163 research outputs found
4,4-Bis(4-methylÂphenylÂsulfanÂyl)-1,1-diphenyl-2-azaÂbuta-1,3-diene
In the title compound, C29H25NS2, both the Cl atoms of the azaÂdiene precursor 4,4-dichloro-1,1-diphenyl-2-azaÂbuta-1,3-diene are replaced by two vicinal S-p-tolyl substituents attached to the terminal C atom of a Ï€-conjugated 2-azaÂbutadiene array. The azaÂdiene chain is planar to within 0.01 Å. One of the phenyl rings seems to be slightly Ï€-conjugated with the azaÂdiene core [dihedral angle 5.1 (2)°]
Syntheses, Crystal Structure and Physico-Chemical Studies of Sodium and Potassium Alcoholates Bearing Thienyl Substituents and their Derived Luminescent Sm(III) Alkoxides
International audienceThe synthesis, structural characterization, electrochemistry and luminescence properties of a series of alkali metal alcoholates and Sm(III) alkoxides with thiophene−based−OR substituents are presented. The alkali metal alcoholates 7-15 have been obtained by deprotonation of the carbinol with NaH or KH. Their molecular structures consist of tetranuclear alkali metal alcoholates with a distorted cubane−like M4O4 core (X-ray structure analyses). Each alkali metal is surrounded by three carbinolate ligands and (depending on the derivative) by additional tetrahydrofuran molecules. The mononuclear samarium alkoxides {Sm[OC(C4H3S)3]3(thf)3} * thf (16) and {Sm[OC(C16H13S)]3(thf)3} * thf (17) were synthesized by the salt metathesis reactions between {[KOC(C4H3S)3]4(thf)2} * thf (7), [NaOC(C4H3S)3]4(thf)2 (8) or {[KOC(C16H13S)]4(thf)3} * ½ thf (11), respectively, and SmCl3 in thf solution. The molecular structures of these air−sensitive base adducts have been determined by single−crystal X−ray crystallography and reveal an approximately octahedral coordination sphere around the samarium metal centres with three methoxido ligands and three facially arranged thf molecules. The electrochemical properties are essentially dominated by the oxidation of the thienyl units. The emission spectra of the carbinols and their derived potassium and sodium compounds display broad bands attributed to the π*→π transitions of the aromatic ligands. Luminescence studies performed on complexes 16 and 17 reveal the typical f−f transitions of the Sm(III) ion. The photophysical data suggest that an energy transfer from the ligand to the metal centre operates
1,3-Dipolar cycloaddition of diaryldiazomethanes across <i>N</i>-ethoxy-carbonyl-<i>N</i>-(2,2,2-trichloroethylidene)amine and reactivity of the resulting 2-azabutadienes towards thiolates and cyclic amides
ChemInform Abstract: Chiral Bipyridine and Terpyridine Ligands Grafted with L-Tyrosine Fragments.
ChemInform Abstract: Synthesis of Soluble Bis-terpyridine Ligands Bearing Ethynylene-Phenylene Spacers.
ChemInform Abstract: Sequential Synthesis of Rigid Multi-bipyridine Ligands Bearing Diethynyl/Phenyl Solubilizing Fragments.
Synthesis of Quasi-Linear and Segmented Bis- to Penta-2,2‘-bipyridine Polytopic Ligands Built via a Convergent Approach
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