Nitrogen Fluorides and their Organic Derivatives.

Hoffman, C. J.; Neville, Roy G.

doi:10.1021/cr60215a001

Cited by 47 publications

(19 citation statements)

References 83 publications

(158 reference statements)

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“…12 We observed the same thing for Cs+NF 3 activated samples. Although we believe that the N-F cluster is simply the NF 3 molecular form because NF 3 is inert at room temperature, 13 we decided not to draw such a conclusion at this point simply based on the atomic ratio between N and F (0.3±0.1) alone. We use NF x to represent the N-F cluster.…”

Section: Submitted To Applied Physics Lettersmentioning

confidence: 99%

The surface activation layer of GaAs negative electron affinity photocathode activated by Cs, Li, and NF3

Sun

Kirby

Maruyama

et al. 2009

Applied Physics Letters

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The lifetime of GaAs photocathodes can be greatly improved by introducing Li in the Cs+NF3 activation process. The surface activation layer of such photocathodes is studied by synchrotron radiation photoemission and is compared with GaAs photocathodes activated without Li. The charge distributions of N, F, and Cs experience significant changes when Li is added in the activation. In addition, the presence of Li causes NFx molecules to take an orientation with F atoms on top. All these changes induced by Li hold the key for the lifetime improvement of GaAs photocathodes.

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Section: Submitted To Applied Physics Lettersmentioning

confidence: 99%

The surface activation layer of GaAs negative electron affinity photocathode activated by Cs, Li, and NF3

Sun

Kirby

Maruyama

et al. 2009

Applied Physics Letters

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“…(16a). The latter compound then decomposes in a first order reaction (with a half life of z 1 hour at -45°C) into nitrogen and lithium bis-(trimethylsily1)amide (14).…”

Section: Reduction Of Bsd With Electropositive Metals[41]mentioning

confidence: 99%

“…Freshly prepared Li[BSD] accordingly does not decompose at -45°C if an equimolar quantity of (14) is added to the reaction solution.…”

Section: Reduction Of Bsd With Electropositive Metals[41]mentioning

confidence: 99%

Bis(trimethylsilyl)diimine: Preparation, Structure, and Reactivity

Wibeŕg¹

1971

Angew. Chem. Int. Ed. Engl.

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Dedicated to my father, Professor Egon Wiberg, on the occasion of his 70th birthdayThe highly reactive compound bis(trimethylsily1)diimine (BSD), which was first prepared by oxidation of lithium tris(trimethylsilyl)hydrazide, is light blue, sensitive to thermolysis and hydrolysis, and ignites spontaneously in air. On the basis of electron transfer, acid-base, or freeradical reactions, it acts in particular as a (preparatively useful) redox system and as an agent for the introduction of azo groups. Redox reactions lead by oxidation or reduction of the other reactant through two oxidation stages to hydrazine derivatives or molecular nitrogen, and in the case of electrochemical reduction, to BSD radical-anions. Azo-group transfers, on the other hand, yield new inorganic azo compounds with no change in the oxidation state of the diimine group. Introductionas the fist diimine completely substituted with silyl groups131, the unexpectedly long-wave light absorption and the resulting radiant blue color of the compound immediately aroused our particular interest. The investigation of this substance, which has lost none of its orig- inal fascination, has proved worth while ; it has revealed a varied, unusual, and interesting chemistry.Various investigators had attempted to prepare a bis-(sily1)diimine. The ability of carbon to fonn azo compounds (Z), which are often surprisingly stable (for example, azobenzene is stable up to 600°C[41), makes the synthesis of "azosilanes" (2) a challenge in view ofthe group relationship between carbon and silicon. A possible preparation method was seen in the oxidation of 1,2-bis(silyl)hydrazines (3).However, several attempts to verify this reactionc5-' I were initially unsuccessful because of failure to find an oxidizing agent that could oxidize bis(sily1)hydrazines (3) only to the stage of the readily oxidizable bis(sily1)-diimines ( 4 ) without oxidizing these further to nitrogen '']. By the action of p-toluenesulfonyl azide on lithium tris-(trimethylsily1)hydrazide (X = Li, Y = SiR, in (3)), we were able to obtain BSD as a readily sublimable product that crystallizes in .the form of needles and melts at -3 OC131. Including BSD and a bis(bory1)diimine that is obtainable from it["], there are now ten classes of isolable diimine derivatives X-N=N-X(counting diimine itself) in which ligands X are linked to the azo group via maingroup elements having various atomic numbers:The arenesulfonyl azide, as in its reactions with CH-acidic methylene derivatives"'], evidently adds first to the silylhydrazide to form a nitrogen chain compound R' SO,-N=N-N-N(SiR,)-N(SiR,),,which can decompose after migration of silyl groups to give the final reaction products.Instead of arenesulfonyl azides, arenesulfonyl chlorides may be used as the oxidizing agents[1g! In this case, however, the reaction no longer follows a single course:R'S0,Li + R,SiClSince BSD is also difficult to separate from trirnethylchlorosilane, the process is less suitable for the preparation of this diimine. However, it may offer advantag...

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“…First discovered by Ruff in 1928 [2], its structure, bonding, and molecular properties have been extensively investigated for many years [3], and new information is still emerging [4,5]. At low temperatures, NF 3 reacts only sluggishly, particularly in the absence of reducing metals.…”

Section: Introductionmentioning

confidence: 99%

“…Various ion-molecule reactions involving the neutral NF 3 have been also observed and investigated [22][23][24]. The interest in this chemistry, that started essentially for fundamental reasons [11,12], has become progressively related to the above-mentioned industrial use of NF 3 .…”

Section: Introductionmentioning

confidence: 99%