Expression of concern: Valence tautomeric interconversion of bis-dioxolene cobalt complex with imino-pyridine functionalized by TEMPO moiety in solid solutions with isostructural nickel analogue: phase transitions and monocrystal destruction.

Expression of concern for 'Valence tautomeric interconversion of bis-dioxolene cobalt complex with imino-pyridine functionalized by TEMPO moiety in solid solutions with isostructural nickel analogue: phase transitions and monocrystal destruction' by Michael P. Bubnov , , 2024, , 9151-9160, https://doi.org/10.

Synthesis of 1,3-Dicarbonyl Azepines via Photoinitiated Reactions of Aryl Azides with Carbon-Based Nucleophiles.

A photoinduced one-pot method for the synthesis of azepines by the reaction of aryl azides with 1,3-dicarbonyl compounds under weakly basic conditions is described. This method offers a simple route for the synthesis of 1,3-dicarbonyl-substituted azepines in good to excellent yields and high regioselectivity and was tested on 1,3-dicarbonyl compounds with different acidity levels. The resulting azepines have electrophilic and nucleophilic centers of varying degrees of activity, which facilitate reactions leading to further structural transformations.

Valence tautomeric interconversion of bis-dioxolene cobalt complex with imino-pyridine functionalized by TEMPO moiety in solid solutions with isostructural nickel analogue: phase transitions and monocrystal destruction.

Valence tautomeric complexes (VT) are promising systems for creating molecular devices. From this viewpoint, valence tautomeric complexes with a hysteresis loop on the magnetic curve are of special interest as potential memory elements. The hysteresis loop is a consequence of retarded structural rearrangements which investigation is an actual problem.

Photoinitiated Rearrangement of Aromatic Azides to 2-Aminonicotinates.

This study describes a one-pot photoinduced method for azepine synthesis and their subsequent rearrangement into pyridines. The rearrangement of the azepine, formed during photolysis, occurs due to both thermal and photochemical activation of the reaction. This requires an electron-donating substituent at the second position of the azepine and an electron-withdrawing substituent at the third position of the azepine.

Lanthanide Coordination Polymers with Soft-Base Ditopic Bisthiazolate Ligands.

In order to prepare the first lanthanide coordination polymers (CPs) based on ditopic sulfide ligands, benzo[1,2-:4,5-']bisthiazole-2,6(3,7)-dithione (HL) was used as a linker. The reactions of lanthanide silylamides Ln[N(SiMe)] (Ln = Nd, Gd, Er, and Yb) with HL result in the formation of soluble dimethyl sulfoxide (DMSO) ionic salts [Ln(DMSO)][L] [Ln = Nd (), Gd (), Er (), and Yb ()]. Due to the lack of coordination of anionic ligands, compounds , , and do not show sensitized metal-centered photoluminescence (PL), while Gd compound shows weak phosphorescence at 77 K.

Novel Rigidochromic and Anti-Kasha Dual Emission Fluorophores Based on D-π-A Dyads as the Promising Materials for Potential Applications Ranging from Optoelectronics and Optical Sensing to Biophotonics and Medicine.

Today we see an increasing demand for new fluorescent materials exhibiting various sensory abilities due to their broad applicability ranging from the construction of flexible devices to bioimaging. In this paper, we report on the new fluorescent pigments AntTCNE, PyrTCNE, and PerTCNE which consist of 3-5 fused aromatic rings substituted with tricyanoethylene fragments forming D-π-A diad. Our studies reveal that all three compounds exhibit pronounced rigidochromic properties, i.

Charge Transfer Chromophores Derived from 3d-Row Transition Metal Complexes.

A series of new charge transfer (CT) chromophores of "α-diimine-M-catecholate" type (where M is 3d-row transition metals-Cu, Ni, Co) were derived from 4,4'-di--butyl-2,2'-bipyridyl and 3,6-di--butyl--benzoquinone () in accordance with three modified synthetic approaches, which provide high yields of products. A square-planar molecular structure is inherent for monomeric () and () chromophores, while dimeric complex () units two substantially distorted heteroleptic D-M-A (where D, M, A are donor, metal and acceptor, respectively) parts through a donation of oxygen atoms from catecholate dianions. Chromophores - undergo an effective photoinduced intramolecular charge transfer (λ = 500-715 nm, extinction coefficient up to 10 M·cm) with a concomitant generation of a less polar excited species, the energy of which is a finely sensitive towards solvent polarity, ensuring a pronounced negative solvatochromic effect.

Binuclear Triphenylantimony(V) Catecholates through N-Donor Linkers: Structural Features and Redox Properties.

A series of binuclear triphenylantimony(V) bis-catecholato complexes - of the type (Cat)PhSb-linker-SbPh(Cat) was prepared by a reaction of the corresponding mononuclear catecholates (Cat)SbPh with a neutral bidentate donor linker ligands pyrazine (Pyr), 4,4'-dipyridyl (Bipy), bis-(pyridine-4-yl)-disulfide (PySSPy), and diazobicyclo[2,2,2]octane (DABCO) in a dry toluene: Cat = 3,6-di-tert-butyl-catecholate (3,6-DBCat), linker = Pyr (); PySSPy (); Bipy (); DABCO (); Cat = 3,5-di-tert-butyl-catecholate (3,5-DBCat), linker = Bipy (); DABCO (); Cat = 4,5-(piperazine-1,4-diyl)-3,6-di-tert-butylcatecholate (pip-3,6-DBCat), linker = Bipy (); DABCO (); Cat = 4,5-dichloro-3,6-di-tert-butylcatecholate (4,5-Cl-3,6-DBCat), linker = Bipy (); DABCO (); and Cat = 4,5-dimethoxy-3,6-di-tert-butylcatecholate (4,5-(MeO)-3,6-DBCat), linker = Bipy (). The same reaction of (4,5-Cl-3,6-DBCat)SbPh with DABCO in an open atmosphere results in a formation of 1D coordination polymer {[(4,5-Cl-3,6-DBCat)SbPh·HO]·DABCO} (). Bis-catecholate complex PhSb(Cat-Spiro-Cat)SbPh reacts with Bipy as 1:1 yielding a rare macrocyclic tetranuclear compound {PhSb(Cat-Spiro-Cat)SbPh∙(Bipy)} ().

-Heterocyclic Carbene-Coordinated M(II) (M = Yb, Sm, Ca) Bisamides: Expanding the Limits of Intermolecular Alkene Hydrophosphination.

A series of NHC-stabilized amido compounds (NHC)M[N(SiMe)] (M = Yb(II), Sm(II), Ca(II); = 1, 2) showed remarkable catalytic efficiency in addition of PhPH and PH to alkenes under mild conditions and low catalyst loading. The effect of σ-donor capacity of NHCs on catalytic activity in hydrophosphination of styrene with PhPH and PH was revealed. For the series of three-coordinate complexes , a tendency to increase the catalytic activity with growth of σ-donating strength of the carbene ligand was clearly demonstrated.

Synthesis and Antioxidant Activity of New Catechol Thioethers with the Methylene Linker.

Novel catechol thio-ethers with different heterocyclic substituents at sulfur atom were prepared by reacting 3,5-di--butyl-6-methoxymethylcatechol with functionalized thiols under acidic conditions. A common feature of compounds is a methylene bridge between the catechol ring and thioether group. Two catechols with the thio-ether group, bound directly to the catechol ring, were also considered to assess the effect of the methylene linker on the antioxidant properties.

Sc and Y bis(alkyl) complexes supported by bidentate and tridentate amidinate ligands. Synthesis, structure and catalytic activity in polymerization of isoprene and 1-heptene.

A series of bis(alkyl) complexes {(Bu)C[N(2,6-MeCH)]}Ln(CHSiMe)(THF) (Ln = Y, = 1 (1); Ln = Sc, = 1 (2)), {2-[PhP(O)]CHNC(Bu)N(2,6-MeCH)}Sc(CHSiMe) (3), {2-[PhP(NPh)]CHNC(Bu)N(2,6-MeCH)}Sc(CHSiMe) (4) coordinated by bidentate (N,N) and tridentate (N,N,O; N,N,N) amidinate ligands are synthesized using an alkane elimination approach. Yttrium complex 1 demonstrated a half-life of ∼2.5 days at room temperature in benzene-D6 (CD) solution, whereas scandium complexes proved to be much more stable (25 d (2), 30 d (3) and 42 d (4)).

Complexes of 1-(2-R(F, CH, Cl)-phenyl)-1,4-dihydro-5H-tetrazole-5-thiones with cadmium chloride: Synthesis, molecular, crystal structures and computational investigation approach.

New complex compounds (I) - (IV) were synthesized by the reaction of 1-(2-fluorofluorophenyl) -1,4-dihydro-5H-tetrazole-5-thione (HL), 1-(2-methylphenyl)-1,4-dihydro-5H-tetrazole-5-thione (HL) and 1-(2-chlorochlorophenyl)-1,4-dihydro-5H-tetrazole-5-thione (HL) with cadmium chloride. By X-ray diffraction analysis, molecular and crystal structures of complexes (I), (II), (III) and (IV) are determined. (CIF files CCDC № 2,003,797 (I), 1,993,454 (II), 2,151,359 (III), 2,098,997 (IV)).

2-Imino-2,3-dihydrobenzoxazole-a useful platform for designing rare- and alkaline earth complexes with variable di- and trianionic O,N,N, ligands.

The reactions of 2-imino-2,3-dihydrobenzoxazole LH with M[N(SiMe)](THF) (M = Yb and Ca) and Y(CHSiMe)(THF) proceed with the opening of the dihydrobenzoxazole ring and the elimination of HN(SiMe) or SiMe. Besides, in the case of Yb[N(SiMe)](THF), an electron transfer from Yb(II) to L takes place and Yb(III) complex 1 is coordinated by a dianionic phenolate ligand containing a pendant radical-anionic diazabutadiene fragment form. When LH is reacted with Ca[N(SiMe)](THF), C-H bond activation of a methyl fragment by imino nitrogen occurs and affords a dimeric calcium complex 2.

Novel Oxidovanadium Complexes with Redox-Active R-Mian and R-Bian Ligands: Synthesis, Structure, Redox and Catalytic Properties.

A new monoiminoacenaphthenone 3,5-(CF)CH-mian (complex ) was synthesized and further exploited, along with the already known monoiminoacenaphthenone dpp-mian, to obtain oxidovanadium(IV) complexes [VOCl(dpp-mian)(CHCN)] () and [VOCl(3,5-(CF)CH-bian)(HO)][VOCl(3,5-(CF)CH-bian)]·2.85DME () from [VOCl(CHCN)(HO)] () or [VCl(THF)]. The structure of all compounds was determined using X-ray structural analysis.

Luminescence thermochromism in novel mixed Eu(II)-Cu(I) iodide.

A new mixed Eu(II)-Cu(I) iodide [Eu(DME)][CuI] (1) was synthesized by the reaction of an organosulphide salt of Eu(II) and CuI in DME media. X-ray analysis revealed that 1 is an ate-complex consisting of Eu(DME) dications and tetraiododicuprate dianions. Upon UV light excitation ( = 365 nm), the compound exhibits intense double-peaked photoluminescence (PL) at 445 and 500 nm.

Heteroleptic La Anilate/Dicarboxylate Based Neutral 3D-Coordination Polymers.

Three new 3D metal-organic frameworks of lanthanum based on mixed anionic ligands, [(La(pQ)(BDC))·4DMF], [(La(pQ)(DHBDC))·4DMF], [(La(CA)(BDC))·4DMF] (pQ-dianion of 2,5-dihydroxy-3,6-di-tert-butyl-para-quinone, CA-dianion of chloranilic acid, BDC-1,4-benzenedicarboxylate, DHBDC-2,5-dihydroxy-1,4-benzenedicarboxylate and DMF-N,N'-dimethylformamide), were synthesized using solvothermal methodology. Coordination polymers demonstrate the rare or topology of a 3D framework. The homoleptic 2D-coordination polymer [(La(pQ))·4DMF] was obtained as a by-product in the course of synthetic procedure optimization.

Triphenylantimony(V) Catecholates of the Type (3-RS-4,6-DBCat)SbPh-Catechol Thioether Derivatives: Structure, Electrochemical Properties, and Antiradical Activity.

A new series of triphenylantimony(V) 3-alkylthio/arylthio-substituted 4,6-di-tert-butylcatecholates of the type (3-RS-4,6-DBCat)SbPh, where R = n-butyl (), n-hexyl (), n-octyl (), cyclopentyl (), cyclohexyl (), benzyl (), phenyl (), and naphthyl-2 (), were synthesized from the corresponding catechol thioethers and PhSbBr in the presence of a base. The crystal structures of , , , and were determined by single-crystal X-ray analysis. The coordination polyhedron of - is better described as a tetragonal pyramid with a different degree of distortion, while that for - was a distorted trigonal bipyramid ( = 0.

Single Crystal X-ray Diffraction Studies of Two Polymorphic Modifications of the Dicarbonyl--Semiquinonato Rhodium Complex at Different Temperatures. Destruction Stimulated by Cooling Versus Stability.

It was found that the dicarbonyl-rhodium--semiquinonate complex (which thread-like crystals can bend reversibly under light/warm activation) can form two polymorphic modifications: isometric prisms () and sticks (). Some thin sticks can bend as mentioned above. X-ray diffraction studies of polymorphic modifications at different temperatures were carried out.

Imine-Based Catechols and -Benzoquinones: Synthesis, Structure, and Features of Redox Behavior.

Novel sterically hindered catechols of the type 3-(RN=CH)-4,6-DBCatH with iminoalkyl or iminoaryl groups in the third position of the aromatic ring have been synthesized and characterized in detail. The -benzoquinones 3-(RN=CH)-4,6-DBBQ have been synthesized by the oxidation of the corresponding catechols. The oxidation of methylimino-substituted catechol with K[Fe(CN)] in alkaline medium leads to the formation of two products: -quinone and diene-dione, the product of the water addition to the corresponding -quinone.

Dual Reactivity of 3a,6a-Diaza-1,4-diphosphapentalene: π-Donor versus n-Donor.

Herein, we present the synthesis, single-crystal X-ray structures, and spectroscopic properties for the 1:1 donor-acceptor complexes of 1,2,4,5-tetracyanobenzene (TCNB) with annelated 3a,6a-diaza-1,4-diphosphapentalenes (DDPs) based on cyclohexanone azine () and tetralone azine (). These are the first complexes of an organic π-acceptor with donor phosphorus heterocycles. According to the X-ray study, the DDPs and TCNB molecules are alternately stacked with interplanar distances of 3.

Ferrocene-Containing Tin(IV) Complexes Based on -Benzoquinone and -Iminobenzoquinone Ligands. Synthesis, Molecular Structure, and Electrochemical Properties.

The addition of different substituted -benzoquinones and -iminobenzoquinones to tin(II) bis(-iminophenolates) of the types (Fc-IP)Sn and (Fc-4,6-IP)Sn (where Fc-IP is anion 2-(ferrocenylmethyleneamino)phenolate [Fc-C(H)═N(CH)O] and Fc-4,6-IP is anion 2-(ferrocenylmethyleneamino)-4,6-di--butylphenolate [Fc-C(H)═N(4,6-tBu-CH)O]) in tetrahydrofuran leads to the oxidation of Sn(II) to Sn(IV) with formation of the corresponding tin(IV) catecholates (Fc-4,6-IP)Sn(3,6-Cat) (), (Fc-IP)Sn(3,6-Cat) (), (Fc-4,6-IP)Sn(4-Cl-3,6-Cat) (), (Fc-IP)Sn(4-Cl-3,6-Cat) (), (Fc-4,6-IP)Sn(4,5-Cl-3,6-Cat) (), and (Fc-IP)Sn(4,5-Cl-3,6-Cat) () or the -amidophenolates (Fc-4,6-IP)Sn(AP-Me) (), (Fc-IP)Sn(AP-iPr) (), and (Fc-4,6-IP)Sn(AP-iPr) (). Here ligands 3,6-Cat, 4-Cl-3,6-Cat, and 4,5-Cl-3,6-Cat are dianions 3,6-di--butyl-, 4-chloro-3,6-di--butyl-, and 4,5-dichloro-3,6-di--butylcatecholates, respectively, and AP-Me and AP-iPr are dianions 4,6-di--butyl--(2,6-dimethylphenyl)--amidophenolate and 4,6-di--butyl--(2,6-diisopropylphenyl)--amidophenolate, respectively. Complexes - have been characterized in detail by IR spectroscopy, cyclic voltammetry, and H, C, and Sn NMR spectroscopy.

Polyfunctional Sterically Hindered Catechols with Additional Phenolic Group and Their Triphenylantimony(V) Catecholates: Synthesis, Structure, and Redox Properties.

New polyfunctional sterically hindered 3,5-di--butylcatechols with an additional phenolic group in the sixth position connected by a bridging sulfur atom-(6-(CH-S-tBuPhenol)-3,5-DBCat)H (), (6-(S-tBuPhenol)-3,5-DBCat)H (), and (6-(S-Phenol)-3,5-DBCat)H () (3,5-DBCat is dianion 3,5-di--butylcatecolate)-were synthesized and characterized in detail. The exchange reaction between catechols and with triphenylantimony(V) dibromide in the presence of triethylamine leads to the corresponding triphenylantimony(V) catecholates (6-(CH-S-tBuPhenol)-3,5-DBCat)SbPh () and (6-(S-Phenol)-3,5-DBCat)SbPh (). The electrochemical properties of catechols - and catecholates and were investigated using cyclic voltammetry.

The Nature of P(σλ↔σλ) Dualism: 3a,6a-Diaza-1,4-diphosphapentalene as a Form of Stabilized Singlet Phosphinidene.

The current study provides a clear understanding of the chemical properties of annelated 3a,6a-diaza-1,4-diphosphapentalenes (DDPs), which are best viewed as stabilized singlet phosphinidenes. It was found that DDPs undergo reversible oligomerization in solution, which provides 1,2,3-diazaphosphole-substituted cyclotetraphosphines, isolated and characterized by X-ray crystal structure analysis. Transformation of the 10-π-electron heteropentalene system into a stabilized phosphinidene occurs when the P-N bond is lengthened, which is facilitated by weak Lewis acids and bases.

Synthesis and ε-Caprolactone Polymerization Activity of Electron-Deficient Gallium and Aluminum Species Containing a Charged Redox-Active dpp-Bian Ligand.

The synthesis of electron-deficient gallium- and aluminum-centered species containing a redox-active dpp-Bian ligand (dpp-Bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) is described. The reaction of digallane [(dpp-Bian)Ga-Ga(dpp-Bian)] with [PhC][PF] or AgPF resulted in polyoxidized species [(dpp-Bian)GaF] (), [(dpp-Bian)H][PF] (), and [(dpp-Bian)GaF(OPF)] (). The reaction of digallane with B(CF) led to electron-deficient gallylene [(dpp-Bian)GaB(CF)] of a dpp-Bian radical anion.

Impact of n,γ-irradiation on organic complexes of rare earth metals.

The complexes of La, Ce, Nd, Sm, Eu, Tb and Yb with benzoxazolyl-phenolate, benzothiazolyl-phenolate, benzoxazolyl-naphtholate, benzothiazolyl-naphtholate and 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione ligands were treated with n,γ-irradiation upon a sustained (45 h, absorbed dose of 120 krad, flux of neutrons 5·10 n/cm) and a pulse mode (3 ms, absorbed dose of 130 krad, flux of neutrons 3.6·10 n/cm). It was found that main characteristics of the compounds (shape of substance, color, IR absorption and photoluminescent spectra) have not changed.