Reactions of Acenaphthenediimine Aluminum Hydride with 1,3-Dicyclohexylcarbodiimide and 2,6-Di-tert-Butyl-4-Methylphenol

Russian Journal of Coordination Chemistry - The reaction of [(Dpp-Bian)AlH(THF)] (I) (Dpp-Bian = 1,2-bis[(2,6-diisopropylphenyl)imi-no]acenaphthene) with 1,3-dicyclohexylcarbodiimide (DCC) is...     

New Bromine-Containing Bis(arylimino)acenaphthenes and Related Metal Complexes

Russian Journal of Coordination Chemistry - The condensation reactions of 5-bromoacenaphthenequinone with 2,6-diisopropylaniline and 4?bromo-2,6-di-iso-propylaniline afford new mono- and...     

Study of charges on heteroatoms in organic compounds of the second-row elements by X-ray fluorescence spectroscopy

The characteristic features of the electronic structure of SbCl₅L complexes has been studied in comparison with those of the SnCl₄L₂ and TiCl₄L₂ complexes. The results of X-ray structural analysis were correlated with the heats of complexation, the data of Mössbauer spectroscopy, derivatography, quantum-chemical PM3 calculations, and stretching frequencies of the donor-acceptor bonds. Based on these data, the contributions of different effects to the stabilities of complexes were determined, complexation enthalpies previously unknown were calculated, and a conclusion was drawn that the electron density transfer from the donor to the acceptor is small. The charge effect of the donor consists primarily in polarization of the acceptor bonds; this polarization decreases as a result of (he change in the geometry of the acceptor upon complexation. The relative stabilities of the complexes with dimethyl sulfide were determined using a unique internal standard technique.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1465–1470, June, 1996.     

Supermolecular structure of teflon and its role in the manufacture of metal-polymer antifriction materials

The question of the formation of supermolecular structures in teflon is considered. It is shown that during processing they become oriented, causing anisotropy of the material properties. The realtive rheological characteristics of the anisotropic materials are given as a function of the directionality of the force field. Specimens are obtained on the basis of the experimentally determined laws and certain properties of a polymer-metal antifriction material consisting of a high tin, porous bronze impregnated with teflon are investigated.Institute of the Chemistry of High Molecular Compounds, AS UkrSSR, Kiev. Translated from Mekhanika Polimerov, Vol. 4, No. 6, pp. 1122–1124, November–December, 1968.     

Aluminum hydrides with radical-anionic and dianionic acenaphthene-1,2-diimine ligands

The reaction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) with LiAlH₄ affords two products regardless of the solvent used (tetrahydrofuran or diethyl ether). These products were isolated as green and colorless crystals. Green crystals of the complex [(dpp-bian)Al(H)₂Li(THF)₃] (1) were obtained from tetrahydrofuran; colorless crystals of the complex [{dpp-bian(H₂)}Al(H)₂Li(Et₂O)₂] (2), from diethyl ether. The reactions of compound 1 with 2,6-di-tert-butyl-4-methylphenol and benzophenone gave monohydrides [(dpp-bian)Al(H)(OC₆H₂-2,6-Bu₂ ^t-4-Me)][Li(THF)₄] (3) and [(dpp-bian)Al(H)(OCHPh₂)- Li(THF)₂] (4), respectively. The diamagnetic aluminum hydride [(dpp-bian)AlH(THF)] (5) was synthesized by the reaction of dichloroalane HAlCl₂ (in situ) with the disodium salt of dpp-bian in THF; the paramagnetic hydride [(dpp-bian)AlH(Cl)] (6) containing the dpp-bian radical anion was synthesized by the reaction of the monosodium salt (dpp-bian)Na with monochloroalane H₂AlCl (in situ) in diethyl ether. The reaction of compound 6 with tert-butyllithium gives the complex [(dpp-bian)AlBu^t(Et₂O)] (7). Diamagnetic derivatives 1—5 and 7 were characterized by ¹Н NMR spectroscopy; paramagnetic compound 6, by ESR spectroscopy. The molecular structures of compounds 1—7 were determined by single-crystal X-ray diffraction.     

Reversible Addition of Carbon Dioxide to Main Group Metal Complexes at Temperatures about 0 °C

The reaction of dialane [LAl-AlL] ( 1 ; L=dianion of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene, dpp-bian) with carbon dioxide results in two different products depending on solvent. In toluene at temperatures of about 0 °C, the reaction gives cycloadduct [L(CO₂)Al-Al(O₂C)L] ( 2 ), whereas in diethyl ether, the reaction affords oxo-bridged carbamato derivative [L(CO₂)(Et₂O)Al(μ-O)AlL] ( 3 ). The DFT and QTAIM calculations provide reasonable explanations for the reversible formation of complex 2 in the course of two subsequent (2+4) cycloaddition reactions. Consecutive transition states with low activation barriers were revealed. Also, the DFT study demonstrated a crucial effect of diethyl ether coordination to aluminium on the reaction of dialane 1 with CO₂. The optimized structures of key intermediates were obtained for the reactions in the presence of Et₂O; calculated thermodynamic parameters unambiguously testify the irreversible formation of the product 3 .     

Borane reduction of carbon dioxide bound to diimine-supported aluminum hydrides

Russian Chemical Bulletin - The borane reduction of carbon dioxide bound to aluminum hydrides supported by redox-active acenaphthene-1,2-diimine ligands, [{(dpp-bian)AlO2CH2}2] (1) (dpp-bian is...     

New functionalized acenaphthene-1,2-diimines and derived zinc and copper complexes

Russian Chemical Bulletin - The new compound 1,2-bis[(2,6-diisopropyl-4-iodophenyl)imino]acenaphthene (I2-dppbian, 1) was synthesized by the condensation of acenaphthenequinone with...     

Reactivity of an aluminum hydride complex with a redox-active diimine ligand

Russian Chemical Bulletin - The reaction of the hydride [(dpp-bian)Al(H)Cl] (1) containing the 1,2-bis[(2,6-diisopropylphenyl) imino]acenaphthene (dpp-bian) radical anion with MeLi affords the...