3+ and [Sb13Se16Br2] 5+ - Double and quadruple spiro cubanes from ionic liquids

Handle URI:
http://hdl.handle.net/10754/563335
Title:
3+ and [Sb13Se16Br2] 5+ - Double and quadruple spiro cubanes from ionic liquids
Authors:
Ahmed, Ejaz; Breternitz, Joachim; Groh, Matthias Friedrich; Isaeva, Anna A.; Ruck, Michael J.
Abstract:
The reaction of antimony and selenium in the bromine-rich Lewis acidic ionic liquid [BMIm]Br·4.7AlBr3 (BMIm: 1-butyl-3- methylimidazolium) in the presence of a small amount of NbCl5 at 160 °C yielded dark-red crystals of [Sb7Se8Br 2][AlX4]3. For X = Cl0.15(1)Br 0.85(1), the compound is isostructural to [Sb7S 8Br2][AlCl4]3 [P212 121, a = 12.5132(5) Å, b = 17.7394(6) Å, c = 18.3013(6) Å]. For a higher chlorine content, X = Cl 0.58(1)Br0.42(1), a slightly disordered variant with a bisected unit cell is found [P21212, a = 12.3757(3) Å, b = 17.4116(5) Å, c = 9.0420(2) Å]. The [Sb 7Se8Br2]3+ heteropolycation (C 2 symmetry) is a spiro double-cubane with an antimony atom on the shared corner. From this distorted octahedrally coordinated central atom, tricoordinate selenium and antimony atoms alternate in the bonding sequence. The terminal antimony atoms each bind to a bromine atom. Quantum chemical calculations confirm polar covalent Sb-Se bonding within the cubes and indicate three-center, four-electron bonds for the six-coordinate spiro atoms. The calculated charge distribution reflects the electron-donor role of the antimony atoms. The use of a chlorine-rich ionic liquid resulted in the formation of triclinic [Sb13Se16Br2][AlX4] 5 with X = Cl0.80(1)Br0.20(1) [P$\bar {1}$, a = 9.0842(5) Å, b = 19.607(1) Å, c = 21.511(1) Å, α = 64.116(6), β = 79.768(7), γ = 88.499(7)]. The cationic cluster [Sb13Se16Br2]5+ is a bromine-terminated spiro quadruple-cubane. This 31 atom concatenation of four cubes is assumed to be the largest known discrete main group polycation. A similar reaction in a chloride-free system yielded [Sb7Se 8Br2][Sb13Se16Br2] [AlBr4]8. In its monoclinic structure [P2/c, a = 27.214(5) Å, b = 9.383(2) Å, c = 22.917(4) Å, β = 101.68(1)], the two types of polycations alternate in layers along the a axis. In the series [Sb4+3nSe4+4nBr2](2+n)+, these cations are the members with n = 1 and 3. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
KAUST Department:
KAUST Solar Center (KSC); Physical Sciences and Engineering (PSE) Division; Chemical Science Program
Publisher:
Wiley-Blackwell
Journal:
European Journal of Inorganic Chemistry
Issue Date:
8-Jan-2014
DOI:
10.1002/ejic.201301155
Type:
Article
ISSN:
14341948
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; KAUST Solar Center (KSC)

Full metadata record

DC FieldValue Language
dc.contributor.authorAhmed, Ejazen
dc.contributor.authorBreternitz, Joachimen
dc.contributor.authorGroh, Matthias Friedrichen
dc.contributor.authorIsaeva, Anna A.en
dc.contributor.authorRuck, Michael J.en
dc.date.accessioned2015-08-03T11:46:02Zen
dc.date.available2015-08-03T11:46:02Zen
dc.date.issued2014-01-08en
dc.identifier.issn14341948en
dc.identifier.doi10.1002/ejic.201301155en
dc.identifier.urihttp://hdl.handle.net/10754/563335en
dc.description.abstractThe reaction of antimony and selenium in the bromine-rich Lewis acidic ionic liquid [BMIm]Br·4.7AlBr3 (BMIm: 1-butyl-3- methylimidazolium) in the presence of a small amount of NbCl5 at 160 °C yielded dark-red crystals of [Sb7Se8Br 2][AlX4]3. For X = Cl0.15(1)Br 0.85(1), the compound is isostructural to [Sb7S 8Br2][AlCl4]3 [P212 121, a = 12.5132(5) Å, b = 17.7394(6) Å, c = 18.3013(6) Å]. For a higher chlorine content, X = Cl 0.58(1)Br0.42(1), a slightly disordered variant with a bisected unit cell is found [P21212, a = 12.3757(3) Å, b = 17.4116(5) Å, c = 9.0420(2) Å]. The [Sb 7Se8Br2]3+ heteropolycation (C 2 symmetry) is a spiro double-cubane with an antimony atom on the shared corner. From this distorted octahedrally coordinated central atom, tricoordinate selenium and antimony atoms alternate in the bonding sequence. The terminal antimony atoms each bind to a bromine atom. Quantum chemical calculations confirm polar covalent Sb-Se bonding within the cubes and indicate three-center, four-electron bonds for the six-coordinate spiro atoms. The calculated charge distribution reflects the electron-donor role of the antimony atoms. The use of a chlorine-rich ionic liquid resulted in the formation of triclinic [Sb13Se16Br2][AlX4] 5 with X = Cl0.80(1)Br0.20(1) [P$\bar {1}$, a = 9.0842(5) Å, b = 19.607(1) Å, c = 21.511(1) Å, α = 64.116(6), β = 79.768(7), γ = 88.499(7)]. The cationic cluster [Sb13Se16Br2]5+ is a bromine-terminated spiro quadruple-cubane. This 31 atom concatenation of four cubes is assumed to be the largest known discrete main group polycation. A similar reaction in a chloride-free system yielded [Sb7Se 8Br2][Sb13Se16Br2] [AlBr4]8. In its monoclinic structure [P2/c, a = 27.214(5) Å, b = 9.383(2) Å, c = 22.917(4) Å, β = 101.68(1)], the two types of polycations alternate in layers along the a axis. In the series [Sb4+3nSe4+4nBr2](2+n)+, these cations are the members with n = 1 and 3. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.en
dc.publisherWiley-Blackwellen
dc.subjectAntimonyen
dc.subjectCluster compoundsen
dc.subjectIonic liquidsen
dc.subjectMain group elementsen
dc.subjectPolycationsen
dc.subjectSeleniumen
dc.subjectSpiro compoundsen
dc.title3+ and [Sb13Se16Br2] 5+ - Double and quadruple spiro cubanes from ionic liquidsen
dc.typeArticleen
dc.contributor.departmentKAUST Solar Center (KSC)en
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentChemical Science Programen
dc.identifier.journalEuropean Journal of Inorganic Chemistryen
dc.contributor.institutionFachrichtung Chemie und Lebensmittelchemie, Technische Universität Dresden, 01062 Dresden, Germanyen
dc.contributor.institutionWestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdomen
dc.contributor.institutionMax-Planck-Institut für Chemische Physik Fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germanyen
kaust.authorAhmed, Ejazen
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