Substitution Of OH Group Research Articles

Exploring Spectral and Electrochemical Behavior of Hydroxy‐N‐Benzylideneanilines by Integrated Theoretical and Experimental Approaches

ABSTRACTThe present work explored the effect of –OH group substitution (o/p) on the spectral and electrochemical behavior of N‐benzylideneaniline. The geometry optimization of unsubstituted and (o/p)‐OH‐substituted analogs revealed the coplanarity of the molecules. The vibrational spectra of the compounds were computed using density functional theory (DFT) and compared with the experimental data. The observed bands were assigned based on total energy distribution (TED). Predicted electronic absorption spectra from time‐dependent density functional theory (TD‐DFT) calculation were compared with the UV–visible spectra of the molecules. The analysis of the lowest spin‐allowed (singlet‐singlet) excited states divulged possible electronic transition. The o‐substituted benzylideneaniline possessed the lowest highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energy gap among the substituted and unsubstituted analogs. The intramolecular contacts were interpreted using natural bond orbital and localized molecular orbital analysis. The –CH=N– linkage was investigated as a bridge for the electron delocalization from the donor to acceptor moieties. The manifestation of a reduction peak in the cyclic voltammetric studies confirmed the electrochemical behavior in the –OH‐substituted molecule, which was diffusion‐controlled. The discrepancy in the electrochemical property concerning the position of the –OH substituent of the candidate molecules was put forward.

Influence of the structure of a mineral adsorbent on the detritization of aqueous solutions

Introduction. Formed in a nuclear reactor, tritium is mainly discharged into the hydrosphere. A significant part of tritium also enters the environment during the reprocessing of spent nuclear fuel. Currently, the problem is the development of effective, simple, affordable, inexpensive and low-energy methods for extracting tritium from large volumes of low- and intermediate-level aqueous solutions. Review of previous publications. At nuclear power plants, it is widely used for the purification of small volumes of highly active process waters by isotopic exchange in the "hydrogen-water" system [patents RU 2380144, RU 2060801, RU 2525423, RU 2148426]. There are methods for isotopic fractionation of НTO by low-temperature rectification, which either requires significant energy consumption or occurs with a very insignificant isotopic effect at the level of 1.1 [patents UA 57558, RU 2010772, RU 2091336]. In world practice, mineral adsorbents are widely used, but there are no developments designed to purify aqueous solutions from tritium. Our previous studies have clarified the possibility of using layered silicates and zeolite for the extraction of tritium from aqueous solutions (patents UA 103033, UA 103050, UA 113348). The ability of other minerals to adsorb tritium from aqueous solutions remains unresolved. In order to solve this problem, we involved in experimental research minerals from the classes of hydroxides, sulfates and chain silicates. Purpose. The aim of the work is to determine the influence of the structural features of mineral adsorbents on the removal of tritium from proto-tritium water ("НTO") and the possibility of using a more expanded spectrum of minerals as such adsorbents. Results. Up to 39% of tritium extracted from tritiated water is retained in hibsite in surface adsorbed form. In the boundary layer, heavier НTO molecules are retained with a greater advantage than H2O molecules (α = 1.14). Gypsum: due to the substitution of OH groups of the gypsum crystal lattice by OT groups in the mineral structure, up to 36% of the absorbed tritium solution with partial isotope-hydrogen fractionation is fixed. Due to the presence of tangled fibrous microtexture in wollastonite, a significant part of tritium absorbed during the experiment from a solution of tritiated water is fixed in a surface adsorbed form (61.3%, fractionation coefficient α = 1.03). The reaction of hydroxylation of CaO when it interacts with tritiated water is accompanied by a predominant binding to calcium of OT groups formed by the dissociation of НTO molecules because heavy hydrogen isotopes form a stronger covalent bond with oxygen than with protium (α = 1.23). Conclusions. The highest total ability to extract tritium from aqueous solution was observed in hibsite (38.7%), and the lowest - in wollastonite (34.5%). The obtained new scientific results with the involvement of the results of our previous studies provide an opportunity for more effective development of methods for detritalization of aqueous so-lutions.

Degradation of p-arsanilic acid by pre-magnetized Fe0/persulfate system: Kinetics, mechanism, degradation pathways and DBPs formation during subsequent chlorination

Pre-magnetized Fe0/persulfate (pre-Fe0/PS) process was innovatively employed for controlling the pollution of p-arsanilic acid (p-ASA). This process showed favorable removal performance, achieving almost complete elimination of 10 mg/L p-ASA within 30 min at the reaction conditions of 0.2 g/L pre-Fe0 and 1 mM PS. The increase of PS concentration and pre-Fe0 dosage was conducive to the degradation. The coexistence of Cl−, NO3− and SO42− accelerated the removal, however the presence of HCO3− and HA presented the opposite trend. The p-ASA degradation decelerated gradually with increasing pH from 5 to 9. Its removal was caused by the attack of reactive oxygen species (i.e., SO4−, OH, O2−), which could be continuously formed via the Fe2+/Fe3+ cycle in solution and on pre-Fe0 surface. In pre-Fe0/PS system, SO4− in solution, surface-bound SO4−, OH, OH in solution, O2− in solution and Fe(IV) contributed to the p-ASA degradation. A plausible transformation route related to the break of C-N and As-C bonds, the substitution of OH group was put forward. More importantly, the released inorganic arsenic during p-ASA decomposition could be effectively controlled through multiple functions including the precipitation, co-precipitation and sorption, which was well confirmed by XPS, FTIR and XRD analysis. Pre-Fe0/PS and Fe0/PS pretreatments both reduced the generation of C-DBPs except for chloral hydrate, while increased the formation of N-DBPs except for trichloroacetamide.

Activity correlation among singlet-oxygen quenching, free-radical scavenging and excited-state proton-transfer in hydroxyflavones: Substituent and solvent effects

Substituent and solvent effects on activities of singlet-oxygen (1O2) quenching, free-radical scavenging and excited-state proton-transfer (ESPT) in hydroxyflavones were investigated by means of laser, stopped-flow and steady-state spectroscopies together with density functional calculations. Some correlations were found among the three reaction activities. Substitution of OH group at the 5-position in hydroxyflavones increases the ionization energy, hinders the electron transfer from the molecule to 1O2 and free-radicals, and causes deactivation of the 1O2 quenching and free-radical scavenging in ethanol, although the ESPT is very efficient. OH substitution at the 7-position has a negligible influence on the 1O2 quenching and free-radical scavenging activities, but induces solvent-assisted ESPT, which is deactivated by substitution of a catechol structure at B-ring. A synergetic effect between the electron transfer and ESPT-induced potential-surface distortion is likely present on the 1O2 quenching and free-radical scavenging activities. The 1O2 quenching activity of 3,3’,4’-trihydroxyflavone monotonously increases with increasing water concentration in the ethanol solution, whereas addition of a small amount of water respectively activates and deactivates the ESPT and free-radical scavenging, whose activity changes are saturated by addition of a large amount. The reason for these results can be explained in terms of the nodal-plane model, ionization energy difference and potential-curve distortion/displacement with regard to the ESPT and solvation.

Antioxidant Activity Evaluation in a Series of Heterocyclic Compounds Derived from 1,8-Diaminonaphthalene

From (2,3-dihydro-1H-perimidin-2-yl)-phenyl, the substitution of OH group in ortho or para position on the phenyl ring, allows us to synthesize the studied compounds. These three compounds have been characterized by conventional spectroscopic methods (NMR and MS). The interest of this work is to review the antioxidant activity of our compounds. The antioxidant activity screening carried out according to FRAP and DPPH methods revealed significant anti-free radical properties for compounds 1 and 2 even at low concentrations. In contrast to the compound 2, compound 3 for which the OH group is substituted in para position has the lowest activity in both cases. Therefore the para position seems to be the least sensitive position to increase the antioxidant activity of this pharmacophore.

Activating Effect of Aluminum Chloride in the Technology of Poly-Sulfides and Materials Based on them

The paper investigates the influence of an electrophilic agent in the inorganic polysulfide technology. A tight contact between the modified silicate filler and sulfur (when heated and then pressed) results in the appearance of new interatomic bonds and interphase interaction forces to ensure the best possible structure formation in a system in the micro and macro level. Cross-linking of silica gel by disulfide fragments shows greater stability. The activation energies were calculated for insertion of diatomic sulfur (singlet and triplet) by an oxygen atom and a silicon atom, with the substitution of OH-group, as well as for addition of diatomic sulfur to the surface of silica gel modified with aluminum chloride. Aluminum chloride acts as an activator for both a silica-containing material and sulfur, and encourages the chemical interaction between the components, and formation of polysulfides and sulfur materials from them, which have high physical mechanical properties.

QSAR models for analgesic activity prediction of terpenes and their derivatives

In the present study, quantitative structure-activity relationship (QSAR) models were developed to predict analgesic activity of some mono-/bicyclic terpenoids and their esters with neurotransmitter amino acids. All the models were developed using structural descriptors calculated by SiRMS approach based on the simplex representation of the molecular structure. Log P, molecular refraction, electronegativity, and molecular mass were used as integral descriptors additionally to calculated 2D simplex descriptors. Predictive QSAR models were obtained using the partial least squares (PLS) method. The analysis of structural factors influence on the manifestation of analgesic activity for studied compounds was carried out in the following pharmacological tests: capsaicin, formalin, allylisothiocyanate, and “hot plate” tests. We found that the most significant contribution to analgesic action in all pharmacological tests exhibited molecular fragments representing menthol and borneol residues. Also, we may conclude that –OH group substitution in terpenoid molecules for GABA or glycine residues leads to enhancement of analgesic effect due to the presence of additional highly reactive C=O and N–H groups playing the role of H-bond donors/acceptors.

Fluorination/Torrefaction Combination to Further Improve the Hydrophobicity of Wood

AbstractFollowing recent works on gas/solid fluorination applied to massive wood that sustainably increased its hydrophobicity thanks to the substitution of OH groups by covalent fluorine atoms, the present paper demonstrates that torrefaction may replace the step of the removal of HF. Because of the strength of covalent CF bonds, torrefaction does not result in defluorination. The fluorination/torrefaction combination acts at two scales: the surface develops hydrophobicity thanks to the presence of fluorine atoms whereas torrefaction enhances the water molecules barrier. Such improvements are achieved whatever the initial hydrophilicity of the wood species contrary to the fluorination or torrefaction alone.

Isolation and acetylation of cellulose nanostructures with a homogeneous system

A homogeneous system for nanocellulose acetylation was investigated. Cellulose nanostructures (CNS) were obtained from microcrystalline cellulose, and modification was conducted to increase hydrophobicity and physico-chemical properties of the nanoparticles. Sulfuric acid and hydrochloric acid were used for the isolation. The CNS were characterized with dynamic light scattering, zeta potential, atomic force microscopy, Fourier-transform infrared spectroscopy, nuclear magnetic resonance, X-ray photoelectron spectrometry, degree of substitution (DS), X-ray diffraction (XRD), and thermogravimetric analysis. Nanostructures obtained with sulfuric acid showed lower particle sizes and lower thermal stability. After modification, the results indicated the substitution of OH groups in cellulose structure by acetyl groups. The XRD patter was considerably modified and it was verified that acetylation increased the thermal stability. Different methods were used to calculate the DS, and the differences between the methodologies were explained. The acetylated samples play an important role in the nanocomposites field, since the hydrophobic surface increase its applications.

HYDROGEN SULFIDE IN NUCLEOPHILIC SUBSTITUTION REACTIONS OF HYDROXY GROUPS IN AROMATIC ALCOHOLS

Most methods of obtaining aromatic thiols are based on nucleophilic substitution reactions at halogen derivatives of aromatic hydrocarbons when used as nucleophilic reagents sodium thiolate, thiourea or potassium xanthate at high temperatures, pressure and in the presence of catalysts. The direct reaction of nucleophilic substitution of OH-groups in the phenols, pyrocatechol and benzyl alcohol to the HS-group in conditions of one-electron reducrion of hydrogen sulfide in acetonitrile and pyridinium ionic liquid was investigated for the first time. The proposed reactions proceed at room temperature and atmospheric pressure. The use of "green" solvent - ionic liquid - reduces the syntheses time in а half, improves ecological safety friendliness of the process and reduces the consumption of reagents. The main positive feature of these studies is not only ecological safety of reactions of nucleophilic substitution (due to the lack of harmful byproducts), but the use of electrochemical reactions in ionic liquid media, that is very relevant in modern science in terms of new environmental technologies development.
 For citation:
 Okhlobystina A.V., Okhlobystin A.O., Berberova N.T., Burmistrova D.A. Hydrogen sulfide in nucleophilic substitution reactions of hydroxy groups in aromatic alcohols. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 36-41
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Condensation of 1,2,4-Butanetriol with Carbonyl Compounds and Reactions of Hydroxyalkyl-1,3-dioxacyclanes

A mixture of isomers of 2-(1,3-dioxolan-4-yl)ethanol and 1,3-dioxan-4-ylmethanol was prepared by reaction of 1,2,4-butanetriol with paraformaldehyde. This mixture was subjected to O-alkylation, O-acylation, condensation with phenyl isocyanate, and substitution of OH groups for Cl. The relative activity of acetone derivatives of glycerol and 1,2,4-butanetriol in reactions with allyl chloride and benzyl chloride was estimated.

The effect of lignin on the reactivity of natural fibres towards molecular fluorine

In this study, a range of natural fibres and their main components have been treated by direct fluorination using F2 gas. Fourier-Transform infrared spectroscopy, 19F solid state Nuclear Magnetic Resonance and tensiometry results underline the substitution of OH groups by fluorine atoms and thus the formation of CF covalent bonds. Fluorination induces a significant decrease in the hydrophilic properties in the case of lignocellulosic materials. The relationship between the chemical composition of the natural fibres and their reactivity during fluorination has been established. Indeed, on the one hand, the affinity for F2 is improved by the presence of lignin, leading to a better conversion of COH into CF bonds. On the other hand, a high cellulose content tends to inhibit the reaction. As a consequence, the cellulose and lignin contents of wood materials can be determined thanks to their reactivity during fluorination. However, for high-content cellulose materials, estimating the cellulose and lignin contents by this method is more difficult because of their low reactivity during fluorination. In this case, a thermal assisted fluorination is necessary to increase reactivity and thus classify samples according to their cellulose content.

Influence of Dissolved Metals on N-Nitrosamine Formation under Amine-based CO2 Capture Conditions.

As the prime contender for postcombustion CO2 capture technology, amine-based scrubbing has to address the concerns over the formation of potentially carcinogenic N-nitrosamine byproducts from reactions between flue gas NOx and amine solvents. This bench-scale study evaluated the influence of dissolved metals on the potential to form total N-nitrosamines in the solvent within the absorber unit and upon a pressure-cooker treatment that mimics desorber conditions. Among six transition metals tested for the benchmark solvent monoethanolamine (MEA), dissolved Cu promoted total N-nitrosamine formation in the absorber unit at concentrations permitted in drinking water, but not the desorber unit. The Cu effect increased with oxygen concentration. Variation of the amine structural characteristics (amine order, steric hindrance, -OH group substitution and alkyl chain length) indicated that Cu promotes N-nitrosamine formation from primary amines with hydroxyl or carboxyl groups (amino acids), but not from secondary amines, tertiary amines, sterically hindered primary amines, or amines without oxygenated groups. Ethylenediaminetetraacetate (EDTA) suppressed the Cu effect. The results suggested that the catalytic effect of Cu may be associated with the oxidative degradation of primary amines in the absorber unit, a process known to produce a wide spectrum of secondary amine products that are more readily nitrosatable than the pristine primary amines, and that can form stable N-nitrosamines. This study highlighted an intriguing linkage between amine degradation (operational cost) and N-nitrosamine formation (health hazards), all of which are challenges for commercial-scale CO2 capture technology.

Mechanistic aspects of superacid mediated condensation of polyphenols with ketones. Implications for polymer synthesis.

A detailed computational study of possible reaction paths for methanesulfonic and triflic acid mediated polyhydroxyalkylation reaction between resorcinol and trifluoracetone accompanied by cyclodehydration to give 9H-xanthene containing polymers has been carried out at M06-2X/6-311+G level of theory. A cluster solvation model was used for the calculations. The calculations revealed that the most kinetically favorable reaction path involves the cyclodehydration occurring during the polymer forming step. In this case 9H-xanthene formation is promoted by the activated phenyl ring in Wheland intermediate assisting the aromatic nucleophilic substitution of OH group which leads to the cyclization. It has been demonstrated that the inability of methanesulfonic acid to catalyze the formation of 9H-xanthene containing polymers is due to the very high barrier of the rate limiting step of the polymer forming reaction and not the cyclodehydration process.

Structure and H position of tetragonal hydrogarnet derived from CaGeO3garnet

Hydrogarnets, represented by hydrogrossular, are produced by the replacement of (ZO4)4- in garnets by (H4O4)4- (Z: tetrahedral cation) and the vacancies of tetrahedral cations are created by this replacement. Most of reported hydrogarnets crystallizes with cubic symmetry (space group Ia-3d). To our knowledge, Ca3Mn2[SiO4]2.07[H4O4]0.93 with space group I41/acd (tetragonal) [1] has been only reported as a low-symmetry hydrogarnet. In the cubic hydrogarnets, all O atoms are crystallographically equivalent, whereas in low-symmetric one, they can be located at non-equivalent sites. Therefore, the investigation of low-symmetry hydrogarnes is important to gain knowledge of the site preference of H atoms. Recently, we have successfully synthesized the single crystal of a new low-symmetry hydrogarnet CaGe0.924O3H0.304 (= Ca3(CaGe)[GeO4]2.696[H4O4]0.304) with tetragonal space group I41/a, at 3 GPa and 1273 K under the presence of H2O component. This tetragonal hydrogarnet is produced by the partial replacement of (GeO4)4- in high-pressure CaGeO3 garnet, Ca3(CaGe)[GeO4]3, by (H4O4)4-. In the present study, we report the single crystal X-ray diffraction study of this hydrogarnet at 98 and 298 K. In the structure refinement at 298 K, the occupancy parameters resulted in 0.393(2) for tetrahedral Z2(Ge) site, coordinated only by O6 atoms, and showed no significant deviation from 1.0 for the remaining cation sites. The bond valence sums of each atom except O6 atom agree with the valences of occupied atoms, whereas that of O6 atom are 1.50, deviating largely from oxygen valence. Thus, the substitution of OH groups for O atoms in the present sample occurs only at O6 site, which indicates that O6 is the most preferential site for the OH substitution. The position of H atom will be examined from the residual electron density distributions at a low temperature of 98 K, and the hydrogen bonding in the crystal structure will be discussed.

Synthesis, DNA-binding study, and antioxidant activity of 14-aryl-14H-dibenzo[a,j]xanthene derivatives

A simple and efficient one-pot method for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthene derivatives using Ni(ClO4)2·6H2O as a catalyst is described. DNA-binding properties of 14-aryl-14H-dibenzo[a,j]xanthene derivatives 1a, 1j, 1l, 1m, and 1n were investigated using calf thymus DNA by electronic absorption spectroscopy and fluorescence spectroscopy. Binding constant (K b) with DNA was calculated from the absorption measurements. The spectral changes observed such as hypochromicity, red shift, and isosbestic point are consistent with the intercalation mode of binding of the chromophore into the stack DNA base pairs. Among the five, compound 1n with strong electron donating substituents on the phenyl ring shows better intercalative binding with DNA. Investigations of antioxidant properties show that the dibenzo[a,j]xanthene 1m with –OH group substitution has high radical scavenging properties against DPPH and ABTS+.

Microwave-assisted synthesis and characterization of phthalocyanines substituted with azo compound containing eugenol moiety

The new metallophthalocyanines (Co, Ni, Cu, and Zn) substituted with azo compound containing eugenol moiety are described. Firstly, azo compound ( I) containing eugenol moiety was synthesized by treating eugenol with p-hydroxyaniline. Then phthalonitrile compound ( 1) was synthesized by microwave-assisted synthesis method. The purification of phthalonitrile compound ( 1) was carried out by column chromatographic separation. Intramolecular hydrogen bonding in the azo compound ( I) prevent base-catalyzed nucleophilic aromatic substitution of OH group belongs eugenol. At the last step, metallophthalocyanines (1a, 1b, 1c, and 1d) were synthesized by the microwave irradiation. The microwave-assisted synthesis method reduces reaction times and enhances the yield of the reactions. All phthalocyanine compounds are soluble in DMF and DMSO. The structures were confirmed by elemental analysis, 1H NMR, 13C NMR, UV/Vis, IR and Mass spectra.

Torsionally Controlled Electronic Coupling in Mixed-Valence Oxodimolybdenum Nitrosyl Scorpionates - a DFT Study

The density functional theory (DFT) method has been used to study the electronic communication in strongly interacting oxo-bridged di-{Mo(II,I)(NO(+))}(3+,2+) complexes stabilized by tris(3-methylpyrazol-1-yl)borate, [Tp(Me)](-) (dihydroxy 1' and its modified analogs), having fully localized valences on the two Mo centers (Class I), despite a short (ca. 3.8 A) Mo...Mo distance. Structural and electrochemical (separation between the redox potentials Delta(red/ox)E(1/2)) properties and IR spectra (in particular the nu(NO) frequencies) obtained from the B3LYP calculations for 1' are successfully related to experimental values. Strongly twisted geometry with the (O)N-Mo1...Mo2-N(O) angle close to 90 degrees (confirmed by DFT modeling performed for 1'(-1,0,+1) and X-ray diffraction study of [{Mo(NO)(Tp(Me2))(OH)}(2)(mu-O)](-) (1) presented herein) is a common, though so far not fully understood, structural feature of this class of mu-oxo species, in contrast to the closely related {Mo(V)(=O)}(3+) analogs. This study shows that the orthogonality of the local equatorial planes for the two Mo centers may be rationalized by the electronic structure, namely from the balance between the destabilizing repulsion of the Mo-based (d, pi(x)*)(b) electron pairs versus a favorable but relatively weak electron delocalization. Strongly repelling electron pairs avoid each other, which enforces the twisted geometries and blocks the electron delocalization. Steric hindrance (a nonbonding repulsion of the adjacent Tp(x) ligands and the weak hydrogen-bonding interactions, i.e., OH...ON, OH...OH, and C-H...O((NO/OH))) is shown not to be decisive since neither the removal of the inner 3-Me groups of [Tp(Me)](-) in complex 1' nor the substitution of OH groups by OCH(3) ligands did substantially influence the dihedral twist angle in the minimum energy structure. Yet the relative orientation of the {Mo(NO)}(2+,3+) cores along with the position of the bridging oxygen (significantly bent upon reduction) controls the prospective intramolecular through-bond electron transfer in the mixed valence form. Our DFT modeling demonstrates that a maximum delocalization (via a hole-transfer mechanism) of the unpaired electron in 1'(-), measured as a spin population on the nonreduced Mo2 center, is achieved for the structure with a torsional deflection of 23 degrees, at a cost of 16.5 kcal/mol. These results show that the electron exchange along the Mo-O-Mo array in the originally fully valence-trapped {17e:16e}(-) complexes may be controlled and can be thermally activated (e.g., using a high-boiling solvent or by irradiation at ca. 50-200 cm(-1)).

Transfection efficiencies of PAMAM dendrimers correlate inversely with their hydrophobicity

Dendriplexes were characterized by ethidium bromide intercalation assay and their transfection efficiency was studied using HEK 293 cells and human mesenchymal stem cells. PAMAM G4 showed a higher transfection efficiency than PAMAM G3–G6, G4-OH, G4-25% or G4-50% dendrimers. Substitution of OH groups for the NH 2 surface groups rendered the dendrimer unable to form dendriplexes and to transfect cells. Partial (25%) substitution of CH 3 groups for the NH 2 groups markedly impaired transfection; 50% substitution decreased the ability of PAMAM G4 to transfect threefold. It was concluded that increased hydrophobicity decreased the ability of dendrimers to transfect. PAMAM G4-50% is highly hydrophobic and forms micelles in solution, which can transfect pGFP. The results of ethidium bromide intercalation assays, ANS fluorescence studies and transfection efficiencies of PAMAM dendrimers were correlated. Subsequently, we constructed a neurotrophin-encoding plasmid and studied its delivery to mesenchymal stem cells using PAMAM G4 dendrimer and Lipofectamine 2000. Lipofectamine 2000 was a more effective carrier (18.5%) than PAMAM G4 dendrimer (1.2%).

Theoretical study of polyoxide clusters Sc20O30, P20O50, Ti20O30F20, and V20O30F20

The structural, electronic, and vibrational characteristics and energies of the isolated polyoxide clusters Sc20O30, P20O50, Ti20O30F20, and V20O30F20 and ammonia complexes Sc20O30 · nNH3 were calculated by the density functional theory B3LYP method with several basis sets. The computation results show that a fullerene-like closo structure Ih with oxygen bridges located above the midpoints of the edges of an empty [M20] dodecahedron is preferable for the Ti20O30F20 and V20O30F20 clusters with four-coordinate metal atoms protected by the outer M-F bonds. This structure with a cage diameter of ∼1 nm and the diameter of nearly planar decagonal faces (windows) of ∼0.5 nm is stable to dissociation into fragments and to strong geometric distortions and retains its closo shape when molecules like NH3 and anions like H− are attached to the cage. An analogous closo structure is favorable for the P20O50 cluster; however, in this structure, the [P20] cage is severely distorted and all 12 windows are strongly corrugated. For Sc20O30, the Ih dodecahedron with bare three-coordinate Sc atoms corresponds to a local minimum of the potential energy surface, which is 170–200 kcal/mol less favorable than compact puck-shaped isomers in which four- and five-coordinate metal atoms and three- and four-coordinate oxygen atom prevail. “Solvation” of the dodecahedral and puck-shaped Sc20O30 isomers by ammonia molecules strongly decreases the energy gap between the isomers; however, the dodecahedron Ih in all cases remains a high-lying intermediate. According to calculations, most polyoxides under consideration have a high electron affinity (comparable with or higher than that of fullerenes) and is able to add three to five or more alkali-metal atoms to form radical salts in which clusters are in the state of polyanions. Because of large sizes of the [M20] cages and their windows, the interior of the cage (as distinct from fullerenes) can accommodate a considerable number of atoms and several small molecules. The V20O30F20 cluster has 20 unpaired electrons and can be treated as a molecular magnet. The properties of the [M20] cages depend only slightly on the outer substituents. It is suggested that the pattern will be retained upon the substitution of OH groups for the F atoms and that the hydroxo-substituted clusters can bind to each other through hydrogen bridges and serve as building blocks for self-assembly into ordered nanometer and crystalline structures of various dimensions.