Pitzer and Pitzer–Simonson–Clegg Modeling Approaches: Ternary HCl + 2-Propanol + Water Electrolyte System

Despite its success for modeling electrolyte thermodynamics in aqueous media, the use of the Pitzer approach for the investigation of electrolytes in nonaqueous or in mixed solvent media is still very limited. Further, a review of the literature reveals that there are no more than a few research groups who have used the exact form of the Pitzer–Simonson–Clegg (PSC) ion-interaction approach for the investigation of electrolytes in mixed solvent systems. As a continuation of our previous studies, the present investigation reports modeling of HCl in the 2-propanol + water mixed solvent system with the Pitzer, PSC and an extended form of the PSC ion-interaction approaches using the experimental potentiometric data from a cell containing pH glass membrane and Ag/AgCl electrodes. The electrochemical measurements were performed over the HCl molality range from 0.01 to 4.5 mol⋅kg⁻¹ in mixed 2-propanol (x%)+water (100−x%) solvents, with different solvent percent mass fractions (x%=10,20,30,40 and 50%) at 298.15±0.05 K.     

Determination of <Superscript>68</Superscript>Ga production parameters by different reactions using ALICE and TALYS codes

Gallium-68 (T _1/2 = 68 min, I _β+ = 89%) is an important positron-emitting radionuclide for positron emission tomography and used in nuclear medicine for diagnosing tumours. This study gives a suitable reaction to produce ⁶⁸Ga. Gallium-68 excitation function via ⁶⁸Zn(p, n)⁶⁸Ga, ⁶⁸Zn(d, 2n)⁶⁸Ga, ⁷⁰Zn(p, 3n)⁶⁸Ga and ⁶⁵Cu(α, n)⁶⁸Ga reactions were calculated by ALICE-91 and TALYS-1.0 codes. The calculated excitation function of ⁶⁸Zn(p, n)⁶⁸Ga reaction was compared with the reported measurement and evaluations. Requisite thickness of the targets was obtained by SRIM code for each reaction. The ⁶⁸Ga production yield was evaluated using excitation function and stopping power.      

Enantioselective Oxidative Aerobic Dealkylation of N‐Ethyl Benzylisoquinolines by Employing the Berberine Bridge Enzyme

N‐Dealkylation methods are well described for organic chemistry and the reaction is known in nature and drug metabolism; however, to our knowledge, enantioselective N‐dealkylation has not been yet reported. In this study, exclusively the (S)‐enantiomers of racemic N‐ethyl tertiary amines (1‐benzyl‐N‐ethyl‐1,2,3,4‐tetrahydroisoquinolines) were dealkylated to give the corresponding secondary (S)‐amines in an enantioselective fashion at the expense of molecular oxygen. The reaction is catalyzed by the berberine bridge enzyme, which is known for C? C bond formation. The dealkylation was demonstrated on a 100 mg scale and gave optically pure dealkylated products (ee>99 %).     

Linking Deltahedral Zintl Clusters with Conjugated Organic Building Blocks: Synthesis and Characterization of the Zintl Triad [R‐Ge9‐CHCHCHCH‐Ge9‐R]4−

The accessibility of triads with deltahedral Zintl clusters in analogy to fullerene–linker–fullerene triads is another example for the close relationship between fullerenes and Zintl clusters. The compound {[K(2.2.2‐crypt)]₄[RGe₉‐CH?CH? CH?CH‐Ge₉R]}(toluene)₂ (R=(2Z,4E)‐7‐amino‐5‐aza‐hepta‐2,4‐dien‐2‐yl), containing two deltahedral [Ge₉] clusters linked by a conjugated (1Z,3Z)‐buta‐1,3‐dien‐1,4‐diyl bridge, was synthesized through the reaction of 1,4‐bis(trimethylsilyl)butadiyne with K₄Ge₉ in ethylenediamine and crystallized after the addition of 2.2.2‐cryptand and toluene. The compound was characterized by single‐crystal structure analysis as well asNMR and IR spectroscopy.     

Facile Heteropolyacid-Promoted Synthesis of Indeno[1,2-b]quinoline-9,11(6H,10H)-dione Derivatives

An efficient synthesis of indeno[1,2-b]quinoline-9,11(6H,10H)-dione derivatives was reported via four-component coupling reaction of aldehydes, dimedone, 1,3-indandione, and amines in refluxing ethanol or three-component condensation of aldehydes, 1,3-indandione, and 5,5-dimethyl-3-arylamino-cyclohex-2-enone derivatives at 120 °C under solvent-free conditions in the presence of a catalytic amount of Preyssler-type heteropolyacid, H₁₄[NaP₅W₃₀O₁₁₀], as a green and reusable catalyst.     

A new three‐dimensional coordination polymer of SrII based on dipicolinic acid,with different coordination environments for SrII

A three‐dimensional coordination polymer of Sr^II based on dipicolinic acid (pydcH₂) has been synthesized and characterized, namely poly[[diaquabis(μ₃‐6‐carboxypyridine‐2‐carboxylato)bis(μ₄‐pyridine‐2,6‐dicarboxylato)tristrontium(II)] dihydrate], {[Sr₃(C₇H₃NO₄)₂(C₇H₄NO₄)₂(H₂O)₂]·2H₂O}_n. The asymmetric unit consists of two unique Sr^II centres (one of them situated on an inversion centre), two independent pydc²⁻ ligands, and one coordinated and one uncoordinated water molecule. The two independent Sr^II cations are surrounded by water and dipicolinate molecules in distorted square‐antiprism and distorted tricapped trigonal prismatic geometries. The dipicolinate ligands adopt μ₃‐ and μ₄‐bridging modes, linking the alkaline earth metal centres into a three‐dimensional coordination framework. One dipicolinate ligand is doubly deprotonated, while the other is singly deprotonated.     

Syntheses and Structures of Organotin(IV) Thioesters of N‐Phthaloylamino Acids

Five organotin(IV) thioesters of N‐phthaloyl amino acids with the general formulae R₃SnL (R = Me, Ph) and nBu₂SnL₂ were synthesized with L = N‐phthaloyl‐thioalanine and N‐phthaloyl‐thioleucine. The structures of trimethyltin(IV) N‐phthaloyl‐thioleucinate ( 1 ), trimethyltin(IV) N‐phthaloyl‐thioalaninate ( 2 ), triphenyltin(IV) N‐phthaloyl‐thioleucinate ( 3 ), triphenyltin(IV) N‐phthaloyl‐thioalaninate ( 4 ), and di‐n‐butyltin(IV) di‐N‐phthaloyl‐thioalaninate ( 5 ) were characterized by means of X‐ray diffractometry. Quantumchemical investigations served to clarify several structural peculiarities of the isolated compounds.     

Synthesis of a series of novel dihydro-[1,2,4]triazolo [1,5-a]pyrimidine scaffolds: Dual solvent-catalyst activity of a low viscous and acid-functionalized ionic liquid

Abstract

The viscosity of neat ionic liquids is very important for their application in organic synthesis as a solvent because most of the neat ionic liquids are very viscous, which would result in the less efficient mass transfer of reactants. In the present study, a series of novel dihydro-[1,2,4]triazolo[1,5-a]pyrimidines were prepared using a low viscous and acid-functionalized ionic liquid. Our results showed that new ionic liquid can act as a green solvent and acid catalyst due to low viscosity and acid functionality. The products were simply extracted and the ionic liquid was retrieved several times without reducing its catalytic efficiency. The current application of TMDPS in the one-pot multicomponent reactions as dual solvent-catalyst highlights the importance of low viscous acid-functionalized ionic liquids in organic synthesis, and we hope that further research will be conducted in the future to finding other applications of TMDPS with promising results.