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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. [ABSTRACT FROM AUTHOR]

Compounds exhibiting main group elements in low oxidation states were found to mimic the reactivity of transition metal complexes. Like the latter, such main group species show a proclivity of changing their oxidation state as well as their coordination number by +2, therefore fulfilling the requirements for oxidative additions. Prominent examples of such main group compounds that undergo oxidative additions with organohalides R−X (R=alkyl, aryl, X=F, Cl, Br, I) are carbenes and their higher congeners. Aluminyl anions, which like carbenes and silylenes oxidatively add to strong σ‐bonds in R−X species, have been recently discovered. We present the first anion based upon a Group 14 element, namely the tris(pentafluoroethyl)silanide anion, [Si(C2F5)3]−, which is capable of oxidative additions towards C−F bonds. This enables the isolation of non‐chelated tetraorganofluorosilicate salts, which to the best of our knowledge had only been observed as reactive intermediates before. [ABSTRACT FROM AUTHOR]

According to a first view on the geometrical and electronic structure of the tris(pentafluoroethyl)silanide, this anion appears as a Lewis base. Quantum chemical calculations on perfluoroalkylated silanides show significantly lower HOMO and LUMO energy levels in comparison to their non‐fluorinated counterparts, which implies reduced Lewis basicity and increased Lewis acidity of the [Si(C2F5)3]− ion. With these findings and a HOMO–LUMO gap of 4.80 eV similar to N‐heterocyclic silylenes (NHSis), perfluoroalkyl silanides are predestined to exhibit Lewis‐amphoteric character similar to silylenes. Deprotonation of Si(C2F5)3H with sterically demanding phosphazene bases afforded thermally stable phosphazenium salts of the [Si(C2F5)3]− anion, which add to benzaldehyde, benzophenone, CS2, and CO2 in various manners. This behavior also mirrors the reactivity of silylenes towards ketones as well as heterocumulenes and is rationalized by Lewis amphotericity being inherent in these silanides. [ABSTRACT FROM AUTHOR]

The reaction of a strongly basic phosphazene (Schwesinger base) with water afforded the corresponding metastable hydroxide trihydrate [OH(OH2)3]− salt. This is the first hydroxide solvate that is not in contact with a cation and furthermore one of rare known water‐stabilized hydroxide anions. Thermolysis in vacuum results in the decomposition of the hydroxide salt and quantitative liberation of the free phosphazene base. This approach was used to synthesize the Schwesinger base from its hydrochloride salt after anion exchange in excellent yields of over 97 %. This deprotonation method can also be used for the phosphazene‐base‐catalyzed preparation of the Ruppert–Prakash reagent Me3SiCF3 using fluoroform (HCF3) as the trifluoromethyl building block and sodium hydroxide as the formal deprotonation agent. [ABSTRACT FROM AUTHOR]

Weakly coordinating anions (WCAs) are important for academic reasons as well as for technical applications. Tetrakis(pentafluoroethyl)gallate, [Ga(C2F5)4]−, a new WCA, is accessible by treatment of [GaCl3(dmap)] (dmap=4‐dimethylaminopyridine) with LiC2F5. The anion [Ga(C2F5)4]− proved to be reluctant towards deterioration by aqueous hydrochloric acid or lithium hydroxide. Various salts of [Ga(C2F5)4]− were synthesized with cations such as [PPh4]+, [CPh3]+, [(O2H5)2(OH2)2]2+, and [Li(dec)2]+ (dec=diethyl carbonate). Thermolysis of [(O2H5)2(OH2)2][Ga(C2F5)4]2 gives rise to a dihydrate of tris(pentafluoroethyl)gallane, [Ga(C2F5)3(OH2)2]. All products were characterized by NMR and IR spectroscopy, mass spectrometry, X‐ray diffraction, and elemental analysis. Furthermore, an outlook for the application of [Li(dec)2][Ga(C2F5)4] as a conducting salt in lithium‐ion batteries is presented. [ABSTRACT FROM AUTHOR]

The tris(pentafluoroethyl)silanide anion is accessible by the deprotonation of Si(C2F5)3H at low temperatures. Subsequent quenching of the resulting salt-like compounds with suitable electrophiles, such as transition-metal complexes or Group 14 element halides, leads to a plethora of novel tris(pentafluoroethyl)silane derivatives. This underlines the versatility of Li[Si(C2F5)3] as a powerful nucleophilic transfer reagent. [ABSTRACT FROM AUTHOR]

The synthesis of the germylene phosphane adduct (C2F5)2Ge⋅PMe3 is described. Starting from (C2F5)3GeH in an excess of PMe3, heating was applied, whereupon reductive elimination of C2F5H occurred. The molecular structure was ascertained by X-ray diffraction and compared with information obtained by quantum chemical methods. The ligand properties were derived by studying the IR spectrum of the nickel(0) complex [Ni(CO)3{Ge(C2F5)2(PMe3)}] in the CO region. (C2F5)2Ge⋅PMe3 turned out to be a π-accepting ligand comparable to PMe3, in terms of Tolman's electronic parameter. Furthermore a [2+4] cycloaddition reaction with 2,3-dimethyl-1,3-butadiene, and σ-bond insertion reactions were recorded. Activation of the C−Cl bond in dichloromethane gives rise to the formation of the phosphonium ylide complex [(C2F5)2Cl2Ge-CH2PMe3], which was fully characterized by X-ray diffraction. [ABSTRACT FROM AUTHOR]

Fluorine, Oxidative Addition, Perfluorosilicates, Silanide Anion, Silicon Frontispiece: Oxidative Additions of C-F Bonds to the Silanide Anion [Si(C2F5)3]- Keywords: Fluorine; Oxidative Addition; Perfluorosilicates; Silanide Anion; Silicon EN Fluorine Oxidative Addition Perfluorosilicates Silanide Anion Silicon 1 1 1 04/14/22 20220419 NES 220419 B Silicon b In their Research Article (e202116468), Berthold Hoge et al. report oxidative additions of [Si(C SB 2 sb F SB 5 sb ) SB 3 sb ] SP - sp to aryl- and alkenylfluorides, enabling the isolation of tetraorganofluorosilicate salts devoid of chelating ligands. [Extracted from the article]

Silicon In their Research Article (e202116468), Berthold Hoge et al. report oxidative additions of [Si(C2F5)3]− to aryl‐ and alkenylfluorides, enabling the isolation of tetraorganofluorosilicate salts devoid of chelating ligands. [ABSTRACT FROM AUTHOR]

Keywords: activation of small molecules; Lewis amphoteric; perfluoroalkyl; silanides; weakly coordinating cations EN activation of small molecules Lewis amphoteric perfluoroalkyl silanides weakly coordinating cations 11533 11533 1 05/13/21 20210517 NES 210517 B The tris(pentafluoroethyl)silanide b anion adds to carbonyl compounds Ph(R)CO (R=Ph, H), CS SB 2 sb , and CO SB 2 sb , allowing the isolation of novel negatively charged species like [Si(C SB 2 sb F SB 5 sb ) SB 3 sb ( SP 2 sp -OC(R)Ph)] SP - sp (R=Ph, H), [Si(C SB 2 sb F SB 5 sb ) SB 3 sb ( SP 2 sp -CS SB 2 sb )] SP - sp , and [Si(C SB 2 sb F SB 5 sb ) SB 3 sb ( SP 2 sp -CO SB 3 sb )] SP - sp . Cover Picture: Evidence of the Lewis-Amphoteric Character of Tris(pentafluoroethyl)silanide, [Si(C2F5)3]- (Angew. Activation of small molecules, Lewis amphoteric, perfluoroalkyl, silanides, weakly coordinating cations. [Extracted from the article]

The research area of perfluoroalkylsilanes is still in its infancy. Although there are already many examples of difluorotriorganylsilicates, the first example of a completely characterized trifluorotriorganylsilicate is presented, the dianion [Si(C2F5)3F3]2−. The strongly electron-withdrawing influence of the pentafluoroethyl groups appears to be a fundamental cause of the stability of this compound. This dianion is also the first structurally characterized example of a tris(pentafluoroethyl)silicon compound. The synthesis and complete characterization of [PPh4]2[Si(C2F5)3F3] and [PPh4][Si(C2F5)3F2] along with the precursor [H(OEt2)2][Si(C2F5)3F2] was achieved from SiCl4 and LiC2F5. [ABSTRACT FROM AUTHOR]

The cover page of the journal "Angewandte Chemie" is presented.

Compounds exhibiting main group elements in low oxidation states were found to mimic the reactivity of transition metal complexes. Like the latter, such main group species show a proclivity of changing their oxidation state as well as their coordination number by +2, therefore fulfilling the requirements for oxidative additions. Prominent examples of such main group compounds that undergo oxidative additions with organohalides R−X (R=alkyl, aryl, X=F, Cl, Br, I) are carbenes and their higher congeners. Aluminyl anions, which like carbenes and silylenes oxidatively add to strong σ‐bonds in R−X species, have been recently discovered. We present the first anion based upon a Group 14 element, namely the tris(pentafluoroethyl)silanide anion, [Si(C2F5)3]−, which is capable of oxidative additions towards C−F bonds. This enables the isolation of non‐chelated tetraorganofluorosilicate salts, which to the best of our knowledge had only been observed as reactive intermediates before. [ABSTRACT FROM AUTHOR]

According to a first view on the geometrical and electronic structure of the tris(pentafluoroethyl)silanide, this anion appears as a Lewis base. Quantum chemical calculations on perfluoroalkylated silanides show significantly lower HOMO and LUMO energy levels in comparison to their non‐fluorinated counterparts, which implies reduced Lewis basicity and increased Lewis acidity of the [Si(C2F5)3]− ion. With these findings and a HOMO–LUMO gap of 4.80 eV similar to N‐heterocyclic silylenes (NHSis), perfluoroalkyl silanides are predestined to exhibit Lewis‐amphoteric character similar to silylenes. Deprotonation of Si(C2F5)3H with sterically demanding phosphazene bases afforded thermally stable phosphazenium salts of the [Si(C2F5)3]− anion, which add to benzaldehyde, benzophenone, CS2, and CO2 in various manners. This behavior also mirrors the reactivity of silylenes towards ketones as well as heterocumulenes and is rationalized by Lewis amphotericity being inherent in these silanides. [ABSTRACT FROM AUTHOR]

Weakly coordinating anions (WCAs) are important for academic reasons as well as for technical applications. Tetrakis(pentafluoroethyl)gallate, [Ga(C2F5)4]−, a new WCA, is accessible by treatment of [GaCl3(dmap)] (dmap=4‐dimethylaminopyridine) with LiC2F5. The anion [Ga(C2F5)4]− proved to be reluctant towards deterioration by aqueous hydrochloric acid or lithium hydroxide. Various salts of [Ga(C2F5)4]− were synthesized with cations such as [PPh4]+, [CPh3]+, [(O2H5)2(OH2)2]2+, and [Li(dec)2]+ (dec=diethyl carbonate). Thermolysis of [(O2H5)2(OH2)2][Ga(C2F5)4]2 gives rise to a dihydrate of tris(pentafluoroethyl)gallane, [Ga(C2F5)3(OH2)2]. All products were characterized by NMR and IR spectroscopy, mass spectrometry, X‐ray diffraction, and elemental analysis. Furthermore, an outlook for the application of [Li(dec)2][Ga(C2F5)4] as a conducting salt in lithium‐ion batteries is presented. [ABSTRACT FROM AUTHOR]

Fluorine, Oxidative Addition, Perfluorosilicates, Silanide Anion, Silicon Frontispiece: Oxidative Additions of C-F Bonds to the Silanide Anion [Si(C2F5)3]- Keywords: Fluorine; Oxidative Addition; Perfluorosilicates; Silanide Anion; Silicon EN Fluorine Oxidative Addition Perfluorosilicates Silanide Anion Silicon 1 1 1 04/14/22 20220419 NES 220419 B Silicon b In their Research Article (e202116468), Berthold Hoge et al. report oxidative additions of [Si(C SB 2 sb F SB 5 sb ) SB 3 sb ] SP - sp to aryl- and alkenylfluorides, enabling the isolation of tetraorganofluorosilicate salts devoid of chelating ligands. [Extracted from the article]

Silicon In their Research Article (e202116468), Berthold Hoge et al. report oxidative additions of [Si(C2F5)3]− to aryl‐ and alkenylfluorides, enabling the isolation of tetraorganofluorosilicate salts devoid of chelating ligands. [ABSTRACT FROM AUTHOR]