title: Ligand functionalization, reactivity, and transformation at the selenide centers of [Pt₂(μ-Se)₂(PPh₃)₄] with organic halides

authors: Yeo, Jeremy S.L.

subjects: ligand functionalisation

abstract: The selenium centers of [Pt₂(μ-Se)₂(PPh₃)₄] are subject to electrophilic attack from various organic halides. Reactions with MeI, n-BuCl, α,α⁶-dichloro-p-xylene, and α,α⁶-dichloro-o-xylene give [Pt₂(μ-Se)(μ-SeMe)(PPh₃)₄]⁺, [Pt₂(μ-Se)(μ-SeBu)(PPh₃)₄]⁺, [Pt₂(μ-Se)(μ-SeCH₂C₆H₄CH₂Cl)(PPh₃)₄]⁺, and [Pt₂(μ-SeCH₂C₆H₄CH₂Se)(PPh₃)₄]²⁺, respectively, preserving the dinuclear core and giving rise to new selenium-derivatized ligand complexes. Reaction with oxalyl chloride gives [Pt(η²-Se₂C₂O₂-Se,Se⁶)(PPh₃)₂], leading to the disintegration of the core to a mononuclear complex supported by a new chelating selenium donor ligand. Reactions with malonyl chloride and succinyl chloride give [(COCH₂COCl)Se]₂ and [(COCH₂CH₂COCl)Se]₂ respectively, leading to complex disintegration and liberation of new selenium materials. The crystal structures of the aggregates [Pt₂(μ-Se)(μ-SeMe)(PPh₃)₄][PF₆], [Pt₂(μ₃-Se)₂(PPh₃)₄(CH₂C₆H₄CH₂)][PF₆]₁.₂₅[Cl]₀.₇₅, and [Pt(η²-Se₂C₂O₂-Se,Se⁶)(PPh₃)₂] are described. The potential of using [Pt₂(μ-Se)₂(PPh₃)₄] as a source for metal-assisted synthesis of new and unusual organoselenium compounds is discussed.

text: Ligand functionalization, reactivity, and transformation at the selenide centers of [Pt₂(μ-Se)₂(PPh₃)₄] with organic halides The selenium centers of [Pt₂(μ-Se)₂(PPh₃)₄] are subject to electrophilic attack from various organic halides. Reactions with MeI, n-BuCl, α,α⁶-dichloro-p-xylene, and α,α⁶-dichloro-o-xylene give [Pt₂(μ-Se)(μ-SeMe)(PPh₃)₄]⁺, [Pt₂(μ-Se)(μ-SeBu)(PPh₃)₄]⁺, [Pt₂(μ-Se)(μ-SeCH₂C₆H₄CH₂Cl)(PPh₃)₄]⁺, and [Pt₂(μ-SeCH₂C₆H₄CH₂Se)(PPh₃)₄]²⁺, respectively, preserving the dinuclear core and giving rise to new selenium-derivatized ligand complexes. Reaction with oxalyl chloride gives [Pt(η²-Se₂C₂O₂-Se,Se⁶)(PPh₃)₂], leading to the disintegration of the core to a mononuclear complex supported by a new chelating selenium donor ligand. Reactions with malonyl chloride and succinyl chloride give [(COCH₂COCl)Se]₂ and [(COCH₂CH₂COCl)Se]₂ respectively, leading to complex disintegration and liberation of new selenium materials. The crystal structures of the aggregates [Pt₂(μ-Se)(μ-SeMe)(PPh₃)₄][PF₆], [Pt₂(μ₃-Se)₂(PPh₃)₄(CH₂C₆H₄CH₂)][PF₆]₁.₂₅[Cl]₀.₇₅, and [Pt(η²-Se₂C₂O₂-Se,Se⁶)(PPh₃)₂] are described. The potential of using [Pt₂(μ-Se)₂(PPh₃)₄] as a source for metal-assisted synthesis of new and unusual organoselenium compounds is discussed.

year: 2002

title: Impact of ownership structure on the level of voluntary disclosure: A study of listed family-controlled companies in Malaysia

authors: Zaini, Syeliya Md

subjects: Social Sciences

abstract: This paper investigates the level of voluntary disclosure in the annual reports of listed companies in Malaysia by examining the impact of ownership structure. A mixed methods approach was adopted to analyse the content and level of information disclosed voluntarily in companies’ annual reports. Family-controlled companies tend to voluntarily disclose information in relation to external factors and global conditions. Most family-controlled companies provide financial warnings in their disclosures. Studies that examine a voluntary disclosure practice by family-controlled companies in Malaysia are limited. As such, little is known about the effect of ownership structure on the level of voluntary disclosure.

text: Impact of ownership structure on the level of voluntary disclosure: A study of listed family-controlled companies in Malaysia This paper investigates the level of voluntary disclosure in the annual reports of listed companies in Malaysia by examining the impact of ownership structure. A mixed methods approach was adopted to analyse the content and level of information disclosed voluntarily in companies’ annual reports. Family-controlled companies tend to voluntarily disclose information in relation to external factors and global conditions. Most family-controlled companies provide financial warnings in their disclosures. Studies that examine a voluntary disclosure practice by family-controlled companies in Malaysia are limited. As such, little is known about the effect of ownership structure on the level of voluntary disclosure.

year: 2020-01-01

title: Cooperation in Maori and European children

authors: Vercoe, Glynis Price

subjects: Maori children

abstract: The object of this study is to compare the cooperative behaviour of Maori and European children and to investigate and compare the effects, upon the performance of the two ethnic groups, of working under cooperative conditions and under competitive conditions. Certain differences are expected to exist between the two ethnic groups as a result of the different child rearing practices employed by the Maoris and by the Europeans.

text: Cooperation in Maori and European children The object of this study is to compare the cooperative behaviour of Maori and European children and to investigate and compare the effects, upon the performance of the two ethnic groups, of working under cooperative conditions and under competitive conditions. Certain differences are expected to exist between the two ethnic groups as a result of the different child rearing practices employed by the Maoris and by the Europeans.

year: 1971