2622
ELOFSON, ANDERSON,GUTOWSKY, SANDIN, .\m SCHULZ
Vol. 85
[CONTRIBUTION FROM THE DEPARTMEST O F CHEMISTRY, c N I \ ' E R s I T Y D F .ILHERTA, EDMOSTOS, CANADA ; T H E RESEARCH C O U S C I L OF .\LRERTA, EDMOSTON, CAXADA: SANDIA LABORATORY, XLBVQT:ERQUE, ?rl.; ASD THE DEPARTMENT O F CHEMISTRY, t T N I V E R S I T Y O F
s.
ILLIXOIS, URBANA, ILL.]
Some Reactions of Solid Tetrakis-(p-dimethylaminopheny1)-ethylene Diiodide Monohydrate BY R. A I . ELOFSON,? D. H . X N D E R S O NH. , ~ S.GUTOWSKY,' R . B. S A S D I NA,N~D K. F. S C I I U L Z ~ RECEIVED APRIL 23, 1903 Freshly prepared solid t e t r a k i s - ( p - d i i n e t l i y l a ~ ~ i i r i ~ ~ p h e ~ ~ y l ) - ediiodide t l ~ y l e n e monolib-driite (1) s h o w very little, if any, free radical activity Compound I undergoes a reversible room temperature dehydration to produce a solid anhydrous product (111 1, accompanied by significant changes in the e . s . r . ,infrared spectra, and color. Compound I1 I exhibits e.s.r. absorption, of Lorentzian shape, which is sensitive t o teniperature and t h e presence of oxygen. T h e heating of I11 above 75' and t h e room temperature extraction of I with benzene leads t o disproportionation into t h e parent olefin I1 and what is probablJ- t h e ditriiodide The e , s , r . of tlie heated solid I\- is similar t o t h a t of I11 except for its insensitivity t o oxygen. T h e complex e.s.r. properties of I11 and IT' are similar t o those found in donor-acceptor complexes.
In a previous communication6 we reported the preparation of tetrakis-(p-dirnethylaminopheny1)-ethylene diiodide monohydrate (I) and its optical and e.s.r. spectra in water and in ethylene chloride. Solutions of I in water gave no e.s.r. signal, whereas I in ethylene chloride gave an intense e.s.r. signal. It was suggested that in ethylene chloride an electron transfer occurred to give a cation radical reminiscent of a a'iirster cation. I t was considered reasonable t h a t an equilibrium favoring ionic species in polar solvent? should shift in the direction favoring less charged forms in less polar solvents. The purpose of the present investigation has been to determine the behavior of I in the solid state under varying conditions of temperature, pressure, and humidity. Experimental Tetrakis-(p-dimethylaminopheny1)-ethylene Diiodide Mono-
drizd material was extracted with cold benzene and afiorded a bl.ick residue (0.2108 g . ) ; calcd. irt. of residue is 0.2027 g . A n a l . Calcd. for CarHlr,S,Is: I, 60.19. Found: I (Carius), 58.74. T h e benzene extract afforded 11. Electron Spin Resonance Measurements.--Measureiiie?its w:r: made with a I-arian Model 4500 e.p.r. spectrometer fitted with a TE 102 100 k c . cavity and a 100 kc. modulation attachm c n t ; 10-mg. samples in 4-tnm. o.d. tubes were positioned for mazimuin s i g d in t h e cavity. M'idth measurements were based on the vanadyl cleuterioporphyriii in berizene.' Estiniates of free radical coiiterit were based o n measurements with 0.25-tng. samples of DI'PII dispersed in starch estimated t o coiitain 3.33 X 10" free radicals ($IOf free rxiical c o n t e n t ) . Estimates were bmxi oil the .issumption t h a t the absorption curves \\.:re Lorentzian in sh:ipe because of exchange narro\riiig anti calculated from t h e relationship n = h ( A H j 2 where h is the aniplitude of t h e first derivative a t tlie poi:it of maximum slope and A N is t h e width a t the point of niaxitiiuni slope, Since this assuniptioii could not be valid for t h e very wide signals observed on tlie ;idmission of ouygeii, t h e latter results were c:rlculntetl by integratio ?s using a plmirneter. Measurements based on III'PH equal to 2.0023 revealed t h a t all the compounds h;id y-\-alucs iri tlic range 2.0030 i 0.0003.
hydrate (I).-Potassium iodide dissolved in water was added t o Spectroscopic Results a n aqueous solution of tetrakis-i~-dinietiiyl~~riinoplieiiyl)Infrared Spectroscopy.-In Fig. 1 are reproduced ethylene dinitratefi which had beeti recrystallized several times from r a t e r below 50". T h e brilliant green diiodide was air dried spectra in Fluorolube mulls of the dinitrate, the green a t room temperature for 24 h r . and contained one molecule of diiodide monohydrate I , the evacuated diiodide I I I , water which could be rernovecl by heating a t 75' i n air and which the heated diiodide IV, the ditriiodide, and the parent could be absorbed b y anhydrous calcium cliloride. olefin I1 in the region 1TOO-1400 ctn-I. These spectra Effect of Benzene Extraction.--,\ weighed sample of I (0.2740 g , ) contained in a weighed Gooch crucible was extracted with cold show that the dinitrate and the ditriiodide have no benzene until the weight (0.1484 9 . ) of black residue was coribenzenoidx absorption at 1520 ern-' and they can s t a n t (calcd. weight of residue from 0.2740 g . of C I ~ H I , I X ~ I ~ . H ~ O , therefore be considered to be essentially quinoid c o n 0.1490 g . ) . pounds with intense absorption a t l(iO0 c m - l . The Anal. Calcd. for C 7 1 H a l , l l I R (black residue): I , 60.19. green hydrate I shows very little if any absorption a t Found: I (Carius), 59.3X. 1,720 cm.-' and must also he in the quinoid form. T h e benzene extract w:is concentrated t o dryness wid afforded tetrakis-( p-dimethylaminoplienyl )-ethylene i I I ) . The et-acuated diiodide shows a small absorption a t Effect of Drying under Vacuum and over Phosphorus Pent1320 cm. --I indicating some benzenoid character. oxide.--h weighed sample of I (0.6610 9.) was placed iii a vacuum The spectra of the heated diiodide shows a much dcsiccator over phosphorus pentoxide. 'The pressure w a s reduced stronger absorption a t this freyuency intlicatii-e of a t o 5 t n m . and after 24 h r . t h e 1os5 in weight, n.liich TWS cotistarit, w:is 0.0166 g . .-lncii Calcd. for C,4H,,8S,I,.H?O: H.0, 2.33. substantial aroniatic content; cj'. spectrum of olefin in Found: HrO, 2.51. T h e dried coin~xiund!$-as exposed t o the lahFig. 1 . oratory air for 24 h r . until the ireiglit (lJ.iiiiO4 9.) I Electron Spin Resonance Spectra.-In Table I some T h e rc-versible detiydration-liydratii,n reacticin could e.s.r. measurements on the complexes of tetrakis-ipnumber of times without x n y apprcciable v:~riatitiii lc t e a t . I t LWS fouiiti tli,it stantlii over pliospliorus p e n t i i ~ i ~ fcir ditiieth~-laminophenyl)-ethylenewith iodine are re1'1 to 48 h r . at atrnospheric pr .urc i\-o111~1 ~ i c c < i i i i ~ ~til(, I i ~ l(IC>i ported. Freshly prepared I dried a t room teriiperaliydruti(in, which could bc rever. I by c\posiirc tii tlic Ialxjratory
of Heating a t 7 5 " in Air.-Coiii~)iiutitl I ( 0 . : 3 7 ~ X g . ) \vas
air a t 75" until the weight \viis constant. - 1 t i i i i . C:ilcC. for CIIHIIISdI?.H.'O: HsO, 2.33. F o u i ~ d : H 2 0 , 2.52. 'l'lie air' 11 T h i ? r p i e a r r h was s u l q m r t e d in part b y t h e Office o f h-aval I < h c k n o w l e d j i m e n t is m a d e t u t h e d r m r i r s of T h e P e t r o l e u m I l e i e a r c admini;trrcd hy t h e American Chemical S u c i e t y , for p a r t i a l s u p p o r t oi t h i s rewarch Furls R r a n c h , Research Council of A l b e r t a , l < d m o n t o n . C a n a d a hanrlia l . a t , r r a t o r y , A I t ~ u ~ ~ u ~Sn ~X if ~ e , l)eT,artmcnt uf C h e m i s t r y . U n i v e r i i t y oi Illinois, U r h a n a , I l l I)eliartrnent uf Chemistry. Cniversity < > fA l b e r t a . ECdmcinton. Canadn. I ) H Anderson 1l hf Iilofsnn. H S C u t o w n k y , S . I.evine, a n d l l B S a n d i n . .I. .-in. Chpnz. So
