File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Structural, dynamic, and theoretical studies of [Au(n)Pt2(PPh3)4(μ-S)(2-n)(μ3-S)(n)L][PF6](n) [n = 1, L = PPh3; n = 2, L = Ph2PCH2PPh2, (C5H4PPh2)2Fe]

TitleStructural, dynamic, and theoretical studies of [Au(n)Pt2(PPh3)4(μ-S)(2-n)(μ3-S)(n)L][PF6](n) [n = 1, L = PPh3; n = 2, L = Ph2PCH2PPh2, (C5H4PPh2)2Fe]
Authors
Issue Date2000
Citation
Inorganic Chemistry, 2000, v. 39, n. 23, p. 5299-5305 How to Cite?
AbstractThree heterometallic Au-Pt complexes [Pt2(PPh3)4(μ-S)(μ3-S)Au(PPh3)][PF6] (2), [Pt2(PPh3)4(μ3-S)2Au2(μ-dppm)]-[PF6]2 (3), and [pt2(Pph3)4(μ3-S)2(μ-dppf)][PF6]2 (4) have been synthesized from Pt2(PPh3)4(μ-S)2 (1) [dppm = Ph2PCH2PPh2; dppf = (C5H4PPh2)2Fe] and characterized by single-crystal X-ray crystallography. In 2, the Au(I) atom is anchored on only one of the sulfur centers. In 3 and 4, both sulfur atoms are aurated, showing the ability of 1 to support an overhead bridge structure, viz. [Au2(P-P)], with or without the presence of Au-Au bond. The change of dppf to dppm facilitates such active interactions. Two stereoisomers of complex 3 (3a,b) have been obtained and characterized by single-crystal X-ray crystallography. NLDFT calculations on 2 show that the linear coordination mode is stabilized with respect to the trigonal planar mode by 14.0 kJ/mol. All complexes (2-4) are fluxional in solution with different mechanisms. In 2, the [Au(PPh3)] fragment switches rapidly between the two sulfur sites. Our hybrid MM-NLDFT calculations found a transition state in which the Au(I) bears an irregular trigonal planar geometry (ΔG(+) = 19.9 kJ/mol), as well as an intermediate in which Au(I) adopts a regular trigonal planar geometry. Complexes 3a,b are roughly diastereoisomeric and related by σ (mirror plane) conversion. This symmetry operation can be broken down to two mutually dependent fluxional processes: (i) rapid flipping of the dppm methylene group across the molecular plane defined by the overhead bridge; (ii) rocking motion of the two Au atoms across the S ···S axis of the {Pt2S2} core. Modeling of the former by molecular mechanics yields a steric barrier of 29.0 kJ/mol, close to that obtained from variable-temperature 31P{1H} NMR study (33.7 kJ/mol). In 4, the twisting of the ferrocenyl moiety across the S ··· S axis is in concert with a rocking motion of the two gold atoms. The movement of dppf is sterically most demanding, and hence, 4 is the only complex that shows a static structure at lower temperatures. Pertinent crystallographic data: (2) space group P1, a = 15.0340(5) Å, b = 15.5009(5) Å, c = 21.9604(7) Å, α = 74.805(1) Å, β = 85.3733(1)°, γ = 78-553(1)°, R = 0.0500; (3a) space group Pna21, a = 32.0538(4) Å, b = 16.0822(3) Å, c = 18.9388(3) Å, R = 0.0347; (3b) space group Pna21, a = 31.950(2) Å, b = 16.0157(8) Å, c = 18.8460(9) Å, R = 0.0478; (4) space group P21/c, a = 13.8668(2) Å, b = 51.7754(4) Å, c = 15.9660(2) Å, β = 113.786(1)°, R = 0.0649.
Persistent Identifierhttp://hdl.handle.net/10722/219445
ISSN
2015 Impact Factor: 4.82
2015 SCImago Journal Rankings: 1.873

 

DC FieldValueLanguage
dc.contributor.authorLi, Z.-
dc.contributor.authorLoh, Z. H.-
dc.contributor.authorMok, K. F.-
dc.contributor.authorHor, T. S A-
dc.date.accessioned2015-09-23T02:57:06Z-
dc.date.available2015-09-23T02:57:06Z-
dc.date.issued2000-
dc.identifier.citationInorganic Chemistry, 2000, v. 39, n. 23, p. 5299-5305-
dc.identifier.issn0020-1669-
dc.identifier.urihttp://hdl.handle.net/10722/219445-
dc.description.abstractThree heterometallic Au-Pt complexes [Pt2(PPh3)4(μ-S)(μ3-S)Au(PPh3)][PF6] (2), [Pt2(PPh3)4(μ3-S)2Au2(μ-dppm)]-[PF6]2 (3), and [pt2(Pph3)4(μ3-S)2(μ-dppf)][PF6]2 (4) have been synthesized from Pt2(PPh3)4(μ-S)2 (1) [dppm = Ph2PCH2PPh2; dppf = (C5H4PPh2)2Fe] and characterized by single-crystal X-ray crystallography. In 2, the Au(I) atom is anchored on only one of the sulfur centers. In 3 and 4, both sulfur atoms are aurated, showing the ability of 1 to support an overhead bridge structure, viz. [Au2(P-P)], with or without the presence of Au-Au bond. The change of dppf to dppm facilitates such active interactions. Two stereoisomers of complex 3 (3a,b) have been obtained and characterized by single-crystal X-ray crystallography. NLDFT calculations on 2 show that the linear coordination mode is stabilized with respect to the trigonal planar mode by 14.0 kJ/mol. All complexes (2-4) are fluxional in solution with different mechanisms. In 2, the [Au(PPh3)] fragment switches rapidly between the two sulfur sites. Our hybrid MM-NLDFT calculations found a transition state in which the Au(I) bears an irregular trigonal planar geometry (ΔG(+) = 19.9 kJ/mol), as well as an intermediate in which Au(I) adopts a regular trigonal planar geometry. Complexes 3a,b are roughly diastereoisomeric and related by σ (mirror plane) conversion. This symmetry operation can be broken down to two mutually dependent fluxional processes: (i) rapid flipping of the dppm methylene group across the molecular plane defined by the overhead bridge; (ii) rocking motion of the two Au atoms across the S ···S axis of the {Pt2S2} core. Modeling of the former by molecular mechanics yields a steric barrier of 29.0 kJ/mol, close to that obtained from variable-temperature 31P{1H} NMR study (33.7 kJ/mol). In 4, the twisting of the ferrocenyl moiety across the S ··· S axis is in concert with a rocking motion of the two gold atoms. The movement of dppf is sterically most demanding, and hence, 4 is the only complex that shows a static structure at lower temperatures. Pertinent crystallographic data: (2) space group P1, a = 15.0340(5) Å, b = 15.5009(5) Å, c = 21.9604(7) Å, α = 74.805(1) Å, β = 85.3733(1)°, γ = 78-553(1)°, R = 0.0500; (3a) space group Pna21, a = 32.0538(4) Å, b = 16.0822(3) Å, c = 18.9388(3) Å, R = 0.0347; (3b) space group Pna21, a = 31.950(2) Å, b = 16.0157(8) Å, c = 18.8460(9) Å, R = 0.0478; (4) space group P21/c, a = 13.8668(2) Å, b = 51.7754(4) Å, c = 15.9660(2) Å, β = 113.786(1)°, R = 0.0649.-
dc.languageeng-
dc.relation.ispartofInorganic Chemistry-
dc.titleStructural, dynamic, and theoretical studies of [Au(n)Pt2(PPh3)4(μ-S)(2-n)(μ3-S)(n)L][PF6](n) [n = 1, L = PPh3; n = 2, L = Ph2PCH2PPh2, (C5H4PPh2)2Fe]-
dc.typeArticle-
dc.description.natureLink_to_subscribed_fulltext-
dc.identifier.doi10.1021/ic991416k-
dc.identifier.pmid11187470-
dc.identifier.scopuseid_2-s2.0-0034645323-
dc.identifier.volume39-
dc.identifier.issue23-
dc.identifier.spage5299-
dc.identifier.epage5305-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats