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The Application of the Hammett Equation to the Solvolysis of Benzyl

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The Application of the Hammett Equation to the Solvolysis of Benzyl Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1952 The pplica ation of the Hammett equation to the solvolysis of benzyl tosylates Jay Kazuo Kochi Iowa State College Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons, and the Physical Chemistry Commons Recommended Citation Kochi, Jay Kazuo, "The ppa lication of the Hammett quae tion to the solvolysis of benzyl tosylates " (1952). Retrospective Theses and Dissertations. 13617. https://lib.dr.iastate.edu/rtd/13617 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. NOTE TO USERS This reproduction is the best copy available. UMI tm APPLICATIOI OF THE HAJIMEfT EQUATION TO THE SOLVOLYSIS OF BI«ZYL TOStLATES Ijy Jay Eazuo Xochi A i'iBssrtation. Submitted to tixe Qradaat® Faculty ia Pftrtinl Fulfillmeat of She E®quir®ffl«at8 for tha Degree of DOCfOit OF PBILOSOPHY Major Sub^Jeets Physloal-Orgaaic CharaiBtry ApproTsd 8 Signature was redacted for privacy. la (^liirg® of Major Work Signature was redacted for privacy. Head "of'' Major "Bepar Signature was redacted for privacy. lii©« of C Iowa State CoHsge 1952 UMI Number: DP12806 INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. UMI UMI Microform DP12806 Copyright 2005 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1346 Qa5-oi ii /)'Y / / TABIB OF COIfMT?; Page ACIMOWSDaillSf iv IIEiOBWTIOi. ... .................. 1 IISTOHICAL. S til® M'f®et of Sttbstituents oa Giieraioal EeactiTity 3 I«4uetiv® 4 Sl00troB)»rio 6 Tha Solwlyses of B®Myi Systems............................ 32 A GoBjiarisoa of Itliyleaes md loetylenss 37 SXPSilMaim. 46 The Preparatioa of Subs-feitutad Still>®n®8 and folaaee........ 46 Praparatlott of S- aad 4-oarbo:cystilbea9..... 46 Preparation of 3- said 4«earbo3cytolan».................... 46 Preparation of 4-QarbO'Xytol8ai0. 47 th® pr@pga*fttioa of 3» aad 4»08crb«tlj)03iy8tilb®n0.......... 49 The prepwralJioa of 3- and t-oftrbtthoarytolaa® 60 fla® praparatioa of S- and 4-hydroxym»thylstilbeae,.. .... 62a T1^9 frefaration of 3- and 4«liydroxyiB0thyitolan«......... 53 Th« r)at«rRdaation of Apparent lonisation Coastaats of Sabstitttt@d B®aKole Acids 64 Sol'^aats • atha&ol and water* 54 Aqueous aleotoolic biearbonate-frae sodium iiydroxida (0.01 I.).,.......,... 64 Benzoio aeid». 54 I'ha titration. 54 7h@ .iiistor SapoBifioations 62 4o0taa« 62 Bioarb©aat®»fr®® sQ&lxm bydroxid®. 62 lydroohlorio aoid solution 62 Fotassiwn acid pfethalate. 63 ladicator 63 Esters 63 Til® sapoaificatioa ratas of tl^s estars.................. 64 f103^0 ili Page Xh0 Solvolysis of Substituted B®aayl fosylates. 68 ko@tom. 68 Lithium p@roMorate* 68 Potassium aitrat® 68 £«.folu«n0sulfonyl ehlorid®. 68 frietbylftmiii®........ 68 Indioator 69 flydroohloric acid.... 69 f h© benzyl alcohols 69 fh® uasaturated alootiols. ............................... 70 Prepar&tloa of substituted benzyl tosylates - general proo0dxur©s. 70 fhe kinetios of th® to«ylat© solvolysis 77 fhe Oltra-S'iolet Speatra. 86 fhe lafra-red Speotra........................................ 6a SBSULTS M li DlSCUSSiOI 92 iv ACKIOILEDGMENT If w® ooasider what persons have stimulated and profited us, w® shall perceive the superiority of th® spontaneous or intuitive principle over the arithmetic or logical. The first ooatains the second, but virtual and latent. Logic is the procession or proportionate unfolding of the intuition. Ralph VJ. Enserson, "Sssaya'*. The conoeptioa and oosnpletloa of th© aspect of the problem presented herein owa much to th® intellectual stiiaulation, profundity and encoiurage- mwttt provided the author by Dr. Oeorge S. Mammond. The aid from the Iowa State Research Institute voider whose auspices much of tiiis work was undertaken is also gratefully acknowledged. 1 IlTROCKflOI Tk® ©orrel&Mon of the reaotion rates aad ©quilibria of mota and para deritatives of hmsBm with substituant groups has been succesBfully under- tskken by th® aufflnett aquation. The applicability of this ©mpirioal ©quatioa in jMuiy reaetion series is a wsll-sstablishsd fact. fhere ara e®rfcaia otfesr cas®®, hGW®T©r, in which the BaEmett relation- bMp iis not quite so a^plioable. la particular, it is neoessary to assign two values of th® substituant constant to the £ara-iaitro group, ono for the r«actioas of phenols and aaother for tho reaction of other b®a«©n® clerimtiv®®, A different class of reactions which show anomalous behavior with th© fiaarostt equation is th® solTolysis of bmz^l chlorides. The studies pertaining to this series of reactions have not been extensively nor systeaatioally carried out with reapest to the correlation of substituent effect &M reaotioa velocity. Since this olass offers a new and promising approach to the aaalysii of th® EaBisiett equation, ar: investigation was mdertaken to sorutinize the equation# la partieular, a study of substituted bea*yl tosylates was mde because of the crystalline nature and imaiabiguous solvolyses of these ooapouads. The solvolysi® 9f benzyl tosylates and the saponification of ethyl benzoates represent two reactions of opposed charge requirements. T&ereas the solvolysis of benzyl tosylate is facilitated by eleotron- repelliag substituents the saponification of ethyl benzoate is retarded by these same groups. fhe extent to which substituents promote the solvolysis of benayl tosylate will depend on the ability of the 2 sul>stit«®at to stabilize th@ transition state. Th® magaitudo of tha staMlisation may be ®sp-eot®d to be MasurQd by th® daviation of the Siibstitueat from tii© Haiamett r®latlonship. 'filth this iaterpratatioa in mind an iavestigation was initiated to determia® the rsXative conjugativ® aptitudes of the earbon - carbon double bond aafi tripl® bond. From a r@ry qualitative oonsideration of [email protected] orbital theory, on® may expect th® tripl® bond to conjugate as w®ll as, if not better tlian, the rioubl® bond with an aromatic system, folan© R»d Stilbeiae were ehossn as th© basic systems to bo studied. 3 HISTQfilCAL fhe Bffeot of Substituants on Ghemioal Reactivity larly atteapts to oorrelat® structure with ohemical reactivity and physical properties provided a stiaulus for the development of modem theoretical organic chemistry. In this respect the interpretation and correlation of ©fleets produced by substituent groups in organic compounds have been one of th® foremost problems confronting organic chemists. Muaerous eii|>iriaal rules devised for classifying these effects before the successful application of electronic theory to chemistry by Lewis^ have been adequately summrized by latson'*P and Eemiok ^. Subsequent studies from varied aspects of mechanistic organic chemistry contributed greatly to the coalescing of fundamental conceptions4 • fhus, concurrent studies of orientation in aromatic substitution, dipole moinsnt measure­ ments, reaction rates in solvolysis, equilibrium determinations of acid - base systems and oxidation <- reduction potentials of organic con4)ounds helped to corroborrate and strengthen the theory. The basis for th® analysis of tha problem of substituent effects can be found in the nature of th© interaction of a series of substituents, S, with a parent molecule* R. In such a series of ooanpounds, R-S, it is ^G.I. Lewis, J. Am. Chem. Soo., 762 (1916). ^1. ftatson, **Modern Theories of Organic Chemistry", Second Edition, Oxford University Press, lew York, M.T., 1941. Eemick, ^Electronic Interpretations of Orgariic Cheadstry", Second Mition, Jotei Wiley and Sons, Inc., Mew York, K.Y., 1949. ^C. Ingold, CheiB* Revs., IS, 226 (1934), 4 to realize the type and magnitude of the perturbation effected by S across th® E-S bond. Of the number of systems of this type that can b® studied the beazenoid aromatie system, where E is benzene or its derivatiTes, has proven to be th© most aunenabla to empirical and theoret­ ical treatments. In subsequent disoussion, for the sake of convenience and without too much loss of generality, we shall restrict ourselves to this interesting system. The influence of substitueats on the reactivity of organic compounds has been interpreted in an illuaiaaatiag manner by the theory of electron B displaoemants . In essence, th© theory accounts for two distinct types of electronic effects, termed the inductive effect and electromeric effect. Each perturbation is considered to be independent and no attempt is Bade to relate tha dependence of one on the other. Inductive effect Studies on the resting state of a molecule by means of dipole measurements have been used to measure quantitatively the permanent
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