Search results for "kristallografia"

Ion pair recognition by ditopic crown ether based bis-urea and uranyl salophen receptors

2016

Iodine(i) complexes incorporating sterically bulky 2-substituted pyridines

2022

The silver(I) and iodine(I) complexes of the 2-substituted pyridines 2-(diphenylmethyl)pyridine (1) and 2-(1,1-diphenylethyl)pyridine (2), along with their potential protonated side products, were synthesised to investigate the steric limitations of iodine(I) complex formation. The complexes were characterised by 1H and 1H–15N HMBC NMR, X-ray crystallography, and DFT calculations. The solid-state structures for the silver(I) and iodine(I) complexes were extensively compared to the literature and analysed by DFT to examine the influence of the sterically bulky pyridines and their anions. peerReviewed

Synthesis of Unexpected Dimethyl 2-(4-Chlorophenyl)-2,3-dihydropyrrolo[2,1-a]isoquinoline-1,3-dicarboxylate via Hydrolysis/Cycloaddition/Elimination …

2021

Hydrolysis/[3 + 2] cycloaddition/elimination cascades employed for the synthesis of unexpected tricyclic compound derived from isoquinoline. Reaction of ethylene derivative 1 with the isoquinoline ester iminium ion 2 in alkaline medium (MeOH/NEt3) under reflux for 1 h resulted in the formation of the fused pyrrolo[2,1-a]isoquinoline derivative 3. Its structure was elucidated by X-ray single crystal and other spectrophotometric tools. Hirshfeld calculations for 3 and its crystal structure analysis revealed the importance of the short O…H (19.1%) contacts and the relatively long H…C (17.1%), Cl…H (10.6%) and C…C (6.1%) interactions in the molecular packing. DFT calculations were used to compu…

Stereoselective Synthesis of New 4-Aryl-5-indolyl-1,2,4-triazole S- and N-β-Galactosides: Characterizations, X-ray Crystal Structure and Hirshfeld Su…

2023

5-(1H-Indol-2-yl)-4-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-thione 1a and 4-(4-chlorophenyl)-5-(1H-indol-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione 1b were galactosylated in the presence of NaHCO3 in ethanol to produce S-galactosides 3,4, whereas, in the presence of K2CO3 in acetone they produced a mixture of S- and N-galactosides 3-6 with a higher yield of S-galactosides over the respective N-galactosides. Improvement in the yields of N-galactosides was produced by thermal migration of the galactosyl moiety from sulfur to nitrogen using fusion. β-Stereoselectivity of galactosylation was determined using the coupling constant value 3J1,2, which exceeded 9.0 Hz in all prepared galactos…

One-Pot Synthesis, X-ray Single Crystal and Molecular Insight of Enaminone-Based β-Morpholino-/N-Methylpiperazinyl-/Pyrrolidinylpropiophenone

2020

One-pot synthesis of three enaminones, (E)-1-(4-chlorophenyl)-3-morpholinoprop-2-en-1-one 1, (E)-1-(4-chlorophenyl)-3-(4-methylpiperazin-1-yl)prop-2-en-1-one 2, and (E)-1-(4-chlorophenyl)-3-(pyrrolidin-1-yl)prop-2-en-1-one 3 were achieved. The synthetic protocol via three components reaction of p-chloroacetophenone with DMFDMA (N,N-dimethylformamid-dimethylacetal) and the corresponding secondary amines (morpholine/N-methylpiperazine/pyrrolidine) in dioxane under heating for 2.5–4 h at 102 °C yielded the requisite enaminones. This protocol has the advantage of no separation of intermediate, no need for column purification with quantitative yield for the target compounds. The chemical feature…

Synthesis and Solid-State X-ray Structure of the Mononuclear Palladium(II) Complex Based on 1,2,3-Triazole Ligand

2022

Herein, we described the synthesis and X-ray crystal structure of the new [Pd(3)2Cl2] complex with 1,2,3-triazole-based ligand (3). In the unit cell, there are two [Pd(3)2Cl2] molecules, and the asymmetric unit comprised half of this formula due to the presence of an inversion symmetry element at the Pd(II) center. The monoclinic unit cell volume is 1327.85(6) Å3, with crystal parameters of a = 10.7712(2) Å, b = 6.8500(2) Å, and c = 18.2136(6) Å, while β = 98.851(2)°. The structure comprised two trans triazole ligand units coordinated to the Pd(II) ion via one of the N-atoms of the triazole moiety. In addition, the Pd(II) is further coordinated with two tran…

N-(2,3,5,6-Tetrafluoropyridyl)sulfoximines : synthesis, X-ray crystallography, and halogen bonding

2020

In the presence of KOH, NH-sulfoximines react with pentafluoropyridine to give N-(tetrafluoropyridyl)sulfoximines (NTFP-sulfoximines) in moderate to excellent yields. Either a solution-based or a superior solvent-free mechanochemical protocol can be followed. X-Ray diffraction analyses of 26 products provided insight into the bond parameters and conformational rigidity of the molecular scaffold. In solid-state structures, sulfoximines with halo substituents on the S-bound arene are intermolecularly linked by C–X⋯O[double bond, length as m-dash]S (X = Cl, Br) halogen bonds. Hirshfeld surface analysis is used to assess the type of non-covalent contacts present in molecules. For mixtures of th…

Experimental and computational investigation on the formation pathway of [RuCl2(CO)2(ERR′)2] (E = S, Se, Te; R, R′ = Me, Ph) from [RuCl2(CO)3]2 and E…

2022

The pathways to the formation of the series of [RuCl2(CO)2(ERR′)2] (E = S, Se, Te; R, R′ = Me, Ph) complexes from [RuCl2(CO)3]2 and ERR′ have been explored experimentally in THF and CH2Cl2, and computationally by PBE0-D3/def2-TZVP calculations. The end-products and some reaction intermediates have been isolated and identified by NMR spectroscopy, and their crystal structures have been determined by X-ray diffraction. The relative stabilities of the [RuCl2(CO)2(ERR′)2] isomers follow the order cct > ccc > tcc > ttt ≈ ctc (the terms c/t refer to cis/trans arrangement of the ligands in the order of Cl, CO, and ERR′). The yields were rather similar in both solvents, but the reactions were signi…

Experimental and computational studies of unconventional main group compounds : stable radicals and reactive intermediates

2017

Ever since their discovery, radicals have intrigued the minds of experimental and theoretical chemists alike. While the vast majority of radicals are transient species, a large number of stable and persistent radicals are also known. This has enabled the use of radicals in different applications. For example, radicals are highly useful in chemical synthesis due to their selectivity and functional group tolerance. Detailed knowledge of the electronic structure of synthetic intermediates, both radical and non-radical, enables chemists to improve existing synthesis routes and to design completely new ones. This thesis is divided into two parts. The first part begins with an introduction to the…

Experimental and computational studies of transition metal complexes with polydentate amino- and amidophenolate ligands : synthesis, structure, react…

2013

Chelating polydentate ligands play a key role in several areas of modern coordination chemistry. They can be exploited, for example, in catalysis, bioinorganic chemistry, heavy metal abstraction and molecular magnetism. Furthermore, compounds of this type can be found in natural chemicals, commercial products and industrial applications. In this dissertation, several 3d, 4d and 5d transition metal complexes with polydentate amino- and amidophenolate ligands were prepared and their structure, reactivity and magnetic properties were studied with experimental and computational techniques. In the first part of the dissertation, the solid-state structure, reactivity and magnetic properties of 12…