U. Swarnalatha

Bio: U. Swarnalatha is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Electrochemistry. The author has an hindex of 2, co-authored 2 publications receiving 9 citations.

Studies on electrochemical and coordination behaviour of phosphiniminocyclotrithiazenes

Abstract: Electrochemical (polarographic, cyclic voltammetric, and coulometric) and coordination behaviour of several symmetrically and unsymmetrically substituted phosphiniminocyclotrithiazenes have been studied. Polarograms of R3PN-S3N3 (R = C6H5, p-ClC6H4, p-H3CC6H4, and (OC4H8N)), Ph2(OC4H8N)PN-S3N3, and Ph(OC4H8N)2PN-S3N3 give two cathodic waves. Cyclic voltammograms of Ph3PN-S3N3 (1) and (OC4H8N)3PN-S3N3 (2) reveal nearly the same oxidation peak potential but different reduction potentials. Controlled potential electrolysis of 1 and 2 at +0.6 V indicates exocyclic cleavage and ring degradation. Cathodic reduction behaviour of Ph3PN-S3N3 suggests the possibility for the formation of 1,5-(Ph3PN)2S4N4 under electrochemical conditions. Reaction of nickel chloride hexahydrate with heterocycle 1 in 1:2 molar ratio in acetonitrile affords the complex, [Ni(S2N2H)2] (A) (90% yield) and [Ph3PNH2]Cl salt as products. Analogous reactions with other ligands of this type (two symmetrical (sym.) and three unsymmetrical (uns...

Studies on Iodination Reactions of Phosphiniminocyclotrithiazenes

Abstract: Iodination reactions of various phosphiniminocyclotrithiazenes [R3PNS3N3; R = (i) phenyl-, (ii) morpholino-, and (iii) p-chlorophenyl-] have been studied under different experimental conditions. Iodination of Ph3PNS3N3 yields interesting products such as [(Ph3PN)2S3N3]I3, ((Ph3PN)3S)2I4, (Ph3PNH2)I3, ((Ph3PSI2)2I2, and [(Ph3PN)3SO]2I6 depending on the experimental conditions. All the products have been isolated and characterized by the spectroscopic and analytical techniques.

Aminophosphines: their chemistry and role as ligands and synthons

Abstract: In recent years, research in organophosphorus chemistry has mainly focused in designing newer and better phosphorus ligands for synthesizing novel metal complexes with improved catalytic activities. Aminophosphines [tricoordinate phosphorus(III)–nitrogen systems] are considered as versatile compounds owing to the presence of nitrogen centres which, in principle, can influence additional reactivity features. They are quite sensitive to air and moisture due to the presence of polar PN bond(s). In spite of this, research in aminophosphine chemistry is gaining momentum day-by-day and this is due mainly to one reason: their rich behaviour as ligands in metal complex chemistry and subsequently in catalysis. Their role as synthons in inorganic heterocyclic chemistry has also helped produce new types of heterocycles. In this paper, the chemistry of simple acyclic aminophosphines (synthesis, characterization, reactivity and applications) is covered and particular focus is given to their ability to form chalcogenides along with their role played as ligands in coordination chemistry and as synthons in inorganic heterocyclic chemistry. Copyright © 2009 John Wiley & Sons, Ltd.

[Cp2TiNi(S2N2)2] – The First Organometallic Derivative of [Ni(S2N2H)2]

Abstract: The synthesis and structural characterization of the first organometallic derivative of [Ni(S2N2H)2] (1) are reported. Treatment of K2[Ni(S2N2)2] (2) with stoichiometric amounts of [Cp2TiCl2] in boiling toluene afforded black, crystalline [Cp2TiNi(S2N2)2] (3) in 50 % yield. According to a single-crystal X-ray diffraction study, the novel heterobimetallic complex 3 comprises a nearly planar TiNi(S2N2)2 arrangement. The Ti···Ni separation in 3 is 2.8348(5) A, a value that is typical for bridged early-late heterobimetallic complexes.

Synthesis and X‐ray Structural Characterization of (Diisopropylamino)(Morpholino)(Phenyl)Phosphine and its Dimeric Copper(I)

Abstract: An electron rich “hybrid” asymmetric aminophosphine, (diisopropylamino)(morpholino) (phenyl)phosphine, L, was synthesized in good yield by step‐wise aminolysis reactions with dichloro(phenyl)phosphine and structurally characterized. The complex, CuCl(L) was readily isolated from both 1∶1 and 1∶2 reactions of L with CuCl. Single crystal X‐ray structures of L and two copper complexes, [CuCl(L) · CH3CN]2 (1) and [CuCl(L) · CH2Cl2]2 (2) have been determined. X‐ray structures reveal pyramidal nature of phosphorus and near planar geometry of nitrogen of the phosphine ligand and the dimeric nature of the complexes with tricoordinate copper(I) centers. The asymmetric phosphine crystallizes in monoclinic system with space group P21/c and unit cell dimensions as a=17.219(1) A, b=13.469(1) A, c=7.395(5) A, α=90.00°, β=93.11(1)°, γ=90.00°. Both acetonitrile (1) and dichloromethane (2) solvates crystallize in triclinic system with space group Pī. The unit cell dimensions of (1) are a=10.143(2) A, b=13.681(3) A, c=16.6...

Studies on Iodination Reactions of Phosphiniminocyclotrithiazenes

Abstract: Iodination reactions of various phosphiniminocyclotrithiazenes [R3PNS3N3; R = (i) phenyl-, (ii) morpholino-, and (iii) p-chlorophenyl-] have been studied under different experimental conditions. Iodination of Ph3PNS3N3 yields interesting products such as [(Ph3PN)2S3N3]I3, ((Ph3PN)3S)2I4, (Ph3PNH2)I3, ((Ph3PSI2)2I2, and [(Ph3PN)3SO]2I6 depending on the experimental conditions. All the products have been isolated and characterized by the spectroscopic and analytical techniques.

Synthesis and Characterization of Some Phosphazenium Chloride Salts, [R3PNH2]+Cl− (R = phenyl, p-chlorophenyl and morpholino)

Abstract: Some phosphazenium chloride salts of the type [R3PNH2]+Cl−, where R = phenyl, p-chlorophenyl and morpholino, were synthesized by the reaction of the corresponding phosphiniminocyclotrithiazene compounds (R3PNS3N3) with diphenyldichlorosilane in acetonitrile. All the products were characterized by analytical and spectroscopic data. The single crystal X-ray structure of [Ph3PNH2]+Cl− was reinvestigated with one mole of water molecule in the crystal lattice, showing an intermolecular hydrogen bonding.