Narender Kumar Kaushik

Bis (π-cyclopentadienyl) N-aryl substituted dithiocarbamato chloro zirconium(IV) compounds

Die Reaktion von Dichloro-bis-[cyclopentadienyl]-zirkonium mit den Ammoniumsalzen der Dithiocarbaminsauren in siedendem Dichlormethan liefert die monomeren, diamagnetischen Komplexe (I) (keine Ausb.-Angabe).

Bis-η5-cyclopentadienyl and Bis-η5-methylcyclopentadienylN,N-dialkyldithiocarbamato(chloro)titanium(IV) compounds

SummaryTitanium(IV)N,N-dialkyldithiocarbamates of the type η5-Cp2Ti (S2CNR2)Cl and (η5-MeCp)2Ti(S2CNR2)Cl (R = Me, Et and i-Pr) have been prepared by the reaction of di--cyclopentadienyldichlorotitanium(IV) and bis-n-methylcyclopentadienyldichlorotitanium(IV) with sodium salts of dithiocarbamic acids in refluxing dichloromethane. Molecular weight, conductance and i.r. studies show these complexes to be monomeric nonelectrolytes in which the dithiocarbamate ligands are bidentate. Therefore, pentacoordination may be assigned to titanium(IV) atom in all six complexes. Electronic and proton n.m.r. studies spectra have also been recorded for the complexes.

Preparation, spectral characterization, in vitro antitumor and thermal studies of new platinum(IV) and palladium(II) thiohydrazone complexes

PtIV and PdII complexes [Pt(L)2Cl2] and [Pd(HL)Cl2] [HL = salicyclaldehyde morpholine N-thiohydrazone (HL1), benzaldehyde morpholine N-thiohydrazone (HL2), acetophenone morpholine N-thiohydrazone (HL3), p-methylacetophenone morpholine N-thiohydrazone (HL4), cinnamaldehyde morpholine N-thiohydrazone (HL5), cyclohexanone morpholine N-thiohydrazone (HL6), benzaldehyde aniline N-thiohydrazone (HL7), benzaldehyde N-(methyl, cyclohexyl)-thiohydrazone (HL8) and benzaldehyde N-(ethyl, cyclohexyl)-thiohydrazone (HL9)] were prepared in MeOH and characterized by elemental analysis, i.r., electronic, 1H-n.m.r. and 13C-n.m.r. spectral data. For some of the complexes cyclic voltammetric and thermal studies were carried out. The in vitro antitumor activity of some complexes was measured.

Synthesis and Characterisation of Bis(π-cyclopentadienyl) N-aryl Substituted Dithiocarbamato Chloro Titanium (IV) Compounds

Abstract Bis(π-cyclopentadienyl) N-aryl substituted dithio-carbamato chloro titanium(IV) compounds have been synthesised by the reaction of bis(π-cyclopentadienyl) titanium(IV) dichloride with ammonium (N-aryl substituted) dithiocarbamates in refluxing dichloromethane. Molecular weight, conductance and infrared studies point out that these complexes are monomeric non-electrolytes in which the dithiocarbamate ligands are bidentate. Therefore, a coordination number of ‘5’ may be assigned to the titanium(IV) atom in all the twelve complexes. Electronic spectra have also been obtained for these complexes

Semi-synthetic antibiotics: Titanium(IV), zirconium(IV) and mercury(II) complexes of 6-amino penicillinic acid

Abstract A number of organometallic derivatives involving 6-amino penicillinic acid ( I ), of the types η 5 -R) 2 M- (Cl)L − Et 3 NH + ( II ), (η 5 -R) 2 M(Cl)L ( III ) and R′HgL [R = cyclopentadienyl (C 5 H 5 ), indenyl (C 9 H 7 ), R′ = phenyl (C 6 H 5 ), p -acetoxyphenyl ( p -CH 3 COOC 6 H 4 ), o -hydroxyphenyl ( o -HOC 6 H 4 ), p -hydroxyphenyl ( p -HOC 6 H 4 ); M = Ti(IV), Zr(IV); LH = 6-amino penicillinic acid] have been synthesized and characterized. Conductance measurements indicate that while the (η 5 -R) 2 M(Cl)L − Et 3 NH + complexes are 1:1 electrolytes, the remaining compounds are non-electrolytes. From IR and UV spectral studies it is concluded that the penicillin moiety is bidentate. PMR and CMR studies support the stoichiometry of the complexes. Fluorescence studies have been carried out for o - and p -HOC 6 H 4 HgL complexes and relevant photochemical parameters have been elucidated. X-ray diffraction studies have been made for the o -HOC 6 H 4 HgL complex. For the C 6 H 5 HgL, p -CH 3 COOC 6 H 4 HgL and p -HOC 6 H 4 HgL complexes, thermal studies (TG and DTA) have been carried out and kinetic parameters for thermal degradation have been enumerated. In addition, the fragmentation pattern of these complexes has been analysed on the basis of mass spectra. The C 6 H 5 HgL and p -CH 3 COOC 6 H 4 HgL complexes show positive bactericidal activities.

Monocyclopentadienyl titanium(IV) dithiocarbamate complexes

Abstract Preparation of titanium(IV) complexes of the type CpTi(dtc)Cl 2 , CpTi(dtc) 2 Cl and CpTi(dtc) 3 has been carried out by reacting CpTiCl 3 and respective sodium dithiocarbamate viz. N-(ethyl, m-tolyl), N-cyclopentyl and N-cycloheptyl dithiocarbamates in the desired metal to ligand ratio in refluxing dichlomethane. Studies of the physical properties reveal monomeric and nonelectrolytic nature of these complexes, where dithiocarbamate behaves as bidentate ligand. Therefore, 5, 6 and 7 coordinate structure can be assigned to CpTi(dtc)Cl 2 , CpTi(dtc) 2 Cl and CpTi(dtc) 3 , respectively.

Bis-N(p-ethoxyphenyl)dithiocarbamato complexes of Cu(II), Zn(II), Cd(II), Sn(II), Sn(IV), Ni(II) and Pd(II)

Abstract Bis- N ( p -ethoxyphenyl)dithiocarbamato complexes of copper(II), zinc(II), cadmium(II), tin(II), tin(IV), nickel(II) and palladium(II), abbreviated as Cu(PED) 2 , Zn(PED) 2 , Cd(PED) 2 , Sn(PED) 2 , Sn(PED) 2 Cl 2 , Ni(PED) 2 and Pd(PED) 2 , have been synthesized. These complexes have been characterized on the basis of elemental analyses, molecular weight determinations, conductance measurements, IR and electronic spectral studies. Thermal studies of these complexes have been carried out in a static air atmosphere to determine their mode of decomposition. Kinetic parameters such as apparent activation energy and order of reaction have been determined using the graphical method of Coats and Redfern. Heats of reaction for different decomposition steps have been calculated from the DTA curves. The intermediates obtained at the end of various thermal decomposition steps were identified on the basis of elemental analyses and IR spectral studies.

Thermal studies on magnesium, barium and lead zirconyl oxalates

Abstract Magnesium, barium and lead zirconyl oxalates (abbreviated as MZO, BZO and LZO, respectively) have been prepared in aqueous medium. These compounds have been characterized on the basis of elemental analysis and IR spectral studies. The thermal behaviour of these compounds has been studied with the aid of TG, DTG and DSC techniques. The graphical method of Coats and Redfern has been employed to calculate the kinetic parameters such as apparent activation energy and order of reaction. Heats of reaction for different decomposition steps have been calculated from the DSC curves. The intermediates obtained at the end of various thermal decomposition steps were identified on the basis of elemental analysis and IR spectral studies.

Preparation and Characterisation of Bis(η5-indenyl)-N,N′-disubstituted Dithiocarbamatochloro Oxomolybdenum(VI) Complexes

Abstract Bis(η5-indenyl)N,N′-disubstituted dithiocarbanatochloro oxomolybdenum(VI) complexes of the type (C9H7)2MoO(S2CNR2)Cl and (C9H7)2MoO(S2CNRR′)Cl (where R = Me, Et, i-Pr and R′ = cyhx) have been prepared by the reaction of stoichiometric amounts of bis(η5-indenyl) oxomolybdenum(VI) dichloride with sodium salts of dithiocarbamic acids in refluxing dichloromethane. Infrared spectral studies demonstrate that in these complexes, dithiocarbamate ligands are bidentate. Therefore the molybdenum (VI) atom may be assigned the coordination number 7 in all these complexes. In addition to infrared studies, electronic spectra, NMR studies, magnetic susceptibility, elemental analyses and conductance measurements have been carried out for these complexes.

Bis(π-cyclopentadienyl) BIS(N-aryl substituted dithiocarbamato) titanium(IV) complexes

Abstract Bis(π-cyclopentadienyl) bis(N-aryl substituted dithiocarbamato) titanium(IV) have been prepared by the reaction of bis(π-cyclopentadienyl) titanium(IV) dichloride with ammonium (N-aryl substituted) dithiocarbamates in aqueous medium. Conductance, IR and molecular weight studies show that these complexes are monomeric non-electrolytes in which the dithiocarbamate ligands are bidentate.