7)(4)(-) ligand is coordinated to the metal atom and to two Te atoms in a "T"-shaped geometry consistent with a hypervalent 10 e(-) center. The planar [AuTe(7)](3)(-) anion may best be described as possessing a square-planar Au(III) atom coordinated to an eta(3)-Te(5)(4)(-) ligand and to an eta(1)-Te(2)(2)(-) ligand. The reaction of [NEt(4)](n)()[MTe(7)] (M = Hg, n = 2; M = Au, n = 3) with the activated acetylene dimethyl acetylenedicarboxylate (DMAD) has yielded the products [NEt(4)](n)()[M(Te(2)C(2)(COOCH(3))(2))(2)] (M = Hg, n = 2; M = Au, n = 1). The metal atoms are coordinated to two Te(COOCH(3))C=C(COOCH(3))Te(2)(-) ligands, for M = Hg in a distorted tetrahedral fashion and for M = Au in a square-planar fashion.     

The correlation equations describing retention index data on OV-101, OV-275 and PEG 20M.n-alkanes andn-alkynes

Summary The correlation equations between Kovats retention indices ofn-alkenes andn-alkynes, column temperature and number of carbon atoms in molecules of these compounds on OV-101, OV-225 and PEG 20M capillary columns have been calculated. The two variable equationI=A + B · n + C / T give a good fit and are the simplest for practical use.     

新型一维[Co(phen)(μ3-md)]n的水热合成与结构

采用有机分子建筑块与金属离子制备具有微孔结构材料在催化、化学吸附、磁性和导电性等方面具有潜在的应用前景, 因而成为研究的热点[1～4]. 近来的研究表明, 多齿的有机配体是很好的建筑块, 其中多羧酸化合物和含多氮化合物均是很好的多齿配体. 多羧酸化合物如均苯四甲酸、间苯三甲酸、对苯二甲酸等, 多氮化合物如1,10-邻菲咯啉、 4,4′-联吡啶、 2,2′-联吡啶等[5～11]. 但对同样具有多齿特征的间苯二甲酸作为配体的化合物研究得很少. 本文采用水热合成法合成了[Co(phen)(μ3-md)]n(phen=1,10-phenanthroline, md=Benzene-1,3-dicarboxylate). 该聚合物呈一维双链结构, 通过间苯二甲酸连接3个Co(Ⅱ)形成双分子链, 间苯二甲酸和它连接的3个Co(Ⅱ)离子在同一平面上, 通过垂直于该平面的phen之间的π-π共轭作用形成二维结构.     

(MN)nHm(M=Ga,In; n=1-4; m=1, 2)团簇的结构与稳定性

采用密度泛函理论(DFT)的B3LYP方法, 在6-31G**和Lanl2dz水平上分别对(MN)nHm(M=Ga, In; n=1-4; m=1, 2)进行了优化和振动频率计算. 得到了上述团簇的最稳定构型、H原子的结合能以及它们的能隙. 结果表明, (MN)nH(M=Ga, In; n=1-4)的基态构型均为双重态, (MN)nH2(M=Ga, In; n=1-4)的基态构型均为单重态; 当氢的个数为1时, 加在N原子上比加在M(M=Ga, In)原子上稳定, 如有N3单元, 那么加在N3单元两侧的构型是相同的, 且它是最稳定的; 当氢的个数为2时, 除n=1外, 分别加在两个N原子上的构型是最稳定的, 如有N3单元, 那么分别加在N3单元分离最远的两个N原子的构型是最稳定的. GaNH、(GaN)3H 和InNH的结合能和能隙都很大, 说明这些团簇都有很高的稳定性.     

FMBen（FM=Fe,Co,Ni;n=1-12）团簇结构和电子性质

采用密度泛函理论中的广义梯度近似对FMBen(FM=Fe,Co,Ni;n=1-12)团簇的几何构型进行优化,并对能量、频率和磁性进行了计算,同时考虑了电子的自旋多重度.结果表明,纯铍团簇的幻数是由电子的壳层模型确定,而FMBen团簇的幻数主要由几何效应来解释;掺杂铁磁性的过渡金属(Fe,Co,Ni)提高了纯团簇的稳定性.二阶能量差分表明FMBen(FM=Fe,Co,Ni)的幻数分别为5,10;5,10;4,10.通过对磁性质的研究发现掺杂不同的过渡金属时,磁矩出现了不同的变化规律.     

螺桨烷型分子BX[(CH_2)_n]_3和BX(CH_2)[CH(CH_2)_nCH](X=N,P)的结构和性质

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)n CH](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)n CH](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)n CH](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.     

大环穴醚双铜硫氰酸根配合物[Cu2(SCN)3(C16H38N6)]2(ClO4)2的合成和结构

合成了大环穴醚配体C_(16)H_(32)N_6。在SCN~-参与下, 进一步合成了大环穴醚配合物[Cu_2(SCN)_3(C_(16)H_(38)N_6)]_2(ClO_4)_2, 并用X射线单晶结构分析测定了其晶体结构。晶体属单斜空间群C_(2h)~4-P2/n, a=1.6274(8), b=0.8114(3), c=2.3199(10) nm, β=98.46(4)°, V=3.0301 nm, Z=2。晶体中的Cu(Ⅱ)的配位几何构型为畸变的四方锥。硫氰酸根有两种配位形式, 一种是以N端的单配位, 处于四方锥的底面; 另一种是以S端和N端的桥连配位, 处于四方锥的顶端, 桥连的硫氰酸根把大环穴醚双铜络合物联成一维无限链状。     

Theoretical studies for structures and energetics of Rgn-N2O (Rg=He, Ne, Ar) clusters

Minimum-energy structures of the Rg(2)-N(2)O (Rg=He, Ne, Ar) clusters have been determined with ab initio MP2 optimization, whereas the minimum-energy structures of the Rg(n)-N(2)O clusters with n = 3-7 have been obtained with the pairwise additive potentials. Interaction energies and nonadditive three-body effects of the Rg(2)-N(2)O ternary complex have been calculated using supermolecule method at MP4 and CCSD(T) levels. It was found from the calculations that there are two minima corresponding to one distorted tetrahedral structure and one planar structure for the ternary complex. The nonadditive three-body effects were found to be small for Rg(2)-N(2)O complexes. Our calculations also indicated that, for He(n)-N(2)O and Ne(n)-N(2)O clusters, the first six He and Ne atoms form the first solvation ring around the middle nitrogen of the N(2)O monomer, while for Ar(n)-N(2)O, the first five Ar atoms form the first solvation ring.     

FMBen(FM=Fe,Co, Ni; n=1-12)团簇结构和电子性质

采用密度泛函理论中的广义梯度近似对FMBen(FM=Fe, Co, Ni; n=1-12)团簇的几何构型进行优化, 并对能量、频率和磁性进行了计算, 同时考虑了电子的自旋多重度. 结果表明, 纯铍团簇的幻数是由电子的壳层模型确定, 而FMBen团簇的幻数主要由几何效应来解释; 掺杂铁磁性的过渡金属(Fe, Co, Ni)提高了纯团簇的稳定性. 二阶能量差分表明FMBen(FM=Fe, Co, Ni)的幻数分别为5, 10; 5, 10; 4, 10. 通过对磁性质的研究发现掺杂不同的过渡金属时, 磁矩出现了不同的变化规律.     

Benzimidazolin-2-stannylenes with N,N'-alkyl (Me and Et) and Lewis base functional groups

Symmetrically and unsymmetrically N,N'-substituted benzimidazolin-2-stannylenes with sterically nondemanding alkyl (Me and Et) and Lewis base functional groups (-(CH2)nOMe, -(CH2)nNMe2; n=2, 3) have been synthesized by the transamination reaction between suitably substituted o-phenylenediamines and Sn[N(SiMe3)2]2. The N,N'-dimethyl-substituted stannylene 3 exists in the solid state as a bimolecular aggregate which is held together by strong intermolecular Sn...N interactions leading to three-coordinated tin atoms. The benzimidazolin-2-stannylenes with N,N'-(CH2)nOMe substituents (5, n=2; 6, n=3) exhibit weak intramolecular Sn...O interactions in solution. Benzannulated stannylenes with N,N'-(CH2)nNMe2 substituents (7, n=2; 8, n=3) are again dimers which exhibit both intramolecular Sn...NMe2 and intermolecular Sn...N interactions, which leads to tri- or tetracoordinated tin atoms. Some unsymmetrically N,N'-substituted benzimidazolin-2-stannylenes have also been synthesized. The molecular structures of 3, 5, and 8 and the relation between the chemical shift recorded for the tin atoms and the solvent (C6D6 or THF-d8) used for recording 119Sn NMR spectra will be discussed.     

Synthesis, structure, and conformation of aza[1n]metacyclophanes

N-Benzyl substituted aza[1n]metacyclophanes (n = 4, 6, 8, and 10) were prepared in overall 40% isolated yields via Pd-catalyzed aminations. Analyses of the reaction mixtures showed that aza[14]metacyclophane and the related polymer were the primary products ( approximately 60% overall yield); aza[1n]metacyclophanes up to n = 14 and linear oligomers with up to 20 nitrogen atoms (with at least three types of end groups) were detected. Macrocyclic structures for n = 4, 6, and 10 were confirmed by X-ray crystallography. 1,3-Alternate (D(2d)) and 1,3,5-alternate (S(6)) conformations in solution on NMR time scale at low temperatures were found for macrocycles with n = 4 and n = 6, respectively; the barrier for ring inversion was considerably lower for the larger macrocycle.     

铜锌异双核配合物[CuZn(fsan)(H_2O)]·H_2O的合成、晶体结构和电化学性质

合成了标题化合物[CuZn(fsan)(H2O)]H2O [H4(fsan)为N, N?- 二(3-羧基水杨醛叉)缩乙撑二胺],用单晶X-ray衍射法测定了它的晶体结构,该晶体属单斜晶系,空间群P21/n,a = 11.695(2), b = 14.646(3), c = 12.265(3) ? ?= 118.46(3)°, V = 1847.0(6) ?,C18H12CuN2O8Zn, Mr = 513.21, Z = 4, Dc = 1.846 g/cm3, (MoK? = 2.502mm-1,F(000) = 1028,R = 0.0478,wR = 0.0902 (I>2(I)), 2951个可观测衍射点。该分子结构为双核单元,铜原子位于“内部”由2个氮原子和2个酚氧原子构成的平面正方场中。“外部”锌原子与2个酚氧原子、2个端基羧氧原子及轴向水分子中的氧原子配位,锌原子处于变形四方锥几何构型之中。金属原子通过2个酚氧原子桥联在一起。结合晶体结构对配合物做了电化学研究。     

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.     

双高烯丙基硫醚和β,γ-及γ,δ-不饱和缩硫酮的区域专一性碳钯化反应

本工作试图把碳钯化反应发展到双主主烯丙基体系,以考察通过杂原子导向的远端区域专一性的反应以及缩硫酮官能团对硫钯化反应的导向作用.     

On triazoles XLVII. Synthesis of 1,3a,5,6,ωc‐pentaazacycloalka[e]acenaphthylenes

To study the influence of planar or bulky cycloalkane rings attached to the 1,3a,5,6,ωc‐pentaazaacen‐aphthylenes to the reactivity of their 4‐alkylthio group toward amines ‐ an unexpected reaction observed recently at 1,3a,5,6,10c‐pentaazaacephenanthrylenes ( 5b , n = 4) ‐ different size 1,3a,5,6,ωc‐pentaazacyclo‐alka[e]acenaphthylenes ( 5a , n = 3; 5c , n = 5; 5d , n = 6; or 5e , n = 10) were synthesised and their spectral data compared with that of 5b (n = 4). Based on the analogy of the chemical shifts of carbon atoms at position 4 with that of 5b , similar electronic structure and thus a possibility of an analogous nucleophilic attack of amines was proposed and subsequently proved by a preparative method.     

1H-, 13C-UND 31P-NMR-SPEKTROSKOPISCHE UNTERSUCHUNGEN AN BIS-(DIALKOXYTHIOPHOSPHORYL)-UND-(DIALKOXYPHOSPHORYL)-SULFANEN UND-POLYSULFANEN

Abstract

Compounds of the following structure

(R¹O)₂(X)P[sbnd]Y–P(X)(OR²)₂

(X = O, Y = S_n (n = 1–4), R¹ = R² = Me, iPr;

X = S, Y = S_n (n = 1–4), R¹, R² = Me, Et, iPr, iBu;

X = S, Y = S-Se-S, S-Te-S, R¹ = R² = Me

were prepared and their NMR spectra were analysed. Depending on the number of sulfur atoms, bonded between the phosphorus atoms, typical ranges of the P-P coupling constants were found for the different sulfanes investigated: ²J_PP from-10 to-20 Hz, ³J_PP less than 3 Hz, ⁴J_PP from +10 to +13 Hz and ⁵J_PP less than 1 Hz. For the small vicinal coupling constants and the relatively large values of ⁴J_PP different possibilities of their interpretation are given.