Structures, IR, NMR Spectra and Thermodynamics Properties of Halogenated Compounds X‐1‐ZB₁₁H₁₀ (ZO, S, Se; XF, Cl, Br): A DFT Study

Abstract

The halogenated compounds of twelve-vertex closo-1-ZB 11 H 11 (Z＝O, S, Se; X＝F, Cl, Br) have unusual stability. The structures of halogenated isomers obtained by DFT method indicate that the halogen atoms are more likely to attack the meta vertexes. The chemical thermodynamic properties show that the halogenations are spontaneous and exothermic. The result that both the optimized and experimental cages of closo-thiaborane have not changed after chlorination indicates that the substitution of a chlorine atom for a hydrogen atom of closo-thiaborane happens at outer of the cage. The calculated electronic structures show that the three-dimensioned aromaticity of cage would like positive chlorine atoms to attack. The halogenations by elemental halogen in the presence of metal halides were proved to belong to the electrophilic substitutions and the mechanism was discussed in details. The suggested transition state interpreted the experiments. The thermal rearrangement which was supposed early according to experiments was verified by the thermodynamic properties of chlorination theoretically. The IR and 11 B/ 1 H NMR isotropic chemical shifts were calculated and compared with the experimental data to reconfirm the structures of chlorinated closo-thiaborane. Furthermore, the predictions on the halogenated closo-oxaborane and closo-selenaborane are significant for the syntheses.

Manipulation of Fischer‐Tropsch Synthesis for Production of Higher Alcohols Using Manganese Promoters

“…The oxygenate products could in turn be easily dehydrated to 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 make the olefins which maximises the yield of LAO products or utilised as a source for long chain alcohols following separation. [39] The high long chain oxygenate selectivity under normal low temperature FT conditions highlights the interest of the work, where conventional cobalt FT produces very little alcohol product. Physical mixture experiments that do not indicate the same performance as the co-mixed cobalt and manganese salts were also presented.…”

One step preparation of porous polyurea by reaction of toluene diisocyanate with water and its characterization

“…Polyureas (PU) can be synthesized either through condensation polymerization of multifunctional isocyanates (NCO, commonly diisocyanate or triisocyanate) with polyamines, or through the reaction of multifunctional isocyanate in excess with water with release of carbon dioxide, which turns the isocyanate groups into amines, followed by the same condensation polymerization of the isocyanate with the in situ produced amines. [1][2][3] PU has been well known to have thermal shock and abrasion resistance, high impact resistance, good exibility and water repellency as well as fast curing etc. 4 Common applications are protective coating materials for different structural materials, including concrete 5,6 and metals, [7][8][9] for instance.…”

“…Up to date, PU materials have been commercialized in a variety of elds, and relevant researches are being conducted to explore their novel applications. 2,3,[10][11][12][13][14] Up to now, most of the reported studies on PU syntheses and structure analyses were mainly focused on the condensation polymerization using diisocyanate and diamines, [15][16][17][18] fewer using multifunctional amines or isocyanates. 19,20 It is to stress that the pathway to PU synthesis, via multi-functional isocyanate reaction with water, followed by condensation reactions between the same isocyanates and the in situ formed amines, [1][2][3]21,22 is advantageous because the reactions involve only isocyanate monomer without need of any other chemicals, and in general, it can be easily performed at ambient temperature.…”

Structural, spectroscopic and magnetic properties of a novel copper(ii)l-tyrosinato complex

“…Cu((Npyridin-2-ylmethyl)-L-Tyr) 2 ]$2H 2 O,44 the rst compound is a chiral two-dimensional coordination polymer consisting of [Cu 2 (L-Tyr) 2 (NO 3 )(4,4 0 -bpy)(H 2 O) 2 ] n units 43 joined by bridging oxygen carboxylate atoms forming m-(O; O 0 ) mode.…”