Open-Flask Synthesis of Amine–Boranes via Tandem Amine–Ammonium Salt Equilibration–Metathesis
作者:P. Veeraraghavan Ramachandran、Ameya S. Kulkarni
DOI:10.1021/acs.inorgchem.5b00572
日期:2015.6.15
An amine–ammonium salt equilibration–metathesis sequence provides high-purity amine–boranes in excellent yields from sodium borohydride in refluxing reagent-grade tetrahydrofuran in an open flask.
Nucleophilic displacement of ammonia from ammonia borane for the preparation of alkylamine-, pyridine- and phosphine-boranes
作者:P. Veeraraghavan Ramachandran、Ameya S. Kulkarni
DOI:10.1039/c4ra03397c
日期:——
A near quantitative and safe preparation of a series of aliphatic amine- and phosphine-boranes from ammonia borane (AB) in refluxing THF has been achieved by exploiting the volatility of ammonia. A one-pot preparation of lithium aminoborohydrides from AB has also been described.
The role of ammonia in promoting ammonia borane synthesis
作者:P. Veeraraghavan Ramachandran、Ameya S. Kulkarni
DOI:10.1039/c6dt02925f
日期:——
Ammonia promotes the synthesis of pure ammoniaborane (AB) in excellent yields from sodium borohydride and ammonium sulfate in tetrahydrofuran under ambient conditions. An examination of the influence of added ammonia reveals that it is incorporated into the product AB, contrary to its perceived function as a catalyst or a co-solvent. Mechanistic studies point to a nucleophilic attack by ammonia on
Amine-Boranes: Green Hypergolic Fuels with Consistently Low Ignition Delays
作者:P. Veeraraghavan Ramachandran、Ameya S. Kulkarni、Mark A. Pfeil、Jacob D. Dennis、Jared D. Willits、Stephen D. Heister、Steven F. Son、Timothée L. Pourpoint
DOI:10.1002/chem.201405224
日期:2014.12.15
them to hypergols or decreases their ignitiondelays (IDs) multifold (with white fuming nitric acid as the oxidant). With consistentlylow IDs, amine–boranes represent a class of compounds that can be promising alternatives to toxic hydrazine and its derivatives as propellants. A structure–hypergolicity relationship study reveals the necessary features for the low ID.
Coordination of aminoborane, NH2BH2, dictates selectivity and extent of H2 release in metal-catalysed ammonia borane dehydrogenation
作者:Vincent Pons、R. Tom Baker、Nathaniel K. Szymczak、David J. Heldebrant、John C. Linehan、Myrna H. Matus、Daniel J. Grant、David A. Dixon
DOI:10.1039/b809190k
日期:——
In
situ
11
B NMR monitoring, computational modeling, and external trapping studies show that selectivity and extent of H2 release in metal-catalysed dehydrogenation of ammonia borane, NH3BH3, are determined by coordination of reactive aminoborane, NH2BH2, to the metal center.
原位 11 B NMR 监测、计算建模和外部捕获研究表明,在金属催化的氨硼烷 NH3BH3 脱氢反应中,H2 的选择性和释放程度取决于活性氨基硼烷 NH2BH2 与金属中心的配位。