Yash Pal Singh

SYNTHESIS AND CHARACTERISATION OF SOME DIPHENYL ANTIMONY(III) COMPLEXES OF CYCLIC-DITHIOCARBAMATES

Abstract Diphenyl-antimony(III) derivatives of cyclic-dithiocarbamates having the general formula (where have been prepared by the reaction of diphenylantimony (III) chloride and the sodium salt of the corresponding ligands. The compounds thus prepared were characterised by elemental analysis, molecular weight measurements, IR, 1H and 13C NMR spectral studies.

β-Ketoester Derivatives of Aluminium: Synthesis and Characterisation

Abstract Some new β-ketoester derivatives of aluminium having the general formula (OPr1)3-nAl[(R)CHCOCOOMe]n (where n = 1, 2 and 3; R = C6H5, p-BrC6H4 and p-BrC6H4) have been synthesised by the reactions of the methyl esters of aroyl pyruvic acids (aroyl = benzoyl, p-chlorobenzoyl and p-bromobenzoyl) with aluminium isopropoxide in stoichiometric ratios in refluxing benzene. A few representative reactions of a representative ligand with anhydrous aluminium chloride have also been carried out. The replacement reactions of alkoxy aluminium pyruvates with higher alcohols, like tert-butanol and insertion reactions across Al-O (in alkoxy groups) with phenyl isocyanate have also been studied. All these derivatives have been characterised by elemental analysis, molecular weight measurements. Their probable structures have been proposed on the basis of i.r. and 1H n.m.r. spectral data.

O,O-dialkyl/alkylene dithiophosphate complexes of organo-rhodium(I)

Abstract Reactions of [(COD)RhCl] 2 with MS 2 P(OR) 2 and H 4 NS 2 POGO yield neutral four-coordinate complexes with the general formulae (COD)Rh[S 2 P(OR) 2 ] and (COD)Rh [S 2 POGO ], respectively [where COD = η-cycloocta-1,5-diene; M = Na or NH 4 ; R = C 2 H 5 , i C 3 H 7 or n -C 3 H 7 ; G = (CH 3 ) 2 C-C(CH 3 ) 2 , CH 2 C(CH 3 2 CH 2 or (CH 3 )CHCH 2 C(CH 3 ) 2 ]. These complexes are monomeric in nature and have been characterized by IR, 1 H and 31 P NMR spectroscopy, the last technique being specially useful in revealing the bidentate nature of the ligand.

Some Substituted Heterocyclic β-diketonates of Zirconium(IV): Syntheses and Characterization

Abstract Reactions of 4-acyl-3-methyl-l-phenyl-2-pyrazolin-5-ones (lig.) (acyl = acetyl, propionyl, benzoyl and p-chlorobenzoyl) were carried out with zirconium isopropoxide in different stoichiometric ratios in non-aqueous solvents yielding corresponding derivatives having the general formula Zr(OPri)4-n(lig)n, respectively, (where n = 1,2, 3 or 4). The complexes have been characterised by elemental analysis and molecular weight determinations. Their probable structures have been proposed, on the basis of molecular weight measurements, i.r., and 1H nmr spectral evidence.

SYNTHESIS AND STRUCTURAL ELUCIDATION OF SOME NEW PHENYLARSENIC(III) DERIVATIVES OF N(-SUBSTITUTED) S-BENZYL DITHIOCARBAZATES

Abstract Some new phenyl arsenic(III) derivatives of N(-substituted) S-benzyldithiocarbazate with the general formula PhAsCl2-n [(X-C6H4)C(R)NNC(S)SCH2C6H5]n where n = 1 or 2; R = H, x = o-OH; R = CH3; x = p- OCH3, p-OH, p- Br, p- F, p- Cl have been synthesised by the reactions of phenylarsenic(III) dichloride with the sodium salt of the corresponding ligand in 1:1 and 1:2 molar ratios in refluxing benzene solution. All these compounds have been characterised by elemental analysis and molecular weight measurements and their plausible structure have been proposed on the basis of spectroscopic evidences. The compounds PhAs[X-C5H4)C(R)NNC(S)SCH2C6H5]2 appears to have distorted octahedral geometry whereas the compounds PhASCl[(X-C6H4)C(R)NNC(S)SCH2C6H5) with trigonal bipyramidal geometry exist in two isomeric forms.

Synthesis and structural elucidation of some new heterocyclic β-diketone derivatives of boron

Abstract Some new β-diketone derivatives of boron having the general formula B 2 O(OAc) 4− n [OC(R) C:CON(Ph)N:C CH 3 ] n (where n = 1 or 2; R = CH 3 , C 2 H 5 , C 6 H 5 and p -ClC 6 H 4 ) have been synthesised by the reactions of oxy- bis (diacetatoborane) and substituted pyrazolones, such as 4-acyl-3-methyl-1-phenyl-2-pyrazolin-5-ones (acyl = acetyl, propionyl, benzoyl and p -chlorobenzoyl) in dry toluene solution in 1:1 and 1:2 molar ratios. These derivatives have been characterised by elemental analysis, molecular weight measurements. Structures have been proposed on the basis of chemical reactions, IR, 1 H and 11 B NMR spectral studies. In the derivatives B 2 O(OAc) 3 [OC(R) C:CON(Ph)N:C CH 3 ] two of the three acetate groups are unidentate and the third is bridged between two boron atoms along with BOB linkage. Whereas the derivatives B 2 O(OAc) 2 [OC(R) C:CON(Ph)N:C CH 3 ] 2 are the mixture of geometrical isomers.

Synthesis and Spectroscopic Characterization of Dibutylgermanium(IV) Complexes of 2-amino-cyclopentene-1-carbodithioic Acid and its N-/S-alkyl Derivatives

Abstract Dibutylgermanium(IV) complexes of the type (where R = H, CH3 C2H3 C4H9) and have been prepared by the reaction of dibutylgermanium(IV) dichloride with the sodium salts of N-/S-alkyl derivatives of 2-aminocyclopentene-l-carbodithioic acid in 1:2 molar ratio in benzene solution. All of these derivatives have been characterized by elemental analyses, spectroscopic (IR, 1H and 13C NMR) studies as well as by molecular weight determinations.

DIORGANOSILICON(IV) COMPLEXES OF HETEROCYCLIC DITHIOCARBAMATES. SYNTHESIS AND STRUCTURAL ELUCIDATIONS

Diorganosilicon(IV) complexes of heterocyclic dithiocarbamates having general formula [CH2CH2(X)CH2CH2NCS2]2SiR2 (where R = CH 3, X = CH 2, CH-CH 3 and R = C 6H5, X = CH 2, CH-CH3 , O) have been synthesized by the interaction of diorganodichlorosilicon with the sodium salt of heterocyclic dithiocarbamates in a 1 : 2 stoichiometric ratio. The resulting complexes were characterized by elemental analysis, molecular weight measurements and a tetracoordinated geometry around silicon atom has been proposed on the basis of IR and. NMR (H, C and Si) spectral studies. Introduction Organosilicon compounds of ligands containing sulphur donor atoms have attracted attention due to their biological importance [1-4], The sulphur-containing ligands are well known for their anticarcinogenic [5], antibacterial [6], tuberculostatic [7] and antifungal [8] activities. Heterocyclic dithiocarbamates constitute an important class of sulphur donor ligands which show pronounced biological activities [9-11], In continuation to our work on heterocyclic dithiocarbamates of group IV organometallics [12-14], we report the synthesis and characterization of diorganosilicon derivatives of these ligands. Table I Analytical and Physical Data of Heterocyclic Dithiocarbamate Complexes of Diorganosilicon(IV) Reactants Molecular Analysis Molecular g (mole) NaCI Formula Weight I I NaS2CNCH2CH2XCH2CH2 R2SiCI2 g (mole) (% yield) m.p. (±1°C) Si% found (Calc.) S% found (Calc.) found (Calc.) X = CH2 R = -CHJ 0.45 CuH26N2S4Si 6.83 33.39 382 1.70 0.50 (0.007) (78) (7.41) (33.86) (378.7) (0.007) (0.003) 100 X = CH-CH3 R = -CH3 0.42 CI6H30N2S4Si 6.36 31.49 410 1.57 0.47 (0.007) (78) (6.90) (31.52) (406.8) (0.007) (0.003) 140 X = CH2 R — —CEHS 0.34 C24H30N2S4SI 5.51 25.12 507 1.30 0.75 (0.005) (83) (5.58) (25.50) (502.8) (0.005) (0.002) 101 X = CH-CHJ R = -C6H5 0.32 C26H34N2S4Si 5.10 24.01 535 1.21 0.71 (0.005) (84) (5.28) (24.15) (530.9) (0.005) (0.002) 110 X = 0 R = -C6H5 0.34 C22H26N202S,Si 5.34 24.12 510 1.30 0.74 (0.005) (82) (5.54) (25.30) (506.8) (0.005) (0.002) 108

Organobismuth(III) derivatives of sterically hindered bifunctional tetradentate schiff bases: Synthesis and spectroscopic characterization

The equimolar reactions of Ph 3 Bi with the bifunctional tetradentate Schiff bases proceed with cleavage of two Bi--C bond of Ph 3 Bi and result in the formation of phenylbismuth(III) derivatives PhBi[RC(NC 6 H 4 S)CH 2 (NC 6 H 4 S)CCOOCH 3 ] where R = C 6 H 5 , 4-ClC 6 H 4 ,4-BrC 6 H 4 , and 4-CH 3 C 6 H 4 . Physico-chemical, IR, and NMR ( 1 H and 13 C) spectral studies have been carried out to investigate the structural aspect of these derivatives which reveal a penta coordination around the central Bi atom.

Synthesis and Characterisation of N-Alkyl-2-Mercaptoacetamide Complexes of Gallium (III)

N-alkyl-2-mercaptoacetamides of gallium having general formula [RNHC(O)CH2S]3Ga, where R = C2H5, n-C3H7, i-C3H7, n-C4H9, i-C4H9, sec-C4H9 have been prepared and characterised by elemental analysis and spectral (IR, 1H & 13C NMR) studies. The complexes appear to exist in two conformational isomeric forms in solution and the probable structure for both the isomers have been proposed.