Tailoring Polyethylenes by Nickel Complexes Bearing Modified 1‑(2-Benzhydryl­naphthylimino)-2-phenylimino­acenaphthylene Derivatives

A series of 1-(2-benzhydryl­naphthylimino)-2-phenylimino­acenaphthylene derivatives (<b>L1</b>–<b>L5</b>) was synthesized, characterized, and then reacted with (DME)­NiBr₂ to form the corresponding [1-(2-benzhydryl­naphthylimino)-2-phenylimino­acenaphthyl]­nickel bromides (<b>C1</b>–<b>C5</b>). All nickel complexes were fully characterized by their FT-IR spectra and elemental analysis. The molecular structures of the representative complexes <b>C1</b> and <b>C4</b> were also determined by single-crystal X-ray diffraction. On activation with either methylaluminoxane (MAO) or diethylaluminum chloride (Et₂AlCl), all title nickel complexes showed high activities toward ethylene polymerization; the resulting polyethylenes showed molecular weights higher than those obtained by using the nickel analogues bearing (2-benzhydryl­naphthylimino)­pyridines and also had branches lower than those obtained by using other diiminoacenaphthylnickel analogues. Therefore, the modification of ligands could affect the catalytic behavior of their nickel complexes in order to tailor the molecular weights and branches of the resulting polyethylenes

Students' qualification in environmental and sustainability education-epistemic gaps or composites of critical thinking

In an 'age of measurement' where students' qualification is a hot topic on the political agenda, it is of interest to ask what the function of qualification might implicate in relation to a complex issue as Education for Sustainable Development (ESD) and what function environmental and sustainability issues serve in science education. This paper deals with how secondary and upper secondary teachers in discussions with colleagues articulate qualification in relation to educational aims of ESD. With inspiration from discourse theory, the teachers' articulations of qualification are analysed and put in relation to other functions of education (qualification, socialisation and subjectification). The results of this study show three discourses of qualification: scientific reasoning, awareness of complexity and to be critical. The discourse of 'qualification as to be critical' is articulated as a composite of differing epistemological views. In this discourse, the teachers undulate between rationalistic epistemological views and postmodern views, in a pragmatic way, to articulate a discourse of critical thinking which serves as a reflecting tool to bring about different ways of valuing issues of sustainability, which reformulates 'matter of facts' towards 'matter of concerns

Synthesis, Structures, and Reactivities of Guanidinatozinc Complexes and Their Catalytic Behavior in the Tishchenko Reaction

Treatment of a secondary amine (pipH, Bz₂NH, Et₂NH) with sequentially diethylzinc and <i>N</i>,<i>N</i>′-dicyclohexylcarbodiimide in hexane has afforded in good yield the new crystalline guanidinatozinc complexes. Each has been X-ray and solution NMR spectrally characterized. Three are dimeric (mono)­guandinatozinc alkyls, two are dinuclear (tris)­guanidinatozinc amides, and one is a homoleptic zinc bis­(guanidinate). The reactions of dinuclear (tris)­guanidinatozinc amides with diethylzinc and <i>N</i>,<i>N</i>′-dicyclohexylcarbodiimide in the molar ratios of 1:2:1 led to the dimeric (mono)­guandinatozinc alkyls; homoleptic zinc bis­(guanidinate) with an equimolar portion of diethylzinc also yielded dimeric (mono)­guandinatozinc alkyls. Each of the complexes exhibited good to excellent catalytic activity for the solvent-free Tishchenko reaction under mild conditions

Synthesis, Structures, and Reactivities of Guanidinatozinc Complexes and Their Catalytic Behavior in the Tishchenko Reaction

Treatment of a secondary amine (pipH, Bz₂NH, Et₂NH) with sequentially diethylzinc and <i>N</i>,<i>N</i>′-dicyclohexylcarbodiimide in hexane has afforded in good yield the new crystalline guanidinatozinc complexes. Each has been X-ray and solution NMR spectrally characterized. Three are dimeric (mono)­guandinatozinc alkyls, two are dinuclear (tris)­guanidinatozinc amides, and one is a homoleptic zinc bis­(guanidinate). The reactions of dinuclear (tris)­guanidinatozinc amides with diethylzinc and <i>N</i>,<i>N</i>′-dicyclohexylcarbodiimide in the molar ratios of 1:2:1 led to the dimeric (mono)­guandinatozinc alkyls; homoleptic zinc bis­(guanidinate) with an equimolar portion of diethylzinc also yielded dimeric (mono)­guandinatozinc alkyls. Each of the complexes exhibited good to excellent catalytic activity for the solvent-free Tishchenko reaction under mild conditions

From Lithium Bis(trimethylsilyl)amide with Cyanoamine into Triazine Compounds: Synthesis and Structures of Lithium 6-((Trimethylsilyl)amido)-2,4-bis(dimethylamino)[1,3,5]triazines and Their Manganese and Cobalt Complexes

Addition reactions of lithium bis­(trimethylsilyl)­amide with dimethylcyanamide lead to novel lithium salts of 6-((trimethylsilyl)­amido)-2,4-bis­(dimethylamino)­[1,3,5]­triazines [<b>L</b>Li­(<b>D</b>)]₂ (<b>L</b> = NC­(NMe₂)­NC­(NMe₂)­NC­(NSiMe₃); <b>D</b> = Me₂NCN (<b>1</b>), Et₂O (<b>2</b>)) and to the Mn and Co complexes [<b>LL′</b>M] (<b>L′ </b>= N­{N­(SiMe₃)­C­(NMe₂)}₂; M = Mn (<b>3</b>), Co (<b>4</b>)); the structures of crystalline <b>1</b>, <b>3</b>, and <b>4</b> are reported. Their formation involves trimethylsilyl shifts, ring formation, and unusual Me₂NSiMe₃ elimination

From Lithium Bis(trimethylsilyl)amide with Cyanoamine into Triazine Compounds: Synthesis and Structures of Lithium 6-((Trimethylsilyl)amido)-2,4-bis(dimethylamino)[1,3,5]triazines and Their Manganese and Cobalt Complexes

Addition reactions of lithium bis­(trimethylsilyl)­amide with dimethylcyanamide lead to novel lithium salts of 6-((trimethylsilyl)­amido)-2,4-bis­(dimethylamino)­[1,3,5]­triazines [<b>L</b>Li­(<b>D</b>)]₂ (<b>L</b> = NC­(NMe₂)­NC­(NMe₂)­NC­(NSiMe₃); <b>D</b> = Me₂NCN (<b>1</b>), Et₂O (<b>2</b>)) and to the Mn and Co complexes [<b>LL′</b>M] (<b>L′ </b>= N­{N­(SiMe₃)­C­(NMe₂)}₂; M = Mn (<b>3</b>), Co (<b>4</b>)); the structures of crystalline <b>1</b>, <b>3</b>, and <b>4</b> are reported. Their formation involves trimethylsilyl shifts, ring formation, and unusual Me₂NSiMe₃ elimination

From Lithium Bis(trimethylsilyl)amide with Cyanoamine into Triazine Compounds: Synthesis and Structures of Lithium 6-((Trimethylsilyl)amido)-2,4-bis(dimethylamino)[1,3,5]triazines and Their Manganese and Cobalt Complexes

Addition reactions of lithium bis­(trimethylsilyl)­amide with dimethylcyanamide lead to novel lithium salts of 6-((trimethylsilyl)­amido)-2,4-bis­(dimethylamino)­[1,3,5]­triazines [<b>L</b>Li­(<b>D</b>)]₂ (<b>L</b> = NC­(NMe₂)­NC­(NMe₂)­NC­(NSiMe₃); <b>D</b> = Me₂NCN (<b>1</b>), Et₂O (<b>2</b>)) and to the Mn and Co complexes [<b>LL′</b>M] (<b>L′ </b>= N­{N­(SiMe₃)­C­(NMe₂)}₂; M = Mn (<b>3</b>), Co (<b>4</b>)); the structures of crystalline <b>1</b>, <b>3</b>, and <b>4</b> are reported. Their formation involves trimethylsilyl shifts, ring formation, and unusual Me₂NSiMe₃ elimination