Synthese, Kristallstruktur und 121Sb‐Mößbauer‐Spektrum von [SbCl2(18‐Krone‐6)]+SbCl6−

Neuhaus, Arndt; Frenzen, G.; Pebler, J.; Dehnicke, Kurt

doi:10.1002/zaac.19926180117

Cited by 22 publications

(12 citation statements)

References 6 publications

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“…The resulting complex of type C has the composition {[(MoCl 4 ) . (L)] + (15C5)} (95). The coordination polyhedron about the molybdenum atom is a distorted octahedron.…”

Section: Molybdenum Halidesmentioning

confidence: 99%

Structural-chemical aspects of complexation in metal halide–macrocyclic polyether systems

Belsky¹,

Булычев²

1999

Russ. Chem. Rev.

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“…The resulting complex of type C has the composition {[(MoCl 4 ) . (L)] + (15C5)} (95). The coordination polyhedron about the molybdenum atom is a distorted octahedron.…”

Section: Molybdenum Halidesmentioning

confidence: 99%

Structural-chemical aspects of complexation in metal halide–macrocyclic polyether systems

Belsky¹,

Булычев²

1999

Russ. Chem. Rev.

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“…1, in which UV spectra of SbCl 5 solution (curve 1) and the complex [SbCl 2 ·(18-Crown-6)] + SbCl 6 -(curve 2) synthesized by method [12] in methylene chloride are shown, the SbCl 6 anion does not have a characteristic maximum, but only shows a long wavelength shift from 267 nm for SbCl 5 to 272 nm for SbCl 6 -. Therefore complex formation of SCl 2 with a Lewis acid was indicated by measurement of the UV spectra of a mixture of SCl 2 -FeCl 3 in which there are two sharp maxima at 315 and 365 ( To obtain an indication of participation of the ionic complexes containing the chlorosulfonium cations as intermediates in the selective chlorination of chlorobenzene in the para-position, we carried out chlorination of chlorobenzene under the influence of the synthesized complexes and catalytic chlorinating SbCl 5 -sulfur-containing cocatalyst-Cl 2 system and compared the relative proportions of para-and ortho-dichlorobenzenes obtained in these pairs of reactions.…”

Section: Resultsmentioning

confidence: 99%

Active intermediates for the selective chlorination of chlorobenzene in the antimony pentachloride–sulfur-containing compound catalytic system

Serguchev

Chernobaev

2010

Theor Exp Chem

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Yu. A. Serguchev and I. I. ChernobaevIonic complexes of trichlorosulfonium, phenyldichlorosulfonium, and bis(p-chlorophenyl)chlorosulfonium hexachloroantimonates have been synthesized. Chlorination of chlorobenzene with the synthesized complexes and chlorine in the presence of the catalytic systems SbCl 5 -sulfur-containing compounds (SCl 2 , Ph 2 S, Ph 2 S 2 ) has been carried out. The close values of the para/ortho ratio of the dichlorobenzenes in these pairs of reactions provides a basis for considering that chlorosulfonium hexachloroantimonates are the para-selective intermediates in the chlorination of chlorobenzene.An important problem in the processes of catalytic chlorination of chlorobenzene is the preparation of a reaction mixture with the possibility of a high content of para-dichlorobenzene since the demand for it is greater than for ortho-dichlorobenzene. With this objective, Lewis acids (FeCl 3 , SbCl 5 , AlCl 3 , etc.) with sulfur-containing compounds are used in the chlorine industry as catalytic compositions. In the case of chlorination of benzene and chlorobenzene to dichlorobenzene the para/ortho ratio of isomers increased from approximately 1.5 using a Lewis catalyst alone to 3.3 and above using sulfur-containing compounds [1][2][3][4]. Despite the wide use of Lewis catalyst-sulfur-containing cocatalyst compositions, experimental demonstration of the participation of active intermediates of these catalytic systems in the selective chlorination of aromatic compounds is scarce in the literature.The most widely studied system is S 2 Cl 2 -AlCl 3 -SO 2 Cl 2 , the active reagent of which is believed [5-7] to be the complex SCl AlCl 3 4 + formed by the oxidation of S 2 Cl 2 by sulfuryl chloride according to the equation:3SO 2 Cl 2 + S 2 Cl 2 + 2AlCl 3 ® 3SO 2 + 2SCl AlClThe ionic structure of the complex, which was also obtained by chlorination of SCl 2 with molecular chlorine in the presence of AlCl 3 at low temperature, was established by Raman spectroscopy and nuclear quadrupole resonance [8]. This complex in a large excess of SO 2 Cl 2 (Ballester reagent) [5][6][7] or with the participation of molecular chlorine [9] is a powerful chlorinating agents for arenes and, in particular, halogenobenzenes with the formation of polychloroaromatic compounds. However in our 102 0040-5760/10/4602-0102

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“…Complexes 1c-1f were synthesized by the procedures in [7][8][9][10]. The complex SbCl 3 ·18C6·CH 3 CN (1c) [7] occurs as white crystals with T mp 142-143°C.…”

Section: Methodsmentioning

confidence: 99%

“…Using familiar procedures, on reaction of crown ethers 18C6 and 12C4 with a mixture of trivalent and pentavalent antimony chlorides, we synthesized the cationic complexes [SbCl 2 ·18C6] + SbCl 6 -(1d) and [Sb(12C4) 2 (CH 3 CN)] 3+ (SbCl 6 ) 3 -(1e), the structures of which, established by X-ray diffraction in [8] and [9] respectively, are shown in Fig. 1.…”

mentioning

confidence: 99%

“…The structure of this complex hinders its interaction with the ortho positions of the chlorobenzene molecule, which promotes an increase in the para selectivity of chlorination. The diameter of the macrocycle for this complex (which we calculated from the known Sb-O bond distances and O-Sb-O angles in the complex [SbCl 2 ·18C6] + SbCl 6 -(1d) from data in [8]) is within the range 4.2-4.8 Å, and the distance between the 12C4 planes of the sandwich complex [Sb(12C4) 2 (CH 3 CN)] 3+ (SbCl 6 ) 3 -(1e) is estimated from data in [9] as 2-3 Å. Therefore the chlorine molecule is more difficult to insert into the cavity of these complexes.…”

mentioning

confidence: 99%

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Selectivity of chlorobenzene chlorination catalyzed by complexes of antimony chloride with crown ethers

2011

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Yu. A. Serguchev, I. I. Chernobaev, and L. F. Lur'eWe have found that the para selectivity of chlorobenzene chlorination increases in the presence of the synthesized complexes and molecular complexes of antimony pentachloride with crown ethers, formed in solution. We show that complexes of antimony trichloride with crown ethers also initiate radical addition of chlorine to the aromatic ring of chlorobenzene and toluene.The most widely used and economically favorable processes for chlorination of aromatic compounds are technologies using Lewis acid catalysts (SbCl 3 , SbCl 5 , FeCl 3 , AlCl 3 , SnCl 4 , etc.). An important problem in processes for chlorination of chlorobenzene is obtaining reaction mixtures with as high a content of the para isomer of dichlorobenzene as possible, since the demand for it is higher than for the ortho isomer. With this goal, Lewis catalysts are usually used with organic sulfur compounds. In this case, the para/ortho ratio for the dichlorobenzenes increases approximately from 1.5-1.9 [1] to 3.3 or higher [2][3][4].In order to improve the para selectivity in chlorination of aromatic compounds, earlier we used a new approach involving the use of complexes of ferric chloride with crown ethers as chlorination catalysts [5]. In that paper, we showed that the selectivity of chlorination of chlorobenzene in the para position increases in the presence of the studied complexes, up to a para/ortho ratio for the dichlorobenzene isomers equal to 2.05-2.65. However, in that paper, we did not establish the correlation between the catalytic activity and the structural features of complexes of FeCl 3 with crown compounds, due to the lack of literature data on the structure of the studied complexes.In this work, we studied the effect on the rate and selectivity of chlorobenzene chlorination from the structure of molecular and cationic complexes of antimony(III) and antimony(V) chlorides with crown ethers having different macrocycle sizes: 18-crown-6 (18C6), 15-crown-5 (15C5), 12-crown-4 (12C4), and dibenzo-18-crown-6 (DB18C6).According to literature data [6], antimony pentachloride does not form stable complexes with intracavity coordination of the Sb(V) atom with the oxygen atoms of the crown ethers. They have not been successfully isolated from solutions in pure form, and therefore chlorination of chlorobenzene in the presence of these complexes occurs in homogeneous solution. We modeled the structure of these complexes by a quantum-chemical calculation using density functional theory (DFT) (we used the hybrid functional B3LYP) in a 3-21G basis, taking into account the effect of the solvent (the PCM method) using the program GAMESS. The structures obtained for SbCl 5 ·15C5 (1a), SbCl 5 ·DB18C6 (1b) are shown in Fig. 1. Characteristic features of these complexes include their electroneutrality and the presence of only one coordination bond Sb(V)-O with calculated bond lengths 2.20-2.24 Å and bond formation energy~34 kJ/mol, which lets us assign them to the class of molecular complexes.

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Synthese, Kristallstruktur und ¹²¹Sb‐Mößbauer‐Spektrum von [SbCl₂(18‐Krone‐6)]⁺SbCl₆⁻

Cited by 22 publications

References 6 publications

Structural-chemical aspects of complexation in metal halide–macrocyclic polyether systems

Structural-chemical aspects of complexation in metal halide–macrocyclic polyether systems

Active intermediates for the selective chlorination of chlorobenzene in the antimony pentachloride–sulfur-containing compound catalytic system

Selectivity of chlorobenzene chlorination catalyzed by complexes of antimony chloride with crown ethers

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