Silicon, Germanium, Tin, and Lead

Kennedy, J. D.; McFarlane, William

doi:10.1007/978-1-4613-1783-8_11

Cited by 41 publications

(27 citation statements)

References 189 publications

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“…The chemical shifts are typical of polyarylsilicon T units [22]. No dispersed inorganic silicon is present, as demonstrated by the lack of any peak at d!K100 ppm where Q units are expected to resonate [23].…”

Section: Resultsmentioning

confidence: 85%

“…It is, however, known that, among the different factors affecting chemical shifts, the observed nucleus atomic charge is related to chemical shift, and that, in the case of 29 Si, electron withdrawing substituents lead to resonances shifted at higher frequency [23,24]. Computational calculations of silicon atomic charge were thus carried out on the two monomers corresponding to products a and b.…”

Section: Resultsmentioning

confidence: 99%

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A covalent organic/inorganic hybrid proton exchange polymeric membrane: synthesis and characterization

Vona

Marani

D’Epifanio

et al. 2005

Polymer

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Commercial polyetheretherketone (Victrex PEEK) was sulfonated up to 90% degree of sulfonation (DS), then reacted with SiCl 4 to obtain a hybrid polymer. The product was characterized by 29 Si NMR and ATR/FTIR spectroscopies demonstrating the formation of covalent bonds between the organic and inorganic components. No dispersed inorganic silicon was present in the product as evidenced by the lack of any resonance at d!K100 ppm. Despite the high DS the physicochemical properties of the hybrid were suitable for the preparation of membranes exhibiting high and stable conductivity values (10 K2 S/cm), hence suitable for application as ion exchange membrane. q

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Section: Resultsmentioning

confidence: 85%

Section: Resultsmentioning

confidence: 99%

A covalent organic/inorganic hybrid proton exchange polymeric membrane: synthesis and characterization

Vona

Marani

D’Epifanio

et al. 2005

Polymer

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“…Monodentate bonding of C5H4NS-through nitrogen would be expected to result in shielding of the tin nucleus, but there do not appear to be any cases in which the ligand binds in this manner, so we discard this possibility. * Increase of the coordination number of tin from four to five or six is known to result in a significant increase in nuclear shielding at tin (17). Accordingly as, for l a points to a coordination number of greater than four at tin.…”

Section: Synthesismentioning

confidence: 99%

“…The compound was found to be monomeric in methylisobutylketone (16), but no evidence seems to be available regarding the exact nature of the Sn(1V)-pyt-interaction for this or related (16) dihalo tin complexes in solution. Tin-1 19 NMR is very senstitive to changes in the coordination number of tin(1V) (17) and so should be of use for determining the denticity of pyt-in Sn(1V)-pyt-complexes. Using " 9~n NMR, we show here that in the series Sn(EPh)4-x(pyt)x the pyt-behaves as a chelate when x = 1 or 2 , while both bidentate and monodentate pytligands occur when x = 3 or 4.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and multinuclear magnetic resonance study of some tin(IV) complexes of pyridine-2-thiolate and related ligands, and the X-ray structural analysis of Sn(C₅H₄NS)₄•C₅H₅NS

Damude¹,

Dean²,

Manivannan³

et al. 1990

Can. J. Chem.

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. Tin metal reacts with 2,2'-dithiobis (pyridine) in refluxing toluene to give the pyridine-2-thiolate complex Sn(C5H4NS)4, l a . Multinuclear ( 7 7~e , '''sn) magnetic resonance shows that ligand redistribution occurs in l~: s n ( E P h )~ (E = S or Se) mixtures to give Sn(EPh)4-,(C5H4NS)x. From the pattern of the "'~n chemical shifts of these series, compared with that of Sn(EPh),-,(SR), (R = simple alkyl or aryl group), the complexes are shown to be five-coordinate Sn(EPh)3(C5H4NS-N,S) when x = 1 and six-coordinate Sn(EPh)4-x(C4H4NS-S)x-2(C5H4NS-N,S)2 when x = 2-4. Reaction of Sn(SPh)' and (C5H&!S)2 yields pure Sn(SPh)2(C5H4NS)2. The 13C NMR spectrum of Sn(C5H4NS-S)2 (C5H4NS-N,S)' is an exchange average down to 178 K, probably as a result of fluxionality. The series Sn(EPh)4-x(L')x (E = Se, L' = 5-nitropyridine-or quinoline-2-thiolate, x = 0-4; E = S or Se, L' = pyridine-2-thiolate-N-oxide, x = 0-2) can beprepared insitu by redox between Sn(EPh)4 and the disulfide (L1)'. Treatment of l a with X2 (X = Br or E-gives SnX4-,(C5H4NS-N,S), (x = 2 or 3), which have been characterized by NMR, and provides a new synthesis of the known dihalo complexes.In a recrystallization of l a from CH2C12:hexane Sn(C5H4NS)4.CsH5NS, 2, was obtained, probably as a result of hydrolysis. The structure of 2 has been solved by single crystal X-ray diffraction techniques. The compound crystallizes in the orthorhombic space group Pbca (No. 61) with a unit cell of dimensions a = 17.132 (2) L'Ctain mitallique rCagit avec la 2,2'-dithiobis (pyridine), dans le tolukne au reflux, pour donner le complexe pyridine-2-thiolate, Sn(C5H4NS)4, l a . La rtsonance magnktique multi-noyaux ( 7 7~e , "'~n) dCmontre que, dans des mClanges de l a : Sn(EPh)4 oh E = S ou Se, il se produit une redistribution des ligands et la formation de composts du type Sn(EPh)4-,(C5H4NS)x. En se basant sur une comparaison des dtplacements chimiques du "' Sn dans les composCs de cette strie avec ceux obsewks dans les produits Sn(EPh),-,(SR), ou R = groupements aryles ou alkyles simples, on a dCmontrC que, si x = I, les complexes sont les entitCs penta-coordonnCes Sn(EPh)3(C5H4NS-N,S) alors que, si x = 2-4, les complexes sont les entitks hexa-coordonn6es Sn(EPh)4-X(C5H4NS-S)2. La reaction du Sn(SPh)' avec le (C5H$JS)2 fournit du Sn(SPh)2(C5HflS)2 a 1'Ctat pur. M&me lorsqu'on abaisse la tempkrature jusqu'i 178 K, le spectre rmn du 13C du Sn(C5H4NS-S)2(C5H4NS-N,S)2 est un spectre moyen rCsultant probablement d'un mtcanisme de fluxion. Faisant appel a une rCaction redox in situ entre l e Sn(EPh)4, et le disulfure (L1)', on peut prCparer les produits de la sCrie Sn(EPh)4-,(L')x (E = Se, L' = 5-nitropyridine-ou quinolkine-2-thiolate, x = 0-4; E = S ou Se, ' L' = pyridine-2-thiolate N-oxyde, x = 0-2). Le traitement du produit l a par du X2 (X = Br ou I) fournit les complexes SnX4-,(C5H4NS-N,S), (x = 2 ou 3) que I'on a caractCrists par rmn; ces rkactions fournissent une nouvelle synthkse de ces complexes dihalogCnCs connus.Lors de la recristallisation du produit l a dans un mClange...

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“…Correlation (1) is obtained from the MR4 (M = Si, Ge; R = Me, Et, Ph, 2-furyl) compounds [22], correlation (2) from MMe3R' (M = Si,Ge) compounds with R' being substituted alkyl or alkenyl ligand, and correlation (3) from alkyl, alkoxy, and halocompounds [5].…”

Section: Correlation Between Theory and Experimentsmentioning

confidence: 99%

Theoretical study on metal NMR chemical shifts: Germanium compounds

Nakatsuji

Nakao

1994

Int J of Quantum Chemistry

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Germanium chemical shifts were studied theoretically by the ab initio molecular orbital method. The compounds studied were GeMe4-,CI, and GeMe4-,Hx(x = 0-4). The calculated values of the germanium chemical shifts agreed well with the available experimental values. The germanium chemical shift is due to the p-electron mechanism that reflects the ligand electronic effect on the p -p ' excitation term in the second-order paramagnetic term. For GeMed-,H,, the chemical shift is almost linear to the number of the ligand, x . On the other hand, a U-shaped dependence is predicted for the chemical shifts of the GeMe4-,C1, series and is shown to be caused by the strong and nonadditive electron-withdrawing ability of the CI ligand. The diamagnetic contribution is relatively small for the chemical shift and is determined solely by a structural factor.

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Silicon, Germanium, Tin, and Lead

Cited by 41 publications

References 189 publications

A covalent organic/inorganic hybrid proton exchange polymeric membrane: synthesis and characterization

A covalent organic/inorganic hybrid proton exchange polymeric membrane: synthesis and characterization

Synthesis and multinuclear magnetic resonance study of some tin(IV) complexes of pyridine-2-thiolate and related ligands, and the X-ray structural analysis of Sn(C₅H₄NS)₄•C₅H₅NS

Theoretical study on metal NMR chemical shifts: Germanium compounds

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Silicon, Germanium, Tin, and Lead

Cited by 41 publications

References 189 publications

A covalent organic/inorganic hybrid proton exchange polymeric membrane: synthesis and characterization

A covalent organic/inorganic hybrid proton exchange polymeric membrane: synthesis and characterization

Synthesis and multinuclear magnetic resonance study of some tin(IV) complexes of pyridine-2-thiolate and related ligands, and the X-ray structural analysis of Sn(C5H4NS)4•C5H5NS

Theoretical study on metal NMR chemical shifts: Germanium compounds

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Synthesis and multinuclear magnetic resonance study of some tin(IV) complexes of pyridine-2-thiolate and related ligands, and the X-ray structural analysis of Sn(C₅H₄NS)₄•C₅H₅NS