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Fluorescence from the 1A2 state of CS2 was found to be quenched by a magnetic field. This is the first observation of the magnetic quenching of emission from the excited singlet state. The quenching was found to be due to the enhancement of intramolecular nonradiative energy transfer by a magnetic field.

Reactions of π-cyclopentadienylbis(triphenylphosphine)rhodium(I) (I) with alkyl halides, olefins, acetylenes, carbon disulfide and elementary sulfur have been investigated. Methyl iodide gives the oxidative-addition product [πC 5 H 5 Rh(PPh 3 ) 2 CH 3 ]I but isopropyl iodide produces the alkyl substituted-cyclopentadienyl complex (π-i-C 3 H 7 C 5 H 4 )Rh(PPh 3 )I 2 . Under a nitrogen atmosphere, olefins and acetylenes give compounds of the composition π-C 5 H 5 Rh(PPh 3 )(L) (L = CH 2 —CHCN, CH 2 —CHCO 2 CH 3 , CH 3 O 2 —CCOO 2 CH 3 ). In the presence of air, however, complexes of the composition π-C 5 H 5 Rh(L) 2 (L = CH 2 —CHCN, CH 2 —CHCO 2 CH 3 , CH 2 —C(CH 3 )CN) and π-C 5 H 5 Rh(L) 3 (L = CH 3 O 2 CC—CCO 2 CH 3 , PhC—CCO 2 CH 3 ) are formed. The reaction of carbon disulfide or sulfur with (I) also gives the compounds π-C 5 H 5 Rh(PPh 3 )(L) (L = CS 2 , CS 3 , S 5 ).

The reaction of bis(acetylacetonato)nickel(II), (Ni(AcAc)2)3, with carbon disulfide, followed by extraction with anhydrous ether yields a reddish brown solid, found on analysis to have the same composition as (Ni(AcAc)2)3. The Ni(AcAc)2 species is confirmed by infrared spectra. In addition, the mass spectra are identical, each containing a peak at m/e 256 corresponding to Ni(AcAc)2 units per molecule. The presence of square planar nickel is shown by magnetic susceptibility measurements. The UV–visible spectrum of the product is typical of those containing square planar nickel. The spectrum in the near-IR confirms the presence of octahedral nickel. The ratio of square planar to octahedral species is shown to be one to three. On the basis of the experimental observations, a structure of the product is proposed.

Das elektronenreiche Olefin 1 reagiert mit den Acyliso- und Acylisothiocyanaten 4a–f zu den Dipolen 6a–f. Diese addieren Perchlorsaure unter Bildung den Imdiazolinium-perchlorate 8a – f. Mit Methyljodid werden die „Isocyanant-Dipole” 6a und b am Stickstoff (9a, b), die „Isothiocyanat-Dipole” 6c–f dagegen am Schwefel methyliert (10a-d), ebenso wie der aus 1 und Schwefelkohlenstoff erhaltene Dipol (11 12). Hydrolysereaktionen mit 6a, 8b, 8d und 10b lieferten den „Co2- Dipole” 13. Die Dipole 6a –f sind charakterisiert durch (3 + 2) Cycloadditionen mit Diacylacetylenne (14, 18a-h) und Isocyanaten (15a, b, 19 a–g); bei der Umsetzung von 6b mit Chlorsulfonyliscoyanat findet nur N-Acylierung zu 17 statt. Die Dipolbildung aus 1 und Acylisothiocyanaten wird limitiert durch Redoxreaktionen, bei denen u. a. die 2,2′-Biimidazolindiium -Salze 20 entstehen. Stable Dipoles from the Reaction of 1,1′,3,3′-Tetraphenyl-2,2′-biimidazolidinylidenes with Acyl Isocyanates or Acyl Isothiocyanates The electron -rich olefine 1 reacts with the acyl isocyanates and acyl isothiocyanates 4a–f to give the dipoles 6a–f. These add perchloric acid to form the imidazolinium perchlorates 8a–f. With methyl iodide the „isocyanate-dipoles” 6a and b are methylated at the nitrogen atom (9a, b), whereas the „isothiocyanate-dipoles” 6c–f are methylated at the sulfur atom (10a –d) as is the dipole obtained from 1 a and carbon disulfide (11 12). Hydrolysis reactions with 6a, 8b, 8d and 10b yielded the „CO2-dipole” 13. The dipoles 6a–f are characterized by (3 + 2)-cycloadditions with diacylacetylenes (14, 18a –h) and isocyanates (15a, b, 19a– g); in the reaction of 6b with chlorosulfonyl isocyanate only N-acylation to 17 takes place. The dipole formation from 1 and acyl isocyanates or acyl isothiocyantes is limited by redox reactions in which, among other products, the 2,2′-biimidazolindiium salts 20 are formed.

It was theorized that the heat stability of PVC may be improved by exchanging the “weak” (allylic and tertiary) chlorines by groups of higher bond strength, e.g., phenyl. Thus PVC was phenylated by ϕ3Al in carbon disulfide slurry for various times (1 to 5 hrs) and temperatures (from −30 to +45°C). The ϕ3Al concentration, temperature and time of ϕ3Al treatment greatly affect the ultimate heat stability of PVC. Significant improvement in the heat stability was obtained by treating PVC in carbon disulfide at 25°C for 1 hr. The mechanism of phenylation was studied by model experiments in which the possible structural irregularities in PVC were simulated by small molecule chlorine compounds, i.e., 3-chloro-1-butene, 1,3-dichloro-1-butene, 4-choro-2-pentene were models for terminal and inchain allylic chlorines, t-butyl chloride was the model for tertiary chlorine at branch site, and isopropyl chloride simulated regular secondary chlorines. The reactions between ϕ3Al and these chlorides were carried out at 35°C for various times and the NMR spectra were analyzed. The ϕ3Al + tBuCl reaction in carbon disulfide gives t-butylbenzene (Wurtz coupling) and isobutylene oligomers. Evidently ϕ3Al (or the ϕ2AlCl formed) dehydrochlorinates tBuCl to isobutylene which rapidly oligomerizes in the presence of Lewis acids. In aromatic diluents, i.e., benzene, chlorobenzene, and o-chlorotoluene, Friedel-Crafts t-butylation of the diluent occurs; in mesitylene t-butylation is absent presumably because of steric hindrance and small amounts of t-butylbenzene are formed by Wurtz coupling. All the allyl chlorides examined are rapidly phenylated by ϕ3Al in carbon disulfide at 35°C and yield the expected products: 3-chloro-1-butene → 1-phenyl-2-butene; 1,3-dichloro-1-butene → 1-chloro-3-phenyl-1-butene; 4-chloro-2-pentene → 4-phenyl-2-pentene. The kinetics of phenylation by ϕ3Al of model compounds have been studied and the following rate constants were obtained: kallyl = too fast to measure, ktBuCl = 1.0, and kiPrCl = 9 × 10−4 l/mole min. Evidently the rate of the ϕ3Al + RCl reaction is mainly determined by the stability of the R⊕ intermediate: substituted allylic⊕ ≫ tertiary⊕ ≫ secondary⊕.

Carbon disulfide, dimethyl disulfide, methyl mercaptan, dimethyl sulfide, and hydrogen sulfide retard nitrification of ammonium in soils incubated in closed systems. The inhibitory effects of these volatile sulfur compounds on nitrification decrease in the order listed. Hydrogen sulfide is a relatively weak inhibitor of nitrification, but carbon disulfide is considerably more effective than patented nitrification inhibitors (N-Serve. AM, and ST) for inhibition of nitrification in closed systems. It is concluded from the work reported that the inhibitory effects of methionine, cystine, cysteine, and other nonvolatile organic sulfur compounds on nitrification in soils may be at least partly due to decomposition of these compounds by soil microorganisms with formation of volatile sulfur compounds that retard nitrification.

Bis(tributylstannyl) mercaptoethanolate (I) and ethanedithiolate reacted with carbon disulfide and isothiocyanates to afford mainly the corresponding cyclic thio- and imino-carbonates, respectively, with elimination of bis(tributylstannyl) sulfide. The carbonate derivatives formed decomposed partially or reacted further with I to give by-products. To clarify the course of the latter reaction compound I and related compounds were treated with thionecarbonate derivatives to afford carbonate derivatives, ethylene sulfide and bis(tributylstannyl) sulfide. These desulfurization reactions of the thione compounds are assumed to proceed via spiro-orthocarbonate derivatives, which then decompose.

The theory of molecular liquids based on the reference interaction site model (RISM) equation is used to describe the intermolecular structures of the liquids carbon tetrachloride, carbon disulfide, carbon diselenide, and benzene. The theory assumes that the equillibrium correlations between molecules in a dense fluid are determined primarily by the short range, harshly repulsive portions of the intermolecular potential. These repulsive interactions are modeled as hard core interactions by assuming molecules are composed of overlapping hard spheres which are rigidly fused together. The centers of the spheres are located at the positions of the nuclei in the molecules. As a result, the model hard core interactions depend on the molecular orientations. The equilibrium pair correlations produced by these interactions are determined from the solutions of the RISM integral equation. This is an approximate (but accurate) equation for the pair correlation functions. The molecular structure factors S(k) for the a...

Infrared absorption intensities of fundamental bands of bromoacetyl chloride were measured in carbon disulfide solution, an absolute intensity method being applied to determine the energy difference between the rotational isomers. In order to determine the dihedral angle of the less stable isomer, normal frequencies and band intensities were calculated for various angles, the results being compared with observed data. The dihedral angle of the gauche isomer was found to be 100°C which is in good agreement with the angle in chloroacetyl chloride. The energy difference, 0.91 kcal/mol, determined in carbon disulfide solution is in good agreement with the value obtained by the temperature variation method.

Infrared absorption and Raman spectra of 1,2-diiodoethane CH 2 ICH 2 I have been observed in solution and in solid phase, and observed fundamental bands have been assigned. Infrared absorption intensifies have been measured in carbon disulfide solution, and by using the absolute intensity method, the energy difference between the rotational isomers has been obtained as 1·38 ± 0·10 (kcal/mol). It is in quite a good agreement with the value obtained here by using the temperature variation technique. In addition, the normal frequencies and the absolute i.r. absorption intensities have been computed for various assumed dihedral angles for the gauche isomer, and the angle giving the best fit between the observed and computed values has been determined as 85° ± 5°.

Dispersion and polar components of surface free energy of ice have been calculated using the principle of additivity and geometrical mean of similar forces interacting across the interface of contiguous phases. Comparison of those components shows a qualitative difference between ice and water surfaces; ice being predominantly of nonpolar character. Surface tension components of chlorobenzene and carbon disulfide have been evaluated by the same method and their spreading pressures on ice were computed. The results show that both liquids form autophobic adsorption layers which change the nature of ice surface.

A novel method for the quantitative estimation of warfarin in plasma is described. Plasma containing warfarin to which a known amount of phenylbutazone is added as internal standard is acidified and extracted with ethylene dichloride. The drug and the internal standard are then back-extracted into alkali which, in turn, is acidified and reextracted with ethylene dichloride. The organic extract, after washing with phosphate buffer (pH 7.2), is evaporated and the evaporated extract is reacted with an ethereal solution of diazomethane (100 μl). The reacted mixture is evaporated and then dissolved in 25 μl of carbon disulfide. Ali-quots (2–3 μl are injected into a gas chromatograph equipped with a flame-ionization detector. The methyl derivatives of warfarin and the internal standard give sharp, well-separated, symmetrical peaks. The method is of sufficient sensitivity to determine plasma levels in humans after single doses (20 mg) of warfarin (sensitivity of 0.25 μg/ml).