N. P. Makarenko

2,5-DI-TERT-BUTYLPHENYLSILANETRIOL : SYNTHESIS AND REACTIVITY

Stable 2,5-di-tert-butylphenylsilanetriol was prepared by a stepwise synthesis. This compound reacted with triethylenediamine and lanthanum silylamide to form a 1∶1 molecular complex and highly thermally stable lanthanosilsesquioxane, respectively.

Influence of the structure of esters on their thermodynamic adsorption characteristics and chromatographic retention in HPLC

The chromatographic behavior of a series of esters was investigated in conditions of normal-phase and reversed-phase high-performance liquid chromatography. The dependence of the retention on the molecular structure of the investigated compounds and their physicochemical parameters is considered.

The reaction of 3,6-di-tert-butyl-1,2-benzoquinone and 3,6-di-tert-butylcatechol withtert-butyl hydroperoxide

Reaction of 3,6-di-tert-butyl-1,2-benzoquinone and 3,6-di-tert-butylcatechol withtert-butyl hydroperoxide in aprotic solvents leads to the generation of semiquinone (SQ.H), alkylperoxy (ROO.), and alkyloxy radicals. The reaction of SQ.H and ROO. produces 2,5-di-tert-butyl-6-hydroxy-1,4-benzoquinone, 3,6-di-tert-butyl-1-oxacyclohepta-3,5-diene-2,7-dione, and 2,5-di-tert-butyl-3,6-dihydroxy-1,4-benzoquinone. The radical generated from solvent attacks SQ.H at position 4 with C−C bond formation. 4-Benzyl-2,5-di-tert-butyl-6-hydroxycyclohexa-2,5-diene-1-dione produced in this way is transformed into 4-benzyl-3,6-di-tert-butyl-1,2-benzoquinone under the reaction conditions.

Synthesis, properties, and reactivity of the stilbene complex of ytterbium (PhCH=CHPh)Yb(THF)2. Crystal structure of (2,4,6-But3C6H2O)2Yb(THF)3

The stilbene complex of ytterbium (PhCH=CHPh)Yb(THF)2 (1) was prepared by the reaction of YbI2(THF)2 with a twofold excess of (PhCH=CHPh)− Li+. Based on the data of IR and ESR spectroscopy and on the results of magnetic measurements, compound1 was characterized as a complex of divalent ytterbium with the stilbene dianion. The reactivity of complex1 toward different types of reagents was studied. The structure of the product of the reaction of1 with 2,4,6-tri(tert-butyl)phenol (2,4,6-But3C6H2O)2Yb(THF)3 was established by X-ray diffraction analysis.

Organoerbium compounds containing dendritic ligands

The reactions of Er[N(SiMe3)2]3 with phenylethynyl dendrons of the first and second generations gave complexes of erbium with dendritic ligands, Er[C≡CC6H3(C≡CPh)2-3,5]3 and Er{C≡CC6H3[C≡CC6H3(C≡CPh)2-3,5]2-3,5}3.

Reactions of 1,1,3,3-tetramethyldisilazane with dicobalt octacarbonyl and iron pentacarbonyl. Thermal decomposition of the cobalt and iron carbonyl silazane complexes

The reaction of (HMe2Si)2NH with Co2(CO)8 gives the complex [Co2(CO)7(SiMe2)2NH2]+[Co(CO)4]−. Its thermal decomposition starts with dissociation into the “acid” HCo(CO)4 and the “base” Co2(CO)7(SiMe2)2NH. After that, the base and the initial complex decompose further under the action of HCo(CO)4. The final products of this reaction are CO, NH3, Co, volatile dimethylcyclosilazane, and a solid residue consisting of cobalt particles encapsulated into a polymethylsiloxane matrix and possessing properties of mixed para- and ferromagnetics with an ultimate specific magnetization of 64–74 G g−1. Tetramethyldisilazane reacts with iron pentacarbonyl under UV irradiation to give relatively stable 1,3-bis(tetracarbonylthydrideiron)-1,1,3,3-tetramethyldisilazane. This product contains Fe−H…N hydrogen bonds, which stabilize it against dehydrogenation and cyclization to diironcyclodisilazane. Thermal decomposition of this product was investigated.

Synthesis and X-Ray Structure of 1,3,5-Tri(phenylethynyl)benzene

Abstract 1,3,5-Tri(phenylethynyl)benzene 1 obtained by coupling triiodobenzene with phenylacetylene shows an unusual non planar molecular structure.