Vladimir Alekseevich Dodonov

Reactivity of the dimeric germanium(II) imide [^H,MeArNGe]₂ as a platform for preparing 6π biradicaloid systems via oxidative addition transformations is investigated. Treatment of [^H,MeArNGe]₂ with o-methoxyphenyl isoselenocyanate at 110 °C does not afford the expected 1,4-oxidation product; instead, it leads to the formation of a selenium-containing product [(^H,MeArNGe)₂Se]₂ (1) (80% yield), in which two molecules of the parent complex are bridged by two Se atoms to form a Ge₂Se₂ ring. The transformation proceeds asymmetrically and corresponds to 2e^– oxidation at one Ge center. Reaction with I₂ (1-2 equiv) yields doubly- (2) and tetraiodinated (3) complexes (up to 88%) and clearly demonstrates the possibility of multielectron (up to 4e^–) transformations preserving the Ge₂N₂ core. The structures of all products are confirmed by XRD, IR, and NMR spectroscopy (for soluble samples). No reaction with H₂ is observed experimentally even at 80 atm and 70 °C. DFT calculations indicate that the process is kinetically prohibited (ΔG ≈ +5.0 kcal/mol; barrier: ~62.0 kcal/mol) and that the 1,4-adducts are thermodynamically less favorable than the 1,1-isomers (ΔG_iso(1,1 → 1,4) = 21.3-53.6 kcal/mol). Additionally, products 1-3 are found to exhibit no luminescence, in contrast to the parent complex.

The reactivity of the α-diimine-ligated dialuminum(II) complex [LAl^II-Al^IIL]^2- (1, dialumane, L = [(2,6-iPr₂C₆H₃)NC(CH₃)]₂) and the corresponding Al(I) species [LAl^I:]^- (aluminyl anion) toward ketones was systematically investigated. Reaction of complex 1 with 9-fluorenone induced pinacol coupling to afford product 2 via two-electron reduction, with one electron derived from the L^2- ligand and the other from the Al(II) center. In contrast, treatment of 1 with 1,3-dimethyl-2-imidazolidinone resulted in the formation of complex 3 through a simple Lewis acid-base addition. Furthermore, the Al(I) species [LAl:]^-, generated via reduction of dialumane 1, reacts with benzophenone and acetophenone to yield the pinacol coupling products 4 and 5, where both electrons are donated by the Al(I) center. Notably, sterically hindered α-hydrogen-containing ketones (1,1-diphenylacetone and 2,4-dimethyl-3-pentanone) underwent enolization to form products 6 and 7 instead of C-C coupling. Compound 7 additionally involved hydrogen migration, featuring an enolized unit (OC(R)═CR'₂) and an alkoxide moiety (OC(H)R₂). Surprisingly, reaction of [LAl:]^- with the bulkier 2,2,4,4-tetramethyl-3-pentanone led to complete C═O bond cleavage, affording product 8 via ligand-based C-C coupling and hydrogen migration from ligand L to the deoxygenated carbon. This represents the first reported instance of Group 13 elements mediating the complete cleavage of the C═O bond in ketones. The newly obtained compounds were fully characterized by EPR/NMR, IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction. Their electronic structures were further elucidated through DFT calculations.

Взаимодействие анилинов R1,MeArNH2 (R1,MeAr = 2,6-((4-R1-C6H4)2CH)2-4-Me-C6H2, R1 = H, Me) с 2 экв. n-BuLi приводит к образованию красных кристаллов N,C-дидепротонированных комплексов 3 и 4 через стадию образования бесцветных продуктов монодепротонирования [R1,MeArN(H)Li] (1, 2). Обработка анилинов 1 экв. (AlMe3)2 при комнатной температуре приводит к образованию аддуктов [R1,MeArNH2AlMe3] (5, 6), тогда как проведение реакции при 60 °C даёт комплекс [Me,MeArN(H)AlMe2] (7), что дополнительно подтверждено термогравиметрическим анализом соединения 6. Состав и строение полученных соединений были установлены методами ИК-, ЯМР-спектроскопии, элементного анализа и РСА (CCDC № 2491614 3, 2491615 5).

Novel Ge( ii ) imide with efficient, temperature-responsive solution and solid-state phosphorescence.

Novel low-valent organotin imide complexes exhibit remarkable phosphorescent properties suitable for advanced luminescent applications.

The silylene [(dpp-bian)Si:] (1), where dpp-bian is 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene, exhibits remarkable reactivity with a variety of substrates. It reacts with chloroform and water via O–H and C–Cl bond activation to yield oxidative addition products 2 and 3, respectively. Reactions of 1 with dibenzylideneacetone and tolane involve exclusively the silicon atom and result in [4 + 1]- and [2 + 1]-cycloaddition products 4 and 6. Treatment with isoselenocyanate results in unprecedented cleavage of the CSe bond, leading to activation product 5. In contrast, treatment with acetylene and phenylacetylene leads to cooperative cycloaddition reactions, producing unique cycloadducts 7 and 8. These reactions represent a new type of cycloaddition to a tetravalent silicon atom, facilitated by a redox-active ligand. The new compounds were characterized by NMR and IR spectroscopy, elemental analysis, and X-ray diffraction studies. Their electronic structures and reaction pathways were investigated using DFT calculations.

The activation of inert C–H bonds remains a challenge in current chemistry. Here, we report the excellent reactivity of the anionic gallylene species [LGa:][Na(THF)₃] (L = [(2,6-iPr₂C₆H₃)NC(CH₃)]₂²⁻, 1) that allows the selective activation one ortho sp² C–H bond of several azobenzene and azide derivatives at ambient temperature, with the transfer of the hydrogen atom to one of the nitrogen atoms. The process leads to the formation of the aryl amido products [LGa-κ²N,C-PhNN(H)(p-R-C₆H₃)][Na(solvent)₃] (2, R = H solvent = DME (1,2-Dimethoxyethane); 3, R = –OMe, solvent = DME; 4, R = –NMe₂ solvent = THF), [LGa-κ²N,C-(m-CH₃-C₆H₄)NN(H)(m-CH₃-C₆H₃)][Na(15-C-5)₂] (5) with new Ga–C and Ga–N bonds. Moreover, 1 is also effective for the C–H activation of two azides RN₃ (R = 2,4,6-Me₃C₆H₂ or 2,6-iPr₂C₆H₃), resulting in the formation of gallium amides [LGa(NH-2-(CH₂)-4,6-Me₂C₆H₂)][Na(15-C-5)₂] (6) and [LGa(NH-2,6-iPr₂C₆H₃)₂][Na(THF)₅] (7) through intra- or intermolecular sp³ C–H amination. Significantly, these reactions occur for the highly challenging activation of inert C(sp²)–H and C(sp³)–H bonds, thus demonstrating the excellent reactivity of the Ga(I) species 1. The products 2–7 were characterized by X-ray crystallography, ¹H and ¹³C NMR, UV–vis spectroscopy, and density functional theory (DFT) calculations.