scholarly journals The relation between the crystal symmetry of the simpler organic compounds and their molecular constitution. —Part II

1913 ◽  
Vol 89 (611) ◽  
pp. 327-339 ◽  
Keyword(s):  
Aromatic Hydrocarbons ◽  
The Other ◽  
Optical Observations ◽  
Monoclinic Crystal System ◽  
Sulphur Compounds ◽  
Monoclinic Crystal ◽  
Optical Character ◽  
Halogen Compounds ◽  
Optical Axes ◽  
Molecular Constitution

In this paper the experimental results concerning the crystalline properties of the unsaturated aliphatic hydrocarbons, the simpler oxygen- and sulphur-compounds of carbon, the halogen-compounds, and the simpler aromatic hydrocarbons are given. Ethylene . —Ethylene, prepared from alcohol and sulphuric acid, was purified by liquefying it and distilling it twice. It crystallises very well, large prisms being formed. Two distinct cleavage systems occur, one parallel to a prism and the other parallel to the basal plane (or an orthodome). The doublerefraction is of middle strength; the extinction is in some sections parallel to the prismatic cleavage, in others it is not. The angle of the optical axes is large, and the optical character negative. These optical observations show that ethylene crystallises in the monoclinic crystal system.

Studies on the Toxicity of Aromatic Hydrocarbons on Chorella Vulgaris by 3D-QSAR Using CoMFA and CoMSIA Methods

2012 ◽  
Vol 610-613 ◽  
pp. 3574-3579
Author(s):  
Cui Hua Wang ◽  
Sheng Long Yang ◽  
Chao Lu ◽  
Hong Xia Yu ◽  
Lian Shen Wang ◽  
...  
Keyword(s):  
Benzene Ring ◽  
Aromatic Hydrocarbons ◽  
Common Factor ◽  
3D Qsar ◽  
The Other ◽  
Contour Maps ◽  
Substituent Group ◽  
Donor And Acceptor ◽  
The Common ◽  
Insight Into

By using CoMFA and CoMSIA methods, the new quantitative structures of 25 aromatic hydrocarbons and the 96 hr-EC50 data with C. vulgaris have been investigated to obtain more detailed insight into the relationships between molecular structure and bioactivity. Compared to CoMFA (the average Q2LOO option =0.610), CoMSIA (the average Q2LOO =0.736) has the better results with robustness and stability. CoMSIA analysis using steric, electrostatic, hydrophobic, and H-bond donor and acceptor descriptors show H-bond donor is the common factor for influencing the toxicity, the steric and electrostatic descriptors are next and the hydrophobic descriptor was last. From the contour maps, the number of benzene ring is more crucial for the compound toxicity and the compounds with more benzene ring make toxicity increased. Under the same number of benzene ring, the kind of substituent group and the formed ability of H-bond are the other parameters to influencing the aromatic hydrocarbons toxicity.

Catalytic Pyrolysis of Waste Achyranthes Root Over Al-MCM-41

2021 ◽  
Vol 21 (7) ◽  
pp. 4081-4084
Author(s):  
Seul-Bee Lee ◽  
Young-Min Kim ◽  
Ji-Hui Park ◽  
Young-Kwon Park
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Aromatic Hydrocarbons ◽  
Catalytic Pyrolysis ◽  
The Other ◽  
Gas Chromatography Mass Spectrometry ◽  
Acidic Properties ◽  
Achyranthes Root ◽  
Formation Efficiency ◽  
Mcm 41

This study examined the thermal and catalytic pyrolysis of waste Achyranthes Root (AR) using pyrolyzer-gas chromatography/mass spectrometry (Py-GC/MS). The non-catalytic pyrolysis of waste AR produced various kinds of oxygenates, such as acetic acid, hydroxy propanone, furfural, phenol, cresol, guaiacols, syringols, and so on. By applying nanoporous Al-MCM-41 with acidic properties and mesopores to the pyrolysis of waste AR, the levels of furan and aromatic hydrocarbons production increased with a concomitant decrease in the other oxygenates. The formation efficiency of furans was improved further by increasing the amount of Al-MCM-41 applied to the catalytic pyrolysis of waste AR.

scholarly journals Optical axes of catadioptric systems including visual, Purkinje and other nonvisual systems of a heterocentric astigmatic eye

2010 ◽  
Vol 69 (3) ◽  
Author(s):  
W. F. Harris
Keyword(s):  
Visual System ◽  
Optical Axis ◽  
The Other ◽  
Optical Systems ◽  
Numerical Examples ◽  
Straight Line ◽  
Optical Axes ◽  
Catadioptric Systems ◽  
Reflecting Surfaces ◽  
Special Case

For a dioptric system with elements which may be heterocentric and astigmatic an optical axis has been defined to be a straight line along which a ray both enters and emerges from the system.  Previous work shows that the dioptric system may or may not have an optical axis and that, if it does have one, then that optical axis may or may not be unique.  Formulae were derived for the locations of any optical axes.  The purpose of this paper is to extend those results to allow for reflecting surfaces in the system in addition to refracting elements.  Thus the paper locates any optical axes in catadioptric systems (including dioptric systems as a special case).  The reflecting surfaces may be astigmatic and decentred or tilted.  The theory is illustrated by means of numerical examples.  The locations of the optical axes are calculated for seven optical systems associated with a particular heterocentric astigmatic model eye.  The optical systems are the visual system, the four Purkinje systems and two other nonvisual systems of the eye.  The Purkinje systems each have an infinity of optical axes whereas the other nonvisual systems, and the visual system, each have a unique optical axis. (S Afr Optom 2010 69(3) 152-160)

scholarly journals Solid state and solution structural investigation of homoleptic tin(IV) alkoxide compounds. Part I. Sn(O—t-Bu)4 and [Sn(O—i-Pr)4•HO—i-Pr]2

1991 ◽  
Vol 69 (1) ◽  
pp. 121-129 ◽  
Author(s):  
Mark J. Hampden-Smith ◽  
Teresa A. Wark ◽  
Arnold Rheingold ◽  
John C. Huffman
Keyword(s):  
Solid State ◽  
Variable Temperature ◽  
Equilibrium Concentration ◽  
Molecular Structures ◽  
Monoclinic Crystal System ◽  
Monoclinic Crystal ◽  
Space Group ◽  
Crystal System ◽  
Reversible Dissociation ◽  
C Nmr

The crystal and molecular structures of Sn(O—t-Bu)4• and [Sn(O—i-Pr)4•HO—i-Pr]2 have been determined by single-crystal X-ray diffraction. Sn(O—t-Bu)4 crystallizes in the monoclinic crystal system with space group C2/c, where a = 17.382(6) Å, b = 8.742(2) Å, c = 15.518(5) Å, β = 116.44(1)°, Z = 4, and R = 2.5%. Sn(O—t-Bu)4 is monomeric in the solid state, with a distorted tetrahedral tin coordination environment. [Sn(O—i-Pr)4•HO—i-Pr]2 crystallizes in the monoclinic crystal system with space group P21/n, where a = 11.808(3) Å, b = 14.356(3) Å, c = 12.380(2) Å, β = 95.27(2)°, Z = 2, and R = 4.9%. [Sn(O—i-Pr)4•HO—i-Pr]2 exhibits an edge-shared, bi-octahedral structure in the solid state that is distorted due to the presence of asymmetric hydrogen bonding between axially coordinated alcohol ligands and an isopropoxide ligand.13C NMR and IR spectroscopic data have been recorded for Sn(O—t-Bu)4 and Sn(O—t-Bu-d9)4 to establish criteria for unambiguous identification of solution structures of tin(IV) alkoxides. It is demonstrated that the two-bond [Formula: see text] coupling constant is larger for terminal alkoxide ligands than for μ2-alkoxide bridges, and the ν(Sn—O) stretching frequency has been assigned. The dynamic solution behaviour of [Sn(O—i-Pr)4•HO—i-Pr]2 has been studied using variable temperature 1H and 13C NMR spectroscopy. The data obtained are consistent with a process that involves rapid reversible dissociation of isopropanol at room temperature. Upon cooling, the equilibrium concentration of the species with coordinated alcohol increases, and the molecule undergoes rapid intramolecular proton transfer (AG≠ < 11.9 kcalmol−1). Upon further cooling, the 13C NMR data are consistent with a solution structure analogous to that found in the solid state. Key words: tin, alkoxide, NMR, dynamic, structure.

I. The refraction equivalents of carbon, hydrogen, oxygen, and nitrogen in organic compounds

1881 ◽  
Vol 31 (206-211) ◽  
pp. 327-330 ◽  
Keyword(s):  
Organic Compounds ◽  
Aromatic Hydrocarbons ◽  
Chemical Society ◽  
The Other ◽  
Royal Institution ◽  
Chemical Constitution ◽  
The Subject ◽  
The One

Since the communication which I had the honour to read before this Society in 1869, “On the Refraction Equivalents of the Elements”, very little has been done on the subject. My own contributions have been almost confined to two communications in the “Journal of the Chemical Society,” in 1870; the one a lecture on the subject in general, the other a paper on the “Refraction Equivalents of the Aromatic Hydrocarbons and their Derivatives;” together with a discourse at the Royal Institution in March, 1877, on “ The Influence of Chemical Constitution on the Refraction of Light.” In the meantime, observations on many substances have gradually accumulated in my note-book.

scholarly journals Synthesis And Structural Characterization Of 1-Butyl-2,3-Dimethylimidazolium Bromide And Iodide

2007 ◽  
Vol 62 (6) ◽  
pp. 868-870 ◽  
Author(s):  
Johanna Kutuniva ◽  
Raija Oilunkaniemi ◽  
Risto S. Laitinen ◽  
Janne Asikkala ◽  
Johanna Kärkkäinen ◽  
...  
Keyword(s):  
Unit Cell ◽  
Monoclinic Crystal System ◽  
Monoclinic Crystal ◽  
Space Group ◽  
X Ray ◽  
Crystal System ◽  
H Nmr ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

1-Butyl-2,3-dimethylimidazolium bromide {(bdmim)Br} (1) and iodide {(bdmim)I} (2) were prepared conveniently by the reaction of 1,2-dimethylimidazole and the corresponding 1-halobutane. The compounds were characterized by 1H and 13C{1H} NMR spectroscopy as well as by X-ray single crystal crystallography. 1 crystallizes in the monoclinic crystal system, space group P21/n, with Z = 4, and unit cell dimensions a = 8.588(2), b = 11.789(1), c = 10.737(2) Å, β = 91.62(3)°. Compound 2 crystallizes in the monoclinic crystal system, space group P21/c, with Z = 8, and unit cell dimensions a = 10.821(2), b = 14.221(3), c = 15.079(2) Å , β = 90.01(3)°. The lattices of the salts are built up of 1-butyl-2,3- dimethylimidazolium cations and halide anions. The cations of 1 form a double layer with the imidazolium rings stacked together due to π interactions. The Br− anions lie approximately in the plane of the imidazolium ring, and the closest interionic Br···H contacts span a range of 2.733(1) - 2.903(1) Å. Compound 2 shows no π stacking interactions. The closest interionic I···H contacts are 2.914(1) - 3.196(1) Å

Lattice-parameter measurements of PbHPO4 single crystals by the ratio method

1983 ◽  
Vol 16 (6) ◽  
pp. 623-628 ◽  
Author(s):  
J. Horváth
Keyword(s):  
Phase Transition ◽  
Single Crystals ◽  
Ferroelectric Phase Transition ◽  
Ferroelectric Phase ◽  
Lattice Parameter ◽  
Ratio Method ◽  
Monoclinic Crystal System ◽  
Monoclinic Crystal ◽  
Temperature Dependences ◽  
Crystal Lattice Parameters

Temperature dependences of PbHPO4 single-crystal lattice parameters were measured by the ratio method in the range 158–421 K. Below the ferroelectric phase transition (T c = 310 K) lattice parameter b increases non-linearly with decreasing temperature while all others decrease linearly. The ratio method was generalized to the monoclinic crystal system for this purpose.

The Swelling of Latex

1930 ◽  
Vol 3 (3) ◽  
pp. 361-369
Author(s):  
F. Evers
Keyword(s):  
Boundary Layer ◽  
Aromatic Hydrocarbons ◽  
Great Increase ◽  
The Other ◽  
Organic Liquids ◽  
Brownian Movement ◽  
Ammonia Content ◽  
Latex Particles ◽  
Benzene Toluene ◽  
The Individual

Abstract The swelling phenomena of latex in organic liquids such as benzene, toluene, or xylene were studied. As factors in the swelling power the following were observed: (1) the ammonia content of the latex; (2) the formation of a boundary layer in the surface of contact of both liquids. Ammonia-rich latex on contact with aromatic hydrocarbons forms a boundary layer which in turn swells, with a great increase in volume. Latex poor in ammonia forms no boundary layer and therefore does not swell. On the other hand, the hydrocarbon may diffuse into the latex without disturbing the Brownian movement. Subsequently the diffused hydrocarbon is able to bring about the swelling of the individual latex particles.

scholarly journals OLIGOMERIC CHROMIUM(III) POLICATION SPECIES-PILLARED LAYERED TETRATITANATES ANION

2010 ◽  
Vol 7 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Hari Sutrisno ◽  
Endang Dwi Siswani
Keyword(s):  
Aqueous Solution ◽  
Ion Exchange ◽  
Room Temperature ◽  
Lattice Parameter ◽  
Bravais Lattice ◽  
Monoclinic Crystal System ◽  
Monoclinic Crystal ◽  
Crystal System ◽  
High Crystallinity

Intercalation of oligomeric chromium(III) polycation species in layered tetratitanates was prepared by three steps: 1) ion-exchange of H+ for K+ in potasium tetratitanates, 2) intercalation of n-alchylamine (n-propylamine, n-butylamine, n-amylamine, and n-hexylamine) compounds in layered hydrogen tetratitanates by adding an aqueous solution of  5M n-alchylamine to  hydogen titanates with stiring at room temperature,  and 3) intercalation of oligomeric chromium(III) polycation species by mixing butylamine-intercalated tetratitanates with an aqueous solution of CrCl3.6H2O at pH various. The procedure was carried out by Chimie Douce method. The results showed that all of n-alchylamine-intercalated tetratitanates crystallize on monoclinic crystal system with the Bravais lattice C. The hight intensity of the first peaks (200)  indicated that butylamine and amylamine-intercalated tetratitanates have a remarkably high crystallinity without impurities phase. The interlayered distance (d) and  the lattice parameter projected along a increase with increasing the amount of C-atoms in n-alchylamine. At pH=1.3, [CrCl(H2O)5]2+ or [CrCl2(H2O)4]+ species was pillared more efective in layered tetratitanates than [Cr(H2O)6]3+ spesies and just one spesies, Cr(H2O)6]3+ at  pH=1.7. On the contrary, [Cr(OH)(H2O)5]2+ or [Cr(OH)2(H2O)4]+ was  intercalated more effevtive than [Cr(H2O)6]3+ species  at pH=5.3.   Keywords: tetratitanates, intercalation, oligomeric chromium(III) species, Chimie Douce.

scholarly journals Degradation of Anthracene by Immobilizing Laccase From Trametes Versicolor onto Chitosan Beads and Hyacinth Plant

2020 ◽  
Vol 31 (3) ◽  
pp. 14
Author(s):  
Ali A. Taha ◽  
Nahida J. Hameed ◽  
Farah Hamed Ali
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Trametes Versicolor ◽  
Free Enzyme ◽  
The Other ◽  
Chitosan Beads ◽  
Immobilized Laccase ◽  
Mediator System ◽  
Polycyclic Aromatic ◽  
The Stability

Polycyclic aromatic hydrocarbons (PAHs) are recognized as a toxic, mutagenic and/or carcinogenic compounds, and their pollution of soil and aquifer is of increasing environmentally risk. Laccases (E.C. 1.10.3.2) are phenoloxidases catalyze the oxidation of PAHs in the presence of a mediator compound and hyacinth plant. In this study laccase from Trametes versicolor was immobilized into chitosan, and the potential to oxidize anthracene in the presence of 1-hydroxybenzotriazole (HBT) was examined. Results indicated that the immobilization enhanced the stability of laccase against temperature, pH, inhibitors and loading time compared with the other cases. The immobilized laccase-mediator system was as efficient as the free enzyme for oxidizing the tested PAHs. After 24h. of incubation, immobilized laccase–HBT showed a system oxidization more than immobilized laccase without (HBT) of PAHs; Chitosan with hyacinth plant and (HBT) resulted better conversion than chitosan with or without HBT. These results indicate a new chance for applying the immobilized laccase in bioremediation.

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