Dec., 1955
1231
NOTES FREEZING POINT DIAGRAMS OF SOME SYSTEMS CONTAINING T N T
80
BY LOHRA. BURKARDT AND DONALD W. MOORE Chemistry Division, U. S . Naval Ordnance Test Station, China Lake, Calijoornia Received July 6 , 1066
I n the course of a study of the physical properties of 2,4,6-trinitrotoluene (TNT) data are being acquired on a number of binary systems containing TNT. Freezing point data on three of these systems, TNT-2,4-dinitromesitylene, TNT-3-nitro-2iodotoluene and TNT-p-dibromobenzene are presented here. These systems do not appear t o have been investigated previously. The T N T used in these studies had a vacuum melting point of 80.9 O . The 2,4-dinitromesitylene was Eastman Kodak Co. material with a melting point of 87.5 O . The 3-nitro-2-iodotoluene was Eastman Kodak Co., mat,erialmelting a t 64". The p-dibromobenzene was Eastman Kodak Co. material which melted a t 88". The apparatus used in these investigations has been described elsewhere.1 Three-gram samples were used and temperatures were determined with 10% rhodium-platinum thermocouples. Supercooling of the melts was minimized by withdrawing small portions of the melt on a platinum ribbon, allowing the material to solidify and returning it to the melt. The system TNT-2,4-dinitromesitylene was found to form an equimolar compound which melted a t 58". Two eutectics, one containing 43.5 mole % of dinitromesitylene and melting a t 51 O , the other containing 56 mole % of dinitromesitylene and melting a t 57O, were found. Data for this system are presented in Fig. 1.
70 60 50
40 30
20 30 40 50 60 70 80 90 100 Mole % 3-nitro-2-iodotoluene. Fig. 2.-Freezing point diagram of the system TNT3-nitro-2-iodotoluene. 0
10
benzene. This eutectic melts a t 61". this system are presented in Fig. 3.
Data for
20 30 40 50 60 70 80 90 100 Mole % p-dibromobenzene. Fig. 3.-Freezing point diagram of the system TNTp-dibromobeneene. 0
10
GASEOUS METAL NITRIDES. I. THEORETICAL DISSOCIATION ENERGIES FOR DIATOMIC N I T R I D E S BYJOHN L. MARGRAVE A N D PRASOM STHAPITANONDA Received July $6, 1966
80
9 70 60 50
20 30 40 50 60 70 80 90 100 Mole % 2,4-dinitromesitylene. Fig. 1.-Freezing point diagram of the system TNT2,4-dinitromesitylene
0
10
The system TNT-3-nitro-2-iodotoluene is found to form one compound containing 66.6 mole % 3nitro-2-iodotoluene which melts a t 48 O . A eutectic containing 59 mole 7 0 of 3-nitro-2-iodotoluene, melting a t 35 O, and a eutectic containing 72 mole yo 3-nitro-2-iodotoluene, melting at 40 ', are found. Data for this system are presented in Fig. 2. The system TNT-p-dibromobenzene forms a single eutectic Containing 33.5 mole % p-dibromo( 1 ) L. A. Burkardt, D. Inst., 40, 461 (1953).
W. Moore
and W. €3. McEman, Rev. Sci.
There are presently available data on nearly 400 gaseous diatomic molecules, including more than 125 Paseous halides. and over 60 gaseous oxides. Surpyisingly enough,' only thirteen gzseous diatomic nitrides are known: AsN, BN, CN, IN, NBr, NH, ND, NO, NO+, NS. PN, SbN and SiN.2 There are no known gaseous nitrides of the "active" or transition metals. This observation arouses considerable interest since (1) nitrogen is a highly electronegative element and (2) many solid metal nitrides are known. It would appear that the binding energies of diatomic nitrides should be comparable with those of oxides, or a t least sulfides or hydrides, which are well known. In view of the success of an ionic model for treating gaseous halides and hydrides of group I, I1 and I11 metal^,^ and of the fact that this (1) Presented a t the 127th Meeting of the American Chemical Society in Cincinnati, Ohio, on April 7, 1955. (2) G. Herrberg, "Spectra of Diatomic Molecules," D. Van Nostrand Go., Inc., New York, N. y.,1950. (3) (a) E. 5. Rittner, J . Chem. Phes., 19, 1030 (1951); (b) W. A . Klemperer and J. L. Margrave, ibid., 20, 527 (1952); ( c ) J. L. filargrave, THISJOURNAL,68, 258 (1054).
