| 词条 | Thioketone |
| 释义 |
Structure and bondingThe C=S bond length of thiobenzophenone is 1.63 Å, which is comparable to 1.64 Å, the C=S bond length of thioformaldehyde, measured in the gas phase. Due to steric interactions, the phenyl groups are not coplanar and the dihedral angle SC-CC is 36°.[4] Consistent with the double bond rule, most alkyl thioketones are unstable with respect to dimerization.[4] The energy difference between the p orbitals of sulfur and carbon is greater than that between oxygen and carbon in ketones.[5] The relative difference in energy and diffusity of the atomic orbitals of sulfur compared to carbon results in poor overlap of the orbitals and the energy gap between the HOMO and LUMO is thus reduced for C=S relative to C=O.[6] The striking blue appearance of thiobenzophenone is due to π→ π* transitions upon the absorption of light with a wavelength of 314.5 nm.[5] Preparative methodsThiones are usually prepared from ketones using reagents that exchange S and O atoms. A common reagent is phosphorus pentasulfide[7] and the related reagent Lawesson's reagent. Other methods uses a mixture of hydrogen chloride combined with hydrogen sulfide. Bis(trimethylsilyl)sulfide has also been employed.[3][8] Thiobenzophenone [(C6H5)2CS] is a stable deep blue compound that dissolves readily in organic solvents. It photooxidizes in air to benzophenone and sulfur. Since its discovery, a variety of related thiones have been prepared.[9]ThiosulfinesThiosulfines, also called thiocarbonyl S-sulfides, are compounds with the formula R2CSS. Although superficially appearing to be cumulenes, with the linkage R2C=S=S, they are more usefully classified as 1,3-dipoles and indeed participate in 1,3-dipolar cycloadditions. Thiosulfines are proposed to exist in equilibrium with dithiiranes, three-membered CS2 rings. Thiosulfines are often invoked as intermediates in mechanistic discussions of the chemistry of thiones. For example, thiobenzophenone decomposes upon oxidation to the 1,2,4-trithiolane (Ph2C)2S3, which arises via the cycloaddition of Ph2CSS to its parent Ph2CS.[10] Selenoketones and telluroketonesSelenoketones and telluroketones are the selenium and tellurium analogues of thioketones. They require greater steric and electronic stabilization.[3][9] Selenobenzophenone reversibly dimerizes. It is known to undergo cycloaddition with 1,3-dienes in a reaction similar to the Diels-Alder reaction.[11]See also
References1. ^{{cite journal |last1=Campainge |first1=E. |title=Thiones and Thials. |journal=Chemical Reviews |date=1 August 1946 |volume=39 |issue=1 |pages=1–77 |doi=10.1021/cr60122a001}} 2. ^{{GoldBookRef|file=T06356|title=Thioketones}} 3. ^1 2 {{cite book|last1=Kuhn, |first1=N. |last2=Verani, |first2=G. |chapter=Chalcogenone C{{=}}E compounds |title=Handbook of Chalcogen Chemistry: New Perspectives in Sulfur, Selenium and Tellurium |date=2007 |publisher=Royal Society of Chemistry |DOI=10.1039/9781847557575-00107}} 4. ^Organosulfur Chemistry I: Topics in Current Chemistry, 1999, Volume 204/1999, 127-181, {{doi|10.1007/3-540-48956-8_2}} 5. ^1 Fisera, L.; Huisgen, R.; Kalwinsch, I.; Langhals,E.; Li, X.; Mloston, G.; Polborn, K.; Rapp, J.; Sicking, W.; Sustmann, R. "New Thione Chemistry". Pure Appl. Chem., 1996, 68, 789-798. {{DOI|10.1351/pac199668040789}} 6. ^1 Sustmann, R.; Sicking, W.; Huisgen, R. "A Computational Study of the Cycloaddition of Thiobenzophenone S-Methylide to Thiobenzophenone". J. Am. Chem. Soc. 2003, 125, 14425-14434. {{doi|10.1021/ja0377551}} 7. ^{{cite journal|first1=Vivek |last1=Polshettiwar |first2=M. P. |last2=Kaushik |title=A new, efficient and simple method for the thionation of ketones to thioketones using P4S10/Al2O3 |journal=Tetrahedron Letters |date=2004 |volume=45 |page=6255–6257 |doi=10.1016/j.tetlet.2004.06.091}} 8. ^{{Cite journal| last1 = Mcgregor | first1 = W. M.| last2 = Sherrington | first2 = D. C.| title = Some recent synthetic routes to thioketones and thioaldehydes| journal = Chemical Society Reviews| volume = 22| issue = 3| pages = 199| year = 1993 | doi = 10.1039/CS9932200199}} 9. ^1 {{Cite journal| pages = 625–630| issue = 9| year = 2000| pmid = 10995200 | doi = 10.1021/ar980073b| volume = 33| journal = Accounts of Chemical Research| last1 = Okazaki | first1 = R.| last2 = Tokitoh | first2 = N.| title = Heavy ketones, the heavier element congeners of a ketone}} 10. ^{{cite journal|author1-link=Rolf Huisgen|last1=Huisgen |first1=R. |last2=Rapp, |first2=J. |title=1,3-Dipolar Cycloadditions. 98. The Chemistry of Thiocarbonyl S-Sulfides |journal=Tetrahedron |date=1997 |volume=53 |page=939–960 |DOI=10.1016/S0040-4020(96)01068-X}} 11. ^{{Cite journal| last1 = Erker | first1 = G.| last2 = Hock| last3 = Krüger| last4 = Werner| last5 = Klärner| last6 = Artschwager-Perl| title = Synthesis and Cycloadditions of Monomeric Selenobenzophenone| journal = Angewandte Chemie International Edition in English| volume = 29| issue = 9| pages = 1067| year = 1990 | doi = 10.1002/anie.199010671 | first2 = R. | first3 = C. | first4 = S. | first5 = F. G. | first6 = U.}} External links and further reading
2 : Thioketones|Functional groups |
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