4 research outputs found
Activation of Dioxygen by Dimethylplatinum(II) Complexes
No full textThe
ligands RN(CH<sub>2</sub>-2-C<sub>5</sub>H<sub>4</sub>N)<sub>2</sub> (<b>L1</b>, R = CH<sub>2</sub>CH<sub>2</sub>OH; <b>L2</b>, R = CH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>OH; <b>L3</b>, R = 2-C<sub>6</sub>H<sub>4</sub>OH) have been designed to give
dimethylplatinum(II) complexes that can activate dioxygen in the absence
of a protic solvent. The ligands react with [Pt<sub>2</sub>Me<sub>4</sub>(SMe<sub>2</sub>)<sub>2</sub>] to give an equilibrium mixture,
with the major constituent being [PtMe<sub>2</sub>(κ<sup>2</sup>-N,N′-<b>L</b>)] (<b>1a</b>, <b>L</b> = <b>L1</b>; <b>1b</b>, <b>L</b> = <b>L2</b>; <b>1c</b>, <b>L</b> = <b>L3</b>). In the absence of air, <b>1a</b> reacts with solvent CH<sub>2</sub>Cl<sub>2</sub> to give
[PtMe<sub>2</sub>(CH<sub>2</sub>Cl)(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>N</i>″-<b>L1</b>]Cl, while <b>1c</b> decomposes with loss of methane to give
[PtMe(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>N</i>″-<b>L3</b>-H)] and then, by reaction with
solvent, the binuclear complex [{PtMe(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>N</i>″-<b>L3</b>-H)}<sub>2</sub>(μ-H)]Cl. In the presence of oxygen
the complexes <b>1</b> in CH<sub>2</sub>Cl<sub>2</sub> solution
react to give [Pt(OH)Me<sub>2</sub>(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>N</i>″-<b>L</b>)]Cl, when <b>L</b> = <b>L1</b> or <b>L2</b>, or
[Pt(OH)Me<sub>2</sub>(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>O</i>-<b>L</b>-H)], when <b>L</b> = <b>L3</b>. The complex [Pt(OH)Me<sub>2</sub>(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>N</i>″-<b>L2</b>)]Cl decomposed in the presence of air to
give the binuclear complex [{PtMe<sub>2</sub>(2-C<sub>5</sub>H<sub>4</sub>NCO<sub>2</sub>)(μ-OH)}<sub>2</sub>]. The factors influencing
reactivity and mechanism in these reactions are elucidated, and the
presence of both a free pyridyl donor (push group) and a free hydroxyl
(pull group) is suggested to give a synergy for dioxygen activation
by dimethylplatinum(II) complexes
Activation of Dioxygen by Dimethylplatinum(II) Complexes
No full textThe
ligands RN(CH<sub>2</sub>-2-C<sub>5</sub>H<sub>4</sub>N)<sub>2</sub> (<b>L1</b>, R = CH<sub>2</sub>CH<sub>2</sub>OH; <b>L2</b>, R = CH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>OH; <b>L3</b>, R = 2-C<sub>6</sub>H<sub>4</sub>OH) have been designed to give
dimethylplatinum(II) complexes that can activate dioxygen in the absence
of a protic solvent. The ligands react with [Pt<sub>2</sub>Me<sub>4</sub>(SMe<sub>2</sub>)<sub>2</sub>] to give an equilibrium mixture,
with the major constituent being [PtMe<sub>2</sub>(κ<sup>2</sup>-N,N′-<b>L</b>)] (<b>1a</b>, <b>L</b> = <b>L1</b>; <b>1b</b>, <b>L</b> = <b>L2</b>; <b>1c</b>, <b>L</b> = <b>L3</b>). In the absence of air, <b>1a</b> reacts with solvent CH<sub>2</sub>Cl<sub>2</sub> to give
[PtMe<sub>2</sub>(CH<sub>2</sub>Cl)(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>N</i>″-<b>L1</b>]Cl, while <b>1c</b> decomposes with loss of methane to give
[PtMe(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>N</i>″-<b>L3</b>-H)] and then, by reaction with
solvent, the binuclear complex [{PtMe(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>N</i>″-<b>L3</b>-H)}<sub>2</sub>(μ-H)]Cl. In the presence of oxygen
the complexes <b>1</b> in CH<sub>2</sub>Cl<sub>2</sub> solution
react to give [Pt(OH)Me<sub>2</sub>(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>N</i>″-<b>L</b>)]Cl, when <b>L</b> = <b>L1</b> or <b>L2</b>, or
[Pt(OH)Me<sub>2</sub>(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>O</i>-<b>L</b>-H)], when <b>L</b> = <b>L3</b>. The complex [Pt(OH)Me<sub>2</sub>(κ<sup>3</sup>-<i>N</i>,<i>N</i>′,<i>N</i>″-<b>L2</b>)]Cl decomposed in the presence of air to
give the binuclear complex [{PtMe<sub>2</sub>(2-C<sub>5</sub>H<sub>4</sub>NCO<sub>2</sub>)(μ-OH)}<sub>2</sub>]. The factors influencing
reactivity and mechanism in these reactions are elucidated, and the
presence of both a free pyridyl donor (push group) and a free hydroxyl
(pull group) is suggested to give a synergy for dioxygen activation
by dimethylplatinum(II) complexes
A Bridging Peroxide Complex of Platinum(IV)
No full textThe photolysis of
the allylplatinum(IV) complex [PtBr(C<sub>3</sub>H<sub>5</sub>)(4-MeC<sub>6</sub>H<sub>4</sub>)<sub>2</sub>(bipy)], <b>1</b>, bipy
= 2,2′-bipyridine, in air yielded [{PtBr(4-MeC<sub>6</sub>H<sub>4</sub>)<sub>2</sub>(bipy)}<sub>2</sub>(μ-O<sub>2</sub>)], <b>2</b>, the first diplatinum(IV) complex containing
a single bridging peroxide ligand. The PtO–OPt bond distance
in <b>2</b> is 1.481(3) Å. Complex <b>2</b> is thought
to be formed by homolysis of the allyl-platinum bond of <b>1</b>, followed by reaction of the platinum(III) intermediate [PtBr(4-MeC<sub>6</sub>H<sub>4</sub>)<sub>2</sub>(bipy)] with oxygen
A Bridging Peroxide Complex of Platinum(IV)
No full textThe photolysis of
the allylplatinum(IV) complex [PtBr(C<sub>3</sub>H<sub>5</sub>)(4-MeC<sub>6</sub>H<sub>4</sub>)<sub>2</sub>(bipy)], <b>1</b>, bipy
= 2,2′-bipyridine, in air yielded [{PtBr(4-MeC<sub>6</sub>H<sub>4</sub>)<sub>2</sub>(bipy)}<sub>2</sub>(μ-O<sub>2</sub>)], <b>2</b>, the first diplatinum(IV) complex containing
a single bridging peroxide ligand. The PtO–OPt bond distance
in <b>2</b> is 1.481(3) Å. Complex <b>2</b> is thought
to be formed by homolysis of the allyl-platinum bond of <b>1</b>, followed by reaction of the platinum(III) intermediate [PtBr(4-MeC<sub>6</sub>H<sub>4</sub>)<sub>2</sub>(bipy)] with oxygen
