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Showing 1 to 19 of 19 for “"boranes"”.
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Fluorinated boranes in dehydrocoupling and hydroboration
… applies to the development of novel perfluoroarylboranes. Chapter 2 details the use of Me2S·BHn(C6F5)3−n in the preparation of the pentafluorophenyl substituted amine borane adducts, LB·BHn(C6F5)3−n (LB = NR3, NHR2, NH2R, py). Their solid state structures feature N—H···H—B and N—H···F—C hydrogen …
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Development of Hydrogen Storage Materials Based on Amine-Boranes
… for hydrogen storage in the form of amine-boranes; where ammonia as a Lewis base forms Lewis adducts with boranes. In the Lewis adducts involving ammonia and boranes, the control of substituents on the boron can serve to influence the hydrogen storage characteristics of the Lewis pair. In …
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Quantum Chemical Studies of Macropolyhedral Boranes and Related Clusters
An Borhydrid-Clustern wurden Dichtefunktional-Rechnungen durchgeführt um Regeln zu finden, die ihren Strukturen und relativen Stabilitäten zugrunde liegen. Dazu wurden Strukturinkremente für unvorteilhafte Strukturmerkmale ermittelt, und zwar in 11-Vertex nido- und 12-Vertex closo- Carboranen, …
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Solid amine-boranes as high performance hypergolic hybrid rocket fuels
… oxidizers. The incorporation of these amine-boranes, specifically ethylenediamine bisborane (EDBB), into various fuel binders has also been found to result in ignition delays between 3-10 ms - the fastest times again for amine based fuels. ^ It was found that the addition of a borane to an …
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Chemistry of B1- and B10- boranes containing halogen or pseudohalogen groups
… and molecular structures of two series of boranes i. e. [BH3X]- and [B10H9X]2- where X = H, CI, CN, NCS, SCN and N3. The calculational method used was the Modified Neglect of Differential Overlap (MNDO) method of Dewar et al. The results were compared where possible with experimental …
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Nickel-catalyzed Suzuki-Miyaura reactions of unactivated halides with alkyl boranes and planar-chiral borabenzene catalysts for Diels-Alder reactions
… reaction of unactivated alkyl bromides and alkyl boranes to include unactivated alkyl chlorides. The new method is adapted for use outside of a glove box and is also found to be applicable not only to the coupling of primary chlorides, but also to the coupling of bromides and iodides, both primary …
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Synthesis and reactivity of ortho-carborane functionalized boron species.
… Hydroboration reactions using secondary boranes have been explored in depth, whereas haloborations reactions are much less studied due to the decomposition pathways and not being selective in nature. In this chapter, we have shown that the use of bis(1-methyl-ortho-carborane)bromo borane …
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Boron ligand design and reactivity in metal complexes.
… Copper acetylides favor alkynyl transfer to boranes, forming stable alkynylboronates, while gold acetylides exhibit distinct covalent bonding that directs reactivity along alternative pathways. These findings demonstrate how subtle differences in metal–acetylide bonding can drastically …
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Structure, heats of formation, and bond dissociation energies of group IIIa-group IVA-group VA molecules for chemical hydrogen storage systems
… Dehydrogenation of methyl-substituted ammonia boranes is most favorable across B-N where methylation at N reduces the reaction exothermocity, becoming more thermoneutral. The adiabatic π-bond energy is defined as the rotational barrier between the ground state and C_s transition state …
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Incorporation of cyanide ligands into models of [FeFe]- and [NiFe]-hydrogenase
… found in [FeFe]-H2ase by coordination of triarylboranes to the [FeFe]-H2ase models [Fe2(pdt)(CO)4(CN)2]2‒ and [Fe2(adt)(CO)4(CN)2]2‒. Treatment of two equivalents of borane to [Fe2(pdt)(CO)4(CN)2]2‒ formed the 2:1 adduct [Fe2(pdt)(CO)4(CNBR3)2]2‒. Attempts to model the inequivalent hydrogen …
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Reactions at coordinated ligands: redox-active ligands and coordination of Lewis acids
… will be explored here in. The coordination of boranes to cyanide ligands is well know, however, this theme has not been applied to hydrogenase models. Cyanide is an essential component of the [FeFe]- and [NiFe]-hydrogenase active sites, both enzymes feature two cyanide ligands, however, models …
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Asymmetric nickel-catalyzed three-component assembly of allylic amines from alkynes, imines and organoboron reagents
… and organoboron reagents (boronic acids or boranes) using a catalyst derived from Ni(cod)2 and (c-CsH9)3P or (o-anisyl)3P. This catalytic, three-component process is tolerant of ketones, esters, and free hydroxyl groups; a degree of functional group compatibility unusual for imine addition …
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Utilising Boron containing Lewis Acid Functions as "Stores" for Hydride and Other functional groups and its impact on Catalytic Reactions
… towards the catalytic dehydrocoupling of amino-boranes.<br/>
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Ligand design in nickel and cobalt complexes for homogeneous catalysis
… ammonia borane (AB) and other amine boranes, releasing 1.7 eq H2 for AB. Stoichiometric addition of AB to (MesCCC)Co-py yielded the hydride-amidoborane complex (MesCCC)CoH(NH2BH3). This species is formed almost immediately in THF and is the catalytic resting state of the catalyst …
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Electroactive Conjugated Polymers as Charge-Transport Materials for Optoelectronic Thin-Film Devices
… and photophysical properties of the triarylboranes 4–6 that the pi–pi-interaction between boron and nitrogen atoms is comparably weak in these molecules. This leads to an unexpected ground-state polarisation with a partially positive boron atom and a partially negative nitrogen atom. …
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Functionalized nido-C4B2, closo-C2B5 and -C2B10 Carboranes, and Reactivity Studies on Electron-Poor 2,3-Dihydro-1,3-diborolyl Complexes of Ruthenium
… and the corresponding aminochloroboranes, respectively. In Chapter 3.5, the unprecedented transformation of 1,3-diiodo-1,3-diborole 37d into the known 2,3,4,5,6-pentacarba-nido- hexaborane(6) cation (63+) is observed. A possible mechanism for its formation is proposed. In Chapter …