Search results for "Dianions"

showing 4 items of 4 documents

Synthesis and Redox Behaviour of the Chalcogenocarbonyl Dianions, [(E)C(PPh2S)2]2−: Formation and Structures of Chalcogen−Chalcogen Bonded Dimers and…

2010

The lithium salts of the chalcogenocarbonyl dianions [(E)C(PPh(2)S)(2)](2-) (E=S (4 b), Se (4 c)) were produced through the reactions between Li(2)[C(PPh(2)S)(2)] and elemental chalcogens in the presence of tetramethylethylenediamine (TMEDA). The solid-state structure of {[Li(TMEDA)](2)[(Se)C(PPh(2)S)(2)]}-[{Li(TMEDA)}(2)4 c]-was shown to be bicyclic with the Li(+) cations bis-S,Se-chelated by the dianionic ligand. One-electron oxidation of the dianions 4 b and 4 c with iodine afforded the diamagnetic complexes {[Li(TMEDA)](2)[(SPh(2)P)(2)CEEC(PPh(2)S)(2)]} ([Li(TMEDA)](2)7 b (E=S), [Li(TMEDA)](2)7 c (E=Se)), which are formally dimers of the radical anions [(E)C(PPh(2)S)(2)](-) (.) (E=S (5 …

Bicyclic moleculeLigandStereochemistryOrganic ChemistryProtonationGeneral ChemistryTetramethylethylenediamineCrystal structureCatalysisAdductchemistry.chemical_compoundCrystallographyChalcogenchemistrychalcogenocarbonyl dianionskalkogeenikarbonyylidianionitSelone
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Addition of dianions of carboxylic acids to imines. Influence of the acid in the outcome of the reaction

2009

The addition of different carboxylic acids dianions to N-benzylidenebenzeneamine have been studied. The outcome of the reaction depends on the acid. Saturated ones lead to β-aminoacids with good yields and syn-selectivity whereas α,β-unsaturated ones lead to α− and γ− regioisomers with a regioselectivity that depends on the steric hindrance around the reactive centre. From some of these unsaturated acids, polyunsaturated carboxylic acids can be obtained as a change in the reaction conditions lead to the in situ elimination of aniline. From o-methyl aromatic acids δ-aminoacids are isolated with uneven results. Those derived from six member arene carboxylic acids give, on standing, dihydro-2-…

DiastereoselectivityDianions ; Imines ; Regioselectivity ; DiastereoselectivityDianionsRegioselectivityUNESCO::QUÍMICA:QUÍMICA::Química orgánica [UNESCO]IminesUNESCO::QUÍMICA::Química orgánica:QUÍMICA [UNESCO]
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Synthesis of tetrahalide dianions directed by crystal engineering

2015

CrystEngComm 17(35), 6641-6645(2015). doi:10.1039/C5CE01288K

Hydrogen bondStereochemistryChemistryRational designCharge (physics)General ChemistryCrystal structureCondensed Matter PhysicsCrystal engineering540crystal engineeringChemical physicsHalogenddc:540tetrahalide dianionsGeneral Materials Scienceta116
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Design of carborane molecular architectures with electronic structure computations: From endohedral and polyradical systems to multidimensional netwo…

2009

11 pags, 6 figs. -- 19th International Conference on Physical Organic Chemistry (ICPOC-19) 13–18 July 2008, Santiago de Compostela, Spain

SingletComputational chemistryIcosahedral symmetryChemistryCASPT2General Chemical EngineeringComputationQuantum chemical computationsMolecular architectureGeneral ChemistryElectronic structureCASSCFDFTElectronic structuresTripletBiradicalsDianionsComputational chemistryAtomCarboraneSinglet stateDimersCarboranes
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