共查询到20条相似文献,搜索用时 0 毫秒
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Fang Z Luo J Kang X Xia H Wang S Wen W Zhou X Wang P 《Physical chemistry chemical physics : PCCP》2011,13(16):7508-7513
The recent mechanistic finding of the hydrogen release pathways from ammonia borane (AB) has sparked new interest in the chemistry and properties of the diammoniate of diborane (DADB), an ionic isomer of AB. We herein report a facile one-step solid-phase synthesis route of DADB using inexpensive starting materials. Our study found that mechanically milling a 1?:?1 NaBH(4)/NH(4)F powder mixture causes the formation of crystalline DADB via a NH(4)BH(4) intermediate. The produced DADB can be readily separated from the sodium fluoride (NaF) by-product by a purification procedure using liquid ammonia at -78 °C. The thermal decomposition behavior of DADB was studied using synchronous thermal analyses, particularly in comparison with AB. It was found that the decomposition steps and products of DADB are similar to those of AB. But meanwhile, DADB exhibits a series of advantages over AB that merit its potential hydrogen storage application, such as lower dehydrogenation temperature, free of foaming and lack of an induction period in the thermal decomposition process. Our study further found that the volatile non-hydrogen products from DADB can be effectively suppressed by milling with MgH(2). 相似文献
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Bowden M Heldebrant DJ Karkamkar A Proffen T Schenter GK Autrey T 《Chemical communications (Cambridge, England)》2010,46(45):8564-8566
[(NH(3))(2)BH(2)](+)[BH(4)](-) is formed from the room temperature decomposition of NH(4)(+)BH(4)(-), via a NH(3)BH(3) intermediate. Its crystal structure has been determined and contains disordered BH(4)(-) ions in 2 distinct sites. Hydrogen release is similar to that from NH(3)BH(3) but with faster kinetics. 相似文献
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The mechanism of formation of ammonia borane (NH(3)BH(3), AB) and the diammoniate of diborane ([H(2)B(NH(3))(2)][BH(4)], DADB) in the reaction between NH(3) and THF·BH(3) was explored experimentally and computationally. Ammonia diborane (NH(3)BH(2)(μ-H)BH(3), AaDB), a long-sought intermediate proposed for the formation of DADB, was directly observed in the reaction using (11)B NMR spectroscopy. The results indicate that dihydrogen bonds between the initially formed AB and AaDB accelerate the formation of DADB in competition with the formation of AB. 相似文献
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Mariappan Periasamy G.P. Muthukumaragopal Nalluri Sanjeevakumar 《Tetrahedron letters》2007,48(39):6966-6969
Diborane is readily generated in situ at 25 °C in toluene using the Bu4NBH4/PhCH2Cl and Bu4NBH4/I2 reagent systems. The reagent prepared in this way is used for the reduction of carbonyl compounds and hydroboration-oxidation of olefins to obtain the corresponding alcohols in good yields. 相似文献
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《Journal of organometallic chemistry》1987,323(2):145-147
Treatment of NaBH4 with I2 in diglyme yields diborane which can be utilized conveniently for the preparation of a borane-N,N-diethylaniline complex and other borane-Lewis base complexes. 相似文献
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《Journal of Coordination Chemistry》2012,65(6):607-611
A new substituted tetra-(4-octanethiol-5-nitro)phthalocyaninatocopper complex was synthesized by nucleophlic substitution of tetra-(4-bromo-5-nitro)phthalocyaninatocopper where the bromo activated by an ortho-nitro group is easily substituted by 1-octanethiol. 相似文献
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AbstractAnilines are rapidly, often within 60?minutes, converted into the corresponding phenols in up to 87% isolated yield. The presented experimentally simple protocol display broad compatibility with a variety of functional groups, and in particular, well suited for the preparation of methyl-substituted phenols. Such phenols are not easily available by other synthetic approaches. The formation of phenolic radical coupling products was not observed even for activated anilines using this open flask method. 相似文献
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Thomas Schaub 《Tetrahedron letters》2005,46(47):8195-8197
An efficient one-pot reaction for the synthesis of biphenylene 1 starting from biphenyl is reported. The final product was prepared from commercially available, cheap materials in moderate yet very competitive yield. Biphenyl was ortho-lithiated to 2,2′-dilithiobiphenyl 2, which was then coupled to biphenylene. 相似文献
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Acylation of 3-methyl-2,3-bis(trimethylsiloxy)-l-butene (PhLi) with (E)-2-methyl-2-butenoyl chloride gives the corresponding 3(2H)-furanone derivative, which can be readily converted to the naturally occurring antitumor agent Geiparvarin by two steps. 相似文献
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The novel compounds tris-diethylaminocyclopropenyl perchlorate, bis-diethylaminocyclopropenone, and bis-dimethylaminocyclopropenone have been made. Pyrolysis of the cyclopropenones affords bis-dimethylamino- and bis-diethylaminoacetylene, and with iron carbonyl these have been converted to iron complexes of tetrakis-dialkylaminocyclopentadienones. 相似文献
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《Journal of fluorine chemistry》1988,41(3):363-369
Chlorofluoro- and perfluoroxy-alkynenitriles were conveniently prepared by the following reaction sequence: cyanomethylenetriphenylphosphorane was acylated by the addition of chlorofluoroalkanoyl chlorides or perfluoroxy-alkanoyl chloride, respectively, to the corresponding fluorinated phosphoranes and the latter compounds submitted to vacuum pyrolysis to afford the title compounds in 53-85% yields. 相似文献
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Rafik Gharbi Anis Romdhane Zine Mighri Marie‐Thrse Martin 《Journal of heterocyclic chemistry》2005,42(1):169-172
New tetracyclic 6H‐[1]benzopyrano[3,4‐e]pyrazolo[1,5‐a]pyrimidin‐6‐ones ( 4a‐e ) have been synthesized through the condensation under acidic conditions of [1]benzopyrano[4,3‐c][1,5]‐benzodiazepin‐7(8H)‐one ( 1 ) and a series of 3,4‐disubsituted 5‐amino‐1H‐pyrazoles 3a‐e . 相似文献