Ab initio molecular orbital study of dications of 1,5-dichalcogenacyclooctanes

Nakayama, Naofumi; Takahashi, Ohgi; Kikuchi, Osamu; Furukawa, Naomichi

doi:10.1002/(sici)1098-1071(2000)11:1<31::aid-hc6>3.0.co;2-8

Cited by 16 publications

(16 citation statements)

References 20 publications

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“…It is known that the oxidation potential of 4 (1,5-dithiocane; Scheme ) is lowered, owing to transannular bond formation, and that the radical cation 4 ‘ and dication 4 ‘ ‘, formed on oxidation, are stabilized. Similar effects are also seen with 5 and with 15 and 16 , the Se and Te analogues of 4 , respectively . Compounds 4 , 5 , 15 , and 16 show unusual redox chemistry, , catalytic activity, and metal coordination abilities .…”

Section: Introductionsupporting

confidence: 66%

“…Similar effects are also seen with 5 and with 15 and 16 , the Se and Te analogues of 4 , respectively . Compounds 4 , 5 , 15 , and 16 show unusual redox chemistry, , catalytic activity, and metal coordination abilities . In 1 and its bicyclic analogues 20 (Chart ), facilitation of oxidation depends not only on the S···S distance but also on the angular relationship of the interacting lone-pair orbitals, e.g., compare planar 1 (higher ionization energy ( I E )) and puckered 20 (lower I E ) .…”

Section: Introductionmentioning

confidence: 61%

“…Synthesis of medium-sized ring (mesocyclic) heterocycles lacking rigid groups can be problematic, often requiring high-dilution techniques or use of metal templates, 4e,9a-c or the gem -dialkyl (“Thorpe-Ingold”) effect. 9d-g A limited number of Se- or Te-containing mesocycles lacking rigid groups are known . We find that new mesocycles 25 , 27 , and 29 (Scheme ) bearing two gem -dimethyl or gem -bis(trimethylsilyl) groups can be easily prepared in fair to good yields without resorting to special techniques by combining bis(halomethyl)-silanes or -stannanes with appropriate S(Se,Te)/Si(Sn) reagents including bis-thioacetates 24 , cyclic diselenides 26 (prepared using Na 2 Se 2 ), 10b,c,f and bis-tellurocyanate 28 . 10e,11a In these syntheses, in contrast to syntheses of 15 and 16 , 2e,11b it is imperative to produce the dichalcogen dianions in the presence of the 1,3-dihalides because the former dianions are unstable and must be immediately trapped. This is accomplished by dropwise addition of a 1:1 mixture of 23 and 24 to dilute ethanolic KOH giving 25 (22−42% yield), of 23 and 26 to dilute NaBH 4 in EtOH-THF giving 27 (58−76% yield), and of 23 and 28 to dilute NaBH 4 in EtOH-DMSO giving 29 (21−23% yield).…”

Section: Resultsmentioning

confidence: 96%

“…In 1 and its bicyclic analogues 20 (Chart ), facilitation of oxidation depends not only on the S···S distance but also on the angular relationship of the interacting lone-pair orbitals, e.g., compare planar 1 (higher ionization energy ( I E )) and puckered 20 (lower I E ) . Exocyclic β-silicon and β-tin groups, e.g., in 2-substituted derivatives of 1,3-dithiane 21 ,2f 1,3-dithioles,6a and oxiranes and thiiranes 22 ,6b can also significantly facilitate one-electron oxidation at the chalcogen atom(s) by the well-known β-effect of these elements 7 when the angular relationship of the C−Si or C−Sn orbitals with adjacent chalcogen p -type lone-pair orbitals is optimum (eclipsed). The lowering of I E and facilitation of oxidation in 1 − 6 as well as in 15 and 16 has been evaluated using photoelectron spectroscopy (PES), cyclic voltammetry (CV), MO calculations, and/or more qualitatively by measuring the I E -proportional λ max of their tetracyanoethylene charge-transfer (TCNE-CT) complexes. 2a,f,

1 Di- and Trithiaheterocycles ( 1 − 6 ), Analogous Mixed Group 14/16 Homologs 7 − 14 , and Related Heterocycles 15 − 19 Prepared in This Work (E = S, Se or Te; M = R 2 Si or R 2 Sn)

1 Radical Cation ( 4 ‘) and Dication ( 4 ‘ ‘) Formation in 1,5-Dithiocane ( 4 )

2 Heterocycles Illustrating Angular Dependence of Orbital Interaction with Chalcogen Lone Pair p -Orbitals …”

Section: Introductionmentioning

confidence: 99%

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Synthesis, Structure, and Chemistry of New, Mixed Group 14 and 16 Heterocycles: Nucleophile-Induced Ring Contraction of Mesocyclic Dications

et al. 2006

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More than 40 new 4- to 12-membered ring heterocycles containing various combinations of Group 14 and 16 elements Si, Sn, S, Se, and Te have been synthesized and fully characterized. Synthesis of these small-ring as well as medium-ring (mesocyclic) heterocycles from alpha,omega-dihalides is facilitated by the presence of gem-dialkylsilyl and gem-dialkylstannyl groups in the precursors. Conformations of several of the new ring systems in the solid state have been determined by X-ray crystal structure analysis. Oxidation of mixed S(Se, Te)/Si eight-membered ring mesocycles with NOPF6 or Br2 gives dications or a bicyclic dibromide, respectively, which can be characterized by NMR methods. On treatment with nucleophiles, mesocyclic dications, or the corresponding radical cations undergo ring contraction, giving five- or six-membered ring heterocycles. Photolysis of a S/Se four-membered ring heterocycle gives selenoformaldehyde, trapped in 80% yield with 2,3-dimethyl-1,3-butadiene.

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Section: Introductionsupporting

confidence: 66%

Section: Introductionmentioning

confidence: 61%

Section: Resultsmentioning

confidence: 96%

1 Di- and Trithiaheterocycles ( 1 − 6 ), Analogous Mixed Group 14/16 Homologs 7 − 14 , and Related Heterocycles 15 − 19 Prepared in This Work (E = S, Se or Te; M = R 2 Si or R 2 Sn)

1 Radical Cation ( 4 ‘) and Dication ( 4 ‘ ‘) Formation in 1,5-Dithiocane ( 4 )

2 Heterocycles Illustrating Angular Dependence of Orbital Interaction with Chalcogen Lone Pair p -Orbitals …”

Section: Introductionmentioning

confidence: 99%

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Synthesis, Structure, and Chemistry of New, Mixed Group 14 and 16 Heterocycles: Nucleophile-Induced Ring Contraction of Mesocyclic Dications

et al. 2006

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“…The research groups of Furukawa − and Glass − energetically studied the chemistry of radical cationic dimers ( 1 · + ( 2 2 · + )) and dicationic dimers ( 1 2+ ( 2 2 2+ )) of 1,5-(dichalcogena)canes ( 2 : A E(CH 2 CH 2 CH 2 ) 2 B E: A E, B E = S, Se, Te, and/or O), together with radical cations and dications of 2 ( 2 · + and 2 2+ , respectively). The transannular interactions between chalcogen atoms in 2 · + and 2 2+ play a crucial role in the chemistry of 2 . − The charged species 1 2+ ( 2 2 2+ ) are the excellent candidates for the formation of A E 2 B E 2 σ(4c–6e) in 1 2+ , together with 1 · + ( 2 2 · + ) for A E 2 B E 2 σ(4c–7e) in 1 · + .…”

Section: Introductionmentioning

confidence: 99%

Linear Four-Chalcogen Interactions in Radical Cationic and Dicationic Dimers of 1,5-(Dichalcogena)canes: Nature of the Interactions Elucidated by QTAIM Dual Functional Analysis with QC Calculations

et al. 2017

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The dynamic and static nature of extended hypervalent interactions of the E···E···E···E type are elucidated for four center-seven electron interactions (4c-7e) in the radical cationic dimers (1·) and 4c-6e in the dicationic dimers (1) of 1,5-(dichalcogena)canes (2: E(CHCHCH)E: E,E = S, Se, Te, and O). The quantum theory of atoms-in-molecules dual functional analysis (QTAIM-DFA) is applied for the analysis. Total electron energy densities H(r) are plotted versus H(r) - V(r)/2 [= (ℏ/8m)∇ρ(r)] at bond critical points (BCPs) of the interactions, where V(r) values show potential energy densities at BCPs. Data from the fully optimized structures correspond to the static nature of the interactions. Those from the perturbed structures around the fully optimized ones are also plotted, in addition to those of the fully optimized ones, which represent the dynamic nature of interactions. The E···E-E···E interactions in 1 are stronger than the corresponding ones in 1·, respectively. On the one hand, for 1 with E,E = S, Se, and Te, E···E are all classified by the shared shell interactions and predicted to have the weak covalent nature, except for those in 1a (E = E = S) and 1d (E = E = Se), which have the nature of regular closed shell (r-CS)/trigonal bipyramidal adduct formation through charge transfer (CT-TBP). On the other hand,E···E are predicted to have the nature of r-CS/molecular complex formation through charge transfer for 1a, 1b (E = Se; E = S), and 1d or r-CS/CT-TBP for 1c (E = Te; E = S), 1e (E = Te; E = Se), and 1f (E = E = Te). TheE···E-E···E interactions in 1· and 1 are well-analyzed by applying QTAIM-DFA.

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