Contrast of Bonding and Characters for C6, B3N3, C6H6 and B3N3H6 Molecules

Through integrative consideration of NICS, MO, MOC and NBO, we precisely investigated delocalization and bonding characters of C₆, C₆H₆, B₃N₃ and B₃N₃H₆ molecules. Firstly, we originally discovered and testified that C₆ cluster was sp² hybridization. Negative NICS values in 0 and 1 Å indicated that C₆ had δ and Π aromaticity. Secondly, B₃N₃ with sp² hybridization had obvious δ aromaticity. Finally, WBI values approved that there were delocalization in C₆, C₆H₆ and B₃N₃ molecules, but B₃N₃H₆ structure did not have delocalization with the WBI 1.0. Moreover, total WBI values of carbon, boron and nitrogen atoms were four, three and three, respectively. Namely, the electrons of B₃N₃H₆ and B₃N₃ were localized in nitrogen atoms and they did not form delocalized bonding. In a word, bonding characters of carbon, boron and nitrogen atoms were dissimilar although the molecules composed of carbon, boron and nitrogen were regarded as isoelectronic structures.     

C3N6H6(H3BO3)2的合成及晶体结构

以三聚氰胺和硼酸为原料在水溶液中反应合成出了一种新的BCN化合物先驱体C3N6H6(H3BO3)2。XRD表征结果表明三聚氰胺和硼酸的最佳配比为1∶3(物质的量比)。用单晶X-射线衍射分析法测定了该化合物的晶体结构。该化合物属单斜晶系,空间群为P21/C,晶胞参数为a=0.3597(7)nm,b=2.0105(4)nm,c=1.4112(3)nm,α=90,°β=92.07(3),°γ=90,°V=1.0199(3)nm3,Z=4,D c=1.627g.cm-3,μ(MoKα)=0.144mm-1,F(000)=520。晶体结构经全矩阵最小二乘法修正,最终可靠因子R1=0.0519,wR2=0.1361。该化合物是由C3N6H6分子和H3BO3分子通过氢键加合组装形成的三维超分子结构化合物。     

Ionization efficiencies of C3H6, C4H8, C6H12, C2H6O,and C3H8O isomers

Ionization efficiencies of 14 organic compounds have been measured in the wavelength region from 105 to 134nm using an ionization chamber. The compounds examined are cyclopropane, propylene, l-butene, isobutene, cis-and trans-2-butenes, cyclohexane, 1-hexane, tetramethylethylene, ethyl alcohol, dimethyl ether, n-, and iso-propyl alcohol, and ethyl methyl ether. The ionization efficiencies of cyclopropane and cyclohexane monotonically increase with increasing photon energy, but those for the others show a peak or a shoulder in the wavelength region of the present work.     

[C6H6, C3H7 +]and [C6H7 +, C3H6] ion-neutral complexes intermediate in the reactions of protonated propylbenzenes

From the mass-analysed ion kinetic energy spectra of labelled ions, kinetic energy releases and thermodynamic data, it is proved that protonated n-propylbenzene (1) isomerizes into protonated isopropyl benzene (2). It is also shown that the dissociation of the less energetic metastable ions of (2), leading to [iso-C₃H₇]⁺ and [C₆H₇]⁺ product ions, is preceded by H exchange. This H exchange involves two interconverting ion-neutral complexes [C₆H₆, iso-C₃H₇⁺] (2π) and [C₆H₇⁺, C₃H₆] (2α).     

Vibrational spectra of melamine diborate,C3N6H62H3BO3

IR and Raman spectra of melamine diborate have been recorded and analysed. Band assignments are given based on the vibrations of melamine and boric acid molecules. Three sets of frequencies observed for the N-H stretching mode region is ascribed to different types of hydrogen bonds in the amino groups of the triazine ring. Due to the lower symmetry of the melamine and boric acid molecules in the crystal, activation of inactive modes and lifting of the degeneracy of certain vibrational modes are observed. Lower symmetry of the melamine molecule in the crystal has resulted in the decrease of intensity of the Raman active melamine band around 1490 cm(-1). All the internal modes of boric acid molecule were identified. All the ring breathing modes of melamine molecule show frequency shift towards the high wavenumber side. In other words, hydrogen bonding affects the ring breathing modes of melamine.     

(m‐CH3C6H4NH3)6P6O18

In hexakis(m‐toluidinium) cyclo­hexaphosphate, 6C₇H₁₀N⁺·­P₆O₁₈^6?, the atomic arrangement is typical of a layer structure. Layers including the centrosymmetric P₆O₁₈ ring anions develop around the (100) planes at x = . The hydrogen‐bond distribution is described.     

Scalable Green Synthesis of Robust Ultra-Microporous Hofmann Clathrate Material with Record C3H6 Storage Density for Efficient C3H6/C3H8 Separation

Developing porous materials for C₃H₆/C₃H₈ separation faces the challenge of merging excellent separation performance with high stability and easy scalability of synthesis. Herein, we report a robust Hofmann clathrate material (ZJU-75a), featuring high-density strong binding sites to achieve all the above requirements. ZJU-75a adsorbs large amount of C₃H₆ with a record high storage density of 0.818 g mL⁻¹, and concurrently shows high C₃H₆/C₃H₈ selectivity (54.2) at 296 K and 1 bar. Single-crystal structure analysis unveil that the high-density binding sites in ZJU-75a not only provide much stronger interactions with C₃H₆ but also enable the dense packing of C₃H₆. Breakthrough experiments on gas mixtures afford both high separation factor of 14.7 and large C₃H₆ uptake (2.79 mmol g⁻¹). This material is highly stable and can be easily produced at kilogram-scale using a green synthesis method, making it as a benchmark material to address major challenges for industrial C₃H₆/C₃H₈ separation.     

Isotropic C6, C8 and C10 interaction coefficients for CH4, C2H6, C3H8, n-C4H10 and cyclo-C3H6

The non-empirical generalized Kirkwood, Unsöld, and the single-Δ Unsöld methods (with double-zeta quality SCF wave-functions) are used to calculate isotropic dispersion (and induction) energy coefficients C_2n, with n ? 5, for interactions involving ground state CH₄, C₂H₆, C₃H₈, n-C₄H₁₀ and cyclo-C₃H₆. Results are also given for the related multipole polarizabilities α_l, multipole sums S₁/(0) and S₁(?1) which are evaluated using sum rules, and the permanent multipole moments. for l = 1 (dipole) to l = 3 (octupole). Estimates of the reliability of the non-empirical methods, for the type of molecules considered, are obtained by a comparison with accurate literature values of α₁S₁(?1) and C₆. This, and the asymptotic properties of the multipolar expansion of the dispersion energy, the use to discuss recommended representation for the isotropic long range interaction energies through R^?10 where R is the intermolecular separation.     

Untersuchungen zu Synthese und Reaktionen von Fluorphenylquecksilber-Derivaten mit den Liganden 2-FC6H4, 2,6-F2C6H3 und 2,4,6-F3C6H2

Investigations on Syntheses and Reactions of Fluorophenylmercury Compounds with the Ligands 2-FC₆H₄, 2,6-F₂C₆H₃, and 2,4,6-F₃C₆H₂ 2,6-F₂C₆H₃HgCl and 2,4,6-F₃C₆H₂HgCl are synthesized via the reactions of the corresponding phenylmagnesium compounds and HgCl₂. 2-FC₆H₄HgCl is selectively obtained only in a reaction involving intermediately formed Cd(2-FC₆H₄)₂. The diphenylmercury derivative Hg(2,4,6-F₃C₆H₂)₂ is obtained while stirring a dichloromethane solution of 2,4,6-F₃C₆H₂HgCl for several days. The direct mercuration of 1,3,5-trifluorobenzene with Hg(OCOCF₃)₂ yields, depending on the stoichiometry, 2,4,6-trifluorophenylmercury trifluoroacetate and 1,3-bis(trifluoroacetatomercuri)-2,4,6-trifluorobenzene which is converted into the corresponding chloromercuri derivative by treatment with hydrochloric acid in CH₃CN. As a product of the reaction of 1,3,5-trifluorobenzene and HgO in CH₃COOH only 2,4,6-trifluorophenylmercury acetate is isolated although spectroscopic evidence has been found for double and triple mercurated derivatives. All compounds are characterized by elemental analyses, nmr and mass spectra. The reaction of Hg(2,4,6-F₃C₆H₂)Cl and Cd(CF₃)₂ · 2 CH₃CN gives Hg(2,4,6-F₃C₆H₂)CF₃ which slowly dismutates in CH₂Cl₂ solution into Hg(2,4,6-F₃C₆H₂)₂ and Hg(CF₃)₂. The ligand exchange of Hg(2,4,6-F₃C₆H₂)₂ and TeCl₄ selectively gives Te(2,4,6-F₃C₆H₂)₂Cl₂ and Hg(2,4,6-F₃C₆H₂)Cl. Transmetalations of Hg(2,4,6-F₃C₆H₂)₂ and gallium or tin give NMR spectroscopic evidence for the new derivates Ga(2,4,6-F₃C₆H₂)₃ and Sn(2,4,6-F₃C₆H₂)₄.     

Hydrothermal Synthesis and Crystal Structure of a New Phosphonate： {[Cu（1,10-phen）]2-（H2O3PCH2C6H4C6H4CH2PO3H）2-（HO3PCH2C6H4C6H4CH2PO3H） }n

1 INTRODUCTION Metal organophosphonates have attracted considerable attention for over three decades due to their potential or practical applications, include- ing ion exchanges[1, 2], molecular sensors[3] and optics[4, 5]. Recently, a number of porous m…