Antimony Atoms Research Articles

First-principles study of three isomers of the large birefringent crystal Sb4O4F4: electronic structure and optical properties

Abstract Metal oxyhalides are becoming an important branch of birefringent materials due to their rich structural types and stable physicochemical properties. In this work, the electronic structure and optical properties of three isomers of antimony oxyhalide Sb4O4F4 (I- Pna21), Sb4O4F4 (II- Pnma), and Sb4O4F4 (III- Pnma) were investigated using first principles method. The results show that the band gap of I and III reaches the ultraviolet region (4.10 eV (I), 3.87 eV (III)). In particular, I-III all exhibit large birefringence of 0.138–0.266 at 1064 nm. Born effective charge, and project density of states results show that the large birefringence of I-III is mainly from the stereochemically active lone pair electrons around the antimony atom. Finally, structure–property relationship studies of I-III indicate that different Sb-F bonds and structural arrangements are the key factors leading to the significantly different properties.

Synthesis, Characterization, and Biological Investigation of Antimony(III) Halide Complexes With Different Coordination Architectures Constructed From Thiophene Thiosemicarbazones

ABSTRACTIn this study, we report the synthesis, characterization, and biological investigation of antimony(III) halide complexes with various coordination architectures constructed from thiophene thiosemicarbazones. Antimony(III) thiophene‐2‐carbaldehyde thiosemicarbazone complexes (1, 2, 4, and 5) exhibit a square pyramidal geometry, with ligands coordinated to the central antimony atom in two distinct binding modes. In contrast, antimony(III) 2‐acetylthiophene thiosemicarbazone complexes (3, 6, and 7) adopt a seesaw geometry. These complexes (1–7) represent the first reported examples of antimony(III) halide thiosemicarbazone compounds. The unique coordination environments observed in these complexes are of significant importance within the realm of antimony chemistry. These synthesized complexes exhibit different coordination geometries as well as potential biological activities. The antiproliferative activity against the human breast adenocarcinoma (MCF‐7) cell line and antimicrobial activity against Gram‐positive and Gram‐negative bacteria were assessed. Antimony(III) thiophene‐2‐carbaldehyde thiosemicarbazone complexes (1, 2, 4, and 5) showed significant antiproliferative activity with IC50 values ranging from 8.5 to 19.1 μM, while antimony(III) 2‐acetylthiophene thiosemicarbazone complexes (3, 6, and 7) had higher IC50 values. Additionally, the antimony complexes demonstrated selective antimicrobial activity against Gram‐negative bacteria.

Investigating the role of graphene in the formation and stability of [formula omitted]-phase antimonene islands

Two-dimensional materials have shown tremendous potential for various technological applications. Particularly, 2D antimony exhibits high applicability in electronics, sensors, and batteries. This 2D material, known as antimonene, presents two stable phases: α (rectangular lattice) and β (honeycomb lattice), whose formation depends on the substrate where antimony is deposited. In this study, we investigated the growth of antimonene islands on graphene, forming an antimonene/graphene heterostructure. To demonstrate the significance of graphene in the synthesis of antimonene, we also studied antimony deposited on a bare copper foil similar to the one used for the graphene substrate. Antimony deposition exhibits the β phase antimonene structure when deposited on top of monolayer graphene, but not when deposited on a bare copper foil, nor on top of multilayer graphene. Additionally, we investigated the stability of the heterostructure after exposure to air. Pure antimony islands are formed when evaporated in high vacuum on top of graphene and copper substrates, and antimony atoms oxidize upon exposure to air. After annealing the sample in ultra-high-vacuum at temperatures lower than 200 °C, more than half of pure antimony is recovered and almost all oxidized antimony is desorbed from the graphene substrate. In contrast, almost none of the oxidized antimony is desorbed from the bare copper substrate, highlighting the key role of the heterostructure on the formation and preservation of the physical and chemical properties of the deposited 2D material.

Antimony-mediated few-layer metallic MoSe2 with rich selenium vacancies for ultrafast sodium/potassium storage

Transition metal dichalcogenides with sandwich structure possess high theoretical capacity, while face the challenge of inferior inherent electronic conductivity and dramatic volume fluctuation during cycling, lessening their fascination for electrochemical energy storage material applications. Herein, we report a crystal phase modulation strategy to modulate the electronic structure by doping cation (Sb) into the few-layer 2H-phase MoSe2 lattice, thereby implants abundant selenium vacancies and expands the layer spacing, which transforms it into a 1T-phase (T-MoSe2/C-1). The few-layer 1T-MoSe2 nanosheets are confined within chlorella-derived N, P-doped bio-carbon, endowing T-MoSe2/C-1 with a rock-solid structure, rapid Na+/K+ transport kinetics, and high reversibility. Density functional theory calculations confirm that the antimony atoms in T-MoSe2/C-1 system significantly increase the electronic conductivity, decrease the Na+/K+ diffusion barrier and reinforce the adsorbed capability for Na+/K+. Consequently, the T-MoSe2/C-1 achieves a reversible capacity of 540 mAh/g at 0.5 A/g and delivers as high as 333 mAh/g even at a high rate of 25 A/g for SIBs. As the anode of PIBs, it maintains a stable capacity of 210 mAh/g after 1,000 cycles at 5 A/g. This study provides a new horizon on the phase regulation of transition metal dichalcogenides (TMDs) to improve sodium/potassium-ions storage.

Synthesis of Sb688-: Crafting a Homoatomic Antimony Nanotorus.

Pure-element cyclic molecules have garnered extensive attention owing to their intriguing structures and promising applications. Among these, carbon-based cyclic molecules such as cyclo[n]carbon (Cn, n = 10-26) and carbon nanotori have ignited significant interest in both experimental and theoretical investigations. However, systematic investigations of analogous cyclic counterparts of heavier main-group elements are limited, with only a few known by theoretical studies. Furthermore, these corresponding cyclic structures lack synthetic examples in the condensed phase, primarily attributed to their high reactivity resulting from lone electron pairs and the absence of electronic delocalization, which typically aids in stabilizing the structure. In this work, we introduce the pioneering synthesis of a pure antimony-based inorganic nanotorus, denoted as Sb688-, facilitated by the incorporation of C60 for oxidation by utilizing wet-chemistry methodologies. The unique nanotorus structure was meticulously examined via single-crystalline X-ray diffraction, unveiling its composition of 68 antimony atoms and forming a tubular structure with approximate dimensions of 18.5 × 18.4 Å2 in a square shape. Theoretical calculations further revealed that the nanotorus structure, characterized by 16 delocalized electrons distributed across eight 3c-2e σ bonds, effectively saturated the eight two-coordinated Sb atoms within the cluster. This study unveils an innovative approach to synthesizing cyclic compounds solely from pure elements, departing from traditional methods dependent on chemical vapor deposition or surface synthesis, and heralds a profound paradigm shift in physical science.

The Elemental Composition Investigation of Silicon Doped with Gallium and Antimony Atoms

The Elemental Composition Investigation of Silicon Doped with Gallium and Antimony Atoms

Turning copper into an efficient and stable CO evolution catalyst beyond noble metals

Using renewable electricity to convert CO2 into CO offers a sustainable route to produce a versatile intermediate to synthesize various chemicals and fuels. For economic CO2-to-CO conversion at scale, however, there exists a trade-off between selectivity and activity, necessitating the delicate design of efficient catalysts to hit the sweet spot. We demonstrate here that copper co-alloyed with isolated antimony and palladium atoms can efficiently activate and convert CO2 molecules into CO. This trimetallic single-atom alloy catalyst (Cu92Sb5Pd3) achieves an outstanding CO selectivity of 100% (±1.5%) at −402 mA cm−2 and a high activity up to −1 A cm−2 in a neutral electrolyte, surpassing numerous state-of-the-art noble metal catalysts. Moreover, it exhibits long-term stability over 528 h at −100 mA cm−2 with an FECO above 95%. Operando spectroscopy and theoretical simulation provide explicit evidence for the charge redistribution between Sb/Pd additions and Cu base, demonstrating that Sb and Pd single atoms synergistically shift the electronic structure of Cu for CO production and suppress hydrogen evolution. Additionally, the collaborative interactions enhance the overall stability of the catalyst. These results showcase that Sb/Pd-doped Cu can steadily carry out efficient CO2 electrolysis under mild conditions, challenging the monopoly of noble metals in large-scale CO2-to-CO conversion.

The Elemental Composition Investigation of Silicon Doped with Gallium and Antimony Atoms

This work is devoted to the development of a diffusion technology for creating gallium antimonide (GaSb)-type complexes in the silicon crystal lattice as well as to the study of the electrical characteristics of the resulting layers. Based on the X-ray spectral analysis of the microcrystals formed on a silicon sample surface that was simultaneously doped with gallium and antimony atoms, it was demonstrated that the sample surface layer contains microcrystals having silicon, gallium, and antimony atoms. This allowed to admit a possibility of the oriented growth of crystals of the composition (GaSb)0.8Si0.2 on the silicon surface. A substantial impact of the processes of the complex formation that occured at high concentrations of ions of diffusing impurities on the distribution profile of charge carriers is demonstrated. Materials containing GaSb-type complexes in the bulk of the silicon lattice can be produced using ion doping, simultaneous diffusion, or epitaxy processes.

Exploring the synthesis, structure and bioactivity of pyrimidine carboxylic acid-derived organic antimony (V) complexes: Cytostatic and antimicrobial evaluations

Eight new organoantimony complexes, R3SbL2 (R = Ph, p-MePh; L = L1, L2) and (R3Sb)2OL2 (R = pHPh, m-MePh; L = L1, L2), [Ph3Sb(C5H3N2O2)2] (1), [(Ph3Sb)2O(C5H3N2O2)2] (2), [(p-tol)3Sb(C5H3N2O2)2] (3), [(m-tol)6Sb2O(C5H3N2O2)2] (4), [Ph3Sb(C5H3N2O2)2] (5), [(Ph3Sb)2O(C5H3N2O2)2] (6), [(p-tol)3Sb(C5H3N2O2)2] (7) and [(m-tol)6Sb2O(C5H3N2O2)2] (8), were designed and synthesized by the reaction of 4-pyrimidine carboxylic acid (HL1) or 5-pyrimidine carboxylic acid (HL2) with organoantimony precursors. All the complexes were characterized by elemental analysis, FT-IR, NMR (1H and 13C), and single crystal X-ray diffraction analysis. Crystal structure results reveal that the central antimony atom of all the complexes displays a triangular biconical geometry. Among them, complexes 1, 3, 5 and 7 show a monomeric structure, while complexes 2, 4, 6 and 8 have a dimeric structure with oxygen bridges. The in vitro cytostatic activities of the eight complexes against a human alveolar basal epithelial lung cancer cell lines (A549) and hepatocellular carcinoma cell lines (HepG-2) were investigated, and the results showed that the organoantimony derivatives with the tolyl groups (3, 4, 7, 8) exhibited higher in vitro cytostatic activities compared with those with the phenyl groups (1, 2, 5, 6). At the same time, bacteriostatic tests were conducted to assess the inhibitory effects of complexes 1–8 against three prevalent plant pathogenic fungi and one bacterium. The results revealed that complex 4 exhibited significant fungicidal activities, on the other hand, complex 3 exhibited higher antibacterial activity against MRSA. These results will provide significant guidance for the further exploration of potential efficient biological activity complexes.

Tunable Pnictogen Bonding at the Service of Hydroxide Transport across Phospholipid Bilayers.

Our growing interest in the design of pnictogen-based strategies for anion transport has prompted an investigation into the properties of three simple triarylcatecholatostiboranes (1-3) of the general formula (o-C6Cl4O2)SbAr3 with Ar = Ph (1), o-tolyl (2), and o-xylyl (3) for the complexation and transport of hydroxide across phospholipid bilayers. A modified hydroxypyrene-1,3,6-trisulfonic acid (HPTS) assay carried out in artificial liposomes shows that 1 and 2 are potent hydroxide transporters while 3 is inactive. These results indicate that the steric hindrance imposed by the three o-xylyl groups prevents access by the hydroxide anion to the antimony center. Supporting this interpretation, 1 and 2 quickly react with TBAOH·30 H2O ([TBA]+ = [nBu4N]+) to form the corresponding hydroxoantimonate salts [nBu4N][1-OH] and [nBu4N][2-OH], whereas 3 resists hydroxide coordination and remains unperturbed. Moreover, the hydroxide transport activities of 1 and 2 are correlated to the +V oxidation state of the antimony atom as the parent trivalent stibines show no hydroxide transport activity.

Особенности строения продуктов реакций деарилирования пентаарилсурьмы полифункциональными кислотами

It has been established that in reactions with pentaphenylantimony, 2,3-dihydroxybenzoic and 5-hydroxypyridine-2-carboxylic acids behave as bifunctional compounds and form binuclear products [Ph4Sb]+[Ph4Sb(O,O¢-C6H3COOH-3]- (I), Ph4SbOC(O)C5H3NOSbPh4-4 (II), respectively. The reaction with 2,3-dihydroxybenzoic acid occurs with the participation of just hydroxy groups, while the interaction with 5-hydroxypyridine-2-carboxylic acid proceeds with the participation of hydroxy and carboxy groups. 2,6-Dihydroxybenzoic acid reacts with penta(para-tolyl)antimony only at the carboxyl group, giving tetra(para-tolyl)antimony 2,6-dihydroxybenzoate p-Tol4SbOC(O)C6H3(OH)2-2,6 (III). The structures of compounds I–III have been characterized by IR spectroscopy and X-ray diffraction. According to the X-ray diffraction data, crystal I contains [Ph4Sb]+ cations with a slightly distorted tetrahedral coordination of the antimony atom (the CSbC angles are 99.18(14)°-118.07(16)°, the Sb-C bonds are 2.093(4)-2.119(3) Å) and anions containing a five-membered metallocycle [SbO2C2], in which the antimony atom is hexacoordinated (the CSbC cis-angles are 91.52(13)°-102.90(13)°; the CSbО angles equal 85.06(12)°-94.73(13)°, the ОSbО angle is 76.22(9)°). The Sb–O distances in the ring are 2.122(2) and 2,215(2) Å. The Sb–C bonds vary in the range 2.175(3)–2.187(4) Å. In molecule II, the antimony atoms are structurally nonequivalent. One of the atoms, associated with the oxygen atom of the hydroxy group, has the coordination of a distorted trigonal bipyramid (the OSbC axial angle equals 174.5(2)°, the CSbC angles in the equatorial plane are 116.2(3)°-120.9(3)°; the Sb-O and Sb-C distances are 2.256(5) Å and 2.108(7)–2.174(7) Å, respectively). The coordination number of the second antimony atom associated with the oxygen of the carboxyl group is increased to 6 due to coordination of the nitrogen atom of the pyridine ring located in the ortho position with respect to the carboxyl group (the Sb∙∙∙N distance is 2.402(6) Å). The coordination polyhedron of the atom is a distorted octahedron (cis-angles at the antimony atom vary in the range 72.22(19)°-103.6(3)°). The Sb–O bond length is 2.194(5) Å, the Sb–C distances are 2.165(7)–2.189(7) Å. In molecule III the coordination of the antimony atom is a distorted trigonal bipyramid: the OSbC axial angle equals 170.30(8)°, the CSbC angles in the equatorial plane are 112.17(9)°-122.09(9)°; the Sb-O bond is 2.527(2) Å, and the Sb-C bond equals 2.031(2)–2.258(3) Å.

Особенности строения полифункциональных карбоксилатов тетраарилсурьмы

From ferrocenedicarboxylic acid, sulfosalicylic acid and pentaarylantimony Ar5Sb (Ar = Ph, p-Tol) in benzene, fully substituted organoantimony derivatives of ferrocenedicarboxylic and sulfosalicylic acids 1–3 were obtained, the structure of which after recrystallization from a benzene-octane mixture was proven by X-ray diffraction analysis. Structures 1–3 were established by X-ray diffraction. Crystals 1 [C68H64FeO4Sb2, M 1244.54; monoclinic syngony, symmetry group C21/c; cell parameters: a = 16.9983(2), b = 10.94570(10), c = 30.3224(3) Å; β = 99.8220(10); V = 5559.04(10) Å3; Z = 4; calc = 1.487 g/cm3; 2 5.28138.76 degrees; total reflections 32707; independent reflections 10281; number of specified parameters 684; Rint = 0.0496; GOOF 1.062; R1 = 0.0345, wR2 = 0.0853; residual electron density (max/min) 0.76/0.90 e/Å3], 2 [C60H48FeO4Sb2, M 1132.33; monoclinic syngony, symmetry group P21/n; cell parameters: a = 12.40720(10), b = 10.30830(10), c = 36.7290(4) Å; β = 94.1110(10) deg., V = 4685.45(8) Å3, Z = 4; calc = 1.605 g/cm3; 2 4.82138.56 degrees; total reflections 27748; independent reflections 8680; number of specified parameters 604; Rint = 0.0367; GOOF 1.033; R1 = 0.0277, wR2 = 0.0709; residual electron density (max/min) 0.86/0.81 e/Å3], 3 [C63H62O7SSb2, M 1206.78; monoclinic syngony, symmetry group P21/c; cell parameters: a = 20.9246(3), b = 13.5375(2), c = 21.4222(3) Å; β = 111.284(2) deg., V = 5654.30(16) Å3, Z = 4; calc = 1.4175 g/cm3; 2 4.54160 degrees; total reflections 48463; independent reflections 11892; number of specified parameters 699; Rint = 0.0443; GOOF 1.024; R1 = 0.0327, wR2 = 0.0907; residual electron density (max/min) 0.93/0.85 e/Å3]. The antimony atoms in molecules 1, 2 have a distorted octahedral configuration, taking into account the coordination of the carbonyl oxygen atoms to the metal atom. Structure 3 contains tetrahedral tetraaryl stibonium cations, the antimony atoms in which are coordinated with the oxygen atoms of sulfo groups (Sb∙∙∙O(5)=S 2.601 Å), and the same oxygen atom is coordinated with the ortho-hydrogen atom of one of the tolyl groups (H(46)∙∙∙O(5)=S 2.60 Å). Water molecules provide a structure to crystal 3 (H(7)∙∙∙O(4)=S 1.98 Å, H(7)∙∙∙O(5)=S 2.60 Å). (CCDC 2320709 for 1, 2320711 for 2, 2320717 for 3; deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk).

Синтез и строение сольвата бис[3,5-динитробензоата] трис(2-метокси)(5-бром)фенилсурьмы [C6H3(2-OMe)(5-Br)]3Sb[OC(O)C6H3(NO2)2-3,5]2 ∙ PhH ∙ ½ C8H18

Tris(2-methoxy)(5-bromo)phenylantimony bis[3,5-dinitrobenzoate] (1) was obtained from 3,5-dinitrobenzoic acid by oxidative addition to triarylantimony in the presence of tertiary butyl hy-droperoxide in ether, and was isolated by recrystallization from a benzene-octane mixture in the form of a crystal solvate with benzene and octane molecules in its crystal lattice. The structure of solvate 1 was established by the IR spectroscopy and X-ray diffraction analysis (XRD). In the IR spectrum of complex 1, in addition to the absorption bands related to the stretching vibrations of the Sb–C, СAr–О–Ме, and carbonyl groups, there are bands corresponding to the stretching vibra-tions of the C–Br bonds (524 and 555 cm–1). The X-ray diffraction data show that the antimony at-oms in complex 1 have a distorted trigonal bipyramid coordination with carboxylate ligands in the axial position. The antimony atom and two oxygen atoms do not lie on the same straight line and are located in such a way that the OSbO angle is 170.79°. The O…Sb distances (2.134(4) and 2.110(5) Å) are close to the sum of the covalent radii of antimony and oxygen. In addition, accord-ing to the X-ray diffraction data, compound 1 crystallizes in the monoclinic crystal system, space group P21/n. The structural organization in the crystal is formed due to short contacts of oxygen atoms in the nitro groups of the carboxylate ligands with carbon and bromine atoms of the aryl lig-ands of neighboring molecules, as well as hydrogen O...H (2.524–2.715 Å) bonds. In addition, a certain contribution to the formation of the crystal structure is made by the p-p stacking between the aromatic rings of crystallization benzene and the methoxy-bromo-phenyl ligands. The aro-matic rings are displaced in relation to each other and the distance between them is 3.367 Å. Melt-ing point of solvate 1 is 172.6 °C, according to the thermal analysis data. However, further in-crease in temperature is accompanied by decomposition of compound 1, and therefore an exo-thermic peak is observed on the DSC curve at 255.7 °C, corresponding to a mass loss of 31 % ac-cording to the TGA data. Complete tables of atom coordinates, bond lengths, and valence angles are deposited at the Cambridge Crystallographic Data Center (No. 2060562, depos-it@ccdc.cam.ac.uk or http://www.ccdc.cam.ac.uk/data_request/cif)

A geminal antimony(iii)/phosphorus(iii) frustrated Lewis pair.

The geminal Lewis pair (F5C2)2SbCH2P(tBu)2 (1) was prepared by reacting (F5C2)2SbCl with LiCH2P(tBu)2. Despite its extremely electronegative pentafluoroethyl substituents, the neutral 1 exhibits a relatively soft acidic antimony function according to the HSAB concept (hard-soft acid-base). These properties lead to a reversibility in the binding of CS2 to 1, as observed by VT-NMR spectroscopy, while no reaction with CO2 is observed. The reaction behaviour towards heterocumulenes and the specific interaction situation in the CS2 adduct were analysed by quantum chemical calculations. The FLP-type reactivity of 1 has also been demonstrated by reaction with a variety of small molecules (SO2, PhNCO, PhNCS, (MePh2P)AuCl). The reactions of 1 with PhNCO and PhNCS led to different types of cyclic addition products: PhNCO adds with its N[double bond, length as m-dash]C bond and PhNCS adds preferentially with its C[double bond, length as m-dash]S bond. The reaction of 1 with (MePh2P)AuCl gave an adduct {[(F5C2)2SbCH2(tBu)2P]2Au}+ with a clamp-like structure binding a chloride anion by its two antimony atoms in chelate mode. Compound 1 and its adducts have been characterised by X-ray diffraction experiments, multinuclear NMR spectroscopy, elemental analyses and computational calculations (DFT, QTAIM, IQA).

Исследование строения -дикетонатов тетраарилсурьмы Ph4Sb[MeC(O)CHC(O)Ph], p-Tol4Sb[MeC(O)CEtC(O)Me] ∙ 1½ PhH, p-Tol4Sb[MeC(O)СHC(O)NHPh

Reaction of pentaphenylantimony and penta(para-tolyl)antimony with -diketones in benzene (100 °C, 1 h) forms tetraarylantimony -diketonates Ph4Sb[MeC(O)CHC(O)Ph] (1), p-Tol4Sb[MeC(O)CEtC(O)Me] ∙ 1½PhH (2), p-Tol4Sb[MeC(O)СHC(O)NHPh] (3), characterized by IR spectra and X-ray diffraction analysis. Crystals 1 [C34H29O2Sb, M 591.32; triclinic system, symmetry group P–1; cell parameters: a = 9.524(13) Å, b = 9.827(10) Å, c = 17.350(18) Å;  = 99.03(3), β = 101.50(6),  = 111.02(4), V = 1438(3) Å3, Z = 2; cal = 1.365 g/cm3], 2 [C44H48O2Sb, M 730.57; triclinic system, symmetry group P–1; cell parameters: a = 9.740(5) Å, b = 14.283(6) Å, c = 15.174(6) Å;  = 107.818(14), β = 90.292(18),  = 105.33(2), V = 1929,7(16) Å3, Z = 2; cal = 1.257 g/cm3], 3 [C34H30NO2Sb, M 606.34; monoclinic system, symmetry group P21/n; cell parameters: a = 9.396(17) Å, b = 10.23(2) Å, c = 29.45(6) Å; β = 95.91(6), V = 2817(10) Å3, Z = 4; cal = 1.430 g/cm3]. The obtained tetraarylantimony -diketonates are crystal-line compounds with a distinct melting point, resistant to moisture and atmospheric oxygen, and highly soluble in aromatic solvents and polyhalide solvents. Complex 2 is a solvate and contains 1½ benzene molecules. According to the X-ray diffraction data, the antimony atoms in complexes 1–3 have a distorted octahedral coordination, with the chelate ring and two aryl substituents locat-ed in the equatorial plane, while two aryl ligands occupy axial positions.

Особенности строения карбоксилатов тетрафенилсурьмы Ph4SbOC(O)R (R = CH2Cl, CH2Br, CH2l, C6H3F2-2,3) и гидрата нитрата тетрафенилсурьмы Ph4SbONO2 ∙ H2O

The structure of tetraphenylantimony carboxylates Ph4SbOC(O)R [R = CH2Cl (1), CH2Br (2), CH2l (3), C6H3F2-2,3) (4)] and nitrate Ph4SbONO2 ∙ H2O (5) was established by X-ray diffraction analysis (XRD). According to the XRD data, the antimony atoms in complexes 1–5 have the coordination of a distorted trigonal bipyramid with an electronegative ligand in the axial position. The CSbO axial angles are 174.05(7); 171.6(2), 170.3(2); 173.10(12); 177.93(5); 178.02(9), 168.11(9), and 169.33(9) respectively. The X-ray diffraction data: (1) [C26H22O2ClSb, M = 523.64; rhombic system, sp. gr. Pbca; cell parameters: a = 14.382(8) Å, b = 16.681(10) Å, c = 19.270(11) Å; β = 90.00, V = 4623(5) Å3, Z = 8; calc = 1.505 g/cm3;  = 1.328 mm–1; F(000) = 2096.0; region 2q collection: 5.64–56.6; –19 ≤ h ≤ 19, –22 ≤ k ≤ 21, –23 ≤ l ≤ 25; total reflections 69348; independent reflections 5710 (Rint = 0.0398); GOOF = 1.067; R-factor 0.0261]; (2) [C52H46O4Br2Sb2, M = 1138.19; triclinic syngony, sp. gr. P–1; cell parameters: a = 11.096(13) Å, b = 12.510(13) Å, c = 17.62(2) Å;  = 78.01(6), β = 89.35(7),  = 89.71(5), V = 2393(5) Å3, Z = 2; calc = 1.577 g/cm3;  = 2.841 mm–1; F(000) = 1120.0; region 2q collection: 5.16–69.06; –16 ≤ h ≤ 16, –14 ≤ k ≤ 14, –23 ≤ l ≤ 23; total reflections 89320; independent reflections 11788 (Rint = 0.0568); GOOF = 1.034; R-factor 0.0519]; (3) [C26H22O2SbI, M = 615.09; monoclinic syngony, sp. gr. P21/c; cell parameters: a = 12.779(6) Å, b = 10.864(4) Å, c = 17.542(9) Å; β = 100.18(3), V = 2397(2) Å3, Z = 4; calc = 1.704 g/cm3;  = 2.458 mm–1; F(000) = 1192.0; region 2q collection: 6.02–71.46; –20 ≤ h ≤ 20, –17 ≤ k ≤ 17, –28 ≤ l ≤ 28; total reflections 70960; independent reflections 11043 (Rint = 0.0510); GOOF = 1.018; R-factor 0,0537]; (4) [C31H23O2F2Sb, M = 587.24; triclinic syngony, sp. gr. P–1; cell parameters: a = 9.862(13) Å, b = 10.154(13) Å, c = 14.298(2) Å;  = 84.03(6), β = 82.76(7),  = 68.41(5), V = 1318.2(5) Å3, Z = 2; calc = 1.479 g/cm3;  = 1.086 mm–1; F(000) = 588.0; region 2q collection: 6.08–74.28; –16 ≤ h ≤ 16, –17 ≤ k ≤ 17, –24 ≤ l ≤ 24; total reflections 88852; independent reflections 13477 (Rint = 0.0353); GOOF = 1.026; R-factor 0.0359]; (5) [C72H62N3O10Sb3, M = 1494.50; monoclinic syngony, sp. gr. P21/n; cell parameters: a = 23.072(7) Å, b = 10.427(3) Å, c = 27.040(10) Å; β = 95.860(13), V = 6472(4) Å3, Z = 4; calc = 1.534 g/cm3;  = 1.305 mm–1; F(000) = 2992.0; region 2q collection: 5.6–62.16; –33 ≤ h ≤ 29, –15 ≤ k ≤ 15, –39 ≤ l ≤ 39; total reflections 228547; independent reflections 20667 (Rint = 0.0432); GOOF = 1.041; R-factor 0.0303]. Complete tables of atomic coordinates, bond lengths, and bond angles for compounds 1–5 are deposited at the Cambridge Crystallographic Data Center (CCDC 2169943, 2170138, 2213768, 2170205, 2147525; deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk).

Oxidation-dependent Lewis acidity in chalcogen adducts of Sb/P frustrated Lewis pairs.

The reactions of the frustrated Lewis pair (F5C2)2SbCH2P(tBu)2 with oxygen, sulphur, selenium and tellurium led to the mono-oxidation products (F5C2)2SbCH2P(E)(tBu)2 (E = O, S, Se, Te). Further oxidation of these chalcogen adducts with tetrachloro-ortho-benzoquinone (o-chloranil) gave (F5C2)2Sb(CH2)(μ-E)P(tBu)2·CatCl (CatCl = o-O2C6Cl4) with a central four-membered ring heterocycle for E = O, S, and Se. For E = Te the elimination of elemental tellurium led to an oxidation product with two equivalents of o-chloranil, (F5C2)2SbCH2P(tBu)2·2CatCl, which is also accessible by reaction of (F5C2)2SbCH2P(tBu)2 with o-chloranil. The synthesised compounds were characterised by NMR spectroscopy and X-ray structure analyses, and the structural properties were analysed in the light of the altered Lewis acidity due to the oxidation of the antimony atoms.

THE NEW POLITYPES STRUCTURES Pd<sub>8</sub><i>T</i><sub>3</sub> (<i>T = </i>As, Sb)

The polytypic structures of Pd8T3 (T = As, Sb) compounds was revealed using the graph method. The topology of the layers and the pattern in the sequence of their alternation are analyzed. The ordering of antimony and arsenic atoms by positions at the nodes of layer-networks and the positional disorder in the sequence of alternating layers, which lead to the formation of different structural polytypes, are considered.

Obtaining Textured Nickel Antimonide Films

It was shown for the first time that when nickel is deposited onto a heated gallium antimonide substrate, diffusion of antimony atoms from the substrate into the growing film occurs and a nickel antimonide film is formed, which has an axial texture with an axis perpendicular to the film plane along the (101) direction.

Obtaining Textured Nickel Antimonide Films

It was shown for the first time that when nickel is deposited onto a heated gallium antimonide substrate, diffusion of antimony atoms from the substrate into the growing film occurs and a nickel antimonide film is formed, which has an axial texture with an axis perpendicular to the film plane along the (101) direction.