Search

Es wird uber physikalisch-chemische und verfahrenstechnische Untersuchungen des Schmelzspinnprozesses und der Fadenbildung bei Polyamid 6 (PA 6) berichtet. Die Versuche erfolgten unter korrespondierenden optimalen Prozesbedingungen. Es wurden u. a. die Einflusse von Spinngeschwindigkeit (bis 2500m/min), Spinntemperaturen (235 bis 300°C), Spritzbedingungen, Dusengeometrie, Spinnpraparierung und Lagerzeit auf Fadenbildung, Verstreckung und Eigenschaften von PA 6-Faden untersucht. Ferner wurde die Fadenbildung im Spinnschacht als Funktion des Dusenabstandes und der Spinngeschwindigkeit studiert. Hierbei waren Memory-Effekte zu beobachten. Anhand einer Storungstheorie wird auf Fragen der Prozesoptimierung des PA 6-Schmelzspinnverfahrens und die damit verbundene Beeinflussung der Fadeneigenschaften eingegangen. Wahrend des Spinnvorgangs vollzieht sich bei PA 6 in sehr kurzer Zeit (ca. 0,1 sec) ein kontinuierlicher Ubergang aus dem schmelzflussigen uber den viskoelastischen in den festen Zustand in Fadenform. Zur theoretischen Deutung werden die Versuchsergebnisse zur partiell-kristallinen Kink- und Faltungsstruktur von PA 6 in Beziehung gesetzt. Abschliesend werden die Grundzuge einer dynamischen Theorie des Schmelzspinnprozesses von PA 6 diskutiert. Results of physico-chemical and technological investigations of melt spinning and fibre formation of polyamide 6 (PA 6) are presented. The experiments were carried out under corresponding optimum process conditions. Hereby, among others, the effects of spinning velocity (up to 2,500 m/min), spinning temperatures (235–300°C), extrusion conditions, dimensions of spinnerets, spinning preparation and time of storage were studied with regard to filament formation, drawing and properties of PA 6-fibres. Furthermore, the fibre formation in the blowing shaft was investigated in dependence of the distance from the spinneret as well as the spinning velocity. Memory effects were observed. On the basis of a perturbation theory the optimation of the melt spinning of PA 6 and its effects with regard to fibre properties are discussed. During spinning there occurs within a very short time(approximately 0.1 sec)a continuous conversion of PA 6 from the liquid melt, over the viscoelastic on to the solid state in form of a thread. For theoretical interpretation the experimental results are related to the semicrystalline supermolecular structure of kinks and chain folding of PA 6. Finally, the main features of a dynamic theory of melt spinning of PA 6 are developed.

Der schrittweise oxydative Austausch der Liganden von Hexa-halogenokomplexen in Losung und im festen Zustand wird durch Isolierung der als Zwischenprodukte auftretenden Gemischtligandkomplexe verfolgt. Die spektrophotometrische Bestimmung des cis-trans-Verhaltnisses zeigt, das sich J und Br durch Oxydation mit Cl2 meistens stereospezifisch ersetzen lassen. In einigen Fallen tritt in Abhangigkeit von den Versuchsbedingungen Isomerisierung oder Konfigurationsumkehr ein. Die Austauschmechanismen werden diskutiert. Oxydative Ligand Exchange for Preparation of Mixed Osmium-Halo-Complexes The stepwise replacement of ligands in hexahalocomplexes by oxydation in solution and solid state is investigated by isolation of intermediately formed mixed-ligand complexes. The spectrophotometric determination of the cis/trans relation shows, that mostly I and Br can be replaced stereospecifically by oxydation with chlorine. Depending on experimental conditions in some cases isomerisation or inversion of configuration takes place. The exchange mechanisms are discussed.

Formation of charge-transfer complexes by solid state reaction was studied for 16 donors and 10 acceptors. The relative reactivity of 160 pairs was determined by the presence or absence of the charge-transfer band on grinding the component pairs of the same concentration (diluted with sodium chloride) for the same length of time. Equilibrium was not reached within the grinding time. This relative reactivity was compared with and found to have a parallel relationship with the relative ease of formation of the charge-transfer complex on evaporating a mixture of the solutions of components, indicating that the relative reactivity is related to an apparent equilibrium established on the grain surface. Relative reactivity was found to be largely dependent on molecular size and geometry. Smaller molecules were more reactive. For molecules with the same number of rings, those with compact structure were more reactive. Most of the new bands given by the reaction were CT bands of microcrystals. They were very broa...

Antimon(V)-chlorid bildet mit Wasser vier bei Raumtemperatur feste Addukte SbCl5 · nH2O I-IV (n = 1, 2, 3, 4). I ist im Festkorper uber H-Brucken zu Oligomeren verknupft. In II, III und IV liegen neben Addukten auch salzartige Produkte H+(H2O)n[SbCl5OH− (n = 1, 2, 3) vor. I und II reagieren mit Natriumchlorid zu Natrium-hexachloroantimonat(V) · 1 bzw. 2 H2O. Die IR- und Raman-Spektren der untersuchten Verbindungen wurden diskutiert. Studies on Water Adducts of Antimony(V) Chloride Antimony(V) chloride gives four solid adducts of sbCl5 · nH2O I-IV (n = 1, 2, 3, 4) at room temperature. In the solid state I is oligomer by hydrogen bridges. In II, III, and IV are besides the adducts ionic products of the constitution H+(H2O)n] SbCl5OH− (n = 1, 2, 3). I and II reacts with sodium chloride to yield sodium hexachloroantimonate(V) · 1 resp. 2 H2O. The vibrational spectra were discussed.

Durch Hochvakuumverschweisung bei Temperaturen oberhalb 1400 °C werden Schichtverbundproben aus den Metallen Nb, Nb-1 Zr und Ta und aus den Oxiden Al2O3 und ZrO2 ohne Bildung von zusatzlichen Zwischenschichten hergestellt. Mo und Al2O3 werden uber eine Nb-Schicht miteinander vereinigt. Die untersuchten Schichtverbundkombinationen sind von technischer Bedeutung fur die Entwicklung von Verbundwerkstoffen und von hochtemperaturbestandigen Verbindungen zwischen metallischen und keramischen Materialien. Es wird uber ihr Gefuge, ihre Eigenschaften und die chemische Vertraglichkeit des Verbunds berichtet. Daruber hinaus wird eine bruchmechanische Methode beschrieben, mit der die Festigkeit des Verbunds uber KIc-Faktoren charakterisiert werden kann. Laminated Composites of Refractory Metals and Oxides. Laminated composites of the metals Nb, Nb-1 Zr and Ta and of the oxides Al2O3 and ZrO2 are manufactured by high vacuum solid state bonding at temperatures above 1400 °C without a formation of intermediate layers. Bulk molybdenum and alumina are joined together by means of a niobium layer. The combinations investigated are of technical importance for the development of high temperature composites and refractory joints between metals and ceramics. The microstructure, the intrinsic chemical compatibility and other properties of the composite samples are described. Moreover, a method based on fracture mechanics is described which characterizes the bond strength between metals and ceramics by means of KIc-factors.

Wahrend FeOF aus α-Fe2O3 und FeF3 bisher nur unter hohem Druck rein dargestellt werden konnte, entsteht eine reine homogene Rutilphase der Zusammensetzung Fex3Ti1-x,O2-xFx mit 0 ≤ x ≤ 0,75 durch Umsetzung von α-Fe2O3 und FeF3 mit TiO2 bereits bei Normaldruck. Die Gitterkonstanten gehen von a = 4,601 und c = 2,969 A bis a = 4,639 und c = 3,026 A. In Bereich 0,75 < x ≤ 1,0 ist die Umsetzung unvollstandig. Das magnetische Verhalten der Rutilphase ist durch starke antiferromagnetische Wechselwirkungen gekennzeichnet. X-Ray and Magnetic Investigation of the System FeOF–TiO2 While pure FeOF has been only prepared under high pressure a pure, homogenous rutile-phase FexTi1−x,O2−xFx (0 ≤ x ≤ 0,75) can be obtained by solid state reaction of α-Fe2O3, FeF3 and TiO2. The lattice parameters range from a = 4.601 and c = 2.969 A to a = 4.639 and 3,026 A. Between 0.75 < x ≤ 1.0 the reaction was not completIy. The magnetic behaviour of the rutile-phase shows strong antiferromagnetic interactions.

Solid state processing of polyethylene (SS60-050) by hydrostatic extrusion is investigated. Measurements are also reported for the tensile properties of polyethylene 60–050 under superposed hydrostatic pressure. With the latter data an estimate is made of the pressure required for extrusion of polyethylene in the absence of losses due to friction and redundant work. The limiting conditions for successful extrusion are discussed.

The i.r. and Raman spectra of CH3NHCOCSNHCH3 and its deuterated analogue are given in the solid state and in solution. The fundamental vibrations have been assigned and special attention has been given to the influence of the hydrogen bonding on the fundamentals. We also studied the influence of the alkyl substituents on the spectra.

A critical analysis was performed on galvanic cell techniques which employ calcia‐stabilized zirconia electrolytes. The presence of low‐level electron or hole conduction in the ionic conducting range of the electrolyte was found to be responsible for oxygen permeation through the electrolyte which can either oxidize or reduce a single‐phase oxide and, hence, lead to drift in the open‐circuit emf with time. Taking oxygen permeation into account quantitatively, a series of isothermal titration experiments in wüstite was performed in which the cell emf was found to be linear with composition (i.e., oxygen‐iron molal ratio). These results are in excellent agreement with a recent composite analysis of all thermodynamic data in the Fe ‐ O system. Previous cell studies in which deviant behavior has been reported are probably due to improper galvanic cell techniques. No evidence was found to support the existence of more than one‐phase or second‐order transitions within the wüstite phase.

The solid state reaction WO3 + SrCO3 → SrWO4 + CO2 was studied with the reactants in form both of separate pellets and of powder mixtures. As for pellets, by an application of Wagner’s method it was possible to state that the governing process is the cation counterdiffusion involving W6+ and Sr2+. Thermogravimetric measurements in the temperature range 663° - 755 °C on equimolar powder mixtures and with SrCO3 in a specially prepared spherulitic form were interpreted using Dünwald- Wagner’s equation

N-alkylmaleimides from the N-methyl to the N-octadecyl derivative were polymerized in the solid state by γ-radiation. Polymerization during irradiation generally showed sigmoidal conversion curves with high rates and complete conversion 10°C below the melting point. Post-irradiation rates were lower and showed the typical approach to a “limiting” conversion. The polymerization rates increased with temperature and radiation dose and with the length of the alkyl chain. N-methylmaleimide had a high rate of in-source polymerization which was attributed to the volatility of the monomer. N-Alkylmaleimide vom N-Methyl-bis zum N-Octadecyl-Derivat wurden durch γ-Strahlung im festen Zustand polymerisiert. Die Polymerisation weist wahrend der Bestrahlung im allgemeinen eine S-formige Umsatzkurve auf, mit hohen Geschwindigkeiten und quantitativem Umsatz bei Temperaturen von 10°C unterhalb des Schmelzpunktes. Die Geschwindigkeiten waren nach der Bestrahlung niedriger und zeigten eine typische Annaherung an einen Grenzumsatz. Die Polymerisationsgeschwindigkeiten nahmen mit der Temperatur und der Bestrahlungsdosis sowie mit der Lange der Alkylkette zu. N-Methylmaleimid zeigte eine hohe Geschwindigkeit bei der Polymerisation in Substanz, die der Fluchtigkeit des Monomers zugeschrieben wurde.

Nuclear magnetic resonance (NMR) has long been a useful technique for the study of solids (1, 2). Within recent years, however, a number of advances have been made both along theoretical and experimental lines which hold promise to expand greatly the utility of nuclear magnetic resonance as an experimental technique for the study of physical and chemical phenomena in solids. Of particular importance are those techniques which are furnishing generally applicable means of measuring chemical shift tensors in solids for the first time. This review has been restricted to a discussion of those developing techniques which, among other possibilities, are allowing high resolution chemical shift tensor measurements in solids. No attempt will be made here for a definitive essay of the theoretical basis of these somewhat complex new techniques, but rather the emphasis will be placed on discussing the nature of the information they allow one to obtain on physical and chemical interactions within solid materials and what the present and future potentials and limitations of the techniques appear to be. Recent efforts in other aspects of solid state NMR have been reviewed (3-12), and the reader is particularly referred to the discussion of sample spinning techniques by Andrew (3), to the summary of theoretical developments in pulsed NMR by Mansfield (4), and to discussions of using NMR for the study of motional effects in solids (5-7) and of surface adsorbed species (8, 9). Additionally, attention is called to the development of more precise techniques for measuring moments of NMR lines by Lowe et al (13) and locating the center of such solid state lines by Kunitomo (14).

The flourescence of benzonaphthofuran was studied in ethanol, in solid state and on Whatman paper. Measurements were carried out at room temperature and 77 °K, respectively. Benzonaphthofuran sensitizes the luminescence of the naphthacene built into its crystal lattice. The phenomenon was applied to the analytical determination of the naphthacene.

An X-ray diffraction study of 2(eq),4(ax),6(eq)-trichlorocyclohexanone, cis-2,6-dichloro- and gem-2,2-dichloro-4-tert-butylcyclohexanones shows the existence of a chair form in the solid state. Analysis of the experimental data shows: - an appreciable contraction of the endocyclic angle at the foot of the carbonyl group in the three molecules; - a strong overlap of the electronic clouds of the oxygen atom and the equatorial chlorine atoms in the α position with respect to the CO bond; - a considerable variation of the dihedral angle formed by the OC 1 C 2 and the C 1 C 2 X eq or C 1 C 2 H eq planes in the different molecules; - a negative or positive effect on ring planarity depending on the nature and position of the substituents.

Low-frequency Raman and far-infrared spectra of polyglycine, poly-L-alanine, and poly-L-valine have been measured. The Raman spectra exhibit an intense band near 100 cm−1 for these homopolypeptides. Lattice calculations of the polyglycines are used to assign the intense Raman band to a rotary lattice mode. For homopolypeptides in the β conformation, an infrared band is observed whose frequency varies inversely with the square root of the mass of the peptide repeating unit. This infrared band is assigned to the hydrogen bond stretching lattice vibration.

Es wurde festgestellt, das der Einbau von Li-Ionen die Geschwindigkeit der Reaktion der Spinellbildung verschiedenartig beeinflust in Abhangigkeit davon, ob die Li-Ionen in das Kristallgitter eines oder beider miteinander reagierender Substanzen vor der Reaktion eingefuhrt wurden. Effect of Li-Doping of MgO and Cr2O3 on the Kinetics of MgCr2O4 Formation It was found that incorporation of Li-ions influences the rate of the spinel formation by the solid state reaction in a different way depending on which of the reacting oxides was doped with these ions.

Low-frequency dielectric measurements have been made in the temperature range from −180°C to +110°C on DNA and a number of proteins in the solid state. The results suggest that a molecular rearrangement may occur in the temperature interval +60°C to +80°C. In terms of these measurements the transition appears to be reversible in DNA if the material remains at +20°C for longer than 60 hr. Such a time-dependent recovery has not been observed for proteins. The application of a pressure of ∼150 MN m−2 for a 3-min. period appears to be capable of reversing the thermal transition in at least some of the proteins studied. These results are compared with the results available from studies of the influence of temperature and pressure variations on similar biological materials in aqueous solutions.

Ba 6 Ti 17 O 40 , Ba 4 Ti 13 O 30 , BaTi 4 O 9 , and Ba 2 Ti 9 O 20 are the only compounds which were found to have a stability range in the subsolidus of the BaTiO 3 TiO 2 system. BaTi 2 O 5 and BaTi 5 O 11 , reported in other studies, apparently are not stable. The compound reported as Ba 2 Ti 5 O 12 appears to have been mistaken for Ba 6 Ti 17 O 40 . X-Ray diffraction powder data are given for this phase which is monoclinic with a = 9.890, b = 17.117, c = 18.933 A and β=98°42.6′. The phase formulated previously as BaTi 3 O 7 is shown to be Ba 4 Ti 13 O 30 based on structural and density considerations, phase equilibria, and single crystal and powder X-ray diffraction data. This compound is orthorhombic with a = 17.072, b = 9.862, and c = 14.059 A, probable space group, Cmca . An idealized structure for this phase is proposed. Ba 2 Ti 9 O 20 decomposes above 1300°C in the solid state to BaTi 4 O 9 plus rutile. Single crystals were grown using BaF 2 as a mineralizer.

A bstract. An inexpensive solid state pH control circuit was built for external use with existing pH meters that can use either a gas or a liquid solution for pH control of culture media. Mastigocladus laminosus showed a 49% reduction in the rate of radiophosphate (P-32) uptake between gas-controlled (30% C02 in air) pH intervals of 8.7 (optimal uptake) and 5.7. Isotope uptake rates at higher pH values (achieved by manual additions of 0.1 N NaOH) decreased slightly between pH 8.7 and 9.7 and declined 36% between 9.7 and 10.7, where trichome motility and the ability to colonize new substratum were inhibited. Suppression of growth based on short-term (96 hr) dry weights, of which only 24 hr were at the selected pH values, was not evident throughout the experimental pH range.

Raman spectroscopy has been used to study the solid state reaction of MoO3 and CoMoO4 with γ-Al2O3 and the compounds formed upon the adsorption of Co(II) an Mo (VI) on γ-Al2O3. Results show that γ-Al2O3 endows CoMoO4 and MoO3 with a high reactivity, giving Raman-inactive compounds.

Conformational studies of a series of oligopeptides (from the tripeptide to the octadecapeptide) with the repeating sequence L-norvalyl-glycyl-L-proline and a polytripeptide with this sequence are reported. By means of chiroptical techniques, unordered conformations are found for all oligopeptides in water, trifluoroethanol, and ethylene glycol and for the water-insoluble polymer in trifluoroethanol. In ethylene glycol the polymer assumes a collagen-like structure. Infrared studies indicate that all the oligomers, in contrast to the polymer, are unordered in the solid state.

Recently, several new approaches to the design of television tuning systems have emerged. Federal regulations concerning equal parity for UHF and VHF tuning systems have caused increased interest in purely electronic tuning systems. In addition, such factors as reliability, economics, aesthetics and convenience, as well as the increased number of channels on UHF and cable, have spurred interest in the development of solid state, totally electronic television tuning capability. The ideal tuning system incorporates all of these features.

Semi-empirical LCAO methods (extended Huckel, iterative extended Huckel and INDO) are examined as a possible simple starting point for constructing solid state interaction potentials for non-bonded interactions from molecular wave functions. These methods are applied to calculate the cohesion energy and lattice equilibrium unit cell dimensions for α and γ nitrogen crystals, the lattice optical mode frequencies at = 0 of α - N2, the electronic Davydov splitting of the molecular 1Πg state in α - N2 and the stability of molecular-ion aggregates. Reasonable agreement is obtained with extended Huckel and iterative extended Huckel methods, while INDO usually yields poor results. The possibility of excimer formation in nitrogen is discussed in light of these calculations. It is concluded that semiquantitative results can be obtained with these methods when they include the gross features essential for description of crystal non-bonded interactions, such as full overlap interactions, approximate magnitude of mole...

The major factors which limit the successful application of solid-state electrochemical cells in high-temperature equilibrium measurements are summarized. Such factors include electronic conduction in the solid electrolyte, difficulties in maintaining a fixed chemical potential at the electrodeelectrolyte interface, and general experimental uncertainties. Particular attention is directed towards cells using ZrO2-based and ThO2-based solid electrolytes. Whenever possible, examples from the literature are used to illustrate particular points. Resume Les auteurs presentent un resume des principaux facteurs qui limitent l'application des cellules electrochimiques a l'etat solide pour la mesure des equilibres a haute temperature. Ces facteurs comprennent la conduction electronique dans l'electrolyte solide, les difficultes pour maintenir un potentiel chimique constant a l'interface electrode-electrolyte, et les incertitudes experimentales en general. Une attention particuliere est accordee aux cellules...

The deaquation-anation reaction of [Ru(H2O)(NH3)5]X3 type complexes in solid state, as shown by the equation, [Ru(H2O)(NH5)3]X5 (s) → [RuX(NH3)5]X2 (s) + H2O (g), where X=NO3 and Br was investigated by means of the differential thermal analysis (DTA) and of the thermogravimetry (TG). The activation energies in the deaquation-anation processes of the nitrate and bromide were calculated as 17.5 and 23.0 kcal/mol by the isothermal rate study, and as 19.0 and 26.8 kcal/mol by the Freeman–Carroll analysis.

Results are given for the latent track stability of fission fragments as well as neutron-induced recoils and α -particles found in Makrofol E and cellulose acetate after a storage time of up to 28 d at a temperature of 0–50°C and at relative air humidities of 0–97%.

Summary The structures of Ph 2 Te(OOOCH 3 ) 2 , Ph 2 Te(OOOPh) 2 and ( p -EtOC 6 H 4 ) 2 -Te(OOCCH 3 ) 2 are considered to be based on a four-coordinate ψ-trigonal bipyramidal arrangement of groups about the central tellurium atom. There is evidence for non-equivalence of carboxylate groups in both the solid state and in solution for Ph 2 Te-(OOOPh) 2 and for ( p -EtOC 6 H 4 ) 2 Te(OOCCH 3 ) 2 . The carboxylate groups are as “ester”-like as in related organotin compounds. Attempts to isolate organotellurium triacetates from solution gave only mixtures of hydrolysis products. The spectrum of Ph 2 Te(NO 3 ) 2 is less readily interpreted but the balance of evidence favours a monomeric structure with unidentate or very unsymmetrically bidentate nitrate groups.

Low-temperature specific heats of a heavily cold-worked and annealed high-purity copper were measured in the temperature range 1·5–4·2°K. The results are compared with similar measurements reported previously (Ahlers 1966). The enhancement of the electronic specific heat coefficient γ is in excellent quantitative agreement with the calculated increase of the specific heat due to vibrations of mobile dislocations (Granato 1958). In the temperature range of the measurement, this increase is proportional to the dislocation density and the temperature. A phenomenological approach to the study of the properties of a liquid via a heavily deformed solid state is discussed in terms of the stored energy and entropy of cold work.

An attempt is made to correlate crystallographic changes arising during the radiation induced polymerisation of trioxane with the morphological changes observed during this process. Particular emphasis is placed on the differences which are noted with changing polymerisation time and temperature, so that both nucleation and growth could be discussed. Die Anderung der Kristallstruktur des Trioxan, die bei der strahleninduzierten Polymerisation beobachtet wird, wurde im Zusammenhang mit den bei diesem Prozes auftretenden morphologischen Veranderungen untersucht. Die Unterschiede, die sich durch geeignete Wahl der Polymerisationszeit und der Temperatur ergeben, bieten die Moglichkeit, sowohl die Keimbildung als auch das Wachstum zu diskutieren.

Infrared spectra of N-methyl- and N,N-dimethylaminobenzoic acids have been investigated. All the acids except N,N-dimethylanthranilic acid showed neutral structures in the solid state. The N,N-dimethylanthranilic acid, however, exhibited a dipolar structure with strong intramolecular hydrogen bonding in the solid state while in solution it is neutral.

(1973). Heterogeneous catalysis: Some aspects of catalysis by metals. C R C Critical Reviews in Solid State Sciences: Vol. 4, No. 1-4, pp. 311-332.

Electronic and far-i.r. spectra show that the complexes of type Ni L 2 X 2 where L is semicarbazide, NH 2 NHCONH 2 , or semicarbazones, NH 2 CONHN : C R 1 R 2 ( R 1 = CH 3 , R 2 = CH 3 or CH 2 CH(CH 3 ) 2 ; C R 1 R 2 = cycloheptane and X = Cl, or Br, have tetragonal 6-co-ordinate structures. The complexes Ni L 2 X 2 . 2H 2 O contain the cation [Ni L 2 (H 2 O) 2 ] 2+ . However the complexes Ni L 2 X 2 where where L is thiosemicarbazide, NH 2 CSNHNH 2 , and X = Cl, or Br, are square planar and the corresponding thiosemicarbazones where L = NH 2 CSNHN : CR 1 R 2 have trigonal bipyramidal5-co-ordinate cations [Ni 2 X ] + in the solid state.

The synthesis and purification of suitable radioactive tracers for organic solid state self diffusion experiments is described. Particular attention is paid to the isotope effect which requires two tracers containing different radioactive isotopes, and with as large a mass difference as possible. The latter is accomplished by incorporating a stable isotope in one of the tracers. Active preparations of adamantane, dl-camphene, bromopentamethyl-ethane, and hexamethylethane are reported.

The report by James and Nolan1 of the vibrational spectra of the tetranitroplatinate (II) ion in the solid state complements our study of the solid state vibrational spectra of a series of Group IA tetranitroplatinate (II) salts.2 Here we report the comparative infrared and low frequency Raman spectra of nitrogen-14 and nitrogen-15 potassium and cesium tetranitro-platinate(II) salts.

The crystal structure of cis-chlorobis(triethylphosphine)-1,10-phenanthrolineplatinum(II) fluoroborate has been determined and refined to an R-value of 0.051. The space group is P21/c and the cell dimensions are a = 0.9215(2), b = 1.1991(3), c = 2.6832(6) nm, β = 99.38(3)°, with 4 molecules per unit cell. The interatomic distances to Pt are: Pt—N(1), 213.7(19); Pt—N(2), 284.3(20); Pt—P(1), 223.9(7); Pt—P(2), 224.1(6); Pt—Cl, 236.1(6) pm.The coordination number and geometry is discussed in terms of 5-coordinate tetragonal pyramidal and 4-coordinate square planar models, the latter being regarded as the more acceptable.Monodentate o-phenanthroline is thus observed for the first time in the solid state. The structure of the complex in solution is discussed with the aid of conductance and nuclear magnetic resonance results which suggest the possibility of a novel fluxional system.

The mechanism for the promoting effects of additives on the formation of MgAl2O4 has been systematically discussed from the results of kinetic measurements. A mixture of MgO and α-Al2O3 powder containing 10 mol% additives (LiF, NaF, MgF2, GaF2, BaF2, NaCl or CaCl2) and that without additives were isothermally heated in N2 atmosphere in the temperature ranges 670–1142°C and 1190–1360 °C. The diffusion-controlled Jander’s equation was applied to all kinetic data obtained. In the case of fluoride additives, it has been found that the promoting actions are in the order LiF≥NaF>BaF2>MgF2>CaF2 and that the cations of fluorides play an important role in accelerating diffusion. The same promoting mechanism seems to be applicable in the case of chloride additives.

The low frequency Raman and far i.r. spectra (650-40 cm−1) of the complexes [MII(NH3)5Y] X2 (M = Ru, Os; X = Cl, Br, I, BF4; Y = N2, CO) have been investigated. The MY solid state vibrational modes were generally assigned by factoring out the vibrations of the pentammine unit, combined with intensifies, deuteration and 15N2 substitution. A similar pattern of MY vibrational modes was found for all of the complexes studied. The factor group splitting observed in the 2000 cm−1 region for the Os complexes has been correlated with the crystal structures.

Monte Carlo calculations have been made on the basis of the rigid-ion model for a number of alkali halides at zero applied pressure in the solid state at 298K and both solid and liquid phases near the melting temperatures. Two different forms of the short-range repulsive interaction were used: an exponential potential of the Huggins-Mayer form (1933) and an inverse-power repulsive potential in the form due to Pauling (1928). The potential parameters were in all cases taken from the work of Tosi and Fumi (1964). Some care has been taken to minimize errors in the calculation of the coulombic energy and the accuracy of the results is believed to be considerably greater than that previously achieved in the computer simulation of ionic systems. The Huggins-Mayer form of the potential is found to be superior to the Pauling form in virtually all respects.

Copper salts of low pH (1.8–2.5) combine with phenyl-2-pyridyl ketone to form a ketone complex [(Py–CO–C6H5)2Cu]2+. An electrically uncharged complex is obtained at pH > 9 [(Py–C(OH)(C6H5)O−)2Cu]0, liberating two protons from two molecules of the ligand. The stability constant of this complex is β = 16.05. By mixing the copper salts (except the halide) containing this ligand with ethylenediamine, a charged triple complex is obtained at pH 9.5, an uncharged triple complex is obtained: {[(Py–C(OH)(C6H5)O−)2Cu}2 · NH2C2H4NH2}0. The copper halide salts produce only an uncharged triple complex; the halide ions are coordinated with the copper atoms. All of these complexes in their solid state, are bi- or polynuclear. As a result, they are magnetically subnormal.

This paper briefly reviews the propulsion, auxiliary electrical, and miscellaneous electrical systems selected for use on the San Francisco Bay Area Rapid Transit District cars. It also discusses the general maintenance philosphies and future activities of the Rolling Stock and Shops Division in anticipation of full BART system operation.

Summary A new series of cationic rhodium complexes; [RhCodL 2 ] + (Cod= 1,5-cyclooctadiene, L =pyridine, 2-vinylpyridine, 2-methylpyridine, 4-methylpyridine) has been prepared by treating [(RhClCod) 2 ] in ethanol with pyridines. IR and NMR spectral analyses lead to structures in agreement with those obtained from elemental analyses. Reactions of these Complexes with carbon monoxide give the new cationic compounds [Rh(CO) 2 L 2 ] + . Studies on the solid state indicate the existence of monomeric and dimeric species. The monomeric species preponderates when the pyridine has an a substituent. In CHCl 3 solution only the monomeric compound exists.

A series of square planar Pd II and Pt II complexes of the type MX 2 (L) [X = Cl, Br, I and L = Ph n P(CH 2 CH 2 CHCH 2 ) 3 − n ; n = 0–2] have been prepared and studied by 1 H and 31 P magnetic resonance, and infrared and Raman spectroscopy. The strength of the metalolefin bond is found to be in the order Pt > Pd. When L = PhP(CH 2 CH 2 CHCH 2 ) 2 or P(CH 2 CH 2 CHCH 2 ) 3 , IR and Raman data indicate only one olefin is coordinated in both the solid state and solution. On the PMR timescale, the olefins undergo rapid intramolecular exchange, offering a system in which one observes average HH and PtH coupling.

Molecular motion of azulene in its own molecular crystal and in its complex with trinitrobenzene has been shown from wide-line n.m.r. and spin–lattice relaxation time measurements to occur in the solid state. Calculations of the n.m.r. spectral parameters based on a model where the azulene molecules are reorienting in their molecular planes by 180° jumps give satisfactory agreement with experimental values. The results are discussed with respect to the available X-ray data.

A new monolithic structure for solid-state traveling-wave amplifiers is proposed, which promises efficient interaction between a drifting charge carrier stream and a slow electromagnetic wave component. The suggested configuration is potentially suitable for operation in the far-ir frequency regime. A one-dimensional analysis of the interaction between the electromagnetic waveguide mode and the carrier current is presented, including the loss contribution due to the nonsynchronous space harmonics of the electromagnetic mode.

The changes and developments which have occurred in high resolution NMR in recent years are reviewed. Firstly, the basic high resolution spectrometer is discussed. The second concern is a new generation of high resolution spectrometers which are being developed: those which are based on the pulse technique followed by Fourier transformation. Finally new experiments which are becoming of interest in high resolution NMR, specifically the measurement of relaxation times and spectra from the solid state, are considered.

The solid state i.r. spectra of m - and p -aminobenzene sulphonic acids, their sodium salts and their deuterated analogues are described for the region 4000–400 cm −1 .