Alkyl–oxygen bond formation in the mass spectra of α-chloromethyl aryl sulphones

When subjected to electron-impact, chloromethyl aryl sulphones (II, X = Cl) fragment predominantly by the loss of CH₂Cl from the molecular ion followed by the loss of SO₂ and in most cases the appropriate metastable peaks are present to confirm the transitions. In addition, alkyl–oxygen bond formation in the molecular ion was revealed by the presence of prominent peaks corresponding to the [R? ?-SO]⁺ ions. In most spectra no evidence for aryl–oxygen bond formation could be found and thus the presence of the chlorine atom was able to effectively reverse the direction of skeletal rearrangement reported for aryl methyl sulphones.     

The crystal structure of CuVo3(II), a high-pressure ilmenite phase

The crystal structure of a second high-pressure copper vanadate phase, CuVO₃(II), has been determined and refined by full-matrix least-squares procedures using automatic diffractometer data to a residual R = 0.042 (R_w = 0.051). The space group is rhombohedral, $\text{R}\text{3}$, with hexagonal unit cell a = 4.966(2) and c = 14.084(5) Å [a_R = 5.501(2) Å and α = 53.66(3)°]. The structure is the fully ordered ilmenite-type and, on the basis of published magnetic data and the interatomic distances, the valence distribution Cu⁺V⁵⁺O₃ is proposed. This represents a unique example of Cu⁺ in an octahedral environment.     

Microwave spectra of transient species — cyclopentadienone

The microwave spectrum of the main isotopic species of cyclopentadienone has been measured and assigned. The rotational constants imply an essentially planar geometry and that the ring is rather “fatter” than the analogous ring in fulvene.The dipole moment, derived from Stark-effect measurements, is 10.4 × 10^?30 C m (3.13 D). A vibrational satel- lite spectrum, which, from its inertial defect, corresponds to an out-of-plane vibration has also been assigned.The life time of cyclopentadienone under our spectroscopic conditions is approximately 15 sec.     

Phase diagram and X-ray diffraction analysis of the acrylic acid–acrylamide system

The phase diagram of the acrylic acid–acrylamide system as determined by DTA and the supporting x-ray diffraction data are presented. This diagram shows that the system forms a 1 : 1 addition compound which decomposes above 0°C. There is also one eutectic point at a 67 mole-% acrylic acid composition.     

Cyclic imides III. A study of the hydroxy- and methoxyphthalimidoacetic acids and the methyl methoxyphthalimidoacetates

The hydroxy- and methoxyphthalimidoacetic acids and the methyl methoxyphthalimidoacetates have been synthesized. The ultraviolet absorption spectra of these compounds in 95% ethanol, aqueous acid, and aqueous base are discussed. Structures are suggested for the hydroxy- and methoxyphthalamate ions which are formed in basic solution. The Gabriel-Colman rearrangements of methyl 3- and 4 - methoxyphthalimidoacetate give, respectively, 8-methoxy-4-hydroxy-3 - carbomethoxy-1(2H)-isoquinolone (VII) and 6-methoxy-4-hydroxy-3-carbomethoxy-1(2H)-isoquinolone (VIII).     

Water-soluble copolymers. XXV. Ion-binding studies of N-substituted acrylamide copolymers using potentiometric and spectroscopic methods

Spectroscopic and potentiometric methods have been used to study the ionic properties of several N-substituted acrylamide copolymers that display unusual ion-binding character. The ionic groups and the amide groups (both on the same repeating unit and on adjacent acrylamide units) in the copolymers are found to chelate calcium ions. The stabilizing effect of this amide chelation is found to be dependent on copolymer composition. A model is proposed to explain the unusual binding behavior of the acrylamide polymers. This involves the formation of an intramonomer chelate or one with neighboring acrylamide units that prevent precipitation of the polymers.     

Isolation of a urease from watermelon seeds and the study of its properties

The enzyme urease has been isolated from the seeds of the watermelon of the Ogonek variety and has been characterized. The molecular weight of a rechromatographed sample of the enzyme has been determined as 480,000. The pH dependence of the activity of the urease and the kinetic parameters of the enzyme have been studied.All-Union Scientific-Research Institute of the Chemistry and Technology of Drugs, Khar'kov. Vitaminy Scientific-Production Amalgamation, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 624–628, September–October, 1983.     

Preparation and Crystal Structure of La3ReO8

The crystal structure of La₃ReO₈, prepared at 1425°C, is reported to be different from a previous result on a preparation at 900°C (BAUD et al., 1979). The high temperature modification crystallizes in the monoclinic space group P2₁/m with a = 7.757(1), b = 7.777(1), c = 5.928(1) Å, γ = 111.1°, Z = 2. The structure was solved by Patterson and Fourier methods from single crystal diffractometer data and refined to final R(F) = 0,073. The structure consists of isolated, distorted ReO₆ octahedra and double chains of edge-shared La₄O tetrahedra.     

FIBER-OPTIC PLANT TISSUES: SPECTRAL DEPENDENCE IN DARK-GROWN AND GREEN TISSUES*

Abstract— The fiber-optic properties of etiolated plant tissues can be used to detect and characterize pigment absorption in vivo. Transmission spectra of light guided through several monocot and dicot etiolated tissues show a decreasing red/far red ratio with increasing tissue length. Absorption bands attributable both to vacuolar pigments such as anthocyanins and to chloroplast pigments lead to the conclusion that the guided light passes through both vacuole and cytoplasm. As etiolated tissue becomes green under white light treatment, the red/far red ratio also changes, the nature of the change depending upon the tissue involved. The blue/red ratio also changes both with increasing length of etiolated tissue and during the greening process, with the changes again dependent on the tissue involved. The spectral dependence of the light-guiding phenomenon in dark grown and green plants may have implications for physiological responses mediated by phytochrome.