摘要:

Reaction of mercury(II) iodide with tetraethylthiuramdisulfide in chloroform and ethanol mixed solvent produced bis(iodo-N,N-diethyldithiocarbamatomercury(II)) and diiodotetraethylthiuramdisulfidemercury(II), HgI2.TETD. The crystal of HgI2.TETD is orthorhombic witha = 13.101(9),b = 13.999(9),c = 22.742(15) Å; space groupPbca. The structure was solved with 1960 observed reflections measured by a G.E. XRD-6 diffractometer. The finalRfactor was 0.064. The mercury atom is four-coordinated with two identical Hg—I distances of 2.668(1) Å and two Hg—S distances of 2.670(7) and 2.737(7) Å. The coordination is tetrahedral.

ISSN:0008-4042    

DOI:10.1139/v77-156

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The single-crystal study of Sb2Tl7confirms the work of Morral and Westgren. The crystal is cubic witha = 11.618(6) Å and space group ofIm3m. There are 54 atoms per unit cell. It is the only known example of this structure type which can be considered as a true superlattice of CsCl. The structure was determined using 106 observed reflections measured on a G.E. XRD-6 diffractometer. The finalRandRwwere 0.097 and 0.060, respectively. The Tl–Tl distances range from 3.21 to 3.55 Å and the mean Sb-Tl distance is 3.27 Å. There is no Sb–Sb contact in the structure

ISSN:0008-4042    

DOI:10.1139/v77-157

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Isothiazolium salts react with a number of carbanions by attack on sulfur. Thiophene derivatives, formed by ring opening and recyclization, are often products but with cyclopentadiene, pseudoazulene products are obtained. 3-Amino-2-acylthiophenes, prepared by suitable nucleophilic attack, are synthetic precursors of thieno[2,3-c]isothiazolium salts

ISSN:0008-4042    

DOI:10.1139/v77-158

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The ecdysteroids were extracted from yew,Taxus cuspidata, needles and twigs and recovered from the aqueous extract by reversed phase adsorption. Purification of the ecdysteroids was achieved by a single solvent partition and a dry column chromatogram followed by fractionation on an adsorptive Porasil A (60) column. Makisterone A was a minor component identified by melting point, liquid chromatography, gas chromatography of the trimethylsilyl ether, mass spectrometry, and nuclear magnetic resonance spectrometry. A second minor component was isolated but not identified.

ISSN:0008-4042    

DOI:10.1139/v77-159

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

13C nmr spectra of the 16 isomericgem-dideuterooctadecanoates were measured and second and third atom deuterium isotope effects calculated for most of the affected carbons of 12 of the isomers. The average value for the second atom effect was −0.20 ppm and for the third atom effect was −0.05 ppm. From these effects and the changes in spectra caused by introduction of two deuterons at positions along the fatty acid chain, chemical shifts were determined for all carbons of methyl octadecanoate. Spectra of seven dideuterooxooctadecanoates, with both deuterons attached to a carbon γ to the oxo group, were measured, and using isotope effects, unambiguous assignments of chemical shift were made. Chemical shifts were thus assigned to all carbons in the 16 isomeric oxooctadecanoates and these show the effect of the carbonyl group at different positions in the chain. The results indicate that, in addition to large effects on carbons α and β to the oxo group, the γ to θ carbons are all shielded with displacements: γ −0.46, δ −0.30, ϵ −0.27, ζ −0.13, η −0.09, and θ −0.06 ppm. The effects of the oxo and ester carbonyls extend over seven methylene groups, but shielding due to ester carbonyl is a little smaller. Spectra of 2- to 9-oxo esters showed that interaction between the two carbonyl groups causes relatively greater shielding of carbons situated between the groups.

ISSN:0008-4042    

DOI:10.1139/v77-160

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

A 2% cross-linked divinylbenzene–styrene copolymer, incorporating trityl chloride groups, (1), was used in the synthesis of insect sex attractants of Lepidoptera by two independent routes. Polymer1reacted with the symmetrical diols 1,6-hexanediol, 1,8-octanediol, and 1,10-decanediol to give the monoblocked polymer-bound diols5–7, respectively. Mesylation of5–7gave the polymer-bound monomesylates8–10, which on coupling with 1-lithio-1-hexyne or 1-lithio-1-butyne gave the polymer-bound alkyne trityl ethers18–20. Alkynols, obtained by hydrolysis from polymers 18-20, were selectively reduced and acetylated to givecis-7-dodecen-1-ol acetate (28),cis-9-tetradecen-1-ol acetate (29), andcis-11-tetradecen-1-ol acetate (30), the sex attractants ofTrichoplusia ni(Hübner),Spodoptera frugiperda(J. E. Smith), andArgyrotaenia velutinana(Walker), respectively. Alternatively, polymer-bound 1,7-heptanediol (33), polymer-bound 1,9-nonanediol (34), and 7 were oxidized with the Sharpless reagent (CrO2Cl2/tert-butyl alcohol/pyridine) to give polymer-bound aldehydes35–37, which on reaction with Wittig reagents and subsequent hydrolysis and acetylation gave28,29, and 10-tetradecen-1-ol acetate (47), the sex attractant ofArchips semiferanus(Walker). A 'reverse' Wittig synthesis of47was achieved by the reaction of polymer10with molten triphenylphosphine followed by base and treatment with butyraldehyde. Subsequent cleavage and acetylation gave47in high yield and stereoselectivity containing greater than 91% of thecisisomer.

ISSN:0008-4042    

DOI:10.1139/v77-161

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The binary equilibrium phase diagrams of the systems CsCl—Cs2ZrCl6, CsCl—Cs2HfCl6, and CsCl—KF were established by cryoscopy. A portion of the ternary CsCl—KF—ZrCl4has also been determined.Equilibrium vapour pressures of the two pure compounds Cs2ZrCl6and Cs2HfCl6, as well as of mixtures of Cs2HfCl6with CsCl, have been measured. The equilibrium reaction is given aswhere M represents Zr or Hf.From the results, activities of CsCl, Cs2HfCl6, and HfCl4were calculated at 825 °C.The low escaping tendency of the MCl4vapour from the CsCl—Cs2MCl6type melts makes these solutions suitable as electrolytes for the recovery of Zr and Hf metal by fused salt electrolysis

ISSN:0008-4042    

DOI:10.1139/v77-162

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The effect of HF, MeOH, H2O, F−, pyridine, Pr4N+MeSiF4−, and temperature on the rate of intermolecular fluorine exchange in the methyltetrafluorosilicate anion has been studied by the dynamic nuclear magnetic resonance technique. The exchange was found to be catalyzed by HF and, to a lesser extent, MeOH and H2O, but inhibited by F−, pyridine, and Pr4N+MeSiF4−. The results are analyzed in terms of the coordination model of reaction mechanisms

ISSN:0008-4042    

DOI:10.1139/v77-163

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

The correlation of structure and reactivity of some excited triplet biphenyl ketones was approached by a combined esr and CIDNP study. The low temperature esr study confirmed the assignment of the triplet π,π* as the lowest triplet state in these biphenyl ketones. An analysis of the zero-field energies suggests that these π,π* triplets have a structure with both the biphenyl and the carbonyl groups being coplanar. Consequently a substantial unpaired spin density may result at the carbonyl oxygen atom which could lead to abstraction reactions. The CIDNP results are consistent with the triplet photoreduction mechanism. The polarization is mainly due to the cage products and the polarization magnitude is therefore dependent upon the light intensity

ISSN:0008-4042    

DOI:10.1139/v77-164

出版商:NRC Research Press    

年代:1977

数据来源: NRC

摘要:

Uniformly balanced (6S3P), (7S3P), and (8S4P) gaussian basis sets with identical exponent sets for functions describing the 2sand 2psubshells have been obtained for the first row atoms. The basis sets have been determined using a direct optimization technique; they are thoroughly balanced and satisfy a rigorous quality criterion. These uniform quality constrained basis sets were designed for applications inab initioprograms of the type of the GAUSSIAN 70 program system, that may utilize the integration-time saving constraint α2s = α2p.

ISSN:0008-4042    

DOI:10.1139/v77-165

出版商:NRC Research Press    

年代:1977

数据来源: NRC