Ein blaues homoleptisches Bismut‐Stickstoff‐Kation

Baumann, Wolfgang; Schulz, Axel; Villinger, Alexander

doi:10.1002/ange.200803987

Cited by 25 publications

(3 citation statements)

References 35 publications

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“…calc.% (found): C 25.98 (26.57), H 6.54 (6.27), N 3.37 (2.99). 31 (18), 93 (13), 100(39), 130(65), 131(50), 147 (20), 159 (18), 173 (21), 174(43), 188 (15), 204(70), 205 (17), 245(41) [Si(Si(CH 3 ) 3 ) 3 -2H], 261 (19), 275 (28), 292 (28) [PN -Si(Si(CH 3 ) 3 ) 3 ], 295(41), 297 (18), 319 (16), 459(41), 460 (15), 461 (23), 563 (15), 581 (17) [M -Si(CH 3 ) 3 + Cl] + , 583 (17), 621 (17) [M + 2H] + .…”

Section: -Chloro-34-bis-tris(trimethylsilyl)silyl-cyclo-diphospha-dia...mentioning

confidence: 99%

Hypersilylated cyclodiphosphadiazanes and cyclodiphosphadiazenium salts

et al. 2009

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Starting from tris(trimethylsilyl)silane the novel 2-chloro-3,4-bis-tris(trimethylsilyl)silyl-cyclo-diphospha-diazenium-tetrachloridogallate salt (7) was prepared in a six step synthetic procedure including the synthesis of N-tris(trimethylsilyl)silyl-aminodichlorophosphine (4) and 1,3-dichloro-2,4-bis-tris(trimethylsilyl)silyl-cyclo-diphospha-diazane (5). All intermediate products along the reaction path have been isolated and fully characterized. The thermally stable cyclo-diphospha-diazenium-tetrachloridogallate (7) represents an interesting example of a binary cyclic P(III)/N four-membered heterocyclic cation, with a di- and tricoordinated P atom and a delocalized bond along the NP(+)N unit. The structures of all compounds are discussed on the basis of experimental X-ray data. Moreover, for comparison the hitherto unknown 1-chloro-3-trifluoromethanesulfonato-2,4-bis-tris(trimethylsilyl)silyl-cyclo-diphosphadiazane (6) has been synthesized and fully characterized.

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Section: -Chloro-34-bis-tris(trimethylsilyl)silyl-cyclo-diphospha-dia...mentioning

confidence: 99%

Hypersilylated cyclodiphosphadiazanes and cyclodiphosphadiazenium salts

et al. 2009

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“…[17] To the best of our knowledge, the influence of the anion with respect to the cation structure and physical properties has not been studied comprehensively. As a model system, we have chosen the N,N-bis[2, 6- [18] [CF 3 SO 3 ] -, [19] [B-(C 6 F 5 ) 4 ] -, [20,21,22] [GaCl 4 ] -, [10,20,23] [SbF 6 ] -, [24] [Al{OCH-…”

Section: Introductionmentioning

confidence: 99%

The N,N‐Bis(terphenyl)aminophosphenium Cation – A Sensitive Probe for Interactions with Different Anions

2011

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A series of salts that contain the terphenyl‐substitutedbis(amino)phosphenium cation with different anions (F–,Cl–, [CF3CO2]–, [CF3SO3]–, [B(C6F5)4]–, [GaCl4]–, [SbF6]–, [Al{OCH(CF3)2}4]– and [CHB11H5Br6]–) has been prepared by different synthetic protocols. All of the products have been characterised spectroscopically and by single‐crystal X‐ray diffraction studies. A detailed analysis of the interionic interactions and their influence on the molecular structure of the phosphenium cation reveals a strong dependence on the capability of the anion to enter the pocket generated by the bulky terphenyl substituents.

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“…Deshalb beschlossen wir, die Synthese des Diazeniumsalzes [(Me 3 Si) 2 NN‐SiMe 3 ] + [GaCl 4 ] − ( 4 [GaCl 4 ]) über Redoxreaktionen ausgehend von Schwermetallhydrazidderivaten, die bereits eine [(Me 3 Si) 2 N‐N‐SiMe 3 ] − ‐Einheit enthalten, zu versuchen. Zum Beispiel schienen das Dihydrazinobismutkation in [Bi{(N(SiMe 3 )N(SiMe 3 ) 2 } 2 ] + [GaCl 4 ] − ( 5 [GaCl 4 ])20 und das neutrale Quecksilber(II)‐dihydrazid Hg[N(SiMe 3 )N(SiMe 3 ) 2 ] 2 ( 6 )21 erfolgversprechende Kandidaten zu sein, da der 100 %‐Peak im CI + ‐Massenspektrum von 5 [GaCl 4 ] und 6 dem Diazeniumkation 4 + zugeordnet werden konnte, was auf ihr Potenzial als Diazeniumquelle hinweist. In der Tat führte die Reaktion von 5 [GaCl 4 ] mit GaCl 3 und elementarem Chlor oder Sulfurylchlorid als Oxidationsmittel in Dichlormethan bei Temperaturen unterhalb −50 °C nach Abfiltrieren des Niederschlages, Einengen im Vakuum und Lagerung bei −80 °C in geringen Ausbeuten zur Abscheidung blauer, extrem temperaturlabiler Kristalle, die durch Einkristallröntgenstrukturanalyse als 4 [GaCl 4 ] identifiziert werden konnten (Schema , oben) 18.…”

Section: Methodsunclassified

Recycling Powered by Release of Carbon Dioxide

2014

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In a cyclic process, fed with external chemical energy generated by the transformation of a compound with high chemical potential to carbon dioxide, the undesired enantiomer from a catalytic asymmetric reaction is continuously recycled to starting reagent. This minor enantiomer recycling is characterized by gradually increasing yields and product enantiomeric ratios. The requirements for maintaining a cyclic procedure are discussed; the necessity of a coupled exergonic process is demonstrated experimentally.Recycling procedures have been invoked in several models for the emergence of homochirality in autocatalytic systems. [1][2][3] Whereas such procedures may be feasible in open systems, incorporation of reverse reactions in models describing closed systems has been subject to intense discussions.[4] As pointed out already by Onsager, in a triangle reaction involving A, B, and C, at equilibrium each transformation is just as likely as its reverse, that is, transformation of A to B takes place as often as transformation of B to A (Scheme 1 a).[5] As each forward and backward reaction must balance, net cycling is not possible; a unidirectional cycle would necessarily involve a thermodynamically uphill process. Continuous addition of a reagent may serve to push the equilibrium for a forward reaction, and consequently for the entire cycle, but this shift does not help the reverse reaction to climb the high energy barrier. However, if a chemical process is performed in a system open to mass flow and coupled to a thermodynamically downhill reaction by transformation of a sacrificial reagent to a by-product with lower chemical potential, a cyclic process operating out of equilibrium may be maintained, [6] in analogy to the way cellular work is powered by adenosine triphosphate through coupling of exergonic to endergonic reactions.Recycling of the undesired enantiomer to achiral starting material may also serve to improve the enantiomeric excess in catalytic reactions. Onsager's example describes an isomerization process, but an analogous situation applies to a reaction network involving an enantioselective reaction with recycling of the minor enantiomer. If the forward, product-forming reaction favors formation of the R enantiomer, the principle of microscopic reversibility states that the reverse reaction cannot favor the reaction of S. However, chemical energy input by influx of a sacrificial reagent (X) with high chemical energy and the removal of compounds (Y and/or Z) with lower energies may serve as the driving force for a cyclic process (Scheme 1 b). [6] For simplicity, it is assumed that the forward reaction of achiral reactant A with reagent X produces a racemic product, that is, k R = k S , in which k R and k S are the rate constants for formation of the R and S enantiomers, respectively, from A, and that the reverse reaction, which restores the starting reagent and produces by-products Y and Z, proceeds with high selectivity, such that k' R % 0, for which k' R is the rate constant for decomposition of the R ...

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Ein blaues homoleptisches Bismut‐Stickstoff‐Kation

Cited by 25 publications

References 35 publications

Hypersilylated cyclodiphosphadiazanes and cyclodiphosphadiazenium salts

Hypersilylated cyclodiphosphadiazanes and cyclodiphosphadiazenium salts

The N,N‐Bis(terphenyl)aminophosphenium Cation – A Sensitive Probe for Interactions with Different Anions

Recycling Powered by Release of Carbon Dioxide

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