F. E. Saalfeld

Ion implantation studies of (SN)x and (CH)x

Abstract We report the results of the initial investigation of the application of ion implantation for the “doping” of the electroactive polymers, (SN) x and (CH) x . Increases in conductivity have been measured for some (CH) x samples after being implanted. Evidence for the formation of a discrete chemical species has been observed in the case of (CH) x implanted with Br + ions. Advantages and drawbacks associated with this technique are discussed.

Mass spectrometric characterization of halogen doped polyacetylene

Abstract Mass spectrometry was used to investigate the volatile species given off when polyacetylene, which had been exposed to I 2 , Br 2 , Cl 2 , or F 2 , was heated in vacuo . A correlation of the conductivity of the samples with the amount of molecular halogen ions (X 2 + ) evolved was observed. These results are consistent with the present concept for the form of the dopant in the polymer. In the I 2 case, two sources of iodine in the (CH) x were found and these were related to the presence of I 3 − and I 5 − in the polymer films.

Identification of the vapor phase species of (SN)x

Abstract A mass spectrometric study of the vapor phase species obtained by heating (SN) x (polythiazyl), polymeric sulfur nitride, at 140°C utilizing direct (collision free) and indirect (multiple wall collisions) sampling is reported. The experiments show that depolymerization occurs and that the major neutral species in the vapor of (SN) x is (SN) 4 , possibly of bent chain structure. Evidence for a hydride impurity in the (SN) x polymer has been obtained.

Mass-spectral investigation of AsF5-doped (CH)x

Abstract Polyacetylene, (CH)x, doped with arsenic pentafluoride has been the subject of considerable study since the discovery of its high electrical conductivity, but controversy has surrounded the form of the dopant in the polymer. We report the results of a mass-spectral study aimed at identifying the arsenic fluoride species present after doping. The results demonstrate that AsF6− is present, and models are proposed to explain the possible source of the controversy concerning previous anlytical results. A method of synthesis is suggested for reproducible production of a pure AsF6−-doped material.

Mass Spectrometry of Low-Dimensional Materials

Mass spectrometry, MS, is applied to almost every area of research being pursued today. Diverse studies such as cancer research, forensic drug analysis, atmosphere, and water environmental analysis, combustion, and lasers have benefited by mass spectrometry.1,2 In these investigations, the mass spectrometer is frequently used either as a chemical reactor or as an analytical instrument. The intent of this chapter is to focus primarily on the use of this instrument for the analysis and characterization of low-dimensional materials.

Nature of the bonding between silicon and the cobalt tetrcarbonyl group in silycobalt tetracarbonyl: III. Mass spectral studies of trichlorosilyltrifluoro-phosphine cobalt carbonyl derivatives

Abstract Mass spectral studies of two cobalt carbonyl compounds, Cl3SiCo(CO)x-(PF3)4-x where x = 2 and 3, including fragmentation patterns, metastable ion current intensities, and appearance potentials have yielded data which are interpreted in support of (d → d)π bonding and/or intramolecular interaction between the silyl substituent and the equatorial ligand. The heat of formation of the two compounds was found to be −748±10 kcal mol−1 for x = 2 and −548±10 kcal mol−1 for x = 3. The Cl3Si–CoL4 bond energy was estimated to be 96±10 kcal mol−1 for both compounds.

MASS SPECTRAL STUDIES OF (SN)x VAPORS

Recent investigations’-’ of polymeric sulfur nitride, (SN),, have created considerable interest in the scientific community. Although most emphasis has been on the conducting properties of (SN), and the mechanism of its conduction, several physical and chemical studies have also been made. Smith et al.4-5 showed from mass spectrometric data that the (SN), vapor species formed by sublimation of the crystal is a single species, (SN),, having a “linear” structure. These studies also revealed a hydride impurity of 1-5 atom percent. No other bulk impurity was detected. This paper reports a more detailed investigation of the hydride impurity. We show that the hydride impurity consists of a single species with a molecular weight of 215 + 5 amu. The magnitude of the hydride impurity concentration in (SN), is rather surprising and has been confirmed by other workers.6 The hydride impurity or its precursor may play a role in the solid-state polymerization of S z N z to (SN),. We have examined (SN), samples prepared in this laboratory and two other laboratories,’ and find the hydride results reported here independent of preparation. In addition, we also report preliminary data o n the vapor species observed when (SNBr,35), is sublimed.’-’’ The mass spectral study of the vapors of this brominated compound provides evidence for the existence of SNBr.

Identification of the vapor phase species of brominated (SN)x

Abstract A mass spectrometric study of the vapor phase evolved from brominated (SN) x is reported. This work identifies the major bromine-containing species in the vapor (SNBr 0.43 ) x using electron impact and field ionization mass spectrometry.

Production of H2O2 in hydrocarbon-O2CF3Br systems

Abstract Hydrogen peroxide is produced when CF 3 Br is added to flowing hydrocarbon-oxygen mixtures at approximately 350 °C. The H 2 O 2 concentration is dependent on the amount of CF 3 Br added to the hydrocarbon-oxygen mixture and maximizes at approximately 40 mole% CF 3 Br.