REPORT of COMMITTEE ON EXAMINATION This is to certify that we the undersigned , as a Committee of the Graduate School , have given - ~;.l.l.. ~.E!-.l'L .~l·. ~.@ ... $.~Yf.r. ~ -~-4. .. final oral examinaticn for the degree of Master of Scienco.... -.. We recommend that the degree of aster of ~ci~~~~ -- be conferred upon the candidate . Minneapolis , innesota ......~ ......... ..: .... -~-:J Chairman of Committee on Thesis The undersi gn d, acting as a Committee of the Graduate School, have r Gl\Cl the. accompanying t. o i s submitted by ..~!-~-~ - ~-8.:l?'.. ...~~ - ;-~- - ~-~.Y.J.1:".; .~~---· · ········· for the dogreo of ·-···· .....~~~~~! --~-~ --- ~-~-~~-~~-! .......... ... -··-·· Th ey approve it as a th~sis m e ting the ~equir"- m•nt s or t he Gradu~te Scl ool of th University or Yj nno ota. and recommend that it be acceptDd in partial f ulfil lment of th req lirem nt for the degree of ... ..... 1laster........ ......... of... · -·-··Science. ....... ...... ... ... .. ...................... ·····-·· .... ~~'---~Chairman ............... ........ .,. ... .................................................. ........[ ___ _,. _.. ................ ········ ..... ·-·········· ........Y..~ (}_:.. ~ .... :... J&----·-··tr-····· ·· ·······-·-···· .. ·-····-····-·-··-···-·······-·················-· THE cmroN OF IODINE ON SODTIP~ TRICHLORPBEio TE A THESIS SUB ITTED r."10 THE FACULTY OJ!' THE GRAD :ATE SC OOL OF THE UNIVERSITY OF Ii '..SOmA by LILL .. • SEYJ.f RIED P R.. L ULFI.!JL~ TT 0 THE RE IRE 'TS FOR THE DEGREE ,,{AS ~R 0 SC IE. CE June 1917 I I I I I I I I '1 I I I I I I I 1 t I I I I .. I . I . II.... I THEORETICAL P.ART During the study of the catalytic decompositions of the silver salts of the symmetrically trihalogenated phenols, it was shown that there resulted a white amorphous compound, the empirical for­ mula of which corresponded to the formula of the original silver salt, less a molecule of silver halide. For instance, from the sil- l ver salt of tribromophenol1 , C6H2 Br3 0Ag, there resulted a compound (CsH2Br20) , and analogous compounds were obtained from the silver n salt of trichlorphenol, which yielded (CsH2Cl20)n• and from the silver salt of tribromresoroinmonomethyl ether, which gave (CsH(OCH3)Br20)n2• It was shown that this reaction occurred by a splitting out of silver halide from the molecule, leaving an un­ saturated residue of the general formula C6H2X2 0, which then poly­ merized to form the above compounds. Further study of this reaction in this laboratory has shown that such unsaturated residues must be formed in the following re­ actions: First, thermal decompositions of the silver salts of the above !!named phenols. In this, the silver salts were heated in benzene, splitting out silv~r halide and leaving the residues, which could be isolated from the benzene by precipitation with alcohol, and proved to be identical with those obtained by the oatalytio decomposition. Second, the action of silver or mercury on tribromphenolbromide This action was orked out by Mr. Woollett3 , who found that bromine --- ----------------------------------------------------------------- 1 Torrey and Hunter, Am . Soc . 33, 196 (1911) l. H. Hunter and others, .Am . Soc . 38, 1761 (1916) Unpublished work •) •) .) ) -2- as split out from t he tribromphenolbromide hen a solution in an indifferent solvent ae shaken up 1th mercury or finely divided silver. It is interesting th t the first recorded formation of the hite amorphous compound, which e obtained from the tribrom­ phenol, ie the formation of a compound from tribro~phenolbromide by the action of light to which Kastle gav~ the erroneous formula oollett as able to show that these compounds re both identical 1th the one obtained from tribromphenol silver salt. The action of the mercury may then be represented by the f ollo ing equ tion: CeH2BraO + 2HgBr n CaH Br20 • (CeH BraO)n Third, the otion of iodine n the s i lver salt of triiodo- phenol• . oollett ob erved that hen the silver salt as armed with ethyl iodide , a reaction exactly like that shOW'?l by the tr bro ophenol silTer salt occurred, yielding silver halide and an uns turated residue which after ard polymerized to the white or­ phoue oxide. CeH3!30Ag Ag! + C4H I 0 CaH I 0 (CaH3I O)n n th silver salt as treate with a very little 1o ine in ater in the oold red orphous substance as for ed in laoe of the hite oxide. This red substance a th t fir t described by L te , and kno ae Laute ann's Red ." It has th identio l co position of the white oxide. On the other hand, hen the salt -------------------------------------------------------------------- 1 27, 34. 1902 2 • Che • J., • Soc., 38, 2 74 1 1916) Ann., 120, 309 (1861 ~)======================================-U t th v ry littl od ne benze h h1te 0 1 a in obt ne . hi oti n led to the 0 1 0 t 0 th :to rth otion o iodine on the pot 881 8 lt 0 triiodo henol t r sol ti on , hi ch led to the orm t on of ute n' e r e Of 10 ne 8 ici nt to br ing bout th s tr ns- ion, hi h roceede ver pidly. t s e pro ble th t otion 1 c in he follo r: io in n- to i lo 1 h r - 0 n th 8 t r e n at te , n t r th h ot i 0 oth ol o 1 . n t t 00 tin o ttin 0 t 0 r lo n bo nd ot 1 l 00 t l n e to th t r idu 0 t ho 0 c . h r c ion nn r e 0' H 1 a o or or ho 1 n c - 5- present in both oases , it would not be possible to follow separate­ ly the fate of both the ''inside" and "outside" halogen. It was decided to carry out the decompositions using to dif­ ferent concentrations of iodbie, a 2/5 gram atom equivalent and the gram atom equivalent, in order to show whether less than one atom equivalent could bring about the decomposition of a whole equiva- lent of sodium salt. The reaction was studied in three solvents; acetone, water and benzene. Reaction in Acetone en sodium trichlorphenolate was heated with a 1/10 gram atom equivalent of iodine in acetone, only a small part ( 270) of the so- di um salt was transformed into the oxide . Heating under the same conditions and for approximately the same time with 1/6 equivalent of iodine increased the salt transformation to 10. 61 , while with 2/6 equivalent , 66.0f- of the sodium salt was converted to the amor­ phous oxide. Increasing the iodine concentration to a gram equi­ valent resulted in 71. 61 of the salt transformed to the oxide . The oxides ere all of the colorless type, and appeared identical ith those prepared from analogous salts in the other ways . Analysis for chlorine showed entire agreement with the theoretical value for the oxide . When an attempt as ma.de to trace the ring halogen and the iodine in this reaction, we discovered that our choice of solvent was an unhappy one . In the presence of halogen, acetone was far from being an indifferent solvent. Our attention was called to this by the very sharp odor of iodo- acetone given off from the reaction mixture. From this we concluded an attemnt to -6- trace quantitatively the action of the two halogens would be unsuc­ cessful. From qualitative experiments, however, we found the io­ dine present as free iodine, and combined with sodium as the iodide, in addition to that in the acetone derivatives. We were also able to show that the ring halogen, at least in part, existed as the chloride combined with sodium. ~he results of the acetone reaction were in accordance with our ideas~but for the reason mentioned, ir.t ~o further work was carried on A this solvent. Reactions in ater The sodium salt when suspended in water with a 2/5 equivalent weight of iodine for 10 days, keeping the reaction flask in a dark place, yielded an amorphous substance slightl pink in color. cept for its color, the oxide was identical with that obtained in the acetone deco~position . The pinx coloration here s extremely interestin , appearing to .indicate the formation of the chlorine analogue of 'Lautemann's Red" , obtained when the potassium salt of triiodophenol was allowed to react with a trace of iodine in ater. In the purification of the oxide by solution in chloroform and re­ preoipi tation by alcohol, most of this color as removed, leaving the pure oxide light tan color. At first it as thot the color might have been due to the adsorption of iodine on the colorless oxide, but no test for free iodine oould be obtained from the al­ cohol used in reprecinitating the purified amorphous substance. Out conclusion here was that a small amount of the colored oxide, analogous to the Lautemann red) had te~porarily formed in the crude oxide. The yield of the amorphous oxide was 63.4 of the original -7- sodium salt. en the same reaction was oarried on using a gram equivalent of iodine the oxide formation inoreased to 79%, which showed that the 2/5 equivalent was sufficient to bring about a practically complete transformation of the sodium salt over to the oxide. A procedure of analysis was then worked out, and a oomplete examination was made on reaction mixture resulting when the salt was allowed to react with a 2/5 equivalent of iodine under the conditions observed in the preliminary experiments. The yield of oxide was 64 .210 of the sodium salt taken, leaving 35.8% to be ac­ counted for.