Kloosterziel, Hendrik

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University of GroningenStructure and function of the sulphonyl groupKloosterziel, HendrikIMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:1952Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):Kloosterziel, H. (1952). Structure and function of the sulphonyl group. s.n.CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 24-12-2025riled for 16 h withaddition of watertH. White needlesY ie ld  1 .19  (8e%)30 ..cohol.Maxima(mp) I 'SUMMARY.In chapter I an interpretation has been given of the sequence ofreactions starting r,r'ith the interaction between diphenyldiazo-methane and sulphur dioxide (Staudinger), i.a. by means of theconcepts of radical formation and mesomerism. The primarilyformed tetraphenylethylenesulphone undergoes, through an inter-mediate biradical, a ring enlargement to the yellow 1,1,3-triphenyl-l,7a-dihydro-isothionaphtene-2-dioxide. The latter readily convertsinto the white l, I,3-triphenyl-1,3-dihydro-isothionaphtene-2-dioxideby a prototropic rearrangement. When heated, this compound losesSO, to give 9,9-diphenyl-9, l0-dihydro-anthracene (Staudinger's un-identifiedhydrocarbon) and 9, l0-diphenyl-9, 10-dihydro-anthracene,the formation of which was predicted by the proposed mechanism.In chapter II the prototropic rearrangement, mentioned above,catalysed by amines in n-hexane, was studied. It is a bimolecularreaction and the catalytic effect of an amine is expressed in thecatalytic constant k". We compared k" (in n-hexane) rvith theionisation constant of the amine in water. The follou'ing resultswere obtained i.a.:a) For 3 types of amines a Bronsted relation is found with thesame a-value.b) Solvation and classical steric hindrance are important factors.c) Hammett's substitution constant for the p-CH, group (andhyperconjugation) depends upon the medium; the sigma-valueranges from water (via aicohoi) to n-hexane, from -0. t7 to - 0.08.d) Ortho alkyl groups enhance the catalytic constant. Two ex-planations have been suggested: steric hindrance of resonance anda solvation effect.e) The Hammett relation holds for substituted o-toluidines and2,6-xylidines; the o-values of thesere lations do not differ signific-antly from the one for anilines.f) In these Hammett relations the (unsubstituted) parent com-pounds show a deviation.h) The total electronic effect of p-CHrS, with regard to hydrogen,is opposite to that of p-CHrO.In chapter III it rvas found from ther catalytic effect of arylsul-phones on the isomerisation (chapter II) that they have basic69t 3D l .6 l80.7 1 .l97 l64tD b7 755520.00010.20017.20022.500t .2501.5408.1008 1 09806706.80060properties, in contrast rvith alkylsulphones. The difference betweenthe two classes has been explained with the aid of resonance, whichinvolves an extension of the octet structure of sulphur in the sul-phonyl group. Log k" (in dioxan) of substituted phenylmethyl-sulphones has been related to Hammett's o-values. The fact that thebasic properties of amines and sulphones in dioxan were found not tobe so widely different as is generally assumed has been ascribedto the absence of solvation of the corresponding ions.In chapter IV the o-values for the meta and para methylsulphonvlgroups were determined. For the latter, different o-values are ob-tained, depending on whether the functional group has a *Meffect or not. This proves that the sulphur atom in sulphones iscapable of extending its octet of electrons.In chapter V 4-methylsulphonyl-3,5-xylenol was studied forinformation about the effect of two ortho methyl groups on theextended resonating system. Qontrary to the corresponding nitro-xylenol, the former shows neither from spectroscopic data nor fromits ionisation constant any evidence of steric inhibition of resonance.On account of the fact that sulphur is a second-row element,coplanarity is no condition for resonance involving the sulphonylgroup.However, to effect such a steric hindrance of resonance in anextended resonating system containing a sulphonyl group, we pre-pared 4-methylsulphonyl-2,6-acetoxylide and measured its ab-sorption spectrum. It shorved the expected characteristics.The last mentioned sulphonyl compounds were prepared by amethod involving thiocyanation, reduction with LiAlH4, methy-lation and oxidation. This is a convenient way to prepare srrl-phones of the desired type in good yields.

Structure and function of the sulphonyl group

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Structure and function of the sulphonyl group

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