Ram G. Goel

Organoantimony compounds : V. Studies on trimethyl- and triphenylantimony(V) derivatives of haloacetic acids☆

Abstract Trimethyl- and triphenylantimony(V) derivatives of fluoro-, chloro-, bromo-, and cyanoacetic acids have been synthesized. Molecular weight, conductance and infrared spectroscopic studies show that these derivatives are pentacoordinated molecular compounds. The carbonyl stretching frequency for these compounds shows a linear dependence upon the p K or the Taft constant σ* for the parent acid. A linear relationship is also observed between the antimony-methyl proton chemical shift and the strength of the parent acid. relationship is also observed between the antimony-methyl proton chemical shift and the strength of the parent acid.

Organobismuth compounds : IV. Preparation and structural characteristics of triphenylbismuth(v) compounds containing a BiOBi bond

Abstract Oxybis(triphenylbismuth) derivatives (Ph3BiOBiPh3)X2 where X=CIO4, NO3, Cl, Br, NCO and CF3COO have been prepared and their structural characteristics have been determined by infrared spectroscopy and conductance measurements. In the solid state a non-ionic structure in which the X groups act as monodentate ligands, is indicated for these compounds. Conductance studies show that the non-ionic structure is maintained in acetonitrile except for X = ClO4. The diperchlorate forms a dihydrate which also appears to have an ionic structure in the solid state as well as in acetonitrile. Conductance and infrared spectroscopic data for the anhydrous as well as the hydrated diperchlorate in dichloromethane suggest the presence of ion-pairs or non-ionic species. Triphenylbismuth oxide has also been isolated and its infrared spectrum indicates that it has a polymeric structure containing-BiOBi- units. The BiOBi stretching frequencies for these compounds have been assigned.

Organoantimony compounds : VIII. Cleavage of Sb—O—Sb bonds in μ—oxybis(triphenyl -chloroantimony) and triphenylantimony oxide by methanol and acetylacetone

Abstract SbOSb bonds in (Ph3ClSb)2O and PH3SbO are cleaved readily by methanol and acetylacetone. The reactions provide convenient synthetic routes for Ph3Sb(OMe)Cl, Ph3Sb(OMe)2, Ph3Sb(acac)Cl, and Ph3Sb(acac)OH. Characterization of these compounds by infrared, Raman, and 1H NMR spectral measurements is reported.

Preparation, Mössbauer and i.r. spectra of alkyltin(IV) derivatives of dibasic acids

Abstract Tri- and di-methyltin sulfate, selenate and chromate have been synthesized and their structural characteristics have been investigated by i.r. and Mossbauer spectroscopy. Similar studies have also been carried out for the solvated products of the above compounds. From the spectroscopic results it is inferred that in the solid state these compounds possess polymeric structures involving five or six coordinate tin.

A convenient synthesis of bis(tri-t-butylphosphine)platinum(0) and its oxidative addition and ligand exchange reactions

Summary Pt[P(t-Bu)3]2 (I) is prepared in high yield from a facile reaction of P(t-Bu)3 with K2PtCl4. Its oxidative addition reactions with CHCl3, CH2Cl2, MeI, and I2, and substitution reactions with CO, M(CO)6 (M=Cr, Mo, W), and t-BuNC have been investigated. Reaction with CHCl3 affords trans-PtHCl[P(t-Bu)3]2 (II) and [ Pt ( µ − Cl ) { P ( t − Bu ) 2 CMe 2 C ︹ H 2 } ] 2 (III), and reaction with CH2Cl2 yields PtCl { P ( t − Bu ) 2 CMe 2 C ︹ H 2 } P(t-Bu) 3 (IV). Pt2Me2(μ-I)2[P(t-Bu)3]2 (VI) and P(t-Bu)3-MeI are formed in the reaction of I with MeI. VI undergoes intramolecular metalation to give [ Pt ( µ − I ) { P ( t − Bu ) 2 CMe 2 C ︹ H 2 } ] 2 (V), and CH4. Reaction of I with I2 results in the formation of V, trans-PtHI[P(t-Bu)3]2 (VII) and P(t-Bu)3I2. CO readily displaces one phosphine from I to give Pt3[P(t-Bu)3]3(CO)3 (VIII). I reacts with M(CO)6 to afford VIII and M(CO)5P(t-Bu)3. t-BuNC replaces both the phosphines from I to give Pt3(t-BuNC)3(μ-t-BuNC)3 (IX).

Organobismuth compounds : X. Preparation and vibrational spectra of complexes of diphenylbismuth(III) derivatives

Abstract The cationic complex [Ph 2 Bi(OAsPh 3 ) 2 ] + and the anionic complexes Ph 2 BiX 2 − (X  Cl, Br, CN, SCN and N 3 ) have been prepared and their vibrational spectra have been investigated. The BiO stretching frequency for the cationic complex and the BiPh and BiX stretching frequencies for the anionic complexes have been assigned.

Organobismuth compounds : V. Preparation, characterization, and properties of triphenylbismuth diazide and dicyanide

Abstract Triphenylbismuth diazide and the dicyanide have been prepared and characterized. Previously reported triphenylbismuth hydroxide cyanide has been shown to be triphenylbismuth dicyanide. A trigonal bipyramidal structure is indicated for both the compounds on the basis of their infrared and laser Raman spectra. The molecular weight and conductance data for the diazide in acetone are also in accord with a molecular structure. The dicyanide is, however, decomposed in solution into diphenylbismuth cyanide and benzonitrile. Thermal decomposition of the solid dicyanide and the diazide has also been studied. The possibility of the conversion of the diazide and the dicyanide into the corresponding dicyanate has been explored. Unlike transition metal azides, the triphenylbismuth diazide does not react with CO. Triphenylbismuth dicyanide could also not be converted into the corresponding dicyanate by reaction with either HgO or MnO 2 . Reaction with HgO afforded triphenylbismuth oxide and the reaction with MnO 2 gave uncharacterized products.

Organoantimony compounds: VII. Preparation and characterization of complex triorganoantimony(V) cations, R3SbL2+2

Abstract Pentacoordinate cationic complexes of the type [R 3 SbL 2 ] (ClO 4 ) 2 , where R = methyl or phenyl, and L = DMSO, DMSO- d 6 , DPSO, Ph 3 PO or Ph 3 AsO, have been isolated and characterized by elemental analysis, infrared and proton NMR spectral and conductance measurements. The SbO stretching frequencies for the complex cations containing DMSO, DMSO- d 6 and Ph 3 AsO occur in the 475 to 400 cm −1 region. For the complexes containing DPSO or Ph 3 PO, definite assignments cannot be made for this frequency. All the complexes behave as 1 2 electrolytes in nitromethane. The infrared spectral measurements in dichloromethane or nitromethane indicate no dissociation of the complex cations in these solvents.

A reinvestigation of the vibrational spectra of mercury (II) halide complexes of triphenylphosphine and tricyclohexylphosphine

Abstract The i.r. (350-130 cm −1 ) and Raman (350 cm − and below) spectra of the 1:1 and 2:1 complexes of mercury (II) halides (chloride, bromide, iodide) with triphenylphosphine and tricyclohexylphosphine have been examined. Spectra for the Ph 3 PHgX 2 and Cy 3 PHgX 2 complexes are consistent with a centrosymmetric dimeric structure of C 2 h skeletal symmetry. Spectra for the (Ph 3 P) 2 HgX 2 and (Cy 3 P) 2 HgX 2 complexes are in accord with a pseudotetrahedral structure of C 2 v symmetry. The Hg-X and Hg-P stretching frequencies for all the complexes have been assigned. The Hg-P stretching frequencies for the 1:1 complexes are higher than those for the 2:1 complexes. In each series of complexes, the Hg-P stretching frequencies decrease in the order Cl > Br > I. For the given mercury (II) halide, the Hg-P stretching frequency is higher for the complex containing less bulky phosphine.

Preparation and facile intramolecular metalation reactions of bis(tri-t-butylphosphine)platinum(II) hydrides

Bis(tri-t-butylphosphine)platinum(II) hydrides, trans-HPtX(P-t-Bu3)2 (where X  Cl, Br, I and CF3CO2) and trans-H2Pt(P-t-Bu3)2, have been prepared and characterized. These hydrides, unlike platinum(II) hydrides containing less bulky phosphines, undergo facile intramolecular metalation to form the internally metalated complexes [t-Bu2PC(CH3)2CH2 ] PtX(P-t-Bu3) and [{t-Bu2PC(CH3)2CH2}PtH]2, respectively.