Iodide Complexes Research Articles

A Purified, Solvent‐Intercalated Precursor Complex for Wide‐Process‐Window Fabrication of Efficient Perovskite Solar Cells and Modules

AbstractA high‐purity methylammonium lead iodide complex with intercalated dimethylformamide (DMF) molecules, CH3NH3PbI3⋅DMF, is introduced as an effective precursor material for fabricating high‐quality solution‐processed perovskite layers. Spin‐coated films of the solvent‐intercalated complex dissolved in pure dimethyl sulfoxide (DMSO) yielded thick, dense perovskite layers after thermal annealing. The low volatility of the pure DMSO solvent extended the allowable time for low‐speed spin programs and considerably relaxed the precision needed for the antisolvent addition step. An optimized, reliable fabrication method was devised to take advantage of this extended process window and resulted in highly consistent performance of perovskite solar cell devices, with up to 19.8 % power‐conversion efficiency (PCE). The optimized method was also used to fabricate a 22.0 cm2, eight‐cell module with 14.2 % PCE (active area) and 8.64 V output (1.08 V/cell).

Aluminum Complexes with Redox-Active Formazanate Ligand: Synthesis, Characterization, and Reduction Chemistry.

The synthesis of aluminum complexes with redox-active formazanate ligands is described. Salt metathesis using AlCl3 was shown to form a five-coordinate complex with two formazanate ligands, whereas organometallic aluminum starting materials yield tetrahedral mono(formazanate) aluminum compounds. The aluminum diphenyl derivative was successfully converted to the iodide complex (formazanate)AlI2, and a comparison of spectroscopic/structural data for these new complexes is provided. Characterization by cyclic voltammetry is supplemented by chemical reduction to demonstrate that ligand-based redox reactions are accessible in these compounds. The possibility to obtain a formazanate aluminum(I) carbenoid species by two-electron reduction was examined by experimental and computational studies, which highlight the potential impact of the nitrogen-rich formazanate ligand on the electronic structure of compounds with this ligand.

Synthesis, characterization and biological evaluation of novel antimony(III) iodide complexes with tetramethylthiourea and N-ethylthiourea

Novel trivalent antimony(III) complexes with tetramethylthiourea (TMTU) and N-ethylthiourea (NETU) were synthesized by the reaction of antimony(III) iodide (SbI3). Antimony(III) iodide complexes of formulae {[SbI2(µ2-I)(TMTU)2]2} (1) and {[(NETU)SbI2(µ2-I)2(µ2-S-NETU)SbI2(NETU)]} (2) were characterized by spectroscopic techniques (FT-IR, FT-Raman, 1H and 13C NMR), TG-DTA analysis and X-ray diffraction (XRD) analysis. Single-crystal X-ray diffraction studies showed that the complexes existed as doubly bridged (1) and triply bridged (2) dimers. Crystal structure of the ligand N-ethylthiourea was also determined with single crystal X-ray diffraction analysis.Complexes 1 and 2 were evaluated for their in vitro cytotoxic activity against human adenocarcinoma cells HeLa (cervix). The toxicity of 1 and 2 was evaluated on normal human fetal lung fibroblast cells (MRC-5). Both complexes showed selectivity against the cancerous, than normal cells. The influence of 1 and 2, on the catalytic peroxidation of the linoleic acid by the enzyme lipoxygenase (LOX) was determined experimentally and theoretically. The complexes 1 and 2 exhibited higher activity than free ligands against LOX. The in vitro antibacterial activities of free ligands and their antimony(III) iodide complexes 1 and 2 were tested against two Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) and two Gram-positive (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212) bacteria. The complexes 1 and 2 were much more effective in terms of antimicrobial activity compared to the free ligands.

Influence of the Counterion on the Synthesis of Cyclic Carbonates Catalyzed by Bifunctional Aluminum Complexes.

New bifunctional aluminum complexes have been prepared with the aim of studying the effect of a counterion on the synthesis of cyclic carbonates from epoxides and carbon dioxide (CO2). Neutral ligand 1 was used as a precursor to obtain four novel mesylate, chloride, bromide, and iodide zwitterionic NNO ligands (2-5). The reaction of these ligands with 1 or 2 equiv of AlR3 (R = Me, Et) allowed the synthesis of mono- and bimetallic bifunctional aluminum complexes [AlR2(κ2-mbpzappe)]X [X = Cl, R = Me (6), Et (7); X = Br, R = Me (8), Et (9); X = I, R = Me (10), Et (11)] and [{AlR2(κ2-mbpzappe)}(μ-O){AlR3}]X [X = MeSO3, R = Me (12), Et (13); X = Cl, R = Me (14), Et (15); X = Br, R = Me (16), Et (17); X = I, R = Me (18), Et (19)] via alkane elimination. These complexes were studied as catalysts for the synthesis of cyclic carbonates from epoxides and CO2. Iodide complex 11 showed to be the most active catalyst for terminal epoxides, whereas bromide complex 9 was found to be the optimal catalyst when internal epoxides were used, showing the importance of the nucleophile cocatalyst on the catalytic activity.

Complex of Cadmium(II) Iodide with 3,4-Diphenyl-1-(Pyridin-2-yl)-6,7-Dihydro-5H-Cyclopenta[c]pyridine: Synthesis and X-ray Diffraction Study

The structure of the cadmium(II) iodide complex with 3,4-diphenyl-1-(pyridin-2-yl)-6,7-dihydro-5H-cyclopenta[c]pyridine is studied and determined by X-ray diffraction analysis (СIF file CCDC no. 1833097). The problem about the possibility of coordination of the phenyl substituents of the ligands to the central cadmium atom is examined. The degree of participation of the π system of the phenyl substituent of the ligand in the coordination to the central ion is analyzed using quantum chemical calculations.

Functionalised Alkaline Earth Iodides from Grignard Synthons “PhAeI(thf)n” (Ae = Mg‐Ba)

Derivatisation of Grignard synthons “PhAeI(thf)n” (Ae = Mg‐Ba) prepared in situ from reactions of metal filings and iodobenzene provides a one‐pot synthesis of heteroleptic N donor alkaline earth iodide complexes. Protolysis of “PhAeI(thf)n” with 3,5‐diphenylpyrazole (Ph2pzH) yields pyrazolate complexes [Mg2(µ‐Ph2pz)2(I)2(thf)3] (1), [Ae(Ph2pz)(I)(thf)4] (Ae = Ca (2), Sr (3)), and [Ba2(Ph2pz)2(µ‐I)2(thf)8] (4). Addition of the Ae‐Ph moiety to carbodiimide MesN=C=NMes (Mes = 2,4,6‐(CH3)3C6H2) gave a series of benzamidinate iodide complexes [Ca2{(MesN)2CPh}2(µ‐I)2(thf)4] (6), [Sr{(MesN)2CPh}(I)(thf)4] (7), and [{Ba{(MesN)2CPh}(µ‐I)(thf)3}∞] (8). By contrast a symmetrical magnesium complex [Mg{(MesN)2CPh}2(thf)] (5) was obtained by Schlenk redistribution. These syntheses proceed without pre‐activation of the metal for strontium and barium, and after activation with 2 mol‐% iodine for calcium. The heavy alkaline earth metal complexes are the first examples of heteroleptic halide pyrazolate or amidinate complexes for strontium and barium. Complexes 1, 3, 4 and 6–8 were characterised crystallographically, revealing diverse structural chemistry of heteroleptic amidinate and pyrazolate iodide complexes across the alkaline earth series. A highlight is [Ba{(MesN)2CPh}(µ‐I)(thf)3]∞ (8) – an iodide bridged infinite 1‐D polymer.

Potentiometric Ion-Selective Electrode Based on a New Single Crystal Cadmium(II) Schiff Base Complex for Detection of Fluoride Ion: Central Composite Design Optimization

Here, we present the use of single crystal structure of cadmium iodide complex (CdLI2) as fixed-charge carriers for the development of fluoride (F−) anion selective electrode. The (E)-N1-(2-nitrobenzylidene)-N2-(2-((E)-(2-nitrobenzylidene) amino) ethyl) ethane-1,2-diamine (L) Schiff base ligand was prepared and its complex via CdI2 (CdLI2) as efficient indicator was impregnated into carbon paste electrode. Physicochemical properties of CdLI2 were identified by FT-IR, FE-SEM and XRD analysis. The effect of CdLI2 concentration on fluoride selective electrode resistance is measured using electrochemical impedance spectroscopy, and a significant increase in electrode resistance is observed with increasing CdLI2 as well as cyclic voltametry was used for estimation of prepared electrode surface area and the interface capacitance of prepared ion selective electrode. The operational parameters in measuring the Nernstian slope of 58.966 mV/decade were investigated and optimized using central composite design. The proposed ISE showed low detection limit, fast response time, and most significantly, very good selectivity with respect to the group of some anions (IO4−, SCN−, SO42−, CN−, ClO3−, Br−, Cl− and I−). The proposed ISE was successfully regenerated by soaking in distillated water and polished on greaseproof paper, and its response was reversible with the relative standard deviation (R.S.D.) at 2.0%.

Simple cuprous iodide complex‐based crystals with deep blue emission and high photoluminescence quantum yield up to 100%

Luminescent cuprous complexes have attracted much attention due to their low cost, rich photophysical properties, and hence extensive applications in various fields. In this work, we report the synthesis, structure and photophysical properties of a simple and highly efficient deep blue emission cuprous iodide complex, namely CuI (PPh3)2(t‐BuPy), where PPh3 and t‐BuPy stand for triphenylphosphine and 4‐tert‐butylpyridine, respectively. The complex was synthesized with a one‐pot method, and showed a super high photoluminescence quantum yield up to 100% and a maximum emission wavelength at 454 nm in crystals at room temperature. Based on density functional theory calculation, the emission likely comes from iodide to 4‐tert‐butylpyridine charge transfer and some copper to 4‐tert‐butylpyridine charge transfer excited states. Two reference complexes, CuI (PPh3)2(IQu) (IQu = isoquinoline) and Cu2I2(PPh3)2(t‐BuPy)2, were also synthesized, and the photophysical properties of the three compounds in various forms such as crystalline powder, thin film and solution at both room temperature and 77 K were studied for comparison. These results give clues on how the N‐heteroaromatic ligand (4‐tert‐butylpyridine vs. isoquinoline), coordinating style (mononuclear vs. binuclear), sample form (crystalline powder vs. thin film vs. solution) and temperature (room temperature vs. 77 K) affect the photophysical properties of luminescent cuprous iodide complex.

Efficiently luminescent copper(i) iodide complexes with crystallization-induced emission enhancement (CIEE).

Luminescent Cu(i) iodide complexes featuring simple neutral diimine and phosphine ligands were prepared. The emission intensity of these complexes was significantly enhanced by crystallization. Intermolecular π-π interactions between the adjacent diimine ligands should be responsible for the crystallization-induced emission enhancement (CIEE) behaviors through consolidating the structural rigidity of these complexes.

СОРБЦІЙНЕ КОНЦЕНТРУВАННЯ ТА ВИЗНАЧЕННЯ СТИБІЮ І ТЕЛУРУ НА МОДИФІКОВАНОМУ СИЛІКАГЕЛІ

Antimony and its compounds are widely used in industry, making it one of the priority pollutants of air and the aquatic environment. Excess of antimony is selectively concentrated in a thyroid gland, a liver, a spleen. The manifestation of the toxic effect of antimony is a variety of impaired functions of the human body, so the content of this element in drinking water normalizes is at the level of 5 μg/l. Recently, tellurium has also been increasingly the subject of research by analyst chemists. Tellurium is a biologically active element and its concentrations in the environment are strictly regulated. According to sanitary rules and regulations, the maximum allowable concentration of tellurium in drinking water is 0.01 mg/l. The article is devoted to the elaboration of solid-phase reagents based on the quaternary ammonium salt (QAS) immobilized on silica gel and to the development on this basis of sorption-spectrometric and visual test-methods of the determination of Sb(III) and Te(IV). The mechanism of the interaction between QAS immobilized on silica gel and the anions iodide complex of antimony and tellurium was studied. It was found that it proceeds by the ion-associative mechanism. Conditions of sorption preconcentration of anionic complexes of elements were optimized. For the quantitative sorption of antimony (III), the weight of the sorbent is 0.020 g and the volume of the solution is 25.0 ml. Under these conditions, the anionic complex is sorbed by 98%. The maximum concentration ratio is 1.25 l/g. The sorption equilibrium in the system is established in 20 minutes. For the quantitative extraction of tellurium (IV), the optimal weight of the sorbent is 0.050 g and a solution volume of 25.0 ml. Under these conditions, the degree of sorption reaches about 80%. The maximum concentration ratio is 0.4 l/g. The sorption equilibrium in the system is established in 15 minutes. The influence of foreign ions on the extraction degree of the investigated elements, and also on the magnitude of analytical signal, was studied. Sorptionspectrometric and visual test-methods of the determination of Sb(III) and Te(IV) in pharmaceutical preparation "Antimonium tartaricum" and "Tellurium Metalicum".

QM/MM studies on luminescence mechanism of dinuclear copper iodide complexes with thermally activated delayed fluorescence.

The QM/MM method is employed to investigate the photophysical mechanism of two dinuclear copper iodide complexes with thermally activated delayed fluorescence (TADF). The S1–T1 energy differences (ΔEST) in these two complexes are small enough so that repopulating the S1 state from T1 becomes energetically allowed. Both forward and reverse intersystem crossing (ISC and rISC) processes are much faster than the corresponding radiative fluorescence and phosphorescence processes [kISC (108 s−1) > kFr (106 s−1), krISC (105 s−1) > kPr (103 s−1)]. The faster rISC process than the phosphorescence emission enables TADF. Moreover, the diphosphine ligands are found to play an important role in regulating the electronic structures and thereto the radiative and nonradiative rate constants. The present work rationalizes experimental phenomena and helps understand the intrinsic luminescence properties. The obtained insights could be useful for tuning the luminescence performance of dicopper-based luminescence materials.

Influence of Anionic Ligand Exchange in Latent Sulfur-Chelated Ruthenium Precatalysts.

Four new cis-dianionic S-chelated ruthenium benzylidenes were synthesized by chloride ligand exchange. The special cis-dianionic conformation of these complexes contributed to a particularly facile anion exchange process, producing room-temperature-latent precatalysts. Their catalytic activity was strongly influenced by the solvent used. The latent iodide complex very efficiently promoted ring-closing metathesis by heating in toluene. Conversely, carboxylate ligands produced quite poor catalysts, but could abstract chlorides from chlorinated solvents to transform into active precatalysts. In tetrahydrofuran (THF), the S-chelated dichloro complex was shown to promote cycloisomerization instead of metathesis; however, the metathesis activity in THF could be recovered in the presence of phenylacetylene as a cocatalyst. Under the same conditions, all the other complexes required addition of LiCl to mimic this dichotomous behavior.

P-Cymene Ruthenium Halide Complexes with a Heterocyclic Carbene

The reaction of (p-cymene)Ru(Me2Im)Cl2 with excess Me2ImCO2 in acetonitrile in the presence of NH4PF6 afforded the amino complex [(p-cymene)Ru(Me2Im)(NH3)Cl]PF6. The reaction of (p‑cymene)Ru(Me2Im)Cl2 with excess anhydrous SnCl2 gave the complex (p-cy-mene)-Ru(Me2Im)Cl(SnCl3), whereas treatment of dimeric iodide complex [(p-cymene)RuI2]2 with Me2ImCO2 in acetonitrile gave the ionic compound [Me2ImH][(p-cymene)RuI3]. CIF files: CCDC nos. 1841649 (I), 1841650 (II), 1841648 (III).

Structural investigation of a new cadmium coordination compound prepared by sonochemical process: Crystal structure, Hirshfeld surface, thermal, TD-DFT and NBO analyses

A new nanostructured cadmium complex containing a tridentate Schiff base ligand was sonochemically synthesized and characterized by XRPD, FT/IR, NMR, and single crystal X-ray crystallography. Structural data showed that cadmium(II) ion is surrounded by three nitrogen atoms of Schiff base ligand and two iodide anions. The crystal packing was contained the intermolecular interactions such as CH⋯O, CH⋯I and π⋯π interactions organizing the self-assembly process. Hirshfeld surfaces and corresponding fingerprint plots have been used for investigation of the nature and proportion of interactions in the crystal packing. FT/IR, NMR and XRD data were in agreement with the X-ray structure and confirm the phase purity of the prepared sample. The molecular structure of the complex was optimized by density functional theory (DFT) calculation at the B3LYP/LANL2DZ level of theory and the results were compared with experimental ones. For more concise study of structure and spectral aspects of the complex, natural bond orbital (NBO) analysis and time-dependent density functional theory (TD-DFT) have been also performed. Thermal stability of the cadmium iodide complex was investigated by thermogravimetric analysis (TGA). Finally, cadmium oxide nanoparticles was prepared by direct calcination of CdLI2 complex as a new precursor.

Luminescence Vapochromism of a Dynamic Copper Iodide Mesocate.

A copper iodide complex coordinated by three phosphine ligands with the formula [Cu2 I2 (Ph2 PC2 (C6 H4 )C2 PPh2 )3 ] exhibits solvatochromic and vapochromic luminescence properties. A mechanism based on solvent-dependent molecular motion appears to occur. The highly contrasted response observed upon THF solvent exposure makes this complex an appealing candidate for chemical sensor applications.

Biosynthetically Inspired Transformation of Iboga to Monomeric Post-iboga Alkaloids

Summary Organisms have evolved to produce various natural products from a common precursor as a means of maximizing the number of secondary metabolites, thus acquiring selectional advantages. By adopting nature's divergent biosynthetic strategy, we transformed (+)-catharanthine to various iboga and post-iboga alkaloids, including (−)-conodusine A, (+)-conodusines B and C, (−)-voatinggine, (−)-tabertinggine, and (+)-dippinine B. Well-orchestrated oxidations and reorganizations of catharanthine derivatives enabled chemical access to these natural products.

Real-Time Mass Spectrometric Investigations into the Mechanism of the Suzuki–Miyaura Reaction

Real-time monitoring of the Suzuki–Miyaura reaction using mass spectrometry during sequential addition of the various reaction components suggests that a dynamic series of equilibria exist in these solutions. Depending on conditions, the boronic acid can be dehydrated, deprotonated, hydroxylated (or alkoxylated), or fluorinated. Palladium–phosphine species present include Pd(0) (to which the aryl iodide rapidly oxidatively adds), the Pd(II) aryl iodide complex, a cationic Pd(II) species formed by dissociation of the iodide ligand, and the Pd(II) bisaryl complex that ultimately extrudes the product through reductive elimination. No fluorinated or hydr(alk-)oxylated palladium complexes were observed under catalytic conditions. Several transmetalation combinations were excluded as reactive partners, but several possibilities remain, and more than one mechanism is likely to be operative, even under similar conditions.

A Base-Free Terminal Actinide Phosphinidene Metallocene: Synthesis, Structure, Reactivity, and Computational Studies

The synthesis, structure, and reactivity of a base-free terminal actinide phosphinidene metallocene have been comprehensively studied. The salt metathesis reaction of the thorium methyl iodide complex Cp‴2Th(I)Me (2; Cp‴ = η5-1,2,4-(Me3C)3C5H2) with Mes*PHK (Mes* = 2,4,6-(Me3C)3C6H2) in THF furnishes the first stable base-free terminal phosphinidene actinide metallocene, Cp‴2Th═PMes* (3). Density functional theory (DFT) shows that the bonds between the Cp‴2Th2+ and [PMes*]2- fragments are more covalent than those in the related thorium imido complex. While the phosphinidene complex 3 shows no reactivity toward alkynes, it reacts with a variety of heterounsaturated molecules such as CS2, isothiocyanate, nitriles, isonitriles, and organic azides, forming carbodithioates, imido complexes, metallaaziridines, and azido compounds. These experimental observations are complemented by DFT computations.

Synthesis, crystalline structures and photophysical properties of new cadmium iodide complexes with thiocarbamoyl-pyrazoline ligands

New mononuclear cadmium (II) complexes based on thiocarbamoyl-pyrazoline ligands were synthesized and structurally characterized. Complexes 1, 2 and 3 possess similar structural behavior around the cadmium (II) atom which presented a distorted tetrahedral coordination geometry determined by using the τ4 (tau four) parameter analysis. Interesting photophysical properties as bluish emission at spectral range (330–450 nm) and nanoseconds fluorescence lifetime (1.05 up to 1.42 ns) were observed upon excitation of the prepared compounds at λex = 300 nm. This emission was tentatively assigned to the LLCT transitions of the type XLCT I(5p6) → π∗(conjugated pyrazoline system) according to the frontier orbital molecular calculations. The complete characterization of the prepared compounds also included X-ray structure determination, elemental analyses, IR spectroscopy, 1H and 13C NMR experiments, molecular absorption (UV–Vis) and luminescence studies.

Four 2-hydroxyethyl substituted NHC iodide complexes: structural characterization and theoretical comparisons

Four 2-hydroxyethyl substituted NHC iodide complexes: structural characterization and theoretical comparisons