K. K. Verma

Self‐Probing of Micellization within Phenyl‐Containing Surfactant Solutions

The propensity of amphiphilic molecules to accumulate at the interface between the solution and adjacent gaseous, liquid, or solid phases is responsible for many remarkable physicochemical properties of aqueous surfactant systems such as wetting, foaming, emulsification, dispersion, adsorption, micellization, detergency, synergistic interactions with other surfactants, solubility, and solubilization, among others.

DIARYLTELLURIUM(IV) CARBOXYLATES: SYNTHESIS VIA TELLUROXIDES AND THEIR CHARACTERIZATION

Abstract The synthesis of some new diaryltellurium(IV) dicarboxylates (salicylate, benzoate, cinnamate) and carboxylates (oxalate, o-phthalate, succinate) by the reactions of bis(p-methoxy-phenyl)telluroxide and bis(p-hydroxyphenyl)telluroxide with the corresponding carboxylic acid is reported. The resulting carboxylates have been subjected to elemental analyses, conductance and cryoscopic measurements, infrared and proton magnetic resonance spectral studies. Solution studies reflect the non-ionic nature of these compounds. Infra-red spectral studies predict the unidentate nature of salicylate, benzoate and cinnamate and bidentate nature of oxalate, o-phthalate and succinate groups. A PMR spectral study confirms their proposed stoichiometry. These compounds possess a trigonal bipyramidal structure with a tetra-coordinate central tellurium atom.

Substituted (Phenacyl)tellurium (IV) Halides: Synthesis and Characterization

Abstract The preparation and properties of some organotellurium(IV) halides obtained by reactions of tellurium tetrachloride with substituted acetophenones are reported. 3-Methoxyacetophenone gave both RTeCl3 and R2TeCl2 type compounds, whereas 2-hydroxyacetophenone and 4-chloroacetophenone yielded only RTeCl3 type compounds. Corresponding organotellurium (IV) bromides and iodides were prepared by halogen-exchange processes. Conductance and cryoscopic measurements reflect the 1:1 electrolytic nature of RTeBr3 and RTeI3, very weak electrolytic nature of RTeCl3 and non-electrolytic nature of R2TeX2 (X = Cl, Br, I) type compounds in solution. The H n.m.r., i.r. and far i.r. spectra suggest the linkage of tellurium to the -CH2- group of the phenacyl moiety. Referee I: J. S. Thayer Referee II: R. W. Geddridge

(Methoxyphenacyl)Tellurium(IV) Halides: Synthesis and Characterization

Abstract The preparation and properties of some organotellurium(IV) halides, RnTeX4-n, (where R = H3COC6COCH2-, X = Cl, Br, I and n = 1, 2), are reported. Cryoscopic measurements, in general, are consistent with the conductivity measurements and reflect the molecular nature of RTeCl3 and R2TeX2, and the 1:1 electrolytic nature of RTeBr3 and RTeI3 in solution. The 1H n.m.r. spectra suggest the linkage of tellurium to the -CH2-group of the phenacyl moiety. The far i.r. spectra reflect the polymeric nature of RTeX3 and the monomeric nature for the R2TeX2 type compounds.

Synthesis and Characterization of Acyl(aryl)tellurium(IV) Dichlorides

The preparation and properties of some unsymmetrical diorganyltellurium(IV) dichlorides, RR′TeCl2 (where R = phenacyl, C6H5COCH2– ; 1‐naphthacyl, C10H7COCH2– ; styrylacyl, C6H5CHCHCOCH2– ; and R′ = p‐anisyl, MeOC6H4– ; p‐hydroxyphenyl, HOC6H4– ; 3‐methyl‐4‐hydroxyphenyl, HOC6H3CH3), are reported. Conductance and cryoscopic measurements reflect their molecular nature in solution. The 1H NMR, IR and far‐IR spectra suggest linkage of tellurium to the acyl carbon (–CH2–) of the phenacyl, 1‐naphthacyl or styrylacyl moiety and to a para carbon atom with respect to –OH or –OMe of the aryl group. A pseudo trigonal‐bipyramidal structure has been suggested for these diorganyltellurium(IV) dichlorides having two different types of tellurium‐carbon bonds.

Synthesis and Characterization of Complexes of Some Hydroxyaryltellurium Trichlorides with N-Donor Ugands

Abstract Twenty new complexes of hydroxyaryltellurium trichlorides derived from isomeric cresols and ortrto-chlorophenol with pyridine (Py), 2, 2′-bipyridyl (Bipy) and piperidine (Pip) have been synthesized and characterized by elemental analyses, conductance, cryoscopy, infrared and proton magnetic resonance studies. Pyridine and piperidine form RTeCI3.L and RTeCI3.2L complexes, whereas 2, 2-bipyridyl which acts as a bidentate ligand and gives only RTeCI3.L complexes. Conductance and cryoscopic measurements reflect their weak or 1:1 electrolytic behaviour in solution of nitrobenzene, acetonitrile and acetone. Spectral studies indicate the linkage of these ligand molecules to the tellurium atom of the hydroxyaryltellurium group through nitrogen atoms. A. square-pyramidal structure is suggested for RTeCI3.Py and RTeCI3.Pip, whereas 1:2 complexes of pyridine and piperidine along with RTeCI3.Bipy, have octahedral stereochemistry.

Complexes of 4-Hydroxyphenyltellurlum Trihalides with Piperidine, Dimethylformamide and Thiourea

Abstract New complexes of 4-hydroxyphenyltellurium trihalides with piperidine (Pip), dimethylformamide (DMF) and thiourea (Tu) have been synthesized and characterized by elemental analyses, conductance, cryoscopy, infrared and proton magnetic resonance spectral studies. RTeCI3. L as well as RTeCl3. 2L type complexes are obtained with all three ligands, whereas RTeBr3 and RTel3 form only 1:1 type complexes with DMF. The RTeCI3. 2Tu complex behaves as a non-electrolyte whereas the others are weak to 1:l electrolytes in solution. Spectral studies reveal the coordination through nitrogen, oxygen and sulphur atoms in piperidine, DMF and thiourea complexes, respectively.

Synthesis and Characterization of Group VB Metal Chloride Adducts of Triphenyltelluronium Chloride

Abstract This paper describes the synthesis and properties of metal chloride (AsCl3, SbCl3, SbCl5 and BiCl3) adducts of triphenyltelluronium chloride. Ph3TeCl.AsCl3, Ph3TeCl.SbCl3, 2Ph3TeCl.SbCl3, 3Ph3TeCl.SbCl3, Ph3TeCl.SbCl5, Ph3TeCl.BiCl3 and 2Ph3TeCl.BiCl3 type products are obtained by the reactions of triphenyltelluronium chloride with these metal chlorides. Conductance, cryoscopic and 1H n.m.r. data are consistent with their dissociation in dilute solution as Ph3Te+ and MCl4 − (M = AsIII, SbIII, BiIII) or SbVCl6 − for 1:1 type adducts, as Ph3Te+ and MCl5 2− (M = SbIII and BiIII) for 2:1 type adducts and as Ph3Te+ and SbIII Cl6 3− for 3:1 type adducts. Far i.r. spectra also reflect the formation of chlorometallate species by transfer of chloride ion of Ph3TeCl to the metal chlorides. Thus, the formulations of these adducts as triphenyltelluronium chlorometallate, i.e. [Ph3Te] [AsCl4], [Ph3Te][SbIIICl4], [Ph3Te]2[SbIIICl5], [Ph3Te]3[SbIIICl6], [Ph3Te][SbVCl6], [Ph3Te][BiCl4] and [Ph3Te]2[BiCl5] is pro...

Studies on 1,10-Phenanthroline Complexes of Some Hydroxyaryltellurium Trihalides

The synthesis and structural features of some newly synthesized 1,10-phenanthroline complexes of p-hydroxyphenyl-and 3-methyl-4-hydroxyphenyltellurium trihalides (chlorides, bromides, and iodides) are reported. The resulting complexes have been subjected to elemental analyses, conductance and cryoscopic measurements, infra-red and proton magnetic resonance spectral studies. Solution studies reveal the weak to 1:1 electrolyte type behavior of these complexes in solution. Spectral studies indicate the linkage of phenanthroline to the tellurium atom through the nitrogen atoms. Central tellurium atom in these complexes is hexa-coordinated in an octahedral way.

Synthesis and Characterization of Pyridine and Bipyridyl Complexes of 4-Hydroxyphenyltellurium Trihalides

Abstract New complexes of 4-hydroxyphenyltellurium trihalides with pyridine and 2,2-bipyridyl have been synthesized and characterized by elemental analyses, conductance measurements, molecular weight determinations, IR and 1H NMR spectral studies. Pyridine forms RTeX3.L and RTeX3.L2 complexes, whereas bipyridyl, which acts as a bidentate ligand, forms only 1:1 complexes. The complexes are weak to 1:1 electrolytes in solution. Coordination occurs through nitrogen atoms of the ligands.