Synthesis and Structure of Bis- and Tris-Benzyl Bismuth Complexes

The first crystallographic characterization of bismuth complexes containing benzyl ligands is reported. The NCN pincer ligand complex, Ar′BiCl₂ [Ar′ = 2,6-(Me₂NCH₂)₂C₆H₃], reacts with (PhCH₂)­MgCl to form Ar′Bi­(η¹-CH₂Ph)₂ in high yield. X-ray crystallography and spectroscopic studies confirm η¹-bonding of the benzyl ligands in Ar′Bi­(η¹-CH₂Ph)₂ as well as in the homoleptic Bi­(η¹-CH₂Ph)₃

Ligand Influence on the Redox Chemistry of Organosamarium Complexes: Experimental and Theoretical Studies of the Reactions of (C5Me5)(2)Sm(THF)(2) and (C4Me4P)(2)Sm with Pyridine and Acridine

International audienceThe reactions of the samarium(II) complexes Tmp2Sm (Tmp = 2,3,4,5-tetramethyl-1H-phosphol-1-yl) and Cp*2Sm(THF)2 (Cp* = 1,2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl) with pyridine were found to be different, despite the fact that the Cp* and Tmp π-ligands are similar in size. With Tmp2Sm, a simple adduct, Tmp2Sm(pyridine)2 is isolated, while with Cp*2Sm(THF)2 pyridine is dimerized with concomitant oxidation of samarium to form [Cp*2Sm(C5H5N)]2[μ-(NC5H5-C5H5N)]. However, reaction of Tmp2Sm with acridine, a better π-acceptor than pyridine, did result in acridine dimerization and the isolation of [Tmp2Sm]2[μ-(NC13H9-C13H9N)]. DFT calculations on the model structures of Tmp2Sm and Cp*2Sm, and on the single electron transfer step from Sm to pyridine and acridine in these ligand environments, confirmed that, even though the Sm−π-ligand bonds are mostly ionic, the different electronic properties of the Tmp ligand versus that of Cp are responsible for the difference in reactivity of Tmp2Sm and Cp*2Sm

Insertion of CO₂ and COS into Bi–C Bonds: Reactivity of a Bismuth NCN Pincer Complex of an Oxyaryl Dianionic Ligand, [2,6-(Me₂NCH₂)₂C₆H₃]Bi(C₆H₂^<i>t</i>Bu₂O)

The reactivity of the unusual oxyaryl dianionic ligand, (C₆H₂^<i>t</i>Bu₂-3,5-O-4)^2–, in the Bi³⁺ NCN pincer complex Ar′Bi­(C₆H₂^<i>t</i>Bu₂-3,5-O-4), <b>1</b>, [Ar′ = 2,6-(Me₂NCH₂)₂C₆H₃] has been explored with small molecule substrates and electrophiles. The first insertion reactions of CO₂ and COS into Bi–C bonds are observed with this oxyaryl dianionic ligand complex. These reactions generate new dianions that have quinoidal character similar to the oxyaryl dianionic ligand in <b>1</b>. The oxyarylcarboxy and oxyarylthiocarboxy dianionic ligands were identified by X-ray crystallography in Ar′Bi­[O₂C­(C₆H₂^<i>t</i>Bu₂-3-5-O-4)-κ²O,O′], <b>2</b>, and Ar′Bi­[OSC­(C₆H₂^<i>t</i>Bu₂-3-5-O-4)-κ²O,S], <b>3</b>, respectively. Silyl halides and pseudohalides, R₃SiX (X = Cl, CN, N₃; R = Me, Ph), react with <b>1</b> by attaching X to bismuth and R₃Si to the oxyaryl oxygen to form Ar′Bi­(X)­(C₆H₂^<i>t</i>Bu₂-3,5-OSiR₃-4) complexes, a formal addition across five bonds. These react with additional R₃SiX to generate Ar′BiX₂ complexes and R₃SiOC₆H₃^<i>t</i>Bu₂-2,6. The reaction of <b>1</b> with I₂ forms Ar′BiI₂ and the coupled quinone, 3,3′,5,5′-tetra-<i>tert</i>-butyl-4,4′-diphenoquinone, by oxidative coupling

Ligand Influence on the Redox Chemistry of Organosamarium Complexes: Experimental and Theoretical Studies of the Reactions of (C₅Me₅)₂Sm(THF)₂ and (C₄Me₄P)₂Sm with Pyridine and Acridine

The reactions of the samarium­(II) complexes Tmp₂Sm (Tmp = 2,3,4,5-tetramethyl-1<i>H</i>-phosphol-1-yl) and Cp*₂Sm­(THF)₂ (Cp* = 1,2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl) with pyridine were found to be different, despite the fact that the Cp* and Tmp π-ligands are similar in size. With Tmp₂Sm, a simple adduct, Tmp₂Sm­(pyridine)₂ is isolated, while with Cp*₂Sm­(THF)₂ pyridine is dimerized with concomitant oxidation of samarium to form [Cp*₂Sm­(C₅H₅N)]₂[μ-(NC₅H₅–C₅H₅N)]. However, reaction of Tmp₂Sm with acridine, a better π-acceptor than pyridine, did result in acridine dimerization and the isolation of [Tmp₂Sm]₂[μ-(NC₁₃H₉–C₁₃H₉N)]. DFT calculations on the model structures of Tmp₂Sm and Cp*₂Sm, and on the single electron transfer step from Sm to pyridine and acridine in these ligand environments, confirmed that, even though the Sm−π-ligand bonds are mostly ionic, the different electronic properties of the Tmp ligand versus that of Cp are responsible for the difference in reactivity of Tmp₂Sm and Cp*₂Sm

Ligand Influence on the Redox Chemistry of Organosamarium Complexes: Experimental and Theoretical Studies of the Reactions of (C₅Me₅)₂Sm(THF)₂ and (C₄Me₄P)₂Sm with Pyridine and Acridine

The reactions of the samarium­(II) complexes Tmp₂Sm (Tmp = 2,3,4,5-tetramethyl-1<i>H</i>-phosphol-1-yl) and Cp*₂Sm­(THF)₂ (Cp* = 1,2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl) with pyridine were found to be different, despite the fact that the Cp* and Tmp π-ligands are similar in size. With Tmp₂Sm, a simple adduct, Tmp₂Sm­(pyridine)₂ is isolated, while with Cp*₂Sm­(THF)₂ pyridine is dimerized with concomitant oxidation of samarium to form [Cp*₂Sm­(C₅H₅N)]₂[μ-(NC₅H₅–C₅H₅N)]. However, reaction of Tmp₂Sm with acridine, a better π-acceptor than pyridine, did result in acridine dimerization and the isolation of [Tmp₂Sm]₂[μ-(NC₁₃H₉–C₁₃H₉N)]. DFT calculations on the model structures of Tmp₂Sm and Cp*₂Sm, and on the single electron transfer step from Sm to pyridine and acridine in these ligand environments, confirmed that, even though the Sm−π-ligand bonds are mostly ionic, the different electronic properties of the Tmp ligand versus that of Cp are responsible for the difference in reactivity of Tmp₂Sm and Cp*₂Sm

Addressing sustainability and consumption

This article examines issues of sustainability in relation to consumption. The authors first discuss the notion of sustainable consumption and the link between individual consumer behavior and the macroconcerns of understanding and influencing aggregate consumption levels. The authors then reflect on the differing perspectives on whether consumption patterns are in need of adjustment In the main pan of the article, the authors then explore the issue of sustainable consumption through the lens of two broadly differing conceptualizations of consumption itself discussing four main questions for each of these conceptualizations: (1) How is this view of consumption linked to prevalent current understandings of sustainable consumption? (2) How would sustainability be achieved following this perspective on consumption? (3) To whom would this view of sustainable consumption appeal or not appeal? and (4) What would the roles and responsibilities of different social actors be in achieving sustainability following this view of consumption