Prasad P. Phadnis

Tri(allyl)- and tri(methylallyl)arsine complexes of palladium(II) and platinum(II): synthesis, spectroscopy, photochemistry and structures

Tri(allyl)- and tri(methylallyl)arsine complexes of palladium(II) and platinum(II) with the formulae [MX2L2] (M=Pd, Pt and X=Cl, Br, I): [Pd2Cl2(μ-Cl)2L2], [PdCl(S2CNEt2)L] and [Pd2Cl2(μ-dmpz)2L2] [L=As(CH2CHCH2)3 (L′), As(CH2CMeCH2)3 (L″), dmpz=3,5-dimethylpyrazolate] have been prepared. All the complexes have been characterized by elemental analyses and by IR and NMR (1H, 13C, 195Pt) spectroscopy. The stereochemistry of the complexes has been deduced from the spectroscopic data. The molecular structures of complexes [MX2{As(CH2CHCH2)3}2] (M=Pd, X=Cl or Br), [MX2{As(CH2CMeCH2)3}2] (M=Pd, X=Cl or Br; M=Pt, X=Cl) and [Pd2Cl2(μ-Cl)2{As(CH2CMeCH2)3}2] have been established by single crystal X-ray diffraction analyses. The mononuclear complexes exclusively adopt the trans configuration with the exception of [PdCl2L″2], which could be isolated as cis and trans isomers. In the binuclear derivative the arsine ligands are attached to an envelope-shaped Pd–(μ-Cl)2–Pd rectangle with a trans (anti) orientation towards each other. The mononuclear complexes are slightly photoreactive upon irradiation in their long-wavelength absorption band.

Configurational selectivity in benzyldimethylarsine complexes of palladium(II) and platinum(II): synthesis, spectroscopy and structures

Benzyldimethylarsine complexes of palladium(II) and platinum(II) with the formulae [MX2(BzAsMe2)2 ]( X/Cl, Br, I), [M2Cl2(mCl)2(BzAsMe2)2], [Pd2Cl2(m-OAc)2(BzAsMe2)2], [Pd2Me2(m-Cl)2(BzAsMe2)2] and [Pd2X2(m-N ffl N)2(BzAsMe2)2 ]( M/Pd or Pt; N ffl N/pyrazolate (pz) or 3,5-dimethylpyrazolate (dmpz)) have been prepared. All complexes have been characterised by elemental analysis, IR, UV/Vis absorption and NMR ( 1 H, 13 C, 195 Pt) spectroscopy. The molecular structures of the complexes [MX2(BzAsMe2)2 ]( M/Pt or Pd; X/Cl, Br or I) have been established by NMR spectroscopy and single crystal X-ray diffraction analysis and reveal a clear dichotomy in solution and in the solid between the compounds with X/Cl in a cis configuration and the trans configured bromide and iodide complexes. # 2002 Elsevier Science B.V. All rights reserved.

Tripropylarsane Complexes of Palladium(II) and Platinum(II) — Syntheses, Spectroscopy, and Structures

Several palladium(II) and platinum(II) complexes of tripropylarsanes (AsR3; R = Pr, iPr) with the formulae, [MCl2(AsR3)2], [M2Cl2(μ-Cl)2(AsR3)2], [Pd2Me2(μ-Cl)2(AsR3)2], [Pd2X2(μ-Pz)2(AsR3)2] (X = Cl or Me, Pz = pyrazolate), [Pd2Cl2(μ-Y)2(AsR3)2] (Y = OAc or SPh), [MCl(S2CNEt2)(AsR3)] and [PdCp(Cl)(AsiPr3)] (M = Pd or Pt) have been prepared. All the complexes have been characterised by elemental analyses, IR and 1H NMR spectroscopy. The stereochemistry of the complexes has been deduced from the spectroscopic data. The structures of [Pd2Me2(μ-X)2(AsiPr3)2] (X = Cl or Pz) have been established by single crystal X-ray diffraction analyses. Both of the complexes have sym-trans configuration. Strong trans influence of the methyl group is reflected on the Pd—X bond distances. Tripropylarsan-Komplexe von Palladium(II) und Platin(II) — Synthesen, Spektroskopie und Strukturen Eine Reihe von Komplexen des Palladium(II) und Platin(II) mit den Tripropylarsanen AsR3 (R = Pr, iPr) in den Zusammensetzungen [MCl2(AsR3)2], [M2Cl2(μ-Cl)2(AsR3)2], [Pd2Me2(μ-Cl)2(AsR3)2], [Pd2X2(μ-Pz)2(AsR3)2] (X = Cl oder Me, Pz = Pyrazolat), [Pd2Cl2(μ-Y)2(AsR3)2] (Y = OAc oder SPh), [MCl(S2CNEt2)(AsR3)] und [PdCp(Cl)(AsiPr3)] (M = Pd oder Pt) wurde hergestellt und elementaranalytisch sowie IR- und 1H-NMR-spektroskopisch charakterisiert. Die Stereochemie der Komplexe konnte den spektroskopischen Daten entnommen werden. Die Strukturen von [Pd2Me2(μ-X)2(AsiPr3)2] (X = Cl oder Pz) wurden kristallstrukturanalytisch bestimmt. Beide Komplexe weisen eine sym-trans-Konfiguration auf. Der starke trans-Einflus der Methylgruppen spiegelt sich in den Pd-X-Bindungslangen wider.

Synthesis, Characterization, and X-Ray Structures of 2-(3,5-Dimethylpyrazol-1-Yl)Phenyl-Based Organoselenium Compounds and Their Glutathione Peroxidase (Gpx) Like Activity

Abstract The synthesis of a series of 2-(3,5-dimethylpyrazol-1-yl)phenyl-based organoselenium compounds, (dmpzC6H4Se)2 (1), dmpzC6H4SeR (dmpz = 3,5-dimethylpyrazol-1-yl; R = (CH2)nY; Y = OH, NH2, and COOH), and dmpzC6H4SeX (X = Cl, Br, or I) is described. The compounds are characterized by IR, NMR (1H, 13C{1H}, 77Se{1H}), and mass spectral (MS) data. The molecular structures of (dmpzC6H4Se)2, dmpzC6H4SeCH2COOH, and dmpzC6H4SeCH2CH2OH have been established by X-ray crystallography. The two latter compounds are associated in the solid state through intermolecular hydrogen bonding between the OH proton and the pyrazolyl nitrogen atom of the adjacent molecule. Glutathione peroxidase (GPx) like catalytic activity of these compounds has been evaluated by using hydrogen peroxide (H2O2) as substrate and dithiothreitol (DTTred) as thiol cofactor in CD3OD, and the progress of the reaction was monitored by 1H NMR spectroscopy. All the compounds exhibited the GPx-like catalytic activity. Among these, the ones containing alkylamino groups showed the best activity. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT

Synthesis, Characterization, and Structures of α-Substituted Selenenyl-Acetophenones

Abstract A series of α-substituted selenenyl acetophenone derivatives of the types, [PhC(OCH2CH2O)CH2Se]2, [PhC(OCH2CH2O)CH2SeR], (PhCOCH2Se)2, and [PhCOCH2SeR] have been prepared. These compounds have been characterized by elemental analyses, IR and NMR (1H, 13C, 77Se) spectroscopy. The compounds, [PhC(OCH2CH2)CH2Se]2 and (PhCOCH2Se)2 have been structurally characterized by single crystal X-ray diffraction analyses. The former shows intra-molecular Se‐ ‐ ‐O interaction, while the latter exhibits inter-molecular nonbonding Se‐ ‐ ‐O interaction. [Supplementary materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text and figures.] GRAPHICAL ABSTRACT