Although the adduct of aluminum trichloride with thionyl chloride has been reported, no thionyl chloride adduct of a main group element Lewis acid or organometallic compound has been structurally ...characterized. In this communication we present the synthesis and reactivity of the structurally ascertained adduct of thionyl chloride with tris(pentafluoroethyl)gallane as a representative of a main group element Lewis acid. Gallium and indium compounds with electron withdrawing groups, e.g. the pentafluoroethyl ligand, display versatile properties. While gallates and indates, MR4–, behave as weakly coordinating anions, neutral gallanes and indanes, MR3, are strong Lewis acids. Salts with the tetrakis(pentafluoroethyl)gallate and ‐indate, M(C2F5)4– (M=Ga, In), have recently been studied in detail. In contrast to this, work on the syntheses of the free Lewis superacids M(C2F5)3 (M= Ga, In) is scarce and underdeveloped. The hydrates M(C2F5)3(OH2)2 proved to be suitable starting materials, particularly due to their thermal stability. Herein we report on synthesis and characterization of reactive adducts, M(C2F5)3D, with the weak donor molecules (D) SOCl2 and Me3SiF. The effective Lewis acidities of Ga(C2F5)3 and In(C2F5)3 were experimentally determined by the (modified) Gutmann‐Beckett method and their catalytic potential is showcased.
Eureka! We found it! Acetonitrile is not easily activated or even deprotonated. A combination of the strong Lewis acid (C2F5)3PF2 and triethylamine, however, are able to deprotonate CH3CN. The ...resulting cyanomethyl function is bound to the phosphorus moiety, affording the highly stable salt HNEt3P(C2F5)3F2(CH2CN). Using more nucleophilic secondary and primary amines instead of NEt3 leads to a phosphate featuring an amidine ligand, which formally results from hydroamination of acetonitrile by the amine. More information can be found in the Full Paper by B. Hoge et al. on page 6975.
Decarbonylation of a cyclic bis-phosphaethynolatostannylene (ADC)Sn(PCO)2 based on an anionic dicarbene framework (ADC = PhC{N(Dipp)C}2 ; Dipp = 2,6-iPr2 C6 H3 ) under UV light results in the ...formation of a Sn2 P2 cluster compound (ADC)SnP2 as a green crystalline solid. The electronic structure of (ADC)SnP2 is analyzed by quantum-chemical calculations. At room temperature, (ADC)SnP2 reversibly binds with CO2 and forms (ADC)2 {SnOC(O)P}SnP. (ADC)SnP2 enables catalytic hydroboration of CO2 and reacts with elemental selenium and Fe2 (CO)9 to afford (ADC)2 {Sn(Se)P2 }SnSe and (ADC)Sn{Fe(CO)4 }P2 , respectively. All compounds are characterized by multinuclear NMR spectroscopy and their solid-state molecular structures are determined by single-crystal X-ray diffraction.
Reaction of the carbyne complexes Tp‘(CO)2M⋮C−PC(NR2)2 (1, 2) Tp‘ = HB(3,5-Me2C3HN2)3; M = Mo (1, 3); W (2, 4); R = Me (a); Et (b) with methyl trifluoromethanesulfonate afforded the orange-red salts ...Tp‘(CO)2M⋮C−P(Me)C(NR2)2SO3CF3 (3, 4), the cations of which can be considered as methylphosphines featuring additional bisaminocarbenium- and metallaalkynyl substituents. Analogously, complex Tp‘(CO)2W⋮C−PC(NEt2)2 (2b) was protonated with ethereal HBF4 in ether at the phosphorus atom to give Tp‘W⋮C−P(H)−C(NEt2)2BF4 (5), which in CH2Cl2 solution experienced a clean rearrangement to the metallaphosphirene (6). Treatment of 2b with F3CSO3H led directly to (6‘). The molecular structures of 4b and 6‘ were established by X-ray structure analysis.
Abstract
C
15
H
16
Cl
2
N
4
O
2
, monoclinic,
P
2
1
/
c
(no. 14),
a
= 26.2014(7) Å,
b
= 7.59320(10) Å,
c
= 17.9766(4) Å,
β
= 109.217(3)°,
V
= 3377.20(14) Å
3
,
Z
= 8,
R
gt
(
F
) = 0.0503,
wR
...ref
(
F
2
) = 0.1411, T = 100.0(1) K.
The Front Cover shows the solid‐state structure of a syn‐biconcave tribenzotriquinacene dimer synthesized by chirality‐controlled two‐fold crosswise Ullmann‐type condensation of an enantiomerically ...pure TBTQ‐based ortho‐iodophenol with (M)‐configuration (X = I, Y = OH). Such highly bowl‐shaped building blocks with single‐wing functionalization at the aromatic periphery were obtained on a gram‐scale via enantioselective enzyme‐catalyzed ester hydrolysis in the key step. More information can be found in the Full Paper by H. Gröger, D. Kuck et al.
Ein zweizähniges Pniktogenbrücken‐Wirtsystem auf der Basis von 1,8‐Diethinylanthracen wurde mittels einer selektiven Zinn‐Antimon‐Austauschreaktion hergestellt und auf seine Fähigkeit untersucht, als ...Lewis‐saure Wirtskomponente für die Komplexierung von Lewis‐basischen oder anionischen Gästen zu fungieren. In dieser Arbeit wurde mit der C≡C−Sb(C2F5)2‐Gruppe eine neuartige Akzeptorfunktion etabliert, mit der das Potenzial von Antimon(III)‐Funktionen als Vertreter der kaum erforschten Pniktogenbrücken‐Donatoren untersucht werden kann. Die Akzeptorfähigkeit dieses teilfluorierten Wirtsystems wurde gegenüber Halogenidanionen (Cl−, Br−, I−), Dimethylchalkogeniden Me2Y (Y = O, S, Se, Te) und Stickstoffheterozyklen (Pyridin, Pyrimidin) untersucht. Einblicke in das Adduktbildungsverhalten sowie die Bindungssituation solcher E⋅⋅⋅Sb−CF‐Einheiten wurden in Lösung mittels NMR‐Spektroskopie, im festen Zustand durch Röntgenbeugung, durch Elementaranalysen sowie durch rechnerische Methoden (DFT, QTAIM, IQA) gewonnen.
Ein zweizähniges Pniktogenbrücken‐Wirtsystem wurde auf der Grundlage von Sb(C2F5)2‐Funktionen konstruiert und seine Wirt‐Gast‐Chemie gegenüber einer Vielzahl von Substraten getestet, darunter Me2O und seine höheren Homologen, Halogenidionen und N‐heterozyklische Basen. Das neue Wirtsystem zeigt eine Kooperativität der beiden C≡C−Sb(C2F5)2‐Funktionen bei der Adduktbildung. Die Komplexe wurden sowohl experimentell (XRD, NMR) als auch mit Berechnungen (DFT, QTAIM, IQA) analysiert.
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