Publications

1979
Nissim Garti, Yoel Sasson, Ben Zion Ginzburg, and Moshe R Bloch. 1979. “Conversion of halophilic algae into extractable oil. 2. Pyrolysis of proteins.” Israel 56851,57712 . Abstract
The pyrolysis reactions with different solvents and reagents of proteins, e.g., albumin, soya protein, lysozyme [9001-63-2] and algae protein, show no significant differences between the behavior of proteins. The reactions yield rather low conversions in the presence of water in spite of the existence of carbonates and catalysts, e.g. NiSO4. The presence of C6H6 [71-43-2] improves the yield, and the presence of a mixt. of K-Mg-Mn salts is beneficial for such a reaction. The N content of liq. oil decreases in the presence of carbonates and other catalysts. The max. amt. of protein converted into liq. oil was 27 wt.% for algae proteins contg. 5.7 wt.% N. The existence of impurities does not affect the yield which is similar to that obtained from pure proteins. The behavior of the proteins under different temps. and in various reaction mixts. is very similar to that found with algae. [on SciFinder(R)]
Nissim Garti and Vered. Kaufman. 1979. “Emulsions of essential oils for citrus beverages.” Israel (IL58111A). Abstract
Cloudy emulsions of citrus peel oil for citrus beverage manuf. may be prepd. by mixing the oil with emulsifying agents, gums, thickening agents, and other additives. Thus, 3.91 g Span 20 [1338-39-2] and 1.09 g Tween 80 [9005-65-6] were mixed with 0.5 g TiO2, 0.025 g xanthan gum [11138-66-2], and 84.47 g water and heated to 70°. Then 10 g orange oil was added and the mixt. was passed 5 times through a colloid mill to give a cloudy emulsion suitable for citrus beverage manuf. [on SciFinder(R)]
Samuel Siegel, James Outlaw Jr., and Nissim. Garti. 1979. “The kinetics, stereochemistry, and mechanism of hydrogenation of some tertbutylbenzenes on a rhodium catalyst.” Journal of Catalysis, 58, 3, Pp. 370–382. Abstract
Kinetics and stereochem. of Rh/Al2O3-catalyzed hydrogenations of p-(Me3C)2C6H4 (I), p-(Me3C)2C6H4 (II), Me3CPh (III), and p-MeC6H4CMe3 (IV) were studied as models for the mechanism of hydrogenation of benzene rings. At approx. atm. pressure, the rates are 0 order in arene, 1st order in H and increased in the order III, I \textless IV \textless II. In competition expts. the order of reactivity is III \textgreater IV \textgreater I \textgreater II. The formation of cyclohexene-type intermediates, dependent on increased pressure, was discussed. A dissociative mechanism due to bulky CMe3 groups was rejected; the orientation of the CMe3 groups, however, affect both the rate of hydrogenation and the proportion of products formed via subsequent alternate reaction paths. [on SciFinder(R)]
1978
Samuel Siegel, James Outlaw Jr., and Nissim. Garti. 1978. “The structure of reactive sites on platinum metal catalysts for the hydrogenation of unsaturated hydrocarbons.” Journal of Catalysis, 52, 1, Pp. 102–115. Abstract
The reactive sites on platinum metal catalysts for the hydrogenation of unsatd. hydrocarbons and related reactions were the most coordinatively unsatd. exposed metal atoms. The surface atoms were divided into 3 groups with one, two, or three units of coordinative unsatn. (corresponding to the no. of monodentate ligands which may become attached) and were symbolized by 1M, 2M, and 3M, then, when exposed to H the 1st structures formed were 2MmH2 and 3MH2, which were transformed, in part, to 2MH and 3MH by diffusion of H from the edge to other surface sites or to the interior of the crystallite. The proportions of 3M and 3MH present during a reaction were a function of the metal and the conditions of prepn. and use. These structures bore a formal relation to the structure of the complexes ClRh(PPh3)2 (I) and HRhCO(PPh3)2 (II) which are formed through the dissocn. of ClRh(PPh3)3 and HRh(CO)(PPh3)3, resp. The catalytic functions of both I and II involved the same kinds of elementary processes, but the presence of the hydrido group in II led to recognizably different phenomena (kinetics, stereochem., exchange reactions). Accordingly, the characteristics of hydrogenations catalyzed by platinum metals may be rationalized by considering the elementary processes which may occur at each category of site. [on SciFinder(R)]
1977
Samuel Siegel and Nissim. Garti. 1977. “The effect of pressure on the catalytic hydrogenation of aromatic hydrocarbons on rhodium.” In Catal. Org. Synth., [Conf.], 6th, Pp. 9–23. Academic. Abstract
Hydrogenation of 1,4- (I) and 1,3-di-tert-butylbenzene (II), p-xylene (III), and m-xylene (IV) over a Rh/Al2O3 catalyst at 0.34-150 atm H pressure was examd. With I, the rate of hydrogenation, the amt. of intermediate cyclohexene formed, and the cis-trans ratio of final product all increased, then decreased, with increasing pressure, but with II the rate and amt. of intermediate increased, while the product cis-trans ratio decreased, with increasing pressure. Hydrogenation of III paralleled that of I, except that the cis-trans ratio of dimethylcyclohexane steadily increased with increasing pressure; the same pressure effect on product isomer distribution was obtained with IV, but with IV the rate of hydrogenation increased with pressure throughout the obsd. range. The results are discussed in terms of possible types of reactive sites and their interconversion. [on SciFinder(R)]
1976
Nissim Garti and Samuel. Siegel. 1976. “Structure and reactivity in the reduction of cycloalkenes and cycloalkadienes by diimide.” Journal of Organic Chemistry, 41, 24, Pp. 3922–3923. Abstract
Diimide, generated from azodicarboxylic acid at 25°, was used to reduce a series of cycloalkenes and cycloalkadienes (C5-C8, C12). In agreement with redns. with diimide conducted at 80°C by Garbisch, Schildcrout, Patterson, and Sprecher (1965), the relative reactivity of the monoenes fall in the order norbornen »C8(cis) \textgreater C5 \textgreater C7 \textgreater C6; however, the spread in rates is greater in the present study. Compared to cyclohexene, the relative reactivity of C8(trans) and norbornene are 2200 and 700, resp., at 25°. 1,3-Cyclohexadiene is more reactive than cyclohexene; however, the cyclo-C5, cyclo-C7, and cyclo-C8-1,3-dienes are less reactive than the monoene each forms on redn. Although conjugation tends to lower the reactivity of a diene, torsional strain, which serves here as a driving force, may reduce the planarity of a conjugated system, as in 1,3-cyclohexadiene, and thus the conjugative interaction as well. [on SciFinder(R)]
S SIEGEL, J OUTLAW, and N Garti. 1976. “STRUCTURE OF REACTIVE SITES ON PLATINUM METAL-CATALYSTS FOR HYDROGENATION OF UNSATURATED-HYDROCARBONS.” ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 172, SEP3, Pp. 1.
1975
Y HALPERN and N Garti. 1975. “ARYLMERCURY COMPOUNDS .3. POLY(ARYLMERCURY) COMPOUNDS VIA SYMMETRIZATION REACTION.” JOURNAL OF APPLIED CHEMISTRY AND BIOTECHNOLOGY, 25, 6, Pp. 403–410.
N Garti and Y HALPERN. 1975. “Arylmercury compounds. General procedure for the preparation of diarylmercury compounds by symmetrization reaction.” JOURNAL OF APPLIED CHEMISTRY AND BIOTECHNOLOGY, 25, 4, Pp. 249–258. Abstract
Symmetrization of ArHgX with EDTA and NH3 24 hr at room temp. in aq. or org.-aq. mixts. gave 40-95% Ar2Hg (Ar = p-Br-, p-Cl-, p-AcNH-, p-NHMe-, Me, p-Et2N-, p-Me2N-, p-MeOC6H4; Ph; m-xylyl, pseudocumyl, pentamethylphenyl, duryl, isoduryl, mesityl, and $\alpha$-naphthyl). Other nucleophiles (e.g. BuNH2) were as effective as NH3, but EDTA was the best chelating agent. [on SciFinder(R)]
Yuval Halpern and Nissim. Garti. 1975. “Arylmercury compounds. II. Recyclization process for preparation of symmetrical diarylmercury compounds.” Industrial & Engineering Chemistry Product Research and Development, 14, 1, Pp. 71–72. Abstract
A high yield recyclization and pollution free process for the manuf. of diarylmercury compds. is described. The new process enables saving of starting materials and recovery of Hg. [on SciFinder(R)]
Yuval Halpern and Nissim. Garti. 1975. “Arylmercury compounds. III. Poly(arylmercury) compounds via symmetrization reactions.” Journal of Applied Chemistry & Biotechnology, 25, 6, Pp. 403–410. Abstract
Treatment of 4 compds. of the type Ar(HgX)2 and of poly[4-(acetoxymercurio)styrene] with EDTA tetra-Na salt [64-02-8] and NH3 [7664-41-7] resulted in symmetrization and polymn. of the monomers and crosslinking of the polystyrene [9003-53-6] by Hg [7439-97-6]. E.g., 2,5-bis(chloromercurio)thiophene gave poly(mercurio-2,5-thiophenediyl) [57715-35-2]. [on SciFinder(R)]
Yuval Halpern and Nissim. Garti. 1975. “Arylmercury compounds. IV. Symmetrization in the absence of auxiliary ligand.” Journal of Organometallic Chemistry, 88, 3, Pp. 315–320. Abstract
PhHgOAc is converted into Ph2Hg via a symmetrization process, in the absence of an auxiliary ligand, at 6.5≥pH\textgreater4.0. Arylmercuric salts, in which the arom. rings contain more than 1 electron donating group, symmetrize in the absence of an auxiliary ligand at a basic pH. Both processes proceed in water or in mixts. of org. solvents and water. The factors influencing the symmetrization at different pH values are discussed. [on SciFinder(R)]
Yuval Halpern and Nissim. Garti. 1975. “Arylmercury compounds. Part VI. Asymmetric diarylmercury compounds.” Israel Journal of Chemistry, 13, 3, Pp. 205–211. Abstract
Asymmetrical diarylmercury compds., e.g. p-MeOC6H4HgC6H4NMe2-p, were produced together with sym. products via a symmetrization process. The asym. products could not be isolated from the reaction mixt. and their existence was indicated through different analyses (m.p., IR, PMR, mass spectra, elemental analysis and DTA). The asym. products are unstable and disproportionate into two sym. compds. at elevated temps., and in org. solvents even at room temp. [on SciFinder(R)]
Y HALPERN and N Garti. 1975. “Arylmercury compounds. VI. Proposed mechanism for the symmetrization of arylmercuric salts in the presence of chelating agents.” Journal of Organometallic Chemistry, 92, 3, Pp. 291–301. Abstract
The mechanism for the symmetrization of arylmercuric salts in the presence of chelating agents includes 3 main steps: (i) dissocn. of the arylmercuric salt; (ii) formation of a reactive complex between the ionized arylmercuric salt and the chelating agent; (iii) an electrophilic substitution at a C-Hg bond via a 2-electron, 3-center bond type transition state. The effect of chelating agents on the reactions of PhHgOAc with piperidine, BuNH2, or CNS- to give Ph2Hg and of m-MeC6H4HgOAc with tetra-Na ethylenediaminetetraacetate to give (m-MeC6H4)2Hg was discussed. [on SciFinder(R)]
1974
Yuval Halpern and Nissim. Garti. 1974. “Production of diarylmercury compounds.” Israel 45319. Abstract
A high yield recyclization and pollution free process for the manuf. of diarylmercury compds. is described. The new process enables saving of starting materials and recovery of Hg. [on SciFinder(R)]

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