The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
Philomena P. Matear - One of the best experts on this subject based on the ideXlab platform.
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the preparation characterisation and subsequent reaction with sulfur diOxide of some triphenylArsine Oxide complexes of manganese ii salts
Inorganica Chimica Acta, 1993Co-Authors: Oraib Elsayrafi, Charles A. Mcauliffe, Philomena P. Matear, Stephen M Godfrey, Robin G PritchardAbstract:Abstract A number of manganese(II) complexes of the type Mn(OAsPh 3 ) n X 2 (X=Cl, Br, I, NCS; n =1, 2, 3 or 4) have been prepared and characterised, but the successful preparation of some of them has been found to be solvent dependent. For example, Mn(OAsPh 3 ) 2 I 2 may be synthesised in toluene or acetone, but Mn(OAsPh 3 ) 3 I 2 will not form in acetone and either ethyl acetate or toluene must be used. Also reported is the first crystallographically characterised manganese(II)/Arsine Oxide complex, Mn(OAsPh 3 ) 2 Cl 2 , which is found to have a pseudo-tetrahedral monomeric structure. A wide spectrum of reactivity towards sulfur diOxide of these complexes slurried in toluene was observed. Thus, for X=Cl, Br, NCS, or the mono ligand complexes only Mn(OAsPh 3 )Br 2 forms a 1:1 SO 2 adduct, whereas all the bis ligand complexes form 1:1 adducts, as does Mn(OAsPh 3 ) 3 (NCS) 2 . Mn(OAsPh 3 ) n I 2 ( n =2, 3) appear to undergo a complex redox reaction with SO 2 to produce materials containing sulfate and where the Ph 3 AsO has been reduced to Ph 3 As. From many of the filtrates from these reactions can be isolated the sulfuric acid derivative (Ph 3 AsOH)HSO 4 .
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Preparation, properties and reactions with sulfur diOxide in the solid state of complexes of the type [Mn(Ph2E(O)YE(O)Ph2)2(H2O)2](ClO4)2 (E=As, P; Y=C2H4, cis-C2H2). The formation of bis-sulfur diOxide complexes which contain both weakly bound and s
Inorganica Chimica Acta, 1992Co-Authors: Samual F. Banda, Oraib El-sayrafi, Charles A. Mcauliffe, Philomena P. MatearAbstract:Abstract Hexacoordinate manganese(II) perchlorate complexes containing diphosphine diOxide, diArsine diOxide or a mixed phosphine Oxide/Arsine Oxide ligand, [Mn(ligand) 2 (H 2 O) 2 ](ClO 4 ) 2 , react in the solid state with sulfur diOxide to form the [Mn(ligand) 2 (H 2 O) 2 (SO 2 ) 2 ](ClO 4 ) 2 adducts, as shown by weight increases. One sulfur diOxide molecule is readily lost on exposure to air, but the second is much more strongly held and is only lost on heating to 65–108 °C. Absorption isotherms have been obtained for the uptake of two molecules of sulfur diOxide by [Mn(dpaeO 2 ) 2 (H 2 O) 2 ](ClO 4 ) 2 and of one molecule of SO 2 by [Mn(dpaeO 2 ) 2 (H 2 O) 2 (SO 2 )](ClO 4 ) 2 (dpaeO 2 = Ph 2 P(O)CH 2 CH 2 As(O)Ph 2 ).
Iraimoudi S Ayene - One of the best experts on this subject based on the ideXlab platform.
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hydroxyethyl disulfide as an efficient metabolic assay for cell viability in vitro
Toxicology in Vitro, 2012Co-Authors: Jie Li, Donglan Zhang, Kathleen M Ward, George C Prendergast, Iraimoudi S AyeneAbstract:Abstract Cell viability assays have a variety of well known practical and technical limitations. All the available approaches have disadvantages, such as non-linearity, high background and cumbersome protocols. Several commonly used tetrazolium chemicals rely upon generation of a colored formazan product formed by mitochondrial reduction of these compounds via phenazine methosulfate (PMS). However, sensitivity is inherently limited because their reduction relies on mitochondrial bioreduction and cellular transport of PMS, as well as accessibility to tetrazolium chemicals. In this study, we identify hydroxethyldisulfide (HEDS) as an inexpensive probe that can measure cellular metabolic activity without the need of PMS. In tissue culture medium, HEDS accurately quantitated metabolically active live cells in a linear manner superior to tetrazolium based and other assays. Cell toxicity produced by chemotherapeutics (cisplatin, etoposide), oxidants (hydrogen perOxide, acetaminophen), toxins (phenyl Arsine Oxide, arsenite) or ionizing radiation was rapidly determined by the HEDS assay. We found that HEDS was superior to other commonly used assays for cell viability determinations in its solubility, membrane permeability, and intracellular conversion to a metabolic reporter that is readily transported into the extracellular medium. Our findings establish the use of HEDS in a simple, rapid and low cost assay to accurately quantify viable cells.
Masaaki Yoshifuji - One of the best experts on this subject based on the ideXlab platform.
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Oxidation of tris(2,4,6-triisopropylphenyl)phosphine and Arsine
Tetrahedron Letters, 2014Co-Authors: Shigeru Sasaki, Katsuhide Sutoh, Yusuke Shimizu, Kiyotoshi Kato, Masaaki YoshifujiAbstract:Abstract A reaction of the radical cation of tris(2,4,6-triisopropylphenyl)phosphine with oxygen gave a phosphonium salt resulting from the introduction of the oxygen atom to the phosphorus and the formation of a five membered ring by participation of the ortho isopropyl group. On the other hand, oxidation of the phosphine with mCPBA afforded the corresponding phosphine Oxide. X-ray crystallography showed that the C P C bond angles and the P C bond lengths of the phosphine Oxide are similar to those of the corresponding phosphine. The corresponding Arsine underwent analogous reactions to afford the arsonium salt and the Arsine Oxide.
Michael Webster - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and characterisation of tin(IV) fluoride complexes of phosphine and Arsine Oxide ligands
Polyhedron, 2006Co-Authors: Martin F. Davis, William Levason, Gillian Reid, Michael WebsterAbstract:The pseudooctahedral complexes [SnF4L2] (L = Ph3PO, Ph3AsO, Me3PO, Me3AsO) and [SnF4(L-L)] (L-L = Ph2P(O)CH2P(O)Ph-2, o-C6H4(P(O)Me-2)(2), o-C6H4(P(O)Ph-2)(2)) have been prepared from [SnF4(MeCN)(2)] and the appropriate ligand in dichloromethane solution. The complexes have been characterised by analysis, IR, H-1, P-31{H-1}, F-19{H-1} and Sn-119 NMR spectroscopy as appropriate; the NMR studies showing that the complexes of the monodentate ligands exist as mixtures of trans and cis isomers in solution. The crystal structures of trans-[SnF4(OPMe3)(2)], [SnF4{o-C6H4(P(O)Ph-2)(2)}] center dot CH2Cl2 center dot H2O and [o-C6H4(P(O)Ph-2)(2)] center dot CH2Cl2 have been determined. Comparison of the structural and NMR spectroscopic data of the tetrafluorotin complexes with those of related [SnX4L2] (X = Cl, Br or 1) shows that SnF4 is the strongest Lewis acid in the series towards hard Lewis bases.
Robin G Pritchard - One of the best experts on this subject based on the ideXlab platform.
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the preparation characterisation and subsequent reaction with sulfur diOxide of some triphenylArsine Oxide complexes of manganese ii salts
Inorganica Chimica Acta, 1993Co-Authors: Oraib Elsayrafi, Charles A. Mcauliffe, Philomena P. Matear, Stephen M Godfrey, Robin G PritchardAbstract:Abstract A number of manganese(II) complexes of the type Mn(OAsPh 3 ) n X 2 (X=Cl, Br, I, NCS; n =1, 2, 3 or 4) have been prepared and characterised, but the successful preparation of some of them has been found to be solvent dependent. For example, Mn(OAsPh 3 ) 2 I 2 may be synthesised in toluene or acetone, but Mn(OAsPh 3 ) 3 I 2 will not form in acetone and either ethyl acetate or toluene must be used. Also reported is the first crystallographically characterised manganese(II)/Arsine Oxide complex, Mn(OAsPh 3 ) 2 Cl 2 , which is found to have a pseudo-tetrahedral monomeric structure. A wide spectrum of reactivity towards sulfur diOxide of these complexes slurried in toluene was observed. Thus, for X=Cl, Br, NCS, or the mono ligand complexes only Mn(OAsPh 3 )Br 2 forms a 1:1 SO 2 adduct, whereas all the bis ligand complexes form 1:1 adducts, as does Mn(OAsPh 3 ) 3 (NCS) 2 . Mn(OAsPh 3 ) n I 2 ( n =2, 3) appear to undergo a complex redox reaction with SO 2 to produce materials containing sulfate and where the Ph 3 AsO has been reduced to Ph 3 As. From many of the filtrates from these reactions can be isolated the sulfuric acid derivative (Ph 3 AsOH)HSO 4 .