Sushil K. Pandey

Synthesis and Characterization of O,O′-(o-, m-, or p-Ditolyl) Dithiophosphate Ligands

O,O ′-(ortho-, meta-, or para-ditolyl) dithiophosphate ligands have been isolated as triethylammonium salts, (o-, m-or p-CH 3 C 6 H 4 O) 2 PS 2 HNEt 3 , by an auto-catalytic reaction of cresols with P 2 S 5 in the presence of Et3N in a 4:1:2 molar ratio in toluene under anhydrous conditions. These triethylammonium salts could be converted into sodium/ammonium salts, (o-, m-, or p-CH 3 C 6 H 4 O) 2 PS 2 Na/NH 4 , by their direct reaction with sodium metal in equimolar ratio or passing dry ammonia gas in toluene. These salts were characterized by elemental analyses (C, H, N, and S) and mass, IR, and NMR ( 1 H, 13 C, and 31 P) spectroscopic studies.

Disubstituted diphenyldithiophosphates of cadmium: synthesis, characterization, and single-crystal X-ray structure

A series of new disubstituted diphenyldithiophosphate complexes of cadmium [{(ArO)2PS2}2Cd] (9–12) have been isolated in aqueous media while their donor stabilized adducts [{(ArO)2PS2}2Cd·2C5H5N] (13–16) [(Ar = 2,4-(CH3)2C6H3, 2,5-(CH3)2C6H3, 3,4-(CH3)2C6H3 and 3,5-(CH3)2C6H3)] have been isolated in chloroform. These newly synthesized complexes were characterized by elemental analyses, IR and NMR (1H, 13C and 31P) spectroscopic analyses. The dithiophosphate ligands are coordinated bidentate to the cadmium ion via the two thiolate sulfurs. The compounds [{(3,5-CH3)2C6H3O}2PS2HNEt3] (4) and [{(3,5-CH3)2C6H3O}2PS2]2Cd(NC5H5)2 (16) crystallize in the monoclinic system with space group P21/c. Single-crystal X-ray analysis of 4 reveals that phosphorus of the anion is tetrahedrally bonded to two S and two O atoms. The structure is stabilized by cation–anion N–H⋯S intermolecular hydrogen bond interactions. In 16, two diphenyldithiophosphate ions are bidentate with both sulfurs coordinated to cadmium. Each forms a four-membered chelate ring in the equatorial plane. Two pyridines are axially coordinated to cadmium leading to octahedral geometry. The thermal properties of this complex have also been examined by combined DTA/DTG thermal analyses. Graphical Abstract

O-Tolyldithiocarbonate Complexes of Iron(II) and Iron(III)

Abstract Reactions of O-tolyldithiocarbonate ligands, (o-, m-, and p-CH3C6H4O)CS2Na, with anhydrous FeCl2 (1:2 molar ratio) and with FeCl3 (1:1 and 1:3 molar ratio) yielded the complexes [{(CreO)CS2}2Fe] and [{(CreO)CS2}nFeCl3–n] (Cre = o-, m-, and p-CH3C6H4; n = 1 and 3), respectively. These complexes were reacted with nitrogen and phosphorus donor ligands in dichloromethane, which afforded the adducts corresponded to [{(CreO)CS2}2Fe.xL] and [(CreO)CS2FeCl2.xL] {x = 1, L = N2C12H8; x = 2, L = NC5H5, P(C6H5)3}. Elemental analyses and IR, UV-visible, and mass spectroscopic and magnetic studies indicated bidentate mode of bonding by dithiocarbonate ligands leading to sixcoordination around the iron atom as a consequence of Fe…Fe interaction in the complexes [{(CreO)CS2}2Fe] and [(CreO)CS2FeCl2]. The complexes exhibited antifungal activity. The fungicidal activity of the complexes has been tested by poisoned food technique using fungi Fusarium sp. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Antifungal Activity. GRAPHICAL ABSTRACT

New chelating ligands based on S-organosulfurdiimides: synthesis and single crystal X-ray structures of their lithium complexes.

Three new diimidosulfinates, [TMSCH(2)S(N(t)Bu)(2)Li](2) (1), [2-PyCH(2)S(N(t)Bu)(2)Li](2) (2), and [{PhCH(2)S(N(t)Bu)(2)Li}(2) x THF] (3) (TMS = trimethylsilyl; Py = 2-pyridyl), have been synthesized by the reaction of functionalized alpha-CH(2)-organolithium compounds with bis-tert-butylsulfurdiimide. These new organolithium chelates are characterized by NMR ((1)H, (13)C, (7)Li, and (29)Si) spectroscopy and single-crystal X-ray diffraction analyses. Compounds 1 and 2 crystallize as dimers without donor molecules, whereas one of the lithium atoms in 3 is coordinated by a single THF molecule. The crystal structure of 1 shows significant intramolecular proximity between one methyl group of the trimethylsilyl (TMS) and one lithium atom, which could be described as an electrostatic Li...C interaction. The coordination sphere of each lithium atom in 2 is completed by donation from the nitrogen atom of the pyridyl ring; however, one of the lithium atoms in 3 is coordinated by a THF molecule. In addition, the first mixed sulfurdiimide species containing a diimidosulfinate and a diimidosulfite fragment, [{PhCHS(N(t)Bu)(2)Li(2)(THF)(2)}{MeS(N(t)Bu)(2)Li(THF)}] (4), was isolated by deprotonation of the alpha-CH(2) group in 3. The single-crystal X-ray structure of 4 revealed two different S-bound substituents coexisting in one dimer and two asymmetrically coordinated lithium atoms.

o,o′-Alkylene dithiophosphato complexes of vanadium(IV) and vanadium(V)

Reactions of VO(acac)2 with alkylene dithiophosphoric acids, POGOS2H, and of VOCl3 with the ammonium salts NH4(POGOS2) in 1:2 molar ratio gave the oxovanadium(IV) alkylene dithiophosphates, [VO(POGOS2)2], and monochloroxovanadium(V) alkylene dithiophosphates, [VOCl(POGOS2)2], respectively, where G = —CH2CMe2-CH2—, —CH2CEt2CH2—, —CHMeCH2CMe2— or —CMe2CMe2—. These complexes are green solids, soluble in common organic solvents and sensitive to moisture. They were characterized by elemental analysis, molecular weight and spectral studies including i.r. and n.m.r. (1H, 13C and 31P), which suggested bidentate bonding of the POGOS2 ligands to give a square pyramidal for the VIV complexes and an octahedral geometry for the VV complexes.

Spirocyclic Phosphazene Complexes of Arsenic(III): Synthesis and Characterization

A new acyclic phosphazene ligand, [HN(PPh 2 NPh) 2 ] ( A ) has been synthesized and characterized. Spirocyclic phosphazene-glycolate complexes of arsenic(III) with ligand ( A ) and [HN(PPh 2 NSiMe 3 ) 2 ] ( B ), having the general formula [N(PPh 2 NPh) 2 {\kern5pt}{\gel}{\kern-24pt}AsOGO ] and [N(PPh 2 NSiMe 3 ) 2 {\kern5pt}{\agel}{\kern-30pt}AsOGO ] (where G = --CH 2 CH 2 m , --CHMeCH 2 m , --CHMeCH 2 CMe 2 m , --CH 2 CH 2 CH 2 m , or --CMe 2 CMe 2 m ) also have been synthesized by their reaction with chloro dioxarsolanes and -arsenanes in anhydrous medium. These moisture sensitive complexes are characterized by elemental analysis, IR, NMR ( 1 H, 13 C, and 31 P), and mass spectral data which have been discussed in relation to plausible structure for these arsenic(III) derivatives.

Electrochemical fluorination of hexahydroazepine, methylpiperidines and methyl 1-hexahydroazepine-acetate: the preparation of F-(1-hexahydroazepine-acetyl fluoride) and its derivatives☆

Abstract The electrochemical fluorination of hexahydroazepine ( 1 ), methylpiperidines ( 2 ) [2-methylpiperidine ( 2a ), 3-methylpiperidine ( 2b ), 4-methylpiperidine ( 2c )] and methyl 1-hexahydroazepine-acetate ( 3 ) was examined. An extensive cleavage of the C–N bond occurred in the fluorination of secondary cyclic amines ( 1 , 2a – c ) resulting in only a small yield of the corresponding F -( N -fluoro cyclic amines). F -(1-hexahydroazepine-acetyl fluoride) ( 4 ) was obtained in a fair yield from the fluorination of 3 along with F -[(methylpiperidino)-acetylfluoride] which was formed as a result of the isomerization of 3 during fluorination. In addition, several derivatives of 4 were synthesized. F -(1-iodomethyl-hexahydroazepine) ( 4a ) was prepared by the reaction of 4 with anhydrous LiI. The compound 4 was converted into its potassium salt ( 4c ) via methyl F -(1-hexahydroazepine-acetate) ( 4b ), which upon pyrolysis in the presence or absence of ethylene glycol resulted in the formation of 1-difluoromethyl-dodecafluoro(hexahydroazepine) ( 4d ) and F -(3,4,5,6-tetrahydroazepine) ( 4e ), respectively. F -(1-hexahydroazepine-acetoamide) ( 4f ), F -(1-hexahydroazepine-acetonitrile) ( 4g ) and corresponding p -methoxyanilide ( 4h ) were also derived from 4 .

Snthesis and x-ray structure of an isomeric cyclophosphazene complex containing antimony(III)

Abstract The monosilylated acyclic phosphazene ligand Me3SiNP(NMe2)2NP(NMe2)2 NH2 (3) has been synthesized and characterized. The reaction of 3 with antimony triacetate, Sb(OOCMe3), in refluxing toluene forms a cyclic phosphazene derivative, [N{P(NMe2)2NH}2Sb(OOCMe)2 (4), which is characterized by elemental analyses, mass, IR and NMR spectroscopy and single-crystal X-ray structural analysis. Complex 4 crystallizes in the form of a cis and trans isomeric chain in the solid state.

Spectroscopic, Thermal, Electrochemical, and Antimicrobial Studies of Mononuclear Manganese(II) Ditolyldithiophosphates

New complexes of manganese(II) corresponding to [{(ArO)2PS2}2Mn] and [{(ArO)2PS2}2Mn.nL] (Ar = o-, m-, p-CH3C6H4 and p-Cl-m-CH3C6H3; n = 1, L = N2C12H8, N2C10H8; n = 2, L = NC5H5, P(C6H5)3) have been synthesized and characterized by microelemental analyses (C, H, and N), magnetic susceptibility, molar conductance, thermogravimetric, cyclic voltammetry, and spectral analyses including ESI mass spectrometry, IR, and UV-visible. The presence of a four-and-six coordinated Mn atoms has been established in the complexes and adducts, respectively. Antimicrobial screening of the complexes against gram negative bacteria E. coli, K. pneumonia, and P. aeruginosa and fungus S. rolfsii has shown potential bioactivity.

Oxovanadium‐Phosphazene Complexes: Synthesis and Characterization

Cyclic vanadium‐phosphazene complexes in 5‐ and 6‐coordination have been synthesized by the reaction of bis(acetylacetonato)oxovanadium(IV), [VO(acac)2], or trichlorooxovanadium(V), [VOCl3], with acyclic phosphazene ligands, [HN(PPh2NR)2], (where R = Ph or SiMe3) in 1:1 and 1:2 molar ratio. These green colored complexes correspond to the general formulae [VO(acac)L], [VOCl2L] and [VOClL2] (where L = [HN(PPh2NR)2]. They are fairly soluble in most organic solvents and sensitive to moisture. These complexes are characterized by various physico‐chemical technique, viz elemental analyses (C, H, N, V and Cl), molecular weight determinations and spectral studies including IR and NMR (1H, 13C and 31P), which indicated the monomeric nature of the complexes having a bidentate mode of bonding with the phosphazene ligand endowing a square‐pyramidal or octahedral geometry around the vanadium atom, respectively.