Hard Rubber. Its Carbon and Hydrogen Content

1936 ◽  
Vol 9 (2) ◽  
pp. 350-355
Author(s):  
Harry L. Fisher ◽  
Y. Schubert
Keyword(s):  
Hydrogen Content ◽  
Total Sulfur ◽  
Double Bonds ◽  
Wijs Method ◽  
Compound C ◽  
Theoretical Amount

Abstract IN THE course of a study of vulcanization it became necessary to compare the ratios of carbon, hydrogen, and sulfur in hard rubber. A search of the literature revealed no analyses for carbon and hydrogen, although many analyses for sulfur in hard rubber have been recorded. Combustion analyses were therefore made on several samples of hard rubber, and the data are recorded here. The saturation of the double bonds in the rubber hydrocarbon with sulfur should give a compound, (C 5H8S)x, which contains 32.02 per cent of combined sulfur, and some of the recorded results agree with this figure. Since it is also possible to obtain products having greater amounts of combined sulfur than that called for by the theory of addition alone, some of the sulfur must consist of sulfur of substitution (7). It is theoretically possible that substitution and addition of sulfur can go on simultaneously; as the result of these two reactions, it may happen that the total sulfur in combination will equal the theoretical amount required by addition alone. In such a case there would be some free double bonds, but attempts to determine free double bonds in several samples by the Kemp-Wijs method (5) were unsuccessful.

scholarly journals Crystal structure of 1,3-diallyl-1,3,3a,4,7,7a-hexahydro-4,7-methano-2-benzothiophene 2,2-dioxide

2014 ◽  
Vol 70 (11) ◽  
pp. o1163-o1164 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Rama Gunta
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
The Other ◽  
Double Bonds ◽  
Envelope Conformation ◽  
Compound C ◽  
Membered Heterocycle

The title compound C15H20O2S, was identified as a product of diallylation of themeso-isomer of the corresponding norbornene sulfone, and it is an achiral compound. The five-membered heterocycle adopts an envelope conformation with the S atom deviating by 0.795 (3) Å from the other atoms of the ring (r.m.s. deviation = 0.0131). Both allyl groups areanti-oriented relative to the S atom but their double bonds are directed in opposite directions relative to the plane of the heterocycle.

scholarly journals (1E,4E)-1,5-Bis[2-(trifluoromethyl)phenyl]penta-1,4-dien-3-one

2013 ◽  
Vol 69 (2) ◽  
pp. o177-o177 ◽  
Author(s):  
Dong Ho Park ◽  
V. Ramkumar ◽  
P. Parthiban
Keyword(s):  
Benzene Ring ◽  
Title Compound ◽  
Crystal Packing ◽  
Double Bonds ◽  
Compound C

In the title compound, C19H12F6O, a monoketone derivative of curcumin, both double bonds have atransconformation. The molecule is mostly planar with all C and O atoms essentially coplanar, with the exception of one benzene ring, which is tilted by 17.18 (1)° with respect to the plane of the remainder of the molecule. The r.m.s. deviation from planarity of the coplanar section is 0.0097 Å. The crystal packing features weak C—H...O and C—H...F interactions.

scholarly journals (2E,4E)-Ethyl 5-(phenylsulfonyl)penta-2,4-dienoate

2012 ◽  
Vol 68 (4) ◽  
pp. o1093-o1093 ◽  
Author(s):  
Ulaganathan Sankar ◽  
V. Sabari ◽  
G. Suresh ◽  
Ramakrishnan Uma ◽  
S. Aravindhan
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Double Bonds ◽  
Compound C

In the title compound, C13H14O4S, both C=C double bonds adopt anEconformation. In the crystal, molecules are linked into centrosymmetricR22(14) dimersviapairs of C—H...O hydrogen bonds.

scholarly journals Crystal structure of a new 2,6-bis(imino)pyridine derivative: (1E,1′E)-1,1′-(pyridine-2,6-diyl)bis[N-(4-chlorophenyl)ethan-1-imine]

2019 ◽  
Vol 75 (2) ◽  
pp. 115-118 ◽  
Author(s):  
Rajagopal Rajesh ◽  
E. S. Sella ◽  
Olivier Blacque ◽  
Kunjanpillai Rajesh
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Pyridine Ring ◽  
Pyridine Derivative ◽  
Asymmetric Unit ◽  
Double Bonds ◽  
Π Interactions ◽  
Compound C ◽  
Independent Molecules

The asymmetric unit of the title compound, C21H17Cl2N3, contains two crystallographically independent molecules (AandB). Both molecules haveEconfigurations for both imine double bonds with regard to the aryl and pyridine groups. The conformations of the two molecules differ with the 4-chlorophenyl rings being inclined to the central pyridine ring by 77.64 (6) and 86.18 (6)° in moleculeA, and 80.02 (5) and 43.41 (6)° in moleculeB. In the crystal, molecules are linked by a number of C—H...π interactions, forming layers parallel to thebcplane.

scholarly journals 1-Ethyl-4-[1-(1-phenylethylidene)hydrazin-2-ylidene]-3,4-dihydro-1H-2λ6,1-benzothiazine-2,2-dione

2012 ◽  
Vol 68 (6) ◽  
pp. o1927-o1927
Author(s):  
Muhammad Shafiq ◽  
Islam Ullah Khan ◽  
Muhammad Nadeem Arshad ◽  
Iftikhar Hussain Bukhari ◽  
Ejaz
Keyword(s):  
Benzene Ring ◽  
Dihedral Angle ◽  
Title Compound ◽  
Phenyl Ring ◽  
The Other ◽  
Double Bonds ◽  
Axis Direction ◽  
Envelope Conformation ◽  
Compound C ◽  
Thiazine Ring

In the title compound, C18H19N3O2S, the thiazine ring adopts an envelope conformation, with the S atom displaced by 0.732 (1) Å from the other atoms of the ring. The phenyl ring is oriented at a dihedral angle of 79.33 (7)° with respect to the fused benzene ring. The conformations about the two double bonds in the R 2C=N—N=C(CH3)Ar grouping are Z and E, respectively. In the crystal, inversion dimers linked by pairs of C—H...O interactions generate R 2 2(8) and R 2 2(12) loops, as parts of infinite chains along the a-axis direction.

scholarly journals 6-Methylideneandrost-4-ene-3,17-dione

2012 ◽  
Vol 68 (4) ◽  
pp. o1263-o1263
Author(s):  
L. C. R. Andrade ◽  
M. J. M. de Almeida ◽  
F. M. Fernandes Roleira ◽  
C. L. Varela ◽  
E. J. Tavares da Silva
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
The Other ◽  
Double Bonds ◽  
Envelope Conformation ◽  
Compound C ◽  
Methylene Group ◽  
Methylene Derivative

In the title compound, C20H26O2, which is the 6-methylene derivative of androstenedione and a synthetic percursor of exemestane, the steroidAring approximates to a sofa (or envelope) conformation, with the methylene group adjacent to the link to theBring lying out of the plane of the other atoms. TheBandCrings have slightly flattened chair conformations and theDring is an envelope, with the CH group forming the flap. In the crystal, molecules are linked by two distinct C—H...O hydrogen bonds, involving acidic H atoms close to C=C and C=O double bonds.

scholarly journals (2E,2′E)-3,3′-(1,4-Phenylene)bis[1-(4-fluorophenyl)prop-2-en-1-one]

IUCrData ◽  
2017 ◽  
Vol 2 (2) ◽  
Author(s):  
C. S. Chidan Kumar ◽  
Ching Kheng Quah ◽  
S. Chandraju ◽  
N. K. Lokanath ◽  
S. Naveen ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Three Dimensional ◽  
Asymmetric Unit ◽  
Double Bonds ◽  
Axis Direction ◽  
Compound C ◽  
Dimensional Network

The title bis-chalcone compound, C24H16F2O2, crystallizes with one half-molecule in the asymmetric unit. The molecule lies about an inversion centre at the centroid of the central benzene ring. The olefinic double bonds adoptEconformations. In the crystal, C—H...O hydrogen bonds form sheets of molecules in theacplane and C—H...F hydrogen bonds form zigzag chains along thea-axis direction. These combine to generate a three-dimensional network of molecules stacked along thec-axis direction.

scholarly journals Iodine value of tung biodiesel fuel using Wijs method is significantly lower than calculated value

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Toshisada Suzuki ◽  
Kazuki Sumimoto ◽  
Kazuhiro Fukada ◽  
Takeshi Katayama
Keyword(s):  
Double Bond ◽  
Iodine Value ◽  
Eleostearic Acid ◽  
Southern China ◽  
Average Molecular Weight ◽  
Atomic Radius ◽  
Biodiesel Fuel ◽  
Double Bonds ◽  
Tung Oil ◽  
Wijs Method

AbstractThe tung tree (Vernicia fordii) is a non-edible oil plant native to southern China and was introduced in Japan in the nineteenth century. The tree produces tung oil, which is composed of approximately 80% α-eleostearic acid (9c, 11t, 13t-octadecatrienoic acid), 7% linoleic acid, and 6% oleic acid. Tung oil may be a non-edible source of biodiesel fuel (BDF) production. The iodine value (IV) is one of parameters to guarantee BDF quality, and the most common method for the determination of IV is the Wijs method. The IV can be calculated from the average molecular weight and the number of double bonds from the GC–MS data. In this study, the IVs of olive, castor, soybean, linseed, and perilla BDF using the Wijs method were found to be almost the same as the calculated IV. On the other hand, the IV of tung BDF by the Wijs method indicated a significantly lower value than that of the calculated value. To determine the cause of this discrepancy, the samples before and after halogenation using the Wijs method, were analyzed by 1H NMR. The conjugated double bond signals did not disappear, and a broad double bond signal remained in the tung BDF spectrum after halogenation. These results demonstrated that iodine, with a large atomic radius, could not react completely with the three conjugated double bonds in α-eleostearic acid. Therefore, the IV of tung BDF was significantly lower than the calculated value.

scholarly journals (2E,2′E)-1,1′-(1,4-Phenylene)bis[3-(3-chlorophenyl)prop-2-en-1-one]

IUCrData ◽  
2017 ◽  
Vol 2 (2) ◽  
Author(s):  
S. Rajendraprasad ◽  
C. S. Chidan Kumar ◽  
S. Chandraju ◽  
N. K. Lokanath ◽  
Ching Kheng Quah ◽  
...  
Keyword(s):  
Benzene Ring ◽  
Torsion Angle ◽  
Inversion Symmetry ◽  
Asymmetric Unit ◽  
Double Bonds ◽  
Compound C

The title bis-chalcone compound, C24H16Cl2O2, crystallizes with one half-molecule in the asymmetric unit. The molecule has crystallographic inversion symmetry and lies about an inversion centre at the centroid of the central benzene ring. The olefinic double bonds adoptEconfigurations. Thes-transconformation of the central C—C bond of the enone group is confirmed by a C—C—C=C torsion angle of −162.88 (17)°.

1,1,2-Trichloro-4,4-bis(4-methylphenylsulfanyl)-3-nitrobuta-1,3-diene

2007 ◽  
Vol 63 (11) ◽  
pp. o4394-o4394
Author(s):  
Cemil Ibis ◽  
N. Gulsah Deniz
Keyword(s):  
Torsion Angle ◽  
Title Compound ◽  
Double Bonds ◽  
Compound C

The title compound, C18H14Cl3NO2S2, was synthesized by the reaction of 1,1,2,4-tetrachloro-4-(4-methylphenylsulfanyl)-3-nitrobuta-1,3-diene with ethanedithiol. The butadiene unit is not completely planar as would be expected if the two double bonds were fully conjugated The torsion angle of the butadiene unit is −82.2 (5)°.

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