COMMUNICATION TO THE EDITOR MASS SPECTRUM OF CARBOK SUBOXIDE Sir:
of GO2. The filament therefore was conditioned wit,h oxygen prior to each run until the m/e = 28 peak was approximately 774 of the m/e = 32 Recently, several articles have appeared in the peak. Iiterature dealing with carbon suboxide (C30Z). The results of two analyses are given in Table I. The presence of C302in a reacting gas system has ,The 100% peak appears a t m/e = 40. COS was been identified by its infrared emission' and gas the only detectable impurity. The amount of chromatography. The published literature, how- COZpresent was 0.177,. ever, does not appear to contain the mass spectrum of C30a. Thus, we have undertaken the task of TABLE I obtaining the cracking pattern of this compound, MASSSPECTRUM OF C,O, The carbon suboxide was prepared by a modificallclative tion of the method of Stock and S t ~ l t z e n b u r g . ~ Peak height intensity From past experience, the impurities in the freshly n1/e lo11 I I1 I I1 prepared carbon suboxide were found to be acetic I ? (2' 178. 253. 2 6 . 0 22.0 acid and carbon dioxide. The acetic acid mas 13 5.3 3.0 0.29 0.27 removed by fractional distillation. The carbon 14 GO -1- + 3.8 0.8 0.10 0.07 dioxide was removed by two techniques. The 14.0 7 . 8 0 . 7 6 0.70 16 0' first involved the distillation of the C302and COZ 24 Cy+ 244. 140. 13.3 12.6 into an evaporator. Helium gas then was passed 3 . 0 0 . 3 3 0.27 25 6 . 0 through the C302 a t a temperature of ca. - 7 8 O to 26 C@+." 7.0 4.0 0.38 0.36 displace the CO;?. The second technique used was 2 . 0 1 . 3 0 . 1 1 0.12 27 to warm the C302 to ca. -40 to -20°, apply a 498. 295. 27.0 26.1 28 COT vacuum for a period of 10-20 see., and then re5,s 3.0 0.30 0.27 29 freeze the C,Oz in liquid nitrogen. This procedure 0.4 0.05 0.04 30 1.0 was repeated several times. Both techniques Ca02J-" 168. 98.1 9.1 8 .9 34 showed the complete removal of C02 within the 3.0 0.28 0.27 34.5 5.2 limits of detection of a Beckman GC-1 gas chro0.5 0.03 0.04 O.D 35 matograph using a silica gel column. 22.8 13.5 7.2 1.2 36 C," The spectrometer used was a General Electric 40 (220" 183!1. 1110. 100. 100. analytical mass spectrometer. About 12 min. 40.5 24.0 2.2 2.2 41 was required to sweep ( 2 3 0 2 from m/e = 12 to 4.0 2.5 0.22 0.22 42 m l e = 70. The rate of leak of C30z expressed 1.3 0.08 0.12 l.D 43 as decrease of pressure in the 2-1. reservoir per 53 c p 44-.2 25.0 2.4 2.3 min. was 2.6. The ion accelerating voltage was 1.5 I .0 0.08 0.09 53 held constant a t 1'750 volts, and the magnetic field CbO?+ 1784. 10 44. !)4.6 !l4.2 scxnned from 45 ma. at m / e = I2 to 110 ma. at, G8 56.0 40. 3 0 3 .6 60 v z / e = 70. The ionizing current and potential 7.6 A5 0.11 0.40 TO i t crc opcmtcd a t 50 pa. and 30 volts, rcspcctivcly. l'rc!tisurt~ i niic.rcJns) 180, I IO. rI'lw oprrationnl prorcdurc \vas as follows : low p r r , ~ h i i r c yof C,O, in thr 2-1. rmrrvoir 11 PTC obtninccl 'h w u t h o r h wislL to arknonledgc the asistailre by cixpaiision from a scrirs of dosing v o h i m e ~ . I'resbiires were measured oil a IllcLcod gage (tilt- of 1)r. B'. .J. Yastola of the Fuel Terhnology Deiiig type). Samples were admitted to the leak 1 partment in preparing this note and the sripporl min. before beginning the sweep. The filament of the above work by the Atomic Energy Combecamc carbonized as a result of the dissociation mission, Contract No. AT(30-1)-1710. ,
(1) L. H. S. Roblee, Jr., J. T ignew, and K. W a r k , Jr., Combust. Flame, 5, 65 (1961) (2) H. B. P a l m e r a n d T. J. Hirt, J. *4m. Chem. S O C 84, , 113 (1962). ( 3 ) A. Stock a n d H. Stolteenbura, Eer., 60, 498 (1917).
FUELTECHYOLOGY DEP~RTYGKT
THOXAS J. HIxr
THE: P E h NSYLVASIA STATE UXIVERSITY JAMES P. WIGHTAfAN USXBERSITY P A R K , PENNSYLVANIA
RECEIVEDAUGUST10, 1962
