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Dinitrogen Tetroxide Complex A STUDY OF THE TERNARY SYSTEM DIOXANE- TETRAHYDROPYRAN-DINITROGEEN TETR OXIDE DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By BETTY JANE GIBBINS,\t 9 B.S. 9, M.S. The Ohio State University 1953 Approved by: 1 ACKNOWLEDGMENTS The author expresses her appreciation to Dr, Harry H. Sisler for suggesting this research and for his constant interest and guidance throughout the course of the investigation. Appreciation is also extended to Dr. Gunther L. Eichhorn and Dr. Bernard Rubin for data for the binary systems. The author also expresses her appreciation to Dr. Fairfax E. Watkins for constructing Figure 28 and to Dr. William J. Taylor for contributing to the discussion of the structure of the dioxane— dinitrogen tetroxide complex. That part of this research was conducted with the assistance of the Ordnance Corps, U.S. Army, through a contract with The Ohio State University Research Foundation, is also gratefully acknowledged. \ 12:\'7'7fy ii TABLE OF CONTENTS Page ACKNOWLEDGMENTS ............................. i LIST OF FIGURES ........................... iv LIST OF TABLES ............................ vl I. INTRODUCTION ................................. 1 II. STRUCTURE OF DINITROGEN TETROXIDE .......... 2 III. MOLECULAR ADDITION COMPOUNDS OF DINITROGEN TETROXIDE .................. 5 IV. TERNARY PHASE DIAGRAMS ................... 11 a. The Phase Rule ........................ 11 b. The Right Triangular Prism ........... 12 c. Plotting Concentrations ............. 13 d. System with no Compounds or Solid Solutions ................... lb 1. Experimental Behavior ........... 15 2. Space Diagram .................... 17 3. Projection of the Space Diagram on the Base ......... 20 e. Systems with Compounds .............. 22 V. CRYOSCOPIC STUDY OF THE SYSTEM, DIOXANE— TETRAHYDROPYRAN-DINITROGEN TETROXIDE .. 24 a. Plan of Investigation ................ 24 Ill Page b. Purification of Materials .............. 26 c. Experimental Procedure .................. 31 d. Results .................................. 38 e. Discussion of Results and Conclusions .. 78 f. Summary ................................... 88 BIBLIOGRAPHY ................................. 92 AUTOBIOGRAPHY ................................ 95 4 iv LIST OF FIGURES Figure Page 1. A Concentration Triangle ............................ 14 2. System with no Compounds or Solid Solutions ...... 16 3. Projection of the Diagram on the Base ............. 21 4. Dinitrogen Tetroxide Purification Apparatus ...... 29 b. Dinitrogen Tetroxide Transfer Cell ................ 30 6 . Ether Storage Flasic ................................. 32 7. Freezing Point Cell ................................. 33 8. Transfer of Dinitrogen Tetroxide to Freezing Point Cell ........................................ 34 9. System: 10/90 mole per cent CeHlo0/0(CH2CH2)20-Na04 42 tt 11 tt it »t tf 10. 2 0 / 8 0 4 4 tt If n tt tt tt 11. 3 0 / 7 0 4 6 M tt tt M ft tt 1 2 . 4 0 / 6 0 4 8 bO/bO !1 *t ti tt tt tt bO 11 tt tt tt tl tt 6 0 / 4 0 b2 It tl tt tl 11 ft 7 0 / 3 0 0 4 tt tf it t1 tt tt 6 0 / 2 0 b6 It ft it tt ft It 17. 8 8 / 1 2 0 8 11 tt tt tt tt tt 18. 9 0 / 1 0 6 0 tt tt it It ft tt 19. 9 2 / 8 6 2 tt tt tt tt tt tt 20. 9 6 / 4 6 4 Figure Page 21. System: 94.1/5.9 mole % CgHioO/NgO^-OlCH2CH2)fiO.. 66 22. " 91.8/8.2 " " " H " ..67 25. " 86.6/13.4 " « « " « ..69 24. " 7 7.2/22.8 ” ,f " H " ..70 2b. " 60.1/34.9 " " n " " ..72 26. " 04.2/40.8 •* " " " " ..73 27. Projection of the Diagram on the Base ........... 76 28. System: Dioxane-Tetrahydropyran-Dinitrogen Tetroxide .................................... 77 v i LIST OF TABLES Tab la Page 1. System 10/90 mole % C6Hio0/0{CH8CHS )s 0-N80. 41 H tl tt H tt 2. 20/80 ” m 43 tf ft tt tt tt 3. 30/70 " e 4b tf tf 4. 40/60 " tt tt ft • 47 ft tt tl tt ft b. 50/50 " • 49 tf If tt tt It 6. 60/40 " * bl M tf tt tt ft 7. 70/30 " • 53 tt tf tt t* tt 8. 80/20 ” • 55 tl ft y . 88/12 " tt tl tt • 57 If 10. tt 90/10 " if tl tf • 59 tt n n tt ft n . 92/8 " • 61 tt H n tv tt 12. 96/4 ” • 63 13. System 94.1/b.9 mole % cbh 10o/nso.- 0(CH8CH2 )20 65 14. tt 91.8/8.2 tt tt n tt tt • 65 lb. n 66.6/13.4 tt tt tt rt M • 68 it tf 16. 77.2/22.8 tt It tl It • 68 17. tt 6b.1/34.9 it tt II tt ft * 71 H tt tt ft tt tt 18. b4.2/4b.8 • 71 19. Maxima from Figures 9 tnrough 26 74 20. Binary Eutectic Mixtures ......... 75 21. Ternary Eutectic Mixtures ........ 79 A STUDY OF THE TERNARY SYSTEM DIOXANE-TETRAHYDROFYRAN-DINITROGEN TETROXIDE I• INTRODUCTION. During the course of an investigation of molecular addition compounds of dinitrogen tetroxide with some ethers Rubin, Sisler, and Shechter^ found that 1,4-dioxane forms an addition compound with properties strikingly different from those of the addition compounds of the other ethers. It was noted that 1,4-dioxane and tetrahydropyran form dinitrogen tetroxide addition compounds with different mole ratios and strikingly different melting points. Dinitrogen tetroxide-dioxane melts at 45.2*C.; dinitrogen tetroxide*2 tetrahydropyran, at -56.8°C. A bicyclic monomer, a dimer, and a polymeric aggregation were proposed as possible structures for the dioxane-dinitrogen tetroxide addition compound, A study of the ternary system dioxane-tetrahydro- pyran-dinitrogen tetroxide was proposed (1) to investigate the possibility of a ternary compound, (2) to compare the stability of the crystalline dinitrogen tetroxide-dioxane compound with that of the crystalline dinitrogen tetroxide- tetrahydropyran compound over a large range In concentra­ tion, and (3) to perhaps more fully substantiate or 2 eliminate some of the structures proposed for the binary compounds. Although compos!tion-temporature phase diagrams have been widely used to detect compounds and solid solutions in equilibrium mixtures of two components, phase diagrams for non metallic, non aqueous, ternary systems are believed to be rare. Study in the field of ternary diagrams is compli­ cated by the relative complexity of the systems and by the necessity or representing the data in three dimensions. The system dioxane-tetrahydropyran-dinitrogen tetroxide thus offered an opportunity to construct a relatively rare type of diagram and to develop technique in determining and representing ternary systems. IX. STRUCTURE OF DINITROGEN TETROXIDE The structure of dinitrogen tetroxide has been a matter of much discussion. The following three structures have received considerable support: I ii III + -0 N -0-N o - n v ',0sn'm-o ./ \ . a 0 0 3 Structure I formerly was favored on the basis of chemical evidence, but now has been discarded on the basis of physical evidence. It was used to explain such reactions as the reaction with olefins to form nitroso, nitro, nitrite, and nitrate derivatives. More recently Levy and 2 Scaife studied this reaction and reported that, unless dinitrogen trioxide is present as an Impurity, no nitroso compounds are formed. The formation of the dinitroalkanes and nitronitrites has been explained by Ingold3 , using structure II and an electrophilic attack. The N0e+ attaches Itself first, and the N0fi” is free to attach either as a nitro or nitrite group. The slight dissociation of dinitrogen tetroxide Into N0+ and N03” , which was indicated by Addison and Thompson,4 can be explained with structure II or III. With structure II, a N-0 bond would be broken and an oxygen atom would be transferred across the weak N-N bond. With structure III, only an electron transfer is necessary. Thus, chemical evidence does not clearly differentiate among the three structures. Structures II and III are supported by both chemical and physical evidence. Infrared absorption and Raman scattering spectra indicate that dinitrogen tetroxide is symmetrical and non- 4 linear. Sutherland'5 Interpreted the low, very intense Raman frequency as evidence for a weak N-N bond and evidence for structure II. Longuet-Higgins6 proposed structure III and stated that the low, very intense Raman frequency could be caused by angular deformation of the ring. Thus, either structure seems to be consistent with spectroscopic data. Longuet-Higgins calculated the entropy value from spectroscopic data, and found that, in order to obtain agreement between his entropy value and the experimental value of Giaque and Kemp7 , he had to assume no free relative rotation of the ends of the molecule. This seemed to give additional support to structure III. More recently, how­ ever, Bernstein and Burns® calculated the entropy, by using structure II and the following bond distances and angles: angle 0N0 = 120°, N-0 - 1.15A°, and N-N * 1.66A®. Finding that they had to assume internal rotation to make their calculated value agree with that of Giaque and Kemp7 , they discarded structure III. The most conclusive evidence seems to be the X-ray data of Broadley and Robertson®. Their study of single crystals of the solid Indicates that the molecule is planar, and the bond distances and angles are as follows: N-N, 1.64 ± 0.03A*; N-0, 1.17 * 0.03*; 0-0 (both on one N 5 atom), 2.09 ± 0.03A*; and the angle 0N0, 126 * 1*. Structure II and the above measurements will be assumed in subsequent discussions. III. MOLECULAR ADDITION COMPOUNDS OF DINITROGEN TETROXIDE. Spath10 prepared crystalline U0 s (N03 )2*2N0s, by adding a mixture of dinitrogen pentoxide and dlnitrogen tetroxide to a solution which had been prepared from partiall dehydrated U02(NOs )2 »6H20 and fuming nitric acid. Composition-temperature phase diagrams constructed by Pascal and Gamier-*--*- indicated the formation of two com­ pounds: 5 dinitrogen tetroxide*4 camphor, with a melting point of -52*C., and 2 dlnitrogen tetroxide*3 camphor, with a melting point of -45.5°C.
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