19F NMR Study of Antimony(III) Fluoride Complexes in Solution

The state of SbF₃, Sb₃O₂F₅, MSb₃F₁₀, MSb₂F₇, M₃Sb₄F₁₅, MSbF₄, and M₂SbF₃, as well as HF and MF (M = Na, K, Rb, Cs, NH₄, and Tl), in a 0.25 M aqueous solution at room temperature was studied by ¹⁹F NMR. It is found that chemical shifts of the ¹⁹F NMR signals (relative to CFCl₃) for the compounds under investigation vary in the 73.3–157.5 ppm range. For the Sb(III) fluoride complexes, chemical shifts in the ¹⁹F NMR spectra vary in the 73.3–85.5 ppm range (relative to CFCl₃). Although the crystals of Sb(III) fluoride complexes contain different polyhedra that are joined in different ways, the NMR spectra of all compounds under study show one narrow signal. The spectra of aqueous solutions of Sb(III) fluoride complexes do not contain signals of free fluoride ions and oxofluoride Sb₃O₂F₅.     

An Antimony(III) Fluoride Oxalate with Large Birefringence

Birefringent materials play a key role in modulating the polarization of light and thus in optical communication as well as in laser techniques and science. Designing new, excellent birefringent materials remains a challenge. In this work, we designed and synthesized the first antimony(III) fluoride oxalate birefringent material, KSb₂C₂O₄F₅, by a combination of delocalized π-conjugated [C₂O₄]²⁻ groups, stereochemical active Sb³⁺ cations, and the most electronegative element, fluorine. The [C₂O₄]²⁻ groups are not in an optimal arrangement in the crystal structure of KSb₂C₂O₄F₅; nonetheless, KSb₂C₂O₄F₅ exhibits a large birefringence (Δn=0.170 at 546 nm) that is even better than that of the well-known commercial birefringent material α-BaB₂O₄, even though the latter features an optimal arrangement of π-conjugated [B₃O₆]³⁻ groups. Based on first-principles calculations, this prominent birefringence should be attributed to the alliance of planar π-conjugated [C₂O₄]²⁻ anions, highly distorted SbO₂F₂ and SbOF₃ polyhedra with a stereochemically active lone pair. The combination of lone-pair electrons and π-conjugated systems boosts the birefringence to a large extent and will help the development of high-performance birefringent materials.     

Antimony(III) Complexes with Quaternary Ammonium Bases: Synthesis, Spectral, and Luminescent Properties

Complexes of antimony(III) halides with quaternary ammonium bases of different composition were synthesized and characterized by elemental and X-ray diffraction analyses and IR and luminescence spectroscopy. For complexes [R"₃R"N]SbHal₄ (Hal = Cl^–, Br^–, R" = R" = CH₃, C₂H₅, C₄H₉), the maximum of the emission band and fluorescence intensity was found to depend on the nature of the halide ion and the alkyl radical length.     

Solution Properties of Azidokojatoiron(III) Complexes

The formation of iron(III) complexes with chelating azidokojate anions L⁻ was investigated in aqueous solutions as a function of the pH and the c(Fe³⁺):c(HL) molar ratio. Based on the stability constants, the distribution among the above complexes, [Fe(H₂O)₆]³⁺, and [Fe(H₂O)₅(OH)]²⁺ were calculated in solutions of various compositions. The complexes are redox stable in aqueous solutions both in the dark and in visible laboratory light. Properties of the investigated azidokojic acid and its iron(III) complexes are compared with those required for therapeutic applications as alternative iron chelators.     

Microwave-Assisted Synthesis,and Stereochemical and Biological Aspects of Some Antimony(III) and Bismuth(III) Complexes with Biologically Potent Bidentate Schiff Bases

Tetra- and pentacoordinated antimony and bismuth derivatives have been prepared by the interactions of monophenylantimonydichloride(III), trichlorostibane, and trichlorobismuthane with the sodium salts of 3-(indolin-2-one)hydrazinecarbothioamide (L¹H) and 3-(indolin-2-one)hydrazinecarboxamide (L²H), under microwave irradiation as well as by conventional heating. These compounds were further characterized by analytical and spectroscopic techniques including UV, IR, ¹H NMR, and ¹³C NMR spectra. Newly synthesized complexes with their corresponding ligands were also tested for their antifungal and antibacterial activities.     

Structures and Chemical Bonding in Antimony(III) Bromide Complexes with Pyridine

Weakly or “partially” bonded molecules are an important link between the chemical and van der Waals interactions. Molecular structures of six new SbBr₃-Py complexes in the solid state have been determined by single-crystal X-ray diffraction analysis. In all complexes all Sb atoms adopt a pseudo-octahedral coordination geometry which is completed by additional Sb⋅⋅⋅Br contacts shorter than the sum of the van der Waals radii, with Br−Sb⋅⋅⋅Br angles close to 180°. To reveal the nature of Sb–Br and Sb–N interactions, the DFT calculations were performed followed by the analysis of the electrostatic potentials, the orbital interactions and the topological analysis. Based on Natural Bond Orbital (NBO) analysis, the Sb–Br interactions range from the covalent bonds to the pnictogen bonds. A simple structural parameter, non-covalence criterion (NCC) is defined as a ratio of the atom-atom distance to the linear combination of sums of covalent and van der Waals radii. NCC correlates with E(2) values for Sb−N, Sb−Cl and Sb−Br bonds, and appears to be useful criterion for a preliminary evaluation of the bonding situation.     

Synthesis,Structure, and Luminescent Properties of Antimony(III) Complexes with N,N"-Diphenylguanidine

Complexes of antimony(III) halides with N,N"-diphenylguanidine were synthesized for the first time and studied using X-ray diffraction analysis and luminescence spectroscopy. The mechanism of sensitization of Sb³⁺luminescence involving the low-lying state of the charge transfer was proposed.     

新型酰胺功能化铱[III]配合物的光电性能

设计并制备三种具不同官能团的铱[III]邻菲啰啉配合物: [Ir(ppy)₂phen-Br]Cl, [Ir(ppy)₂phen-COOH]Cl, [Ir(ppy)₂phen-Si]Cl,以及对比参照物[Ir(ppy)₂phen-NH₂]Cl.其中, ppy为2-苯基吡啶, phen-Br为2-溴-2甲基-N-(1, 10-菲啰啉-5-基)丙酰胺, phen-COOH为4-[(1, 10-菲啰啉-5-基)氨基]-4-酰基丁烯酸, phen-Si为5-[N, N-二-3-(三乙氧硅)基]酰亚胺-1, 10-菲啰啉, phen-NH₂为5-氨基-邻菲啰啉,并采用核磁共振(NMR)、质谱(MS)、紫外-可见(UV-Vis)吸收光谱、荧光(PL)光谱法和循环伏安法(CV)等对上述配合物进行了分析和表征.光物理性能研究结果表明:这些配合物在蓝-紫色可见光区域有较强吸收,可发射出明亮的黄色到橙红色荧光,量子效率达到12%以上.相比较于参照物[Ir(ppy)₂phen-NH₂]Cl (5.78 μs),三种新型配合物在量子效率未明显降低甚至提高的前提下,荧光寿命有了显著的提高(9.18-12.00 μs).其中, [Ir(ppy)₂phen-Br]Cl (1)不但有最高的荧光量子产率(32%)和最长的荧光寿命(12.00 μs),而且也具有最好的氧传感性能, I₀/I (无氧与纯氧条件下的荧光强度比值)可达到10.91.这使得[Ir(ppy)₂phen-Br]Cl有望成为接枝型,较高性能的光学氧传感器的候选氧敏指示剂.除此之外,还通过含时密度泛函理论(TD-DFT)计算对配合物光电性能进行补充说明,理论计算表明:这些配合物是以铱为中心的近似八面体结构,理论计算结果与实际实验数据相一致.     

Redox Properties of Rhodium(III) Oxo-Bridged Carboxylate Complexes

Chemical and electrochemical oxidation of rhodium (III) oxo-bridged carboxylate complexes was studied. The chemical [with O₃ and Ce(IV) salts] or electrochemical (at potentials of 1.00-1.20 V) oxidations of the binuclear complexes [Rh₂(-O)(-O₂CCH₃)₂(H₂O)₆]^{2 +} and [Rh₂(-O)(-O₂CCF₃)₂(H₂O)₆]^{2 +} leads to the superoxo complexes [Rh₂(-O)(O₂-)(-O₂CCH₃)₂(H₂O)₅]⁺ and [Rh₂(-O)(O₂ ^-)(-O₂CCF₃)₂(H₂O)₅]⁺ with terminal coordination of O₂-. The trinuclear acetate [Rh₃(₃-O)(-O₂CCH₃)₆(H₂O)₃]⁺, unlike its trifluoroacetate analog [Rh3(₃-O)(-O₂CCF₃)₆(H₂O)₃]⁺, is oxidized only electrochemically at a potential of 1.38 V. The oxidation of [Rh₃(₃-O)(-O₂CCH₃)₆(H₂O)₃]⁺ is reversible and involves formation of an unstable superoxo group O₂ ^- between two Rh₃III(₃-O) cores.     

Synthesis and Crystal Structures of Antimony(III) Complexes With a Bis(amino)silane Ligand

Bis(amino)silane bearing bulky substituents on nitrogen, LH₂ [L = Me₂Si(NDipp)₂, Dipp = 2, 6‐diisopropylphenyl] was reacted with nBuLi (ratio 1:1 and 1:2) in toluene. The Me₂Si(LiNDipp)₂ was treated with SbCl₃ in a 1:1 ratio to yield the four‐membered SiN₂Sb ring compound of composition [η²(N,N)‐Me₂Si(NDipp)₂SbCl] ( 1 ). The mono lithiated bis(amino)silane was used to synthesize the monodentate heterotetraatomic complex [(η¹‐Me₂SiNDipp)NHDippSbCl₂] ( 2 ) by the reaction with SbCl₃. The complexes were characterized by ¹H and ¹³C NMR, elemental analysis, IR, and single‐crystal X‐ray structural analysis.     

Crystal Structure of A Molecular Complex Compound of Antimony(III) Fluoride with L-Leucine

Single crystal X-ray diffraction analysis is used to determine the crystal structure of a newly synthesized molecular complex compound of antimony(III) fluoride with L-leucine of the composition SbF₃(C6H₁₃NO₂) (orthohombic crystal system: a = 5.7948(8) ?, b = 6.2433(9) ?, c = 28.594(4) ?, Z = 4, P2₁2₁2₁ space group). The structure consists of SbF₃ molecules and L-leucine bound into polymer chains by bidentate bridging carboxyl groups of amino acid molecules. Weak Sb…F(1)^b bonds combine the adjacent chains into polymer ribbons organized by N-H…. F and N-H…. O hydrogen bonds into a framework.     

Antimony(III) Chloride Complexes with Benzylpyridines: Synthesis and Luminescence. Crystal Structure of Bis(2-benzylpyridinium) Pentachloroantimonate(III)

The antimony(III) chloride complexes with 2- and 4-benzylpyridine were synthesized and studied using elemental analysis, X-ray diffraction analysis, IR spectroscopy, and luminescence spectroscopy. The crystal structure of bis(2-benzylpyridinium) pentachloroantimonate(III) was determined. The crystals are triclinic: a = 9.628(1) Å, b = 15.284(2) Å, c = 19.174(2) Å, = 99.962(2)°, = 101.233(2)°, = 99. 216(2)°; Z = 4, (calcd) = 1.591 g/cm³, space group P , R = 0.0358. The structure consists of polymeric chains of [Sb₂Cl₁₀]^4n– _n anions and [C₁₂H₁₁NH]⁺ cations combined into a framework by the N–H···Cl hydrogen bonds. The electronic and geometrical factors responsible for a relatively low intensity of the luminescence emitted by the complexes of antimony(III) chloride with 2- and 4-benzylpyridine at 77 K are discussed.     

Luminescence Spectral Properties of Europium(III) and Terbium(III) Complexes with Cinnamic Acid

Europium and terbium mixed-ligand complexes with cinnamic acid of composition Ln(Cin)₃· nD · xH₂O, where Ln = Eu³⁺or Tb³⁺, Cin is a cinnamate ion (C₆H₅CH=CHCOO^–), D = 1,10-phenantroline, 2,2"-dipyridyl, benzotriazole (n= 2, x= 0), triphenylphosphine oxide (n= 1, x= 2), or H₂O (n= 0 or 1, x= 0), were synthesized. The compounds were characterized by elemental analysis, IR and luminescence spectroscopy. The Stark structure of the ⁵ D ₀–⁷ F _j(j= 0, 1, 2) electronic transitions in the low-temperature luminescence spectra of europium complexes was analyzed. IR study has revealed a bidentate coordination of the cinnamate ion in the compounds.     

Preparation and Optical Properties of Au(III) Phenylpyridynate Complexes

Russian Journal of General Chemistry -     

铕(III)三元配合物荧光性质的研究

According to fluorescent spectra of a series of Eu(III) ternary complexes in the three solvents EtOH, DMF and CH3CN, the fluorescence is stronger in the solvent CH3CN than in the solvents EtOH and DMF, and fluorescent intensity is contrary to the affinity of three solvents with rare earth ions. Center ions emit fluorescence mainly by an intramolecular energy transfer from the broad absorbing β-diketonate TTA, BTA or BA to the chelated rare earth ions.     

Synthesis and Spectral Properties of Terbium(III) and Gadolinium(III) Complexes with Hydroxybenzoic Acids

Russian Journal of General Chemistry - Coordination compounds of terbium(III) and gadolinium(III) with some hydroxybenzoic acids were electrochemically synthesized. Structure and spectral...     

Antimony(III) and bismuth(III) halide complexes of 2-methyl-benzoxazole

In the antimony(III) and bismuth(III) complexes of 2-methyl-benzoxazole: SbX₃·L (X = Cl, Br), SbI₃·2.5L, MX₃·L·H₂O (M = Sb, X = I; M = Bi, X = Cl, Br), SbCl₄·HL, SbBr₅·2HL, BiCl₅·2HL. Bi₂X₉·3HL (X = Br, I) the ligand is O-bonded to the metal.     

双环金属铱(Ⅲ)异腈配合物的二阶非线性光学性质

采用密度泛函理论(DFT)方法对双环金属Ir(III)异腈配合物的非线性光学(NLO)性质进行计算研究。用B3PW91(UB3PW91)(金属原子采用LANL2DZ基组,非金属原子采用6-31G*基组)方法对配合物进行几何结构优化。在优化构型基础上,采用B3PW91(UB3PW91)和B3LYP(UB3LYP)方法计算了配合物的第一超极化率(βtot),并用CAM-B3LYP(UCAM-B3LYP)(金属原子采用LANL2DZ基组,非金属原子采用6-31G**基组)方法模拟配合物的吸收光谱。结果表明,主配体的取代基(R1)和副配体的取代基(R2)对第一超极化率值贡献不大。配合物发生氧化还原反应,电荷转移方式增多,电荷转移程度增大,使βtot值显著增加,其中1a+([(C∧N)2Ir(CNR)2]+(R=CH3))发生氧化反应和还原反应的βtot值分别增大了75倍和144倍。因此,这类双环金属铱(III)异腈配合物的氧化还原反应可以有效地调节其二阶NLO性质。     

稀土配合物的发光特性及其能量传递研究

利用激光诱导荧光技术研究了稀土铕等金属配合物的发光特性及其能量传递动力学过程．得到了这些稀土配合物中中心离子Eu（3 ）的激发光谱，配体的三线态发时光谱和单线态发射光谱；在实验上观察到由于中心离子Eu（3 ）的5D2←7F0马跃迁吸收造成的配体发射光谱中的凹陷行为