The Experts below are selected from a list of 45 Experts worldwide ranked by ideXlab platform

Michael Webster - One of the best experts on this subject based on the ideXlab platform.

  • Yttrium halide complexes of phosphine- and Arsine Oxides: synthesis, multinuclear NMR and structural studies
    Polyhedron, 2002
    Co-Authors: Nicholas J. Hill, William Levason, Michael C Popham, Gillian Reid, Michael Webster
    Abstract:

    The reactions of YCl3.6H(2)O, YBr3.6H(2)O and YI3.8H(2)O with Ph3PO, Ph3AsO, Ph2MePO, Me3PO, Me3AsO, o-C6H4{P(O)Ph-2}(2), (ppO(2)) and Ph2P(O)CH2P(O)Ph-2 (dppmO(2)) have been examined in EtOH or Me2CO solution. Complexes isolated in the solid state include [YX2(Ph3PO)(4)]Z (X = Cl, Br or I; Z = X or PF6), [YX3(Ph2MePO)(3)], [YCl2(Ph2MePO)(4)]PF6, [YCl(Ph3PO)(5)][SbCl6](2), [Y(Me3PO)(6)]X-3, [YX2(Ph3AsO)(4)]X, [Y(Me3AsO)(6)]Cl-3 and [YCl2(L-L)(2)]Cl (L-L = ppO(2) or dppmO(2)) which were characterised by analysis, IR and multinuclear (H-1, P-31{H-1} and Y-89) NMR spectroscopy and conductance measurements. The X-ray crystal structures of [YCl2(Ph3PO)(4)]Cl.2.5EtOH.H2O, [YBr2(Ph3PO)(4)]PF6.Et2O and [Y(Me3PO)(6)]Br-3 are reported and discussed. The solution speciation (in CH2Cl2) in the various systems was examined by variable temperature multinuclear NMR spectroscopy. The Y-89 NMR chemical shifts show systematic trends with donor set which are described. No reaction between these ligands and YF3.1/2H(2)O was observed.

  • Scandium halide complexes of phosphine- and Arsine-Oxides: synthesis, structures and 45Sc NMR studies
    Polyhedron, 2002
    Co-Authors: Nicholas J. Hill, William Levason, Michael C Popham, Gillian Reid, Michael Webster
    Abstract:

    The reactions of ScCl(3)(.)6H(2)O, ScBr(3)(.)6H(2)O and Scl(3)(.)8H(2)O with Ph3PO, Ph3AsO, Ph2MePO, Me3PO and Me3AsO have been examined in EtOH or Me2CO solution. The new complexes [ScCl(Me3PO)(5)]Cl-2, [Sc(Me3PO)(6)]X-3 (X = Br or 1), [ScX,(Ph3PO)4]X (X = Cl, Br or 1), [ScX2(Ph3AsO)(4)]X, [Sc(Me3AsO)(6)]X-3 (X = Cl, Br or 1), [ScCl3(Ph2MePO)(3)] and [ScBr2(PhMePO)(4)]Br were isolated as solids and were characterised by analysis, IR and multinuclear (H-1, P-31{H}: and Sc-45) NMR spectroscopy and conductance measurements. The crystal structures of [ScBr2(Ph3PO)(4)]Br(.)1/2Et(2)O, [ScCl2(Ph3AsO)(4)]Cl and [Sc(Me3AsO)(6)]Br-3 are also reported. The solution speciation (in CH2Cl2 or MeNO2) in the various systems was examined by multinuclear NMR spectroscopy. The Sc-45 NMR chemical shifts and line widths show systematic trends with donor set and symmetry. which are described. No reaction between these ligands and ScF3.1/2H(2)O was observed.

  • scandium yttrium and lanthanum nitrate complexes of tertiary Arsine Oxides synthesis and multinuclear spectroscopic studies x ray structures of m me3aso 6 no3 3 m sc or y sc ph3aso 3 no3 2 no3 m ph3aso 4 no3 2 no3 m y or la and la ph3aso 2 etoh no3 3
    Polyhedron, 2001
    Co-Authors: William Levason, Michael C Popham, Gillian Reid, Bhavesh Patel, Michael Webster
    Abstract:

    The reaction of Ph3AsO with Sc(NO3)(3). 5H(2)O, Y(NO3)(3). 6H(2)O or La(NO3)(3). 6H(2)O in acetone gave [Sc(Ph3AsO)(2)(NO3)(3)], [Y(Ph3AsO)(4)(NO3)(2)]NO3, [La(Ph3AsO)(4)(NO3)(2)]NO3, and [La(Ph3AsO)(3)(NO3)(3)], whilst from ethanol solution [Sc(Ph3AsO)(3)(NO3)(2)]NO3, [Y(Ph3AsO)(2)(EtOH)(NO3)(3)] and [La(Ph3AsO)(2)(EtOH)(NO3)(3)] were produced. Similar reactions using Me3AsO produced [M(Me3AsO)(6)](NO3)(3) (M = SC, Y or La) and [La(Me3AsO)(2)(H2O)(NO3)(3)]. All complexes were characterised by analysis, IR and H-1, Sc-45 or Y-89 NMR spectroscopy, and conductance measurements. The solution speciation and interconversions of the Sc and Y complexes have been probed by Sc-45 and Y-89 NMR spectroscopy. X-Ray crystal structures are reported for the 6-coordinate [M(Me3AsO)(6)](NO3)(3) (M = Sc or Y), seven-coordinate [Sc(Ph3AsO)(3)(NO3)(2)]NO3, eight-coordinate [M"(Ph3AsO)(4)(NO3)(2)]NO3 (M" = Y or La), and nine-coordinate [La(Ph3AsO)(2)(EtOH)(NO3)(3)].

William Levason - One of the best experts on this subject based on the ideXlab platform.

  • Yttrium halide complexes of phosphine- and Arsine Oxides: synthesis, multinuclear NMR and structural studies
    Polyhedron, 2002
    Co-Authors: Nicholas J. Hill, William Levason, Michael C Popham, Gillian Reid, Michael Webster
    Abstract:

    The reactions of YCl3.6H(2)O, YBr3.6H(2)O and YI3.8H(2)O with Ph3PO, Ph3AsO, Ph2MePO, Me3PO, Me3AsO, o-C6H4{P(O)Ph-2}(2), (ppO(2)) and Ph2P(O)CH2P(O)Ph-2 (dppmO(2)) have been examined in EtOH or Me2CO solution. Complexes isolated in the solid state include [YX2(Ph3PO)(4)]Z (X = Cl, Br or I; Z = X or PF6), [YX3(Ph2MePO)(3)], [YCl2(Ph2MePO)(4)]PF6, [YCl(Ph3PO)(5)][SbCl6](2), [Y(Me3PO)(6)]X-3, [YX2(Ph3AsO)(4)]X, [Y(Me3AsO)(6)]Cl-3 and [YCl2(L-L)(2)]Cl (L-L = ppO(2) or dppmO(2)) which were characterised by analysis, IR and multinuclear (H-1, P-31{H-1} and Y-89) NMR spectroscopy and conductance measurements. The X-ray crystal structures of [YCl2(Ph3PO)(4)]Cl.2.5EtOH.H2O, [YBr2(Ph3PO)(4)]PF6.Et2O and [Y(Me3PO)(6)]Br-3 are reported and discussed. The solution speciation (in CH2Cl2) in the various systems was examined by variable temperature multinuclear NMR spectroscopy. The Y-89 NMR chemical shifts show systematic trends with donor set which are described. No reaction between these ligands and YF3.1/2H(2)O was observed.

  • Scandium halide complexes of phosphine- and Arsine-Oxides: synthesis, structures and 45Sc NMR studies
    Polyhedron, 2002
    Co-Authors: Nicholas J. Hill, William Levason, Michael C Popham, Gillian Reid, Michael Webster
    Abstract:

    The reactions of ScCl(3)(.)6H(2)O, ScBr(3)(.)6H(2)O and Scl(3)(.)8H(2)O with Ph3PO, Ph3AsO, Ph2MePO, Me3PO and Me3AsO have been examined in EtOH or Me2CO solution. The new complexes [ScCl(Me3PO)(5)]Cl-2, [Sc(Me3PO)(6)]X-3 (X = Br or 1), [ScX,(Ph3PO)4]X (X = Cl, Br or 1), [ScX2(Ph3AsO)(4)]X, [Sc(Me3AsO)(6)]X-3 (X = Cl, Br or 1), [ScCl3(Ph2MePO)(3)] and [ScBr2(PhMePO)(4)]Br were isolated as solids and were characterised by analysis, IR and multinuclear (H-1, P-31{H}: and Sc-45) NMR spectroscopy and conductance measurements. The crystal structures of [ScBr2(Ph3PO)(4)]Br(.)1/2Et(2)O, [ScCl2(Ph3AsO)(4)]Cl and [Sc(Me3AsO)(6)]Br-3 are also reported. The solution speciation (in CH2Cl2 or MeNO2) in the various systems was examined by multinuclear NMR spectroscopy. The Sc-45 NMR chemical shifts and line widths show systematic trends with donor set and symmetry. which are described. No reaction between these ligands and ScF3.1/2H(2)O was observed.

  • scandium yttrium and lanthanum nitrate complexes of tertiary Arsine Oxides synthesis and multinuclear spectroscopic studies x ray structures of m me3aso 6 no3 3 m sc or y sc ph3aso 3 no3 2 no3 m ph3aso 4 no3 2 no3 m y or la and la ph3aso 2 etoh no3 3
    Polyhedron, 2001
    Co-Authors: William Levason, Michael C Popham, Gillian Reid, Bhavesh Patel, Michael Webster
    Abstract:

    The reaction of Ph3AsO with Sc(NO3)(3). 5H(2)O, Y(NO3)(3). 6H(2)O or La(NO3)(3). 6H(2)O in acetone gave [Sc(Ph3AsO)(2)(NO3)(3)], [Y(Ph3AsO)(4)(NO3)(2)]NO3, [La(Ph3AsO)(4)(NO3)(2)]NO3, and [La(Ph3AsO)(3)(NO3)(3)], whilst from ethanol solution [Sc(Ph3AsO)(3)(NO3)(2)]NO3, [Y(Ph3AsO)(2)(EtOH)(NO3)(3)] and [La(Ph3AsO)(2)(EtOH)(NO3)(3)] were produced. Similar reactions using Me3AsO produced [M(Me3AsO)(6)](NO3)(3) (M = SC, Y or La) and [La(Me3AsO)(2)(H2O)(NO3)(3)]. All complexes were characterised by analysis, IR and H-1, Sc-45 or Y-89 NMR spectroscopy, and conductance measurements. The solution speciation and interconversions of the Sc and Y complexes have been probed by Sc-45 and Y-89 NMR spectroscopy. X-Ray crystal structures are reported for the 6-coordinate [M(Me3AsO)(6)](NO3)(3) (M = Sc or Y), seven-coordinate [Sc(Ph3AsO)(3)(NO3)(2)]NO3, eight-coordinate [M"(Ph3AsO)(4)(NO3)(2)]NO3 (M" = Y or La), and nine-coordinate [La(Ph3AsO)(2)(EtOH)(NO3)(3)].

Gillian Reid - One of the best experts on this subject based on the ideXlab platform.

  • Yttrium halide complexes of phosphine- and Arsine Oxides: synthesis, multinuclear NMR and structural studies
    Polyhedron, 2002
    Co-Authors: Nicholas J. Hill, William Levason, Michael C Popham, Gillian Reid, Michael Webster
    Abstract:

    The reactions of YCl3.6H(2)O, YBr3.6H(2)O and YI3.8H(2)O with Ph3PO, Ph3AsO, Ph2MePO, Me3PO, Me3AsO, o-C6H4{P(O)Ph-2}(2), (ppO(2)) and Ph2P(O)CH2P(O)Ph-2 (dppmO(2)) have been examined in EtOH or Me2CO solution. Complexes isolated in the solid state include [YX2(Ph3PO)(4)]Z (X = Cl, Br or I; Z = X or PF6), [YX3(Ph2MePO)(3)], [YCl2(Ph2MePO)(4)]PF6, [YCl(Ph3PO)(5)][SbCl6](2), [Y(Me3PO)(6)]X-3, [YX2(Ph3AsO)(4)]X, [Y(Me3AsO)(6)]Cl-3 and [YCl2(L-L)(2)]Cl (L-L = ppO(2) or dppmO(2)) which were characterised by analysis, IR and multinuclear (H-1, P-31{H-1} and Y-89) NMR spectroscopy and conductance measurements. The X-ray crystal structures of [YCl2(Ph3PO)(4)]Cl.2.5EtOH.H2O, [YBr2(Ph3PO)(4)]PF6.Et2O and [Y(Me3PO)(6)]Br-3 are reported and discussed. The solution speciation (in CH2Cl2) in the various systems was examined by variable temperature multinuclear NMR spectroscopy. The Y-89 NMR chemical shifts show systematic trends with donor set which are described. No reaction between these ligands and YF3.1/2H(2)O was observed.

  • Scandium halide complexes of phosphine- and Arsine-Oxides: synthesis, structures and 45Sc NMR studies
    Polyhedron, 2002
    Co-Authors: Nicholas J. Hill, William Levason, Michael C Popham, Gillian Reid, Michael Webster
    Abstract:

    The reactions of ScCl(3)(.)6H(2)O, ScBr(3)(.)6H(2)O and Scl(3)(.)8H(2)O with Ph3PO, Ph3AsO, Ph2MePO, Me3PO and Me3AsO have been examined in EtOH or Me2CO solution. The new complexes [ScCl(Me3PO)(5)]Cl-2, [Sc(Me3PO)(6)]X-3 (X = Br or 1), [ScX,(Ph3PO)4]X (X = Cl, Br or 1), [ScX2(Ph3AsO)(4)]X, [Sc(Me3AsO)(6)]X-3 (X = Cl, Br or 1), [ScCl3(Ph2MePO)(3)] and [ScBr2(PhMePO)(4)]Br were isolated as solids and were characterised by analysis, IR and multinuclear (H-1, P-31{H}: and Sc-45) NMR spectroscopy and conductance measurements. The crystal structures of [ScBr2(Ph3PO)(4)]Br(.)1/2Et(2)O, [ScCl2(Ph3AsO)(4)]Cl and [Sc(Me3AsO)(6)]Br-3 are also reported. The solution speciation (in CH2Cl2 or MeNO2) in the various systems was examined by multinuclear NMR spectroscopy. The Sc-45 NMR chemical shifts and line widths show systematic trends with donor set and symmetry. which are described. No reaction between these ligands and ScF3.1/2H(2)O was observed.

  • scandium yttrium and lanthanum nitrate complexes of tertiary Arsine Oxides synthesis and multinuclear spectroscopic studies x ray structures of m me3aso 6 no3 3 m sc or y sc ph3aso 3 no3 2 no3 m ph3aso 4 no3 2 no3 m y or la and la ph3aso 2 etoh no3 3
    Polyhedron, 2001
    Co-Authors: William Levason, Michael C Popham, Gillian Reid, Bhavesh Patel, Michael Webster
    Abstract:

    The reaction of Ph3AsO with Sc(NO3)(3). 5H(2)O, Y(NO3)(3). 6H(2)O or La(NO3)(3). 6H(2)O in acetone gave [Sc(Ph3AsO)(2)(NO3)(3)], [Y(Ph3AsO)(4)(NO3)(2)]NO3, [La(Ph3AsO)(4)(NO3)(2)]NO3, and [La(Ph3AsO)(3)(NO3)(3)], whilst from ethanol solution [Sc(Ph3AsO)(3)(NO3)(2)]NO3, [Y(Ph3AsO)(2)(EtOH)(NO3)(3)] and [La(Ph3AsO)(2)(EtOH)(NO3)(3)] were produced. Similar reactions using Me3AsO produced [M(Me3AsO)(6)](NO3)(3) (M = SC, Y or La) and [La(Me3AsO)(2)(H2O)(NO3)(3)]. All complexes were characterised by analysis, IR and H-1, Sc-45 or Y-89 NMR spectroscopy, and conductance measurements. The solution speciation and interconversions of the Sc and Y complexes have been probed by Sc-45 and Y-89 NMR spectroscopy. X-Ray crystal structures are reported for the 6-coordinate [M(Me3AsO)(6)](NO3)(3) (M = Sc or Y), seven-coordinate [Sc(Ph3AsO)(3)(NO3)(2)]NO3, eight-coordinate [M"(Ph3AsO)(4)(NO3)(2)]NO3 (M" = Y or La), and nine-coordinate [La(Ph3AsO)(2)(EtOH)(NO3)(3)].

Michael C Popham - One of the best experts on this subject based on the ideXlab platform.

  • Yttrium halide complexes of phosphine- and Arsine Oxides: synthesis, multinuclear NMR and structural studies
    Polyhedron, 2002
    Co-Authors: Nicholas J. Hill, William Levason, Michael C Popham, Gillian Reid, Michael Webster
    Abstract:

    The reactions of YCl3.6H(2)O, YBr3.6H(2)O and YI3.8H(2)O with Ph3PO, Ph3AsO, Ph2MePO, Me3PO, Me3AsO, o-C6H4{P(O)Ph-2}(2), (ppO(2)) and Ph2P(O)CH2P(O)Ph-2 (dppmO(2)) have been examined in EtOH or Me2CO solution. Complexes isolated in the solid state include [YX2(Ph3PO)(4)]Z (X = Cl, Br or I; Z = X or PF6), [YX3(Ph2MePO)(3)], [YCl2(Ph2MePO)(4)]PF6, [YCl(Ph3PO)(5)][SbCl6](2), [Y(Me3PO)(6)]X-3, [YX2(Ph3AsO)(4)]X, [Y(Me3AsO)(6)]Cl-3 and [YCl2(L-L)(2)]Cl (L-L = ppO(2) or dppmO(2)) which were characterised by analysis, IR and multinuclear (H-1, P-31{H-1} and Y-89) NMR spectroscopy and conductance measurements. The X-ray crystal structures of [YCl2(Ph3PO)(4)]Cl.2.5EtOH.H2O, [YBr2(Ph3PO)(4)]PF6.Et2O and [Y(Me3PO)(6)]Br-3 are reported and discussed. The solution speciation (in CH2Cl2) in the various systems was examined by variable temperature multinuclear NMR spectroscopy. The Y-89 NMR chemical shifts show systematic trends with donor set which are described. No reaction between these ligands and YF3.1/2H(2)O was observed.

  • Scandium halide complexes of phosphine- and Arsine-Oxides: synthesis, structures and 45Sc NMR studies
    Polyhedron, 2002
    Co-Authors: Nicholas J. Hill, William Levason, Michael C Popham, Gillian Reid, Michael Webster
    Abstract:

    The reactions of ScCl(3)(.)6H(2)O, ScBr(3)(.)6H(2)O and Scl(3)(.)8H(2)O with Ph3PO, Ph3AsO, Ph2MePO, Me3PO and Me3AsO have been examined in EtOH or Me2CO solution. The new complexes [ScCl(Me3PO)(5)]Cl-2, [Sc(Me3PO)(6)]X-3 (X = Br or 1), [ScX,(Ph3PO)4]X (X = Cl, Br or 1), [ScX2(Ph3AsO)(4)]X, [Sc(Me3AsO)(6)]X-3 (X = Cl, Br or 1), [ScCl3(Ph2MePO)(3)] and [ScBr2(PhMePO)(4)]Br were isolated as solids and were characterised by analysis, IR and multinuclear (H-1, P-31{H}: and Sc-45) NMR spectroscopy and conductance measurements. The crystal structures of [ScBr2(Ph3PO)(4)]Br(.)1/2Et(2)O, [ScCl2(Ph3AsO)(4)]Cl and [Sc(Me3AsO)(6)]Br-3 are also reported. The solution speciation (in CH2Cl2 or MeNO2) in the various systems was examined by multinuclear NMR spectroscopy. The Sc-45 NMR chemical shifts and line widths show systematic trends with donor set and symmetry. which are described. No reaction between these ligands and ScF3.1/2H(2)O was observed.

  • scandium yttrium and lanthanum nitrate complexes of tertiary Arsine Oxides synthesis and multinuclear spectroscopic studies x ray structures of m me3aso 6 no3 3 m sc or y sc ph3aso 3 no3 2 no3 m ph3aso 4 no3 2 no3 m y or la and la ph3aso 2 etoh no3 3
    Polyhedron, 2001
    Co-Authors: William Levason, Michael C Popham, Gillian Reid, Bhavesh Patel, Michael Webster
    Abstract:

    The reaction of Ph3AsO with Sc(NO3)(3). 5H(2)O, Y(NO3)(3). 6H(2)O or La(NO3)(3). 6H(2)O in acetone gave [Sc(Ph3AsO)(2)(NO3)(3)], [Y(Ph3AsO)(4)(NO3)(2)]NO3, [La(Ph3AsO)(4)(NO3)(2)]NO3, and [La(Ph3AsO)(3)(NO3)(3)], whilst from ethanol solution [Sc(Ph3AsO)(3)(NO3)(2)]NO3, [Y(Ph3AsO)(2)(EtOH)(NO3)(3)] and [La(Ph3AsO)(2)(EtOH)(NO3)(3)] were produced. Similar reactions using Me3AsO produced [M(Me3AsO)(6)](NO3)(3) (M = SC, Y or La) and [La(Me3AsO)(2)(H2O)(NO3)(3)]. All complexes were characterised by analysis, IR and H-1, Sc-45 or Y-89 NMR spectroscopy, and conductance measurements. The solution speciation and interconversions of the Sc and Y complexes have been probed by Sc-45 and Y-89 NMR spectroscopy. X-Ray crystal structures are reported for the 6-coordinate [M(Me3AsO)(6)](NO3)(3) (M = Sc or Y), seven-coordinate [Sc(Ph3AsO)(3)(NO3)(2)]NO3, eight-coordinate [M"(Ph3AsO)(4)(NO3)(2)]NO3 (M" = Y or La), and nine-coordinate [La(Ph3AsO)(2)(EtOH)(NO3)(3)].

Nicholas J. Hill - One of the best experts on this subject based on the ideXlab platform.

  • Yttrium halide complexes of phosphine- and Arsine Oxides: synthesis, multinuclear NMR and structural studies
    Polyhedron, 2002
    Co-Authors: Nicholas J. Hill, William Levason, Michael C Popham, Gillian Reid, Michael Webster
    Abstract:

    The reactions of YCl3.6H(2)O, YBr3.6H(2)O and YI3.8H(2)O with Ph3PO, Ph3AsO, Ph2MePO, Me3PO, Me3AsO, o-C6H4{P(O)Ph-2}(2), (ppO(2)) and Ph2P(O)CH2P(O)Ph-2 (dppmO(2)) have been examined in EtOH or Me2CO solution. Complexes isolated in the solid state include [YX2(Ph3PO)(4)]Z (X = Cl, Br or I; Z = X or PF6), [YX3(Ph2MePO)(3)], [YCl2(Ph2MePO)(4)]PF6, [YCl(Ph3PO)(5)][SbCl6](2), [Y(Me3PO)(6)]X-3, [YX2(Ph3AsO)(4)]X, [Y(Me3AsO)(6)]Cl-3 and [YCl2(L-L)(2)]Cl (L-L = ppO(2) or dppmO(2)) which were characterised by analysis, IR and multinuclear (H-1, P-31{H-1} and Y-89) NMR spectroscopy and conductance measurements. The X-ray crystal structures of [YCl2(Ph3PO)(4)]Cl.2.5EtOH.H2O, [YBr2(Ph3PO)(4)]PF6.Et2O and [Y(Me3PO)(6)]Br-3 are reported and discussed. The solution speciation (in CH2Cl2) in the various systems was examined by variable temperature multinuclear NMR spectroscopy. The Y-89 NMR chemical shifts show systematic trends with donor set which are described. No reaction between these ligands and YF3.1/2H(2)O was observed.

  • Scandium halide complexes of phosphine- and Arsine-Oxides: synthesis, structures and 45Sc NMR studies
    Polyhedron, 2002
    Co-Authors: Nicholas J. Hill, William Levason, Michael C Popham, Gillian Reid, Michael Webster
    Abstract:

    The reactions of ScCl(3)(.)6H(2)O, ScBr(3)(.)6H(2)O and Scl(3)(.)8H(2)O with Ph3PO, Ph3AsO, Ph2MePO, Me3PO and Me3AsO have been examined in EtOH or Me2CO solution. The new complexes [ScCl(Me3PO)(5)]Cl-2, [Sc(Me3PO)(6)]X-3 (X = Br or 1), [ScX,(Ph3PO)4]X (X = Cl, Br or 1), [ScX2(Ph3AsO)(4)]X, [Sc(Me3AsO)(6)]X-3 (X = Cl, Br or 1), [ScCl3(Ph2MePO)(3)] and [ScBr2(PhMePO)(4)]Br were isolated as solids and were characterised by analysis, IR and multinuclear (H-1, P-31{H}: and Sc-45) NMR spectroscopy and conductance measurements. The crystal structures of [ScBr2(Ph3PO)(4)]Br(.)1/2Et(2)O, [ScCl2(Ph3AsO)(4)]Cl and [Sc(Me3AsO)(6)]Br-3 are also reported. The solution speciation (in CH2Cl2 or MeNO2) in the various systems was examined by multinuclear NMR spectroscopy. The Sc-45 NMR chemical shifts and line widths show systematic trends with donor set and symmetry. which are described. No reaction between these ligands and ScF3.1/2H(2)O was observed.