| 词条 | Isothiouronium |
| 释义 |
In organic chemistry, isothiouronium is a functional group with the formula [RSC(NH2)2]+ (R = alkyl, aryl) and is the acid salt of isothiourea. The H centres can also be replaced by alkyl and aryl. Structurally, these cations resemble guanidinium cations. The CN2S core is planar and the C-N bonds are short.[1] SynthesisSalts comprising these anions are typically prepared by alkylation of thiourea: SC(NH2)2 + RX → [RSC(NH2)2]+X− ReactionsHydrolysis of isothiouronium salts gives thiols.[2][RSC(NH2)2]+X− + NaOH → RSH + OC(NH2)2 + NaX Isothiouronium salts in which the sulfur has been alkylated, such as S-methylisothiourea hemisulfate (CAS No: 867-44-7), will convert amines into guanidinium groups. This approach is sometimes called the Rathke synthesis [3] after Bernhard Rathke[4] who first reported it in 1881.[5] RNH2 + [MeSC(NH2)2]+X− → RNC(NH2)2]+X− + MeSHChelating resins with isothiouronium groups are used to recover mercury and noble metals including platinum from solutions.[6] References1. ^{{cite journal | doi = 10.1107/S0108270198008166 | title = S-Benzylisothiouronium Chloride | year = 1998 | last1 = Barker | first1 = J. | last2 = Powell | first2 = H. R. | journal = Acta Crystallographica Section C | volume = 54 | issue = 12 | pages = 2019}} 2. ^{{OrgSynth|author=Helmer Kofod|year=1963|title=Furfuryl Mercaptan|volume=4|pages=13|collvol=1|collvolpages=66|prep=CV4P0491}} 3. ^{{cite journal|last1=Palmer|first1=David C.|title=S-Methylisothiourea|journal=e-EROS Encyclopedia of Reagents for Organic Synthesis|year=2001|doi=10.1002/047084289X.rm199s}} 4. ^{{cite journal|title=Heinrich Bernhard Rathke. (1840-1923)|journal=Berichte der deutschen chemischen Gesellschaft (A and B Series)|date=8 October 1924|volume=57|issue=9|pages=A83–A92|doi=10.1002/cber.19240570929}} 5. ^{{cite journal|last1=Rathke|first1=B.|title=Ueber Derivate und Constitution des Schwefelharnstoffs|journal=Berichte der deutschen chemischen Gesellschaft|date=July 1881|volume=14|issue=2|pages=1774–1780|doi=10.1002/cber.18810140247}} 6. ^{{cite web | url = http://www.purolite.com/default.aspx?RelID=606267&ProductID=19 | title = Purolite S920 Isothiouronium Chelating Resin | publisher = Purolite}} 3 : Functional groups|Thioureas|Cations |
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