Base Dimethyl Sulfoxide Research Articles

Bismuth Complex Controlled Morphology Evolution and CuSCN-Induced Transport Improvement Enable Efficient BiI3 Solar Cells.

Bismuth triiodide (BiI3) is a particularly promising absorber material for inorganic thin-film solar cells due to its merits of nontoxicity and low cost. However, one key factor that limits the efficiency of BiI3 solar cells is the film morphology, which is strongly correlated with the trap states of the BiI3 film. Herein, we report a coordination engineering strategy by using Lewis base dimethyl sulfoxide (DMSO) to induce the formation of a stable BiI3(DMSO)2 complex for controlling the morphology of BiI3 films. Density functional theory calculations further provide a theoretical framework for understanding the interaction of the BiI3(DMSO)2 complex with BiI3. The obtained BiI3(DMSO)2 complex could assist the fabrication of highly uniform and pinhole-free films with preferred crystallographic orientation. This high-quality film enables reduced trap densities, a suppressed charge recombination, and improved carrier mobility. In addition, the use of copper(I) thiocyanate (CuSCN) as a hole transport layer improves the charge transport, enabling the realization of solar cells with a record power conversion efficiency of 1.80% and a champion fill factor of 51.5%. Our work deepens the insights into controlling the morphology of BiI3 thin films through the coordination engineering strategy and paves the way toward further improving the photovoltaic performances of BiI3 solar cells.

Effect of the Sterical Factor on the Kinetics of Octa(4-tert-butylphenyl)tetrapyrazinoporphyrazine in a Nitrogen-Containing Base–Dimethylsulfoxide System

Effect of the Sterical Factor on the Kinetics of Octa(4-tert-butylphenyl)tetrapyrazinoporphyrazine in a Nitrogen-Containing Base–Dimethylsulfoxide System

Kinetic Stability of Tetra(1,2,5-selenodiazolo)porphyrazine in the Nitrogen-Containing Base-Dimethyl Sulfoxide System

The behavior of tetra(1,2,5-selenodiazolo)porphyrazine in DMSO and in the DMSO-base (pyridine, 2-methyl-pyridine, morpholine, and piperidine) systems has been studied. It has been shown that the π-chromophore system of the macrocycle is decomposed with time in strongly basic media. The proton-transfer complex H2PA(SeN2)4·2DMSO formed in DMSO has been less kinetically stable in the presence of morpholine (piperidine) than the H2PA(SN2)4·2DMSO complex.

Tuning Molecular Interactions for Highly Reproducible and Efficient Formamidinium Perovskite Solar Cells via Adduct Approach.

The Lewis acid-base adduct approach has been widely used to form uniform perovskite films, which has provided a methodological base for the development of high-performance perovskite solar cells. However, its incompatibility with formamidinium (FA)-based perovskites has impeded further enhancement of photovoltaic performance and stability. Here, we report an efficient and reproducible method to fabricate highly uniform FAPbI3 films via the adduct approach. Replacement of the typical Lewis base dimethyl sulfoxide (DMSO) with N-methyl-2-pyrrolidone (NMP) enabled the formation of a stable intermediate adduct phase, which can be converted into a uniform and pinhole-free FAPbI3 film. Infrared and computational analyses revealed a stronger interaction between NMP with the FA cation than DMSO, which facilitates the formation of a stable FAI·PbI2·NMP adduct. On the basis of the molecular interactions with different Lewis bases, we proposed criteria for selecting the Lewis bases. Owed to the high film quality, perovskite solar cells with the highest PCE over 20% (stabilized PCE of 19.34%) and average PCE of 18.83 ± 0.73% were demonstrated.

Kinetic characteristics of the destruction of β,β-annelated porphyrazines in a nitrogen-containing base–dimethylsulfoxide system

The state of tetra(1,2,5-thiadiazolo)porphyrazine in a dimethyl sulfoxide medium is investigated. Relatively high stability is observed for the resulting proton-transfer complex, and a chemical structure is proposed for it. It is shown that the nature of the substituent in the porphyrazine macrocycle influences the kinetic parameters of the destruction of tetra(1,2,5-thiadiazolo)porphyrazine, tetra(5-tert-butylpyrazino) porphyrazine, octaethyltetrapyrazinoporphyrazine, and octaphenyltetrapyrazinoporphyrazine in a nitrogen-containing base–dimethylsulfoxide system. The effect the NH acidity of the porphyrazine macrocycle and the nature of the nitrogenous bases have on the reaction rate and activation parameters of the destruction of β,β-annelated porphyrazine proton-transfer complexes is established.

Kinetic stability of tetra(1,2,5-thiadiazolo)porphyrazine in the system nitrogen-containing base-dimethyl sulfoxide

The behavior of tetra(1,2,5-thiadiazolo)porphyrazine in dimethyl sulfoxide has been studied, and fairly high stability of the resulting proton-transfer complex has been revealed. The complex is kinetically unstable in strongly basic media. The effects of the nitrogen-containing base and NH acidity of the porphyrazine macrocycle on the rate and activation parameters of decomposition of the proton-transfer complex have been estimated.

Mediated kinetic medium effect in the reaction of bis-3,5-di-iso-propylsalicylatozinc(II) with tert-butylperoxyl radicals

Absolute rate constants for the reaction of ZnII(3,5-di-iso-propylsalicylate)2 with tert-butylperoxyl radicals were determined by means of kinetic electron paramagnetic resonance measurements at −31.5°C in 10% (v/v) chlorobenzene in hexane, as well as with addition of approximately equivalent amounts of the Lewis base dimethylsulfoxide (DMSO). Differential pulse voltammetry was used to determine the redox behavior of this chelate with different amounts of DMSO in a CH2Cl2 medium at 25°C. A good correlation was observed between the kinetic effect of the DMSO on the antiperoxyl radical reactivity of the zinc complex, which is due to transfer of a hydrogen atom from the ligand, and the redox behavior. These also correlated with changes in the 1H NMR and FTIR spectra of the chelate in these media. A mediated kinetic medium (solvent) effect (MKME or MKSE) for DMSO has been established. The essence is that electron pair donors such as DMSO at molar equivalent quantities do not directly impede the reaction center of radical scavenging (hydrogen atoms of salicylic OH groups that are not involved in intramolecular hydrogen bonding), but act indirectly by bonding axially to the zinc, which changes the coordination geometry in such a way as to increase intramolecular hydrogen bonding within the coordinated ligand and thus considerably diminish the fraction of OH groups available to transfer a hydrogen atom. As a result, the antiperoxyl radical H-atom donating reactivity of ZnII(3,5-di-iso-propylsalicylate)2 decreases upon coordination of DMSO.

Effect of dimethyl sulfoxide on electrochemical and antiradical properties of ascorbic acid

Solvent effect of dimethyl sulfoxide (DMSO) on the oxidation-reduction properties of ascorbic acid (AA) was studied by the electroanalytical method of differential pulse voltammetry (DPV) in a three-electrode cell at 37 °C. Dimethylsulfoxide was found to considerably decrease the oxidation ability of AA due to the formation of molecular complexes between AA and DMSO through the intermolecular hydrogen bonds and shift the anodic peak potential toward the positive values, with its intensity being decreased. Kinetic spectrophotometric measurements in the UV-vis regions of the reaction of the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH·) with AA confirmed the stabilizing effect of the Lewis base DMSO on the reactivity of the neutral form of AA and its intermediates with respect to DPPH·. The mechanism of oxidation of AA with the radical DPPH· in the presence of DMSO was considered.

The Kinetic Stability of Octaphenyltetrapyrazinoporphyrazine in the Nitrogen Base—Dimethylsulfoxide System

The state of octaphenyltetrapyrazinoporphyrazine in dimethylsulfoxide was studied. The proton transfer complex formed was found to be fairly stable; its structure was suggested. The complex was kinetically unstable in strongly basic media. The influence of the nature of cyclic and acyclic nitrogen bases on the rate and activation parameters of the destruction of the proton transfer octaphenyltetrapyrazinoporphyrazine complex was studied.

Organophosphorus Compounds, 112. Lewis Acid Mediated Spirocyclotrimerization of Kinetically Stabilized Phosphaalkynes – Key Step for the Selective Generation and Trapping of Triphospha Dewar Benzenes

AbstractIn the presence of Lewis acidic derivatives of group 13 elements, phosphaalkynes 7 undergo spirocyclotrimerization with incorporation of the corresponding Lewis acids to form 10a–f. Scope and limitations of this novel cyclooligomerization process are examined. Starting from the spirocyclotrimer 10a reaction with the Lewis base dimethyl sulfoxide, we have in hand for the first time a method for the selective generation of two isomeric triphospha Dewar benzene derivatives (18, 19). Both can be trapped efficiently by further reaction with the phosphaalkyne to furnish the two novel phosphaalkyne cyclotetramers 20 and 21, both still possessing a phosphorus–carbon double bond. In the case of 21, further functionalization of the phosphaalkene unit is possible by [3 + 2] cycloaddition with a nitrile oxide (→ 23).

ChemInform Abstract: REACTION OF KETOXIMES WITH ACETYLENE: NEW GENERAL METHOD FOR THE SYNTHESIS OF PYRROLES (REVIEW)

AbstractReview: In der Übersichtsarbeit wird die Pyrrolsynthese auf der Basis der Umsetzung von Ketoximen mit Acetylenen in Gegenwart starker Basen, insbesondere bezüglich der Reaktionsbedingungen, der Brauchbarkeit der Reaktion zur Herstellung von Vinylpyrrolen, der präparativen Grenzen der Reaktion und des Reaktionsmechanismus eingehend untersucht.

Reaction of ketoximes with acetylene: A new general method for the synthesis of pyrroles (review)

The results of the development of a new general synthesis of pyrroles based on the reaction of ketoximes with acetylene in Superbase catalytic systems of the strong base-dimethyl sulfoxide (DMSO) type are analyzed thoroughly. The experimental conditions, the preparative possibilities, the probable mechanisms, and the prospects for the further development of the reaction are examined.