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Papers by amey wadawale
![Research paper thumbnail of Syntheses of platinum(II) complexes of cyclo-octenyl group and isolation of a self-assembled oxo-bridged macrocyclic complex [Pt 4(Spy) 4(C 8H 12OC 8H 12) 2]](https://attachments.academia-assets.com/50422677/thumbnails/1.jpg)
](Journal of Organometallic Chemistry, 2011
Reactions of [Pt2(μ-Cl)2(C8H12OMe)2] (1) (C8H12OMe = 8-methoxy-cyclooct-4-ene-1-yl) with various ... more Reactions of [Pt2(μ-Cl)2(C8H12OMe)2] (1) (C8H12OMe = 8-methoxy-cyclooct-4-ene-1-yl) with various anionic chalcogenolate ligands have been investigated. The reaction of 1 with Pb(Spy)2 (HSpy = pyridine-2-thiol) yielded a binuclear complex [Pt2(Spy)2(C8H12OMe)2] (2). A trinuclear complex [Pt3(Spy)4(C8H12OMe)2] (3) was isolated by a reaction between 2 and [Pt(Spy)2]n. The reaction of 1 with HSpy in the presence of NaOMe generated 2 and its demethylated oxo-bridged tetranuclear complex [Pt4(Spy)4(C8H12-O-C8H12)2] (4). Treatment of 1 with ammonium diisopropyldithiophosphate completely replaced C8H12OMe resulting in [Pt(S2P{OPri}2)2] (5), whereas non-rigid 5-membered chelating ligand, Me2NCH2CH2E−, produced mononuclear complexes [Pt(ECH2CH2NMe2)(C8H12OMe)] (E = S (6), Se (7)). These complexes have been characterized by elemental analyses, NMR (1H, 13C{1H}, 195Pt{1H}) and absorption spectroscopy. Molecular structures of 2, 3, 4, 5 and 7 were established by single crystal X-ray diffraction analyses. Thermolysis of 2, 6 and 7 in HDA gave platinum nanoparticles.The reaction of [Pt2(μ-Cl)2(C8H12OMe)2] (C8H12OMe = 8-methoxy-cyclooct-4-ene-1-yl) with anionic chalcogenolate ligands yields a variety of platinum complexes. A unique demethylated oxo-bridged tetranuclear complex [Pt4(Spy)4(C8H12-O-C8H12)2] has been isolated and structurally characterized. Thermolysis of these complexes in HDA gave platinum nanoparticles.► Pt(II) complexes with weak octenyl group and strong chalcogenolate ligand were synthesized and structurally characterized. ► A new oxo-bridged tetranuclear macrocyclic Pt(II) complex [Pt4(Spy)4(C8H12-O-C8H12)2] has been structurally characterized. ► Binuclear Pt(II) complexes with pyridine-2-thiolate ligand exist as two isomeric forms. ► Platinum complexes containing strong Pt–E (E = S or Se) bond after pyrolysis yield platinum nanoparticles rather than PtE.
…, 2012
PbTiO 3 nanotube arrays have been synthesized via sol-gel template method, and their morphology a... more PbTiO 3 nanotube arrays have been synthesized via sol-gel template method, and their morphology and structures have been determined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The diameter and length of these nanotubes are about 300 nm and 50 m, respectively, and their wall thickness is typically several tens of nanometers. XRD data shows that as-prepared PTO nanotubes possess perovskite structure, and electron diffraction demonstrates that they are polycrystalline. Photoluminescence spectrum of PTO nanotubes reveals an intense and wide emission band centered at 505 nm. Polarization-electric field (P-E) response curves of PTO nanotube array were measured, and the hysteresis loops illustrate a room temperature ferroelectric characteristic of as-prepared PTO nanotubes.
Journal of Chemical …, 2007
... Shamik Ghoshala, Amey Wadawalea, Vimal K. Jaina* and Munirathinam Nethajib aChemistry Divisio... more ... Shamik Ghoshala, Amey Wadawalea, Vimal K. Jaina* and Munirathinam Nethajib aChemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India bDepartment of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India ...
Inorganic Chemistry Communications, 2010
Monoselenocarboxylate–bridged binuclear complexes of RhIII and IrIII, [(Cp∗MCl)2(μ-SeCOAr)2] (1) ... more Monoselenocarboxylate–bridged binuclear complexes of RhIII and IrIII, [(Cp∗MCl)2(μ-SeCOAr)2] (1) (M = Rh or Ir; Cp∗ = pentamethylcyclopentadienyl; Ar = Ph, C6H4Me–4), have been isolated either by the reaction between [Cp∗2M2(μ-Cl)2Cl2] with KSeCOAr in acetonitrile or by treatment of [Cp∗MCl(solvent)2][PF6] with KSeCOAr in acetone. The novel binuclear complexes, [Cp∗IrCl(μ-SeCOAr)(κ2-SeCOC6H3R–)IrCp∗] (2) (R = H or Me-4) with ortho-metallation at one of the iridium centres have been isolated following the use of excess AgPF6. The single crystal structure of [Cp∗IrCl(μ-SeCOC6H5)(κ2-SeCOC6H4–)IrCp∗] (2a) exhibits two phenylcarboselenolate moieties situated in syn fashion with respect to the “Ir2Se2” plane, one of which leans towards the metal centre in order to undergo ortho-metallation after iridium–chlorine bond dissociation.Monoselenocarboxylate–bridged binuclear complexes of Rh(III) and Ir(III), [Cp∗2M2Cl2(μ-SeCOAr)2] (1) (M = Rh or Ir; Ar = Ph, C6H4Me-4) and [Cp∗IrCl(μ-SeCOC6H5)(κ2-SeCOC6H3R–)IrCp∗] (2) (R = H, Me) have been isolated and characterized. X-ray crystal structure of [Cp∗IrCl(μ-SeCOC6H5)(κ2-SeCOC6H4–)IrCp∗] (2a) revealed orthometallation at one of the iridium centre via iridium–chlorine bond dissociation.
Journal of Chemical …, 2010
Page 1. JOURNAL OF CHEMICAL RESEARCH 2010 RESEARCH PAPER 485 SEPTEMBER, 485488 Diorganogallium c... more Page 1. JOURNAL OF CHEMICAL RESEARCH 2010 RESEARCH PAPER 485 SEPTEMBER, 485488 Diorganogallium complexes containing tripodal Schiff bases: synthesis and structure of [N{Me2GaO(C6H4)CH=NCH2CH2-}3] ...
![Research paper thumbnail of Synthesis and spectroscopy of cis-configured mononuclear palladium(II) and platinum(II) complexes of chalcogeno o-carboranes and structures of [Pt(SCb oPh) 2(dppm)], [Pt(SeCb oPh) 2(dppm)], [Pt(SCb oS)(PMe 2Ph) 2] and [Pt(SCb oS)(PMePh 2) 2]](https://attachments.academia-assets.com/50422680/thumbnails/1.jpg)
](Journal of Organometallic Chemistry
The reactions of [MCl2(P∩P)] and [MCl2(PR3)2)] with 1-mercapto-2-phenyl-o-carborane/NaSeCboPh and... more The reactions of [MCl2(P∩P)] and [MCl2(PR3)2)] with 1-mercapto-2-phenyl-o-carborane/NaSeCboPh and 1,2-dimercapto-o-carborane yield mononuclear complexes of composition, [M(SCboPh)2(P∩P)], [M(SeCboPh)2(P∩P)] (M = Pd or Pt; P∩P = dppm (bis(diphenylphosphino)methane), dppe (1,2-bis(diphenylphosphino)ethane) or dppp (1,3-bis(diphenylphosphino)propane)) and [M(SCboS)(PR3)2] (2PR3 = dppm, dppe, 2PEt3, 2PMe2Ph, 2PMePh2 or 2PPh3). These complexes have been characterized by elemental analysis and NMR (1H, 31P, 77Se and 195Pt) spectroscopy. The 1J(Pt–P) values and 195Pt NMR chemical shifts are influenced by the nature of phosphine as well as thiolate ligand. Molecular structures of [Pt(SCboPh)2(dppm)], [Pt(SeCboPh)2(dppm)], [Pt(SCboS)(PMe2Ph)2] and [Pt(SCboS)(PMePh2)2] have been established by single crystal X-ray structural analyses. The platinum atom in all these complexes acquires a distorted square planar configuration defined by two cis-bound phosphine ligands and two chalcogenolate groups. The carborane rings are mutually anti in [Pt(SCboPh)2(dppm)] and [Pt(SeCboPh)2(dppm)].Cis-configured palladium and platinum complexes with chalcogeno o-carboranes have been isolated and characterized by NMR (1H, 31P, 77Se and 195Pt) spectroscopy and X-ray crystallography. The 1J(Pt–P) values and 195Pt NMR chemical shifts are influenced by the nature of phosphine as well as thiolate ligand.► Cis-configured mononuclear Pd/Pt chalcogenolate complexes have been isolated. ► The magnitude of 1J(Pt–P) is dependent on the nature of phosphine and thiolate ligand. ► The nature of phosphine and thiolate ligand influences the 195Pt NMR chemical shifts. ► The carboranes adopt a mutually anti-confirmation. ► The platinum atom in these complexes acquires a distorted square planar configuration.
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Journal of …, 2009
The reactions of [M2Cl2(μ-Cl)2(PMe2Ph)2] with mercapto-o-carboranes in the presence of pyridine a... more The reactions of [M2Cl2(μ-Cl)2(PMe2Ph)2] with mercapto-o-carboranes in the presence of pyridine afforded mono-nuclear complexes of composition, [MCl(SCb°R)(py)(PMe2Ph)] (M = Pd or Pt; Cb° = o-C2B10H10; R = H or Ph). The treatment of [PdCl2(PEt3)2] with PhCb°SH yielded trans-[Pd(SCb°Ph)2(PEt3)2] (4) which when left in solution in the presence of pyridine gave another substitution product, [Pd(SCb°Ph)2(py)(PEt3)] (5). The structures of [PdCl(SCb°Ph)(py)(PMe2Ph)] (1), [Pd(SCb°Ph)2(PEt3)2] (4) and [Pd(SCboPh)2(py)(PEt3)] (5) were established unambiguously by X-ray crystallography. The palladium atom in these complexes adopts a distorted square-planar configuration with neutral donor atoms occupying the trans positions. Thermolysis of [PdCl(SCb°)(py)(PMe2Ph)] (2) in TOPO (trioctylphosphine oxide) at 200 °C gave nanocrystals of TOPO capped Pd4S which were characterized by XRD pattern and SEM.The reactions of [M2Cl2(μ-Cl)2(PMe2Ph)2] with mercapto-o-carboranes in the presence of pyridine afforded mono-nuclear complexes of composition, [MCl(SCb°R)(py)(PMe2Ph)] (M = Pd or Pt; Cbo = o-C2B10H10; R = H or Ph) (1–3). The treatment of [PdCl2(PEt3)2] with PhCboSH yielded trans-[Pd(SCb°Ph)2(PEt3)2] (4) which when left in solution in the presence of pyridine gave another substitution product, [Pd(SCb°Ph)2(py)(PEt3)] (5). Thermolysis of [PdCl(SCb°)(py)(PMe2Ph)] (2) in TOPO (trioctylphosphine oxide) at 200 °C gave nanocrystals of TOPO capped Pd4S which were characterized by XRD pattern and SEM (scanning electron microscopy).
Inorganica Chimica …, 2011
Journal of …, 2012
A series of nicotinoyl based organoselenium compounds, [2-NC 5 H 3 (3-COOH)Se] 2 (1), [2-NC 5 H 3... more A series of nicotinoyl based organoselenium compounds, [2-NC 5 H 3 (3-COOH)Se] 2 (1), [2-NC 5 H 3 (3-CO)SeeSe] (2), [2-NC 5 H 3 (3-CONH 2 )Se] 2 (3), [2-NC 5 H 3 (3-CONHPh)Se] 2 (4), [2-NC 5 H 3 (3-CONHpyrimidine)Se] 2 (5), [2-NC 5 H 3 (3-CONHPh)SeBr] (6) and [2-NC 5 H 3 (3-CONHPh)SeI] have been synthesized and characterized by absorption, IR, NMR ( 1 H, 13 C{ 1 H}, 77 Se{ 1 H}) and mass spectrometry. The crystal structures of [2-NC 5 H 3 (3-CO) SeeSe] (2) and [2-NC 5 H 3 (3-CONHPh)Se] 2 (4) have been determined. The structure of (4) revealed the existence of two intra-molecular Se/X (X ¼ O and N) interactions, as a result of this, CeSeeSeeC torsion angle is unusually large (180 ). The GPx mimicking activity of these compounds has been evaluated using methods based on 1 H NMR spectroscopy and HPLC. Free radical scavenging ability of the compounds was examined by DPPH and deoxyribose assay. All these studies indicated that the compound (3) not only showed highest GPx activity but also has a very good free radical scavenging ability thus making it a novel structure for development of nicotine based antioxidants.
Inorganica Chimica …, 2010
Synthesis of a series of monoorganobismuth dithiocarboxylate complexes, [RBi(S 2 CAr) 2 ] (R = Me... more Synthesis of a series of monoorganobismuth dithiocarboxylate complexes, [RBi(S 2 CAr) 2 ] (R = Me, Ph, tol; Ar = Ph, tol), has been reported. They have been characterized by elemental analyses and spectroscopic methods. Molecular structures of [RBi(S 2 Ctol) 2 ] (R = Me or ...
X-ray Structure Analysis Online, 2009
Journal of Organometallic Chemistry, 2010
The reactions of PhCboSeNa (Cbo = o-C2B10H10), prepared by reductive cleavage of Se–Se bond in (P... more The reactions of PhCboSeNa (Cbo = o-C2B10H10), prepared by reductive cleavage of Se–Se bond in (PhCboSe)2 by NaBH4 in methanol, with Na2PdCl4, MCl2(PR3)2 and [M2Cl2(μ-Cl)2(PR3)2] afforded a variety of complexes, viz., [Pd(SeCboPh)Cl] (1), [M(SeCboPh)2(PR3)2], [M2Cl2(μ-SeCboPh)(μ-Cl)(PR3)2] (M = Pd, Pt) and [Pd2Cl(SeCb0Ph)(μ-Cl)(μ-SeCboPh)(PEt3)2] (7) have been isolated. These complexes were characterized by elemental analyses and NMR (1H, 31P, 77Se, 195Pt) spectroscopy. The structures of [Pd(SeCboPh)2(PEt3)2] (2), [Pt(SeCboPh)2(PMe2Ph)2] (3), [Pd2Cl2(μ-SeCboPh)(μ-Cl)(PMe2Ph)2] (5) and [Pd2Cl(SeCboPh)(μ-Cl)(μ-SeCboPh)(PEt3)2] (7) were established by X-ray crystallography. The latter represents the first example of asymmetric coordination of selenolate ligands in binuclear bis chalcogenolate complexes of palladium and platinum. Thermolysis of [Pd(SeCboPh)2(PEt3)2] (2) in HDA (hexadecylamine) at 330 °C gave nano-crystals of Pd17Se15.The reactions of PhCboSeNa (Cbo = o-C2B10H10), with Na2PdCl4, MCl2(PR3)2 and [M2Cl2(μ-Cl)2(PR3)2] afforded a variety of complexes, viz., [Pd(SeCboPh)Cl], [M(SeCboPh)2(PR3)2], [M2Cl2(μ-SeCboPh)(μ-Cl)(PR3)2] (M = Pd, Pt) and [Pd2Cl(SeCb0Ph)(μ-Cl)(μ-SeCboPh)(PEt3)2]. The latter represents the first example of asymmetric coordination of selenolate ligands in binuclear bis chalcogenolate complexes of palladium and platinum. Thermolysis of [Pd(SeCboPh)2(PEt3)2] in HDA (hexadecylamine) at 330 °C gave nano-crystals of Pd17Se15.
…, 2012
Oxidative addition reaction of dipyridyl ditellurides to [Pt 2 (dppm) 3 ] gave two types of compl... more Oxidative addition reaction of dipyridyl ditellurides to [Pt 2 (dppm) 3 ] gave two types of complexes, [Pt{2-Te-C 5 H 3 (3-R)N} 2 (dppm)]
![Research paper thumbnail of Diorgano-gallium and -indium complexes with N-heterocyclic carboxylic acids: Synthesis, characterization and structures of [Me 2M(O 2C–C 5H 4N)] 2, M = Ga or In](https://attachments.academia-assets.com/50422683/thumbnails/1.jpg)
](Journal of Organometallic Chemistry, 2007
The reaction of triorgano-gallium and -indium etherate with heterocyclic carboxylic acids in benz... more The reaction of triorgano-gallium and -indium etherate with heterocyclic carboxylic acids in benzene at room temperature yields complexes of the type [R2M(L)]n(M = Ga or In; R = Me or Et; L = 2-(C5H4N)CO2, 2-(C4H3N2)CO2 or 2-(C9H6N)CO2). These complexes have been characterized by elemental analysis, IR, UV–vis, NMR (1H and 13C{1H}) and mass spectral data. Complexes with L = (C5H4N)CO2- and (C9H6N)CO2- showed photoluminescence on excitation with ∼250 or ∼310 nm radiation, respectively. Single crystal X-ray structural analysis of [Me2M(O2C–C5H4N-2)]2 (M = Ga or In), revealed a dimeric structure with five-coordinate metal atoms arising from the presence of two tridentate bridging picolinate ligands.The reaction of triorgano-gallium and -indium etherate with heterocyclic carboxylic acids in benzene at room temperature yields complexes of the type [R2M(L)]n(M = Ga or In; R = Me or Et; L = 2-(C5H4N)CO2, 2-(C4H3N2)CO2 or 2-(C9H6N)CO2). Single crystal X-ray structural analysis of [Me2M(O2C–C5H4N-2)]2 (M = Ga or In), revealed a dimeric structure with five-coordinate metal atoms arising from the presence of two tridentate bridging picolinate ligands.
Organic & …, 2011
A series of 2-(3,5-dimethylpyrazol-1-yl)ethylseleno derivatives has been synthesized. The glutath... more A series of 2-(3,5-dimethylpyrazol-1-yl)ethylseleno derivatives has been synthesized. The glutathione peroxidase like catalytic activity of these compounds has been studied in a model system, in which reduction of hydrogen peroxide with dithiothreitol (DTT red ), in the presence of an organoselenium compound was investigated by 1 H NMR spectroscopy. All these compounds exhibit GPx like catalytic activities and the catalytic reaction proceeds through a selenoxide intermediate, identified by 77 Se{ 1 H} NMR spectroscopy.
Inorganica Chimica Acta, 2010
Synthesis of a series of monoorganobismuth dithiocarboxylate complexes, [RBi(S2CAr)2] (R = Me, Ph... more Synthesis of a series of monoorganobismuth dithiocarboxylate complexes, [RBi(S2CAr)2] (R = Me, Ph, tol; Ar = Ph, tol), has been reported. They have been characterized by elemental analyses and spectroscopic methods. Molecular structures of [RBi(S2Ctol)2] (R = Me or Ph) have been established by single crystal X-ray diffraction studies. The bismuth atom in these complexes adopts a square pyramidal configuration with the R group at the apical position. In the solid state, these complexes show supra-molecular association devoid of Bi⋯S secondary interactions. Thermolysis of [RBi(S2Ctol)2] (R = Me or Ph) in refluxing diphenylether yielded Bi2S3 nanocrystals which were characterized by XRD, EDAX and SEM. The complex [PhBi(S2Ctol)2] has been employed for deposition of thin films of Bi2S3 by AACVD.A series of monoorganobismuth dithiocarboxylate complexes, [RBi(S2CAr)2] were synthesized and characterized. The bismuth atom in [MeBi(S2Ctol)2] and [PhBi(S2Ctol)2] adopts a square pyramidal configuration with the R group at the apical position and show supra-molecular association devoid of Bi⋯S secondary interactions. Nanocrystals and thin films of Bi2S3 were prepared from these complexes.
Journal of …, 2009
Sodium ethylselenolates with functional groups X (where X = –OH, –COOH, –COOMe and –COOEt) at β-c... more Sodium ethylselenolates with functional groups X (where X = –OH, –COOH, –COOMe and –COOEt) at β-carbon were prepared in situ by reductive cleavage of corresponding diselenide with NaBH4 either in methanol or aqueous ammonia. Treatment of these selenolates with [M2Cl2(μ–Cl)2(PR3′)2] (M = Pd or Pt; PR3′ = PMePh2, PnPr3) in different stoichiometry yielded various bi- and tri-nuclear complexes. The homoleptic hexanuclear complexes [Pd(μ–SeCH2CH2X)2]6 (X = OH, COOH, COOEt), were obtained by reacting Na2PdCl4 with NaSeCH2CH2X. All these complexes have been fully characterized. Molecular structures of ethylselenolates containing hydroxyl and carboxylic acid groups revealed solid state associated structures through inter-molecular hydrogen bond interactions. Trinuclear complex, [Pd3Cl2(μ–SeCH2CH2COOH)4(PnPr3)2] (3a), was disposed in a boat form unlike chair conformation observed for the corresponding methylester complex. The effect of β-functionality in ethylselenolate ligands towards reactivity, structures and thermal properties of palladium and platinum complexes has been extensively studied.A series of mono-, bi- and poly-nuclear palladium and platinum complexes have been synthesized by employing β-substituted ethylselenolate ligands. β-Substitution results in different nucleophilicity of ethylselenolate ligands which is reflected on reactivity, structures and thermal behavior of palladium and platinum complexes. Presence of protic groups in XCH2CH2Se− (X = OH, COOH) modified the solid state structures which exhibited functional group mediated aggregation via hydrogen-bonding.
Dalton …, 2011
The complexes, [Cu{EC 5 H 3 (R-3)N}] 4 (E/R = Se/Me or Te/R; R = H or Me) were isolated by the re... more The complexes, [Cu{EC 5 H 3 (R-3)N}] 4 (E/R = Se/Me or Te/R; R = H or Me) were isolated by the reaction between CuCl and NaEC 5 H 3 (R-3)N and were characterized by elemental analyses, uv-vis and NMR ( 1 H, 13 C) spectroscopy. The crystal structures of [Cu{SeC 5 H 3 (Me-3)N}] 4 and [Cu(TeC 5 H 4 N)] 4 revealed that the molecules are tetrameric in which each copper atom lies at the vertex of the tetrahedron and each face of the tetrahedron is capped by the bridging pyridylchalcogenolate ligand. Thermal behavior of these complexes was studied by thermogravimetric analysis. Depending on reaction conditions, thermolysis gave both stoichiometric and non-stoichiometric copper chalcogenides, which were characterized by XRD, EDX, SEM, TEM and SAED techniques. These precursors were used for the preparation of nanocrystals and for deposition of thin films of copper chalcogenides by AACVD (Aerosol Assisted Chemical Vapor Deposition).
Bulletin of The Chemical Society of Japan, 2008
Treatment of a methanolic solution of metal acetate with bis(1-methylimidazolyl)diselenide, [(MeI... more Treatment of a methanolic solution of metal acetate with bis(1-methylimidazolyl)diselenide, [(MeImSe) 2 ], yields complexes of composition [M(OAc) 2 {(MeImSe) 2 }] (M = Zn, Cd, or Hg) whereas reactions of [MX 2 (Me 2 NCH 2 CH 2 -NMe 2 )] (X = Cl or OAc) with sodium 1-methylimidazole-2-selenolate gave selenolate complexes of the general formula [M(MeImSe) 2 ] (M = Zn or Cd). The complexes were characterized by elemental analysis, IR, UV-vis, NMR ( 1 H, 13 C, and 77 Se) data. The crystal structure of [Cd(OAc) 2 {(MeImSe) 2 }] was established by single-crystal X-ray diffraction. The cadmium atom adopts a distorted octahedral configuration defined by asymmetrically chelated acetate groups and chelating diselenide ligand. Thermal behavior of adducts was studied by thermogravimetric analysis. Pyrolysis in hexadecylamine/tri-n-octylphosphine oxide gave MSe quantum dots, which were characterized by UV-vis, photoluminescence, XRD, EDAX, SAED, and TEM.
Journal of Organometallic Chemistry, 2011
Reactions of [Pt2(μ-Cl)2(C8H12OMe)2] (1) (C8H12OMe = 8-methoxy-cyclooct-4-ene-1-yl) with various ... more Reactions of [Pt2(μ-Cl)2(C8H12OMe)2] (1) (C8H12OMe = 8-methoxy-cyclooct-4-ene-1-yl) with various anionic chalcogenolate ligands have been investigated. The reaction of 1 with Pb(Spy)2 (HSpy = pyridine-2-thiol) yielded a binuclear complex [Pt2(Spy)2(C8H12OMe)2] (2). A trinuclear complex [Pt3(Spy)4(C8H12OMe)2] (3) was isolated by a reaction between 2 and [Pt(Spy)2]n. The reaction of 1 with HSpy in the presence of NaOMe generated 2 and its demethylated oxo-bridged tetranuclear complex [Pt4(Spy)4(C8H12-O-C8H12)2] (4). Treatment of 1 with ammonium diisopropyldithiophosphate completely replaced C8H12OMe resulting in [Pt(S2P{OPri}2)2] (5), whereas non-rigid 5-membered chelating ligand, Me2NCH2CH2E−, produced mononuclear complexes [Pt(ECH2CH2NMe2)(C8H12OMe)] (E = S (6), Se (7)). These complexes have been characterized by elemental analyses, NMR (1H, 13C{1H}, 195Pt{1H}) and absorption spectroscopy. Molecular structures of 2, 3, 4, 5 and 7 were established by single crystal X-ray diffraction analyses. Thermolysis of 2, 6 and 7 in HDA gave platinum nanoparticles.The reaction of [Pt2(μ-Cl)2(C8H12OMe)2] (C8H12OMe = 8-methoxy-cyclooct-4-ene-1-yl) with anionic chalcogenolate ligands yields a variety of platinum complexes. A unique demethylated oxo-bridged tetranuclear complex [Pt4(Spy)4(C8H12-O-C8H12)2] has been isolated and structurally characterized. Thermolysis of these complexes in HDA gave platinum nanoparticles.► Pt(II) complexes with weak octenyl group and strong chalcogenolate ligand were synthesized and structurally characterized. ► A new oxo-bridged tetranuclear macrocyclic Pt(II) complex [Pt4(Spy)4(C8H12-O-C8H12)2] has been structurally characterized. ► Binuclear Pt(II) complexes with pyridine-2-thiolate ligand exist as two isomeric forms. ► Platinum complexes containing strong Pt–E (E = S or Se) bond after pyrolysis yield platinum nanoparticles rather than PtE.
…, 2012
PbTiO 3 nanotube arrays have been synthesized via sol-gel template method, and their morphology a... more PbTiO 3 nanotube arrays have been synthesized via sol-gel template method, and their morphology and structures have been determined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The diameter and length of these nanotubes are about 300 nm and 50 m, respectively, and their wall thickness is typically several tens of nanometers. XRD data shows that as-prepared PTO nanotubes possess perovskite structure, and electron diffraction demonstrates that they are polycrystalline. Photoluminescence spectrum of PTO nanotubes reveals an intense and wide emission band centered at 505 nm. Polarization-electric field (P-E) response curves of PTO nanotube array were measured, and the hysteresis loops illustrate a room temperature ferroelectric characteristic of as-prepared PTO nanotubes.
Journal of Chemical …, 2007
... Shamik Ghoshala, Amey Wadawalea, Vimal K. Jaina* and Munirathinam Nethajib aChemistry Divisio... more ... Shamik Ghoshala, Amey Wadawalea, Vimal K. Jaina* and Munirathinam Nethajib aChemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India bDepartment of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India ...
Inorganic Chemistry Communications, 2010
Monoselenocarboxylate–bridged binuclear complexes of RhIII and IrIII, [(Cp∗MCl)2(μ-SeCOAr)2] (1) ... more Monoselenocarboxylate–bridged binuclear complexes of RhIII and IrIII, [(Cp∗MCl)2(μ-SeCOAr)2] (1) (M = Rh or Ir; Cp∗ = pentamethylcyclopentadienyl; Ar = Ph, C6H4Me–4), have been isolated either by the reaction between [Cp∗2M2(μ-Cl)2Cl2] with KSeCOAr in acetonitrile or by treatment of [Cp∗MCl(solvent)2][PF6] with KSeCOAr in acetone. The novel binuclear complexes, [Cp∗IrCl(μ-SeCOAr)(κ2-SeCOC6H3R–)IrCp∗] (2) (R = H or Me-4) with ortho-metallation at one of the iridium centres have been isolated following the use of excess AgPF6. The single crystal structure of [Cp∗IrCl(μ-SeCOC6H5)(κ2-SeCOC6H4–)IrCp∗] (2a) exhibits two phenylcarboselenolate moieties situated in syn fashion with respect to the “Ir2Se2” plane, one of which leans towards the metal centre in order to undergo ortho-metallation after iridium–chlorine bond dissociation.Monoselenocarboxylate–bridged binuclear complexes of Rh(III) and Ir(III), [Cp∗2M2Cl2(μ-SeCOAr)2] (1) (M = Rh or Ir; Ar = Ph, C6H4Me-4) and [Cp∗IrCl(μ-SeCOC6H5)(κ2-SeCOC6H3R–)IrCp∗] (2) (R = H, Me) have been isolated and characterized. X-ray crystal structure of [Cp∗IrCl(μ-SeCOC6H5)(κ2-SeCOC6H4–)IrCp∗] (2a) revealed orthometallation at one of the iridium centre via iridium–chlorine bond dissociation.
Journal of Chemical …, 2010
Page 1. JOURNAL OF CHEMICAL RESEARCH 2010 RESEARCH PAPER 485 SEPTEMBER, 485488 Diorganogallium c... more Page 1. JOURNAL OF CHEMICAL RESEARCH 2010 RESEARCH PAPER 485 SEPTEMBER, 485488 Diorganogallium complexes containing tripodal Schiff bases: synthesis and structure of [N{Me2GaO(C6H4)CH=NCH2CH2-}3] ...
Journal of Organometallic Chemistry
The reactions of [MCl2(P∩P)] and [MCl2(PR3)2)] with 1-mercapto-2-phenyl-o-carborane/NaSeCboPh and... more The reactions of [MCl2(P∩P)] and [MCl2(PR3)2)] with 1-mercapto-2-phenyl-o-carborane/NaSeCboPh and 1,2-dimercapto-o-carborane yield mononuclear complexes of composition, [M(SCboPh)2(P∩P)], [M(SeCboPh)2(P∩P)] (M = Pd or Pt; P∩P = dppm (bis(diphenylphosphino)methane), dppe (1,2-bis(diphenylphosphino)ethane) or dppp (1,3-bis(diphenylphosphino)propane)) and [M(SCboS)(PR3)2] (2PR3 = dppm, dppe, 2PEt3, 2PMe2Ph, 2PMePh2 or 2PPh3). These complexes have been characterized by elemental analysis and NMR (1H, 31P, 77Se and 195Pt) spectroscopy. The 1J(Pt–P) values and 195Pt NMR chemical shifts are influenced by the nature of phosphine as well as thiolate ligand. Molecular structures of [Pt(SCboPh)2(dppm)], [Pt(SeCboPh)2(dppm)], [Pt(SCboS)(PMe2Ph)2] and [Pt(SCboS)(PMePh2)2] have been established by single crystal X-ray structural analyses. The platinum atom in all these complexes acquires a distorted square planar configuration defined by two cis-bound phosphine ligands and two chalcogenolate groups. The carborane rings are mutually anti in [Pt(SCboPh)2(dppm)] and [Pt(SeCboPh)2(dppm)].Cis-configured palladium and platinum complexes with chalcogeno o-carboranes have been isolated and characterized by NMR (1H, 31P, 77Se and 195Pt) spectroscopy and X-ray crystallography. The 1J(Pt–P) values and 195Pt NMR chemical shifts are influenced by the nature of phosphine as well as thiolate ligand.► Cis-configured mononuclear Pd/Pt chalcogenolate complexes have been isolated. ► The magnitude of 1J(Pt–P) is dependent on the nature of phosphine and thiolate ligand. ► The nature of phosphine and thiolate ligand influences the 195Pt NMR chemical shifts. ► The carboranes adopt a mutually anti-confirmation. ► The platinum atom in these complexes acquires a distorted square planar configuration.
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Journal of …, 2009
The reactions of [M2Cl2(μ-Cl)2(PMe2Ph)2] with mercapto-o-carboranes in the presence of pyridine a... more The reactions of [M2Cl2(μ-Cl)2(PMe2Ph)2] with mercapto-o-carboranes in the presence of pyridine afforded mono-nuclear complexes of composition, [MCl(SCb°R)(py)(PMe2Ph)] (M = Pd or Pt; Cb° = o-C2B10H10; R = H or Ph). The treatment of [PdCl2(PEt3)2] with PhCb°SH yielded trans-[Pd(SCb°Ph)2(PEt3)2] (4) which when left in solution in the presence of pyridine gave another substitution product, [Pd(SCb°Ph)2(py)(PEt3)] (5). The structures of [PdCl(SCb°Ph)(py)(PMe2Ph)] (1), [Pd(SCb°Ph)2(PEt3)2] (4) and [Pd(SCboPh)2(py)(PEt3)] (5) were established unambiguously by X-ray crystallography. The palladium atom in these complexes adopts a distorted square-planar configuration with neutral donor atoms occupying the trans positions. Thermolysis of [PdCl(SCb°)(py)(PMe2Ph)] (2) in TOPO (trioctylphosphine oxide) at 200 °C gave nanocrystals of TOPO capped Pd4S which were characterized by XRD pattern and SEM.The reactions of [M2Cl2(μ-Cl)2(PMe2Ph)2] with mercapto-o-carboranes in the presence of pyridine afforded mono-nuclear complexes of composition, [MCl(SCb°R)(py)(PMe2Ph)] (M = Pd or Pt; Cbo = o-C2B10H10; R = H or Ph) (1–3). The treatment of [PdCl2(PEt3)2] with PhCboSH yielded trans-[Pd(SCb°Ph)2(PEt3)2] (4) which when left in solution in the presence of pyridine gave another substitution product, [Pd(SCb°Ph)2(py)(PEt3)] (5). Thermolysis of [PdCl(SCb°)(py)(PMe2Ph)] (2) in TOPO (trioctylphosphine oxide) at 200 °C gave nanocrystals of TOPO capped Pd4S which were characterized by XRD pattern and SEM (scanning electron microscopy).
Inorganica Chimica …, 2011
Journal of …, 2012
A series of nicotinoyl based organoselenium compounds, [2-NC 5 H 3 (3-COOH)Se] 2 (1), [2-NC 5 H 3... more A series of nicotinoyl based organoselenium compounds, [2-NC 5 H 3 (3-COOH)Se] 2 (1), [2-NC 5 H 3 (3-CO)SeeSe] (2), [2-NC 5 H 3 (3-CONH 2 )Se] 2 (3), [2-NC 5 H 3 (3-CONHPh)Se] 2 (4), [2-NC 5 H 3 (3-CONHpyrimidine)Se] 2 (5), [2-NC 5 H 3 (3-CONHPh)SeBr] (6) and [2-NC 5 H 3 (3-CONHPh)SeI] have been synthesized and characterized by absorption, IR, NMR ( 1 H, 13 C{ 1 H}, 77 Se{ 1 H}) and mass spectrometry. The crystal structures of [2-NC 5 H 3 (3-CO) SeeSe] (2) and [2-NC 5 H 3 (3-CONHPh)Se] 2 (4) have been determined. The structure of (4) revealed the existence of two intra-molecular Se/X (X ¼ O and N) interactions, as a result of this, CeSeeSeeC torsion angle is unusually large (180 ). The GPx mimicking activity of these compounds has been evaluated using methods based on 1 H NMR spectroscopy and HPLC. Free radical scavenging ability of the compounds was examined by DPPH and deoxyribose assay. All these studies indicated that the compound (3) not only showed highest GPx activity but also has a very good free radical scavenging ability thus making it a novel structure for development of nicotine based antioxidants.
Inorganica Chimica …, 2010
Synthesis of a series of monoorganobismuth dithiocarboxylate complexes, [RBi(S 2 CAr) 2 ] (R = Me... more Synthesis of a series of monoorganobismuth dithiocarboxylate complexes, [RBi(S 2 CAr) 2 ] (R = Me, Ph, tol; Ar = Ph, tol), has been reported. They have been characterized by elemental analyses and spectroscopic methods. Molecular structures of [RBi(S 2 Ctol) 2 ] (R = Me or ...
X-ray Structure Analysis Online, 2009
Journal of Organometallic Chemistry, 2010
The reactions of PhCboSeNa (Cbo = o-C2B10H10), prepared by reductive cleavage of Se–Se bond in (P... more The reactions of PhCboSeNa (Cbo = o-C2B10H10), prepared by reductive cleavage of Se–Se bond in (PhCboSe)2 by NaBH4 in methanol, with Na2PdCl4, MCl2(PR3)2 and [M2Cl2(μ-Cl)2(PR3)2] afforded a variety of complexes, viz., [Pd(SeCboPh)Cl] (1), [M(SeCboPh)2(PR3)2], [M2Cl2(μ-SeCboPh)(μ-Cl)(PR3)2] (M = Pd, Pt) and [Pd2Cl(SeCb0Ph)(μ-Cl)(μ-SeCboPh)(PEt3)2] (7) have been isolated. These complexes were characterized by elemental analyses and NMR (1H, 31P, 77Se, 195Pt) spectroscopy. The structures of [Pd(SeCboPh)2(PEt3)2] (2), [Pt(SeCboPh)2(PMe2Ph)2] (3), [Pd2Cl2(μ-SeCboPh)(μ-Cl)(PMe2Ph)2] (5) and [Pd2Cl(SeCboPh)(μ-Cl)(μ-SeCboPh)(PEt3)2] (7) were established by X-ray crystallography. The latter represents the first example of asymmetric coordination of selenolate ligands in binuclear bis chalcogenolate complexes of palladium and platinum. Thermolysis of [Pd(SeCboPh)2(PEt3)2] (2) in HDA (hexadecylamine) at 330 °C gave nano-crystals of Pd17Se15.The reactions of PhCboSeNa (Cbo = o-C2B10H10), with Na2PdCl4, MCl2(PR3)2 and [M2Cl2(μ-Cl)2(PR3)2] afforded a variety of complexes, viz., [Pd(SeCboPh)Cl], [M(SeCboPh)2(PR3)2], [M2Cl2(μ-SeCboPh)(μ-Cl)(PR3)2] (M = Pd, Pt) and [Pd2Cl(SeCb0Ph)(μ-Cl)(μ-SeCboPh)(PEt3)2]. The latter represents the first example of asymmetric coordination of selenolate ligands in binuclear bis chalcogenolate complexes of palladium and platinum. Thermolysis of [Pd(SeCboPh)2(PEt3)2] in HDA (hexadecylamine) at 330 °C gave nano-crystals of Pd17Se15.
…, 2012
Oxidative addition reaction of dipyridyl ditellurides to [Pt 2 (dppm) 3 ] gave two types of compl... more Oxidative addition reaction of dipyridyl ditellurides to [Pt 2 (dppm) 3 ] gave two types of complexes, [Pt{2-Te-C 5 H 3 (3-R)N} 2 (dppm)]
Journal of Organometallic Chemistry, 2007
The reaction of triorgano-gallium and -indium etherate with heterocyclic carboxylic acids in benz... more The reaction of triorgano-gallium and -indium etherate with heterocyclic carboxylic acids in benzene at room temperature yields complexes of the type [R2M(L)]n(M = Ga or In; R = Me or Et; L = 2-(C5H4N)CO2, 2-(C4H3N2)CO2 or 2-(C9H6N)CO2). These complexes have been characterized by elemental analysis, IR, UV–vis, NMR (1H and 13C{1H}) and mass spectral data. Complexes with L = (C5H4N)CO2- and (C9H6N)CO2- showed photoluminescence on excitation with ∼250 or ∼310 nm radiation, respectively. Single crystal X-ray structural analysis of [Me2M(O2C–C5H4N-2)]2 (M = Ga or In), revealed a dimeric structure with five-coordinate metal atoms arising from the presence of two tridentate bridging picolinate ligands.The reaction of triorgano-gallium and -indium etherate with heterocyclic carboxylic acids in benzene at room temperature yields complexes of the type [R2M(L)]n(M = Ga or In; R = Me or Et; L = 2-(C5H4N)CO2, 2-(C4H3N2)CO2 or 2-(C9H6N)CO2). Single crystal X-ray structural analysis of [Me2M(O2C–C5H4N-2)]2 (M = Ga or In), revealed a dimeric structure with five-coordinate metal atoms arising from the presence of two tridentate bridging picolinate ligands.
Organic & …, 2011
A series of 2-(3,5-dimethylpyrazol-1-yl)ethylseleno derivatives has been synthesized. The glutath... more A series of 2-(3,5-dimethylpyrazol-1-yl)ethylseleno derivatives has been synthesized. The glutathione peroxidase like catalytic activity of these compounds has been studied in a model system, in which reduction of hydrogen peroxide with dithiothreitol (DTT red ), in the presence of an organoselenium compound was investigated by 1 H NMR spectroscopy. All these compounds exhibit GPx like catalytic activities and the catalytic reaction proceeds through a selenoxide intermediate, identified by 77 Se{ 1 H} NMR spectroscopy.
Inorganica Chimica Acta, 2010
Synthesis of a series of monoorganobismuth dithiocarboxylate complexes, [RBi(S2CAr)2] (R = Me, Ph... more Synthesis of a series of monoorganobismuth dithiocarboxylate complexes, [RBi(S2CAr)2] (R = Me, Ph, tol; Ar = Ph, tol), has been reported. They have been characterized by elemental analyses and spectroscopic methods. Molecular structures of [RBi(S2Ctol)2] (R = Me or Ph) have been established by single crystal X-ray diffraction studies. The bismuth atom in these complexes adopts a square pyramidal configuration with the R group at the apical position. In the solid state, these complexes show supra-molecular association devoid of Bi⋯S secondary interactions. Thermolysis of [RBi(S2Ctol)2] (R = Me or Ph) in refluxing diphenylether yielded Bi2S3 nanocrystals which were characterized by XRD, EDAX and SEM. The complex [PhBi(S2Ctol)2] has been employed for deposition of thin films of Bi2S3 by AACVD.A series of monoorganobismuth dithiocarboxylate complexes, [RBi(S2CAr)2] were synthesized and characterized. The bismuth atom in [MeBi(S2Ctol)2] and [PhBi(S2Ctol)2] adopts a square pyramidal configuration with the R group at the apical position and show supra-molecular association devoid of Bi⋯S secondary interactions. Nanocrystals and thin films of Bi2S3 were prepared from these complexes.
Journal of …, 2009
Sodium ethylselenolates with functional groups X (where X = –OH, –COOH, –COOMe and –COOEt) at β-c... more Sodium ethylselenolates with functional groups X (where X = –OH, –COOH, –COOMe and –COOEt) at β-carbon were prepared in situ by reductive cleavage of corresponding diselenide with NaBH4 either in methanol or aqueous ammonia. Treatment of these selenolates with [M2Cl2(μ–Cl)2(PR3′)2] (M = Pd or Pt; PR3′ = PMePh2, PnPr3) in different stoichiometry yielded various bi- and tri-nuclear complexes. The homoleptic hexanuclear complexes [Pd(μ–SeCH2CH2X)2]6 (X = OH, COOH, COOEt), were obtained by reacting Na2PdCl4 with NaSeCH2CH2X. All these complexes have been fully characterized. Molecular structures of ethylselenolates containing hydroxyl and carboxylic acid groups revealed solid state associated structures through inter-molecular hydrogen bond interactions. Trinuclear complex, [Pd3Cl2(μ–SeCH2CH2COOH)4(PnPr3)2] (3a), was disposed in a boat form unlike chair conformation observed for the corresponding methylester complex. The effect of β-functionality in ethylselenolate ligands towards reactivity, structures and thermal properties of palladium and platinum complexes has been extensively studied.A series of mono-, bi- and poly-nuclear palladium and platinum complexes have been synthesized by employing β-substituted ethylselenolate ligands. β-Substitution results in different nucleophilicity of ethylselenolate ligands which is reflected on reactivity, structures and thermal behavior of palladium and platinum complexes. Presence of protic groups in XCH2CH2Se− (X = OH, COOH) modified the solid state structures which exhibited functional group mediated aggregation via hydrogen-bonding.
Dalton …, 2011
The complexes, [Cu{EC 5 H 3 (R-3)N}] 4 (E/R = Se/Me or Te/R; R = H or Me) were isolated by the re... more The complexes, [Cu{EC 5 H 3 (R-3)N}] 4 (E/R = Se/Me or Te/R; R = H or Me) were isolated by the reaction between CuCl and NaEC 5 H 3 (R-3)N and were characterized by elemental analyses, uv-vis and NMR ( 1 H, 13 C) spectroscopy. The crystal structures of [Cu{SeC 5 H 3 (Me-3)N}] 4 and [Cu(TeC 5 H 4 N)] 4 revealed that the molecules are tetrameric in which each copper atom lies at the vertex of the tetrahedron and each face of the tetrahedron is capped by the bridging pyridylchalcogenolate ligand. Thermal behavior of these complexes was studied by thermogravimetric analysis. Depending on reaction conditions, thermolysis gave both stoichiometric and non-stoichiometric copper chalcogenides, which were characterized by XRD, EDX, SEM, TEM and SAED techniques. These precursors were used for the preparation of nanocrystals and for deposition of thin films of copper chalcogenides by AACVD (Aerosol Assisted Chemical Vapor Deposition).
Bulletin of The Chemical Society of Japan, 2008
Treatment of a methanolic solution of metal acetate with bis(1-methylimidazolyl)diselenide, [(MeI... more Treatment of a methanolic solution of metal acetate with bis(1-methylimidazolyl)diselenide, [(MeImSe) 2 ], yields complexes of composition [M(OAc) 2 {(MeImSe) 2 }] (M = Zn, Cd, or Hg) whereas reactions of [MX 2 (Me 2 NCH 2 CH 2 -NMe 2 )] (X = Cl or OAc) with sodium 1-methylimidazole-2-selenolate gave selenolate complexes of the general formula [M(MeImSe) 2 ] (M = Zn or Cd). The complexes were characterized by elemental analysis, IR, UV-vis, NMR ( 1 H, 13 C, and 77 Se) data. The crystal structure of [Cd(OAc) 2 {(MeImSe) 2 }] was established by single-crystal X-ray diffraction. The cadmium atom adopts a distorted octahedral configuration defined by asymmetrically chelated acetate groups and chelating diselenide ligand. Thermal behavior of adducts was studied by thermogravimetric analysis. Pyrolysis in hexadecylamine/tri-n-octylphosphine oxide gave MSe quantum dots, which were characterized by UV-vis, photoluminescence, XRD, EDAX, SAED, and TEM.