Rakesh Bohra

Triorganoantimony(V) complexes with internally functionallized oximes: synthetic, spectroscopic and structural aspects of [R3Sb(Br)L], [R3Sb(OH)L] and [R3SbL2], crystal and molecular structures of [Me3Sb{ONC(Me)C4H3O}2], [Me3Sb{ONC(Me)C4H3S}2], 2-OC4H3C(Me)NOH and 2-SC4H3C(Me)NOH

Triorganoantimony(V) complexes with internally functionallized oximes of the type [R3Sb{ON=C(Me)Ar}2] (1) [R=Me, Pri; Ar=C5H4N, C4H3S, C4H3O] have been prepared by the reaction of R3SbBr2 with the corresponding oximes in 1:2 molar ratio in anhydrous benzene. Treatment of 1 with one equivalent of R3SbX2 afforded a redistribution product [R3Sb(X){ON=C(Me)Ar}] (2) [X=(a):Br, (b):OH]. The species, R3Sb(OH)L, may also be obtained by the controlled hydrolysis of 1 (R=Pri; Ar=C5H4N). All of these complexes have been characterized by elemental analyses, and IR and NMR (1H and 13C) spectroscopic studies. Crystal structures of [Me3Sb{ON=C(Me)C4H3O-2}2] (3), [Me3Sb{ON=C(Me)C4H3S-2}2] (4) 2-OC4H3C(Me)=NOH (5) and 2-SC4H3C(Me)=NOH (6) are reported. The geometry around the antimony atom in 3 and 4 is distorted trigonal bipyramidal with the carbon atoms of the SbMe3 unit in equatorial positions and the two oxygen atoms of the oxime group occupying axial positions (O(1)---Sb---O(2) 171.67(12) in 3 and 169.14(13) in 4). The free oxime is clearly hydrogen bonded (H---N 2.08 A in 6) to essentially form a dimer.

Synthesis, spectroscopic and structural aspects of some tetraorganodistannoxanes with internally functionalized oxime: crystal and molecular structures of [{R2Sn(ONC(Me)py)}2O]2 (R=Bun and Et) and 2-NC5H4C(Me)NOH

Diorganotin(IV) complexes of the type [{R2Sn(ON=C(Me)py)}(2)O](2)(R = Bu-n(1), Pr-n(2), Et (3) and Me (4)) have been synthesized by the condensation reaction of R2SnO with 2-NC5H4(Me)C=NOH (5) in 1:1 molar ratio in refluxing anhydrous benzene-toluene and characterized by elemental analyses and IR and NMR (H-1, C-13 and Sn-119) spectroscopy. Two sets of Sn-119 chemical shifts are observed in the Sn-119-NMR spectra of all of these compounds indicating the presence of two types of environment around the tin atoms in solution. The crystal structures of 1, 3 and 5 have been established by single crystal X-ray diffraction, The bonding in 1 differs from that in 3 but in both structures two different environments around the tin atoms are evident with the geometry around each tin atom being that of a distorted trigonal bipyramid with alkyl groups at the equatorial positions. The structure of 5 consists of chains of molecules arising from intermolecular hydrogen bonding involving the nitrogen atom of the ring.

Oxime and hydroxylamine derivatives of metals and metalloids

Diacetyl dioxime (commonly known as dimethylglyoxime) was the first organic reagent to be used in analytical chemistry for estimation of nickel’. Since then the analytical applications of a number of bidentate chelating ligands like dioximes, acyloinoximes and aromatic ohydroxy-aldoximes have been developed extensively and apart from analytical applications, studies have centered around their stability data with a variety of metal ions in aqueous medium’. Due to the highly hydrolysable nature of E&O-Nbond present in derivatives of simple oximes and substituted hydroxylamines with a number of elements like B, Al, Si, Ge, Sn, Pb, Ti, Zr, V, Nb, Ta, P, As, Sb and Bi, synthesis of such derivatives has been achieved in non-aqueous media, mainly during the last decade (out of the 170 references at the end of this article, more than 150 pertain to post-1960 period). This review would deal particularly with the above derivatives. However, as derivatives of these ligands with organometallic moieties have been reviewed recently3, these have been omitted from the present article except for brief references. Addition compounds of these ligands prepared in non-aqueous (or even pseudoaqueous) media are also just mentioned mainly in the preparative section. 2. Methods of Preparations

Synthesis and characterization of some unique heterocyclic derivatives containing aluminium(III) atoms in different coordination states—4. Reaction of bis(β-diketonato) aluminium(III)-di-μ-isopropoxo-di-isopropoxo aluminium(III) with 8-hydroxyquinoline

Abstract Reactions of bis(β-diketonato)aluminium(III)-di-μ-isoproxo-di-isopropoxo aluminium(III), [(CH3COCHCOR)2Al(μ-OPri)2Al(OPri)2] with 8-hydroxyquinoline, C9H6NOH in 1 : 1 and 1 : 2 molar ratios, have resulted in the synthesis of [(CH3COCHCOR)2Al(μ-OPri)2Al(ONC9H6)(OPri)] and [(CH3COCHCOR)2Al(μ-OPri)2Al(ONC9H6)2], respectively. These are soluble in a variety of organic solvents (e.g. benzene, chloroform and dimethylsulfoxide), except [(CH3COCHCOCH3)2Al(μ-OPri)2Al(ONC9H6)2] and [(CH3COCHCOOC2H5)2Al(μ-OPri)2Al(ONC9H6)2], which are insoluble in benzene but soluble in chloroform and dimethylsulfoxide. These derivatives show dinuclear behaviour in chloroform. Plausible structures have been proposed on the basis of elemental analyses, molecular weight measurements, IR and NMR (1H, 13C and 27Al) spectral studies. 27Al NMR spectra show the presence of six and four/five coordinated aluminium sites.

X-ray crystal structure of Bis(4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-onato) dibutyl Tin(IV), C42H44N4O4Sn, with trans RR Sn configuration

Abstract A dialkyl tin complex of composition Bu2SnL2 (I) (L is a monofunctional bidentate ligand) has been made by reaction of ClBu2SnOSnBu2Cl with the substituted pyrazolone, PhCO C:C(OH)N(Ph)N:C CH3, in dry benzene. Crystals of I (M= 787.5) are monoclinic, space group P21/C, a= 9.714(6), b=19.621(6), c=22.68(1) A, β=114.00(4)°, V=3949.2 A3, Z=4, Dcalc=1.3240 cm−3, λ(Mo Kα)=0.71069 A, μ=6.960 cm−1, T=295 K, F(000)=1624, R=0.0628 for 2187 unique reflections. The molecule has a distorted octahedral geometry with Bu groups trans to each other. Four oxygen atoms of the pyrazolone moieties and the central Sn atom lie in the same plane.

Synthesis and spectral studies of diorganotin heterocyclic dithiocarbamate complexes: The crystal structure of (CH3)2Sn[(S2CNCH2CH2CH2CH2CH2]2

Abstract Some new diorganotin(IV) complexes of heterocyclic dithiocarbamates having general formula [ CH 2 CH 2 (X)CH 2 CH 2 NCS2]2Sn R2 (where X = CH2, CHCH3, NCH3, O; R = CH3) have been synthesized and characterized by IR and NMR (1H, 13C and 119Sn) spectral data. The crystal structure of (CH3)2Sn[S2 CNCH 2 CH 2 CH 2 CH 2 CH2]2 has been determined.

Methylplatinum(II) complexes containing 2-(diphenylphosphino)pyridine (Ph2Ppy). Crystal and molecular structure of [PtMe(η2-Ph2Ppy)(Ph2Ppy)][BPh4]

The reaction of [PtMeX(COD)] with 2-(diphenylphosphino)pyridine (Ph2Ppy) in 1 : 2 stoichiometry yields [PtMeX(Ph2Ppy)2] (X = Me, Ia; Cl, Ib; or I, Ic). Reaction of [PtMeCl(COD)] with one equivalent of Ph2Ppy gives the dinuclear complex [PtMeCl(Ph2Ppy)]2 (II). Several reactions of Ib have been studied. Treatment of Ib with NaY gives the cationic complexes [PtMe(η2-Ph2Ppy)(Ph2Ppy)][Y] (Y = BPh4, Id or BF4, Ie). The crystals of Id are triclinic, space group P1 with two molecules in a unit cell of dimensions a 10.006(6), b 14.240(8), c 18.368(6) A, α 80.93(4), β 74.60(3), γ 89.23(5)°. The platinum atom has square planar geometry. The phosphorus atom of the chelated phosphine is trans to the methyl group

O,O′-dialkyl, diaryl and alkylene dithiophosphato derivatives of copper(II) and copper(I); adducts of copper(I) dithiophosphates with triphenyl phosphine: crystal and molecular structure of Cu[S2]·2P(C6H 5)3

Abstract Copper(II) bis(dithiophosphates), Cu[S2P(OR)2]2 (where R =CH2CH2CH3; C6H5) and Cu[S2POGO]2 [where G =C(CH3)2CH2CH(CH3),CH2C(CH3)2CH2, C(CH3)2C(CH3)2 and CH2CH2CH(CH3)−], were precipitated from aqueous solutions of CuSO4·5H2O and ammonium salts of dithiophosphoric acids and gave on treatment with CH3OH in CH2Cl2 solution the corresponding copper(I) derivatives, which form 1:2 adducts with triphenylphosphine. These compounds have been characterized by molecular weights, magnetic moments, IR, electronic, 1H and 31P NMR spectral measurements. Square planar geometry for the copper(II) complexes and tetrahedral geometry for the copper(I) complexes are suggested. The structure of a representative compound Cu[S2 POCH 2 C(CH 3 ) 2 CH 2 O ]·2P(C6H5)3 has been characterized by single crystal diffraction. Attachment of the dithiophosphato group to copper(I) is almost symmetrical with CuSav = 2.461 A and the overall geometry around the metal is distorted tetrahedral.

Addition of methylene groups to Fe3(CO)9(μ3-Te)2

Abstract At room temperature, Fe 3 (CO) 9 (μ-Te) 2 reacts with diazomethane to form (CO) 6 Fe 2 (μ-TeCH 2 Te) (I) and (CO) 6 Fe 2 Te 2 (CH 2 ) 2 (II). Complexes I and II have been separated by chromatography and characterised by IR and NMR spectroscopy, mass spectrometry and microanalysis. Complex I was also subjected to an X-ray diffraction study. The crystals are monoclinic, space group P 2 1 / c with a = 6.864(2), b = 13.926(3), c = 14.159(3) A, β = 104.43(2)°, V = 1310.6(5) A, Z = 4, D c = 2.79 g cm −3 and R = 0.043.

Synthesis, spectroscopic and structural aspects of some tetraorganodistannoxanes with internally functionalized oxime. 2. Crystal and molecular structure of [{Me2Sn(ON=C(Me)C5H4N)}2O}]2·2[2-NC5H4(Me)C=NOH]

The title compound [{Me2Sn(ON=C(Me)C5H4N)}2O}]2·2[2-NC5H4(Me)C=NOH] was obtained during the reaction of Me2SnCl2 with the sodium salt of the ligand in 1:2 molar ratio in a refluxing methanol–benzene mixture. X-ray diffraction analysis of the compound reveals that it is the first tetraorganodistannoxane structural motif in which two molecules of free oxime are connected to the stannoxane framework and the two Sn---O distances of the four-membered planar Sn2O2 ring are identical.