Cationic Triarylchlorostibonium Lewis Acids

Organometallics, Journal Year: 2023, Volume and Issue: 42(5), P. 339 - 346

Published: Feb. 20, 2023

Organopnictogen cations show promise as powerful, tunable main-group Lewis acid catalysts. The synthesis, solid-state structures, and reactivity of a series weakly coordinated triarylchlorostibonium salts [Ar3SbCl][B(C6F5)4] (Ar = Ph, 3-FC6H4, 4-FC6H4, 3,5-F2C6H3, 2,4,6-F3C6H2) are reported. cation in each adopts tetrahedral coordination environment antimony, with near complete separation from the anion. Structural, computational, studies reveal that acidity [Ar3SbCl]+ generally increases increased fluorination Ar substituents, secondary quenching effect para fluorination. is reduced to Ar3Sb presence Et3SiH, mechanism this reaction has been modeled computationally. Preliminary demonstrate they useful catalysts for dimerization 1,1-diphenylethylene Friedel–Crafts alkylation benzene.

Language: Английский

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Mechanistic Investigations on Bismuth Catalyzed Reduction of Ketones and Phosphine Oxides

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(42)

Published: May 17, 2023

Abstract Lewis acidic bismuth compounds have found catalytic applications in the reduction of unsaturated bonds. In this work, we present inferences from mechanistic studies on ketones and phosphine oxides using organobismuth dication [NMe 2 C 6 H 4 Bi(L) 3 ][Al{OC(CF ) } ] presence silanes as reducing agents. Experiments computations converge to a Si−H activation pathway process.

Language: Английский

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Analyzing Fluoride Binding by Group 15 Lewis Acids: Pnictogen Bonding in the Pentavalent State

Published: June 16, 2023

We report the results of a computational investigation into fluoride binding by series pentavalent pnictogen Lewis acids: pentahalides (PnX5), tetraphenyl pnictogeniums (PnPh4+), and triphenyl tetrachlorocatecholates (PnPh3Cat). Activation strain energy decomposition analyses adducts clearly delineate electrostatic orbital contributions to these acid-base interactions, but they also highlight importance Pauli repulsion molecular flexibility in determining relative acidity among pnictogens.

Language: Английский

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Binuclear Triphenylantimony(V) Catecholates through N-Donor Linkers: Structural Features and Redox Properties

Molecules, Journal Year: 2022, Volume and Issue: 27(19), P. 6484 - 6484

Published: Oct. 1, 2022

A series of binuclear triphenylantimony(V) bis-catecholato complexes 1-11 the type (Cat)Ph3Sb-linker-SbPh3(Cat) was prepared by a reaction corresponding mononuclear catecholates (Cat)SbPh3 with neutral bidentate donor linker ligands pyrazine (Pyr), 4,4'-dipyridyl (Bipy), bis-(pyridine-4-yl)-disulfide (PySSPy), and diazobicyclo[2,2,2]octane (DABCO) in dry toluene: Cat = 3,6-di-tert-butyl-catecholate (3,6-DBCat), Pyr (1); PySSPy (2); Bipy (3); DABCO (4); 3,5-di-tert-butyl-catecholate (3,5-DBCat), (5); (9); 4,5-(piperazine-1,4-diyl)-3,6-di-tert-butylcatecholate (pip-3,6-DBCat), (6); (10); 4,5-dichloro-3,6-di-tert-butylcatecholate (4,5-Cl2-3,6-DBCat), (7); (11); 4,5-dimethoxy-3,6-di-tert-butylcatecholate (4,5-(MeO)2-3,6-DBCat), (8). The same (4,5-Cl2-3,6-DBCat)SbPh3 an open atmosphere results formation 1D coordination polymer {[(4,5-Cl2-3,6-DBCat)SbPh3·H2O]·DABCO}n (12). Bis-catecholate complex Ph3Sb(Cat-Spiro-Cat)SbPh3 reacts as 1:1 yielding rare macrocyclic tetranuclear compound {Ph3Sb(Cat-Spiro-Cat)SbPh3∙(Bipy)}2 (13). molecular structures 1, 3, 4, 5, 8, 10, 12, 13 crystal state were established single-crystal X-ray analysis. Complexes demonstrate different types relative spatial positions moieties. nature chemical bonds, charges distribution, energy Sb...N interaction investigated example 5. electrochemical behavior depends on coordinated N-donor ligand. pyrazine, Bipy, at antimony atom changes their mechanism electrooxidation: instead two successive redox stages Cat/SQ SQ/Cat, one multielectron stage observed. ligand is accompanied significant shift oxidation potentials catecholate to cathodic region (by 0.4 V), compared initial complex.

Language: Английский

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From Sn(II) to Sn(IV): Enhancing Lewis Acidity Via Oxidation

Inorganic Chemistry, Journal Year: 2023, Volume and Issue: 62(37), P. 14828 - 14832

Published: Sept. 7, 2023

We demonstrate the increased Lewis acidity on going from Sn(II) to Sn(IV) by oxidizing TpMe2SnOTf (OTf = SO3CF3) TpMe2SnF(OTf)2. Replacement of fluoride ion in TpMe2SnF(OTf)2 a triflate, resulting TpMe2Sn(OTf)3 further enhances at tin. 119Sn NMR spectroscopy, modified Gutmann-Beckett test, computational analysis, and catalytic phosphine oxide deoxygenation support claims.

Language: Английский

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