Properties Of Chloroform Research Articles

Pd catalyzed synthesis of 4‐aryl 1,8‐naphthalimide dyes: Determining photophysical parameters and antimicrobial properties

Herein, novel luminescent 4-phenyl 1,8 naphthalimide derivatives whose color range from cream to green are reported. These dyes were obtained from 4-Bromo cyclohexyl-1,8- naphthalimide (NI) via Suzuki–Miyaura cross-coupling reactions with high yield (up to 99% product yield for isolated products) using previously presented NHC-Pd(II) complex 2d (Çakır et al. 2018), as the catalyst and K2CO3 as the base in isopropyl alcohol (IPA) under mild conditions. The basic photophysical properties in chloroform were investigated and discussed. Their absorption and emission maxima ranged from 344 nm to 359 nm and from 399 nm to 450 nm, respectively. NI-MN showed different fluorescent behaviors compared to other synthesized compounds. Antimicrobial activities of synthesized dyes were evaluated against selected six microorganisms by measuring the minimum inhibitory concentration (MIC) values. The results revealed that the novel dyes had the most antimicrobial activities against Escherichia coli and Pseudomonas aeruginosa. These dyes are valuable because they have the potential for a wide range of application areas such as chemistry, textile industry, medicine, biological, and organic electronic applications.

Secondary Metabolites Profiling of Acinetobacter baumannii Associated with Chili (Capsicum annuum L.) Leaves and Concentration Dependent Antioxidant and Prooxidant Properties.

Secondary bioactive compounds of endophytes are inevitable biomolecules of therapeutical importance. In the present study, secondary metabolites profiling of an endophytic bacterial strain, Acinetobacter baumannii, were explored using GC-MS study. Presence of antioxidant substances and antioxidant properties in chloroform (CHL), diethyl ether (DEE), and ethyl acetate (EA) crude extracts of the endophytic bacteria were studied. Total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and ferrous ion chelating assay were evaluated. A total of 74 compounds were identified from the GC-MS analysis of the EA extract representing mostly alkane compounds followed by phenols, carboxylic acids, aromatic heterocyclic compounds, ketones, aromatic esters, aromatic benzenes, and alkenes. Among the two phenolic compounds, namely, phenol, 2,4-bis(1,1-dimethylethyl)- and phenol, 3,5-bis(1,1-dimethylethyl)-, the former was found in abundance (11.56%) while the latter was found in smaller quantity (0.14%). Moreover, the endophytic bacteria was found to possess a number of metal ions including Fe(II) and Cu(II) as 1307.13 ± 2.35 ppb and 42.38 ± 0.352 ppb, respectively. The extracts exhibited concentration dependent antioxidant and prooxidant properties at high and low concentrations, respectively. The presence of phenolic compounds and metal ions was believed to play an important role in the antioxidant and prooxidant potentials of the extracts. Further studies are suggested for exploring the untapped resource of endophytic bacteria for the development of novel therapeutic agents.

Anti-Cancer Screening of Some Transition Metal Ion Complexes with Coumarin Derivatives

In this study, an equal amount of -4-methyl-5,7-(bis p-chlorophenyl azo) coumarin (ligand 6-hydroxy) and copper, cobalt, and nickel (metals) were reacted to synthesize the respective metal ion complexes. The synthesized metal complexes were characterized using various approaches such as CHN elemental analysis, 1H-NMR, mass spectral data, and FTIR. The outcome of the spectroscopic analysis showed the coordination of the ligand to the metal ion that is in the complexes through hydroxyl group; the data also showed the complexes to exhibit octahedral geometry. Further studies on the solid complexes were performed by molar conductance where all the synthesized metal complexes exhibited nonconductive properties in chloroform. An MTT-based cytotoxicity screening of the complexes against lung and breast cancer cells showed Co(II), Cu(II), and Ni(II) complexes to exhibit cytotoxic activity against the studied cells at low concentrations.

Mono azo dyes derived from 5-nitroanthranilic acid: Synthesis, absorption properties and DFT calculations

Four new azo dyes: 2-[(3,5-diamino-1H-pyrazol-4-yl)diazenyl]-5-nitrobenzoic acid (A), 2-[(3-hydroxy-5-methyl-1H-pyrazol-4-yl)diazenyl]-5-nitrobenzoic acid (B), 2-[(3,5-dimethyl-1H-pyrazol-4-yl)diazenyl]-5-nitrobenzoic acid (C) and 2-[(5-amino-3-methyl-1H-pyrazol-4-yl)diazenyl]-5-nitrobenzoic acid (D) which have the same 4-nitrobenzene/azo/pyrazole skeleton and different substituted groups are synthesized in this work. The structures and spectroscopic properties of these new azo dyes are characterized by using spectroscopic methods such as FT-IR, 1H NMR, 13C NMR and UV–vis. Their solvatochromic properties in chloroform, acetic acid, methanol, dimethylformamide (DMF) and dimethylsulphoxide (DMSO) are studied. Moreover, molecular structures and some spectroscopic properties of azo dyes are investigated by utilizing the quantum computational chemistry method based on Density Functional Theory (DFT) employing B3LYP hybrid functional level with 6-31G(d) basis set. It is seen that experimental and theoretical results are compatible with each other.

Molecular-Based Fluorescent Nanoparticles Built from Dedicated Dipolar Thienothiophene Dyes as Ultra-Bright Green to NIR Nanoemitters.

Fluorescent Organic Nanoparticles (FONs), prepared by self-aggregation of dedicated dyes in water, represent a promising green alternative to the toxic quantum dots (QDs) for bioimaging purposes. In the present paper, we describe the synthesis and photophysical properties of new dipolar push-pull derivatives built from thieno[3,2-b]thiophene as a π-conjugated bridge that connects a triphenylamine moiety bearing various bulky substituents as electron-releasing moiety to acceptor end-groups of increasing strength (i.e., aldehyde, dicyanovinyl and diethylthiobarbiturate). All dyes display fluorescence properties in chloroform, which shifts from the green to the NIR range depending on the molecular polarization (i.e., strength of the end-groups) as well as a large two-photon absorption (TPA) band response in the biological spectral window (700–1000 nm). The TPA bands show a bathochromic shift and hyperchromic effect with increasing polarization of the dyes with maximum TPA cross-section reaching 2000 GM for small size chromophore. All dyes are found to form stable and deeply colored nanoparticles (20–45 nm in diameter) upon nanoprecipitation in water. Although their fluorescence is strongly reduced upon aggregation, all nanoparticles show large one-photon (up to 108 M−1·cm−1 in the visible region) and two-photon (up to 106 GM in the NIR) brightness. Interestingly, both linear and non-linear optical properties are significantly affected by interchromophoric interactions, which are promoted by the molecular confinement and modulated by both the dipolar strength and the presence of the bulky groups. Finally, we exploited the photophysical properties of the FONs to design optimized core-shell nanoparticles built from a pair of complementary dipolar dyes that promotes an efficient core-to-shell FRET process. The resulting molecular-based core-shell nanoparticles combine large two-photon absorption and enhanced emission both located in the NIR spectral region, thanks to a major amplification (by a factor of 20) of the core fluorescence quantum yield. These novel nanoparticles, which combine huge one-and two-photon brightness, hold major promise for in vivo optical bioimaging.

Solvent effects on the absorption spectrum and first hyperpolarizability of keto-enol tautomeric forms of anil derivatives: A Monte Carlo/quantum mechanics study.

Theoretical results for the absorption spectrum and electric properties of the enol and keto tautomeric forms of anil derivatives in the gas-phase and in solution are presented. The electronic properties in chloroform, acetonitrile, methanol, and water were determined by carrying out sequential Monte Carlo simulations and quantum mechanics calculations based on the time dependent density functional theory and on the second-order Møller-Plesset perturbation theory method. The results illustrate the role played by electrostatic interactions in the electronic properties of anil derivatives in a liquid environment. There is a significant increase of the dipole moment in solution (20%-100%) relative to the gas-phase value. Solvent effects are mild for the absorption spectrum and linear polarizability but they can be particularly important for first hyperpolarizability. A large first hyperpolarizability contrast between the enol and keto forms is observed when absorption spectra present intense lowest-energy absorption bands. Dynamic results for the first hyperpolarizability are in qualitative agreement with the available experimental results.

Photochromism of boron difluoride-based diarylethenes

The synthesis and characterization of two novel photochromic diarylethenes containing boron difluoride chromophores is described. The boron difluoride chromophores are connected directly to the thiophene rings and participate in the photoisomerization reaction. X-ray single crystal structure analysis of the diarylethenes indicates that intermolecular planar π–π interactions are significantly alleviated, due to various intermolecular non-covalent bondings. Therefore, they show almost the same fluorescent properties in the solid state as in dilute chloroform solutions. These two diarylethenes show typical photochromic properties in chloroform and also in poly(methyl methacrylate) film. During the photochromism, fluorescence of the diarylethenes could be reversibly tuned.

Sandwich-type heteroleptic tris(phthalocyaninato) terbium triple-decker: Single crystal structure and self-assembled nanostructures

The single crystal molecular structure of the tris(phthalocyaninato) terbium triple-decker [(Pc)Tb{Pc(OC8H17)8}Tb(Pc)] was determined by X-ray single-crystal diffraction analysis. Its self-assembling properties in chloroform and n-hexane vapors were comparatively investigated using UV, SEM and XRD techniques. Intermolecular π–π interactions, in cooperation with the van der Waals interaction of the triple-decker complex [(Pc)Tb{Pc(OC8H17)8}Tb(Pc)] and solvent–solute interactions, lead to the formation of dendrite-shaped and cube-shaped nanostructures in chloroform and n-hexane vapors, respectively. UV and XRD results clearly reveal the effect of the solvent on tuning the intermolecular interaction, and in turn, the molecular packing mode in the self-assembled nanostructures of [(Pc)Tb{Pc(OC8H17)8}Tb(Pc)]. Furthermore, the single crystal structure obtained through the present study renders it possible to investigate the formation mechanism as well as the molecular packing conformation of self-assembled nanostructures in a more confirmed manner.

Chloroform Anesthesia and the Saville Kent Murder in 1860

The discovery of the anesthetic properties of chloroform by Sir James Simpson is one of the therapeutic triumphs of the 19th century. Queen Victoria requested chloroform anesthesia for the birth of her second son, Prince Leopold, and from then until the end of century chloroform was the most popular general anesthetic for obstetrics and surgery. Chloroform was so pleasant to inhale that it became a drug of abuse and was involved in all sorts of criminal activity. Despite its wide usage, chloroform was not thought to be part of the brutal murder of 3-year-old Saville Kent on the night of June 30, 1860, outside his manor house in southwest England. The events surrounding and after the murder have recently been documented by Kate Summerscale in a book entitled, "The Suspicions of Mr. Whicher," the Detective Inspector assigned to the case by Scotland Yard. According to Ms Summerscale's records, Mr Whicher ignored the possibility that chloroform was involved in Saville's death. However, evidence supports the view that chloroform played a critical role in the crime and indicates that the guilty plea by Samuel Kent's daughter, Constance, for which she spent 20 years to the day in prison, was as inaccurate as it was incomplete.

Shape-persistent macrocycles comprising perfluorinated benzene subunits: synthesis, aggregation behaviour and unexpected μ-rod formation

The synthesis of a series of shape-persistent macrocycles (SPMs) (1-4 and 6) comprising different numbers and/or spatial arrangement of meta-substituted tetrafluorobenzene and benzene subunits interlinked with diacetylenes is described. To increase their solubility, all five SPMs were functionalized by four peripheral hexyl chains. These SPMs were assembled from common diacetylene building blocks by a modular synthetic strategy based on palladium and/or copper catalyzed versions of acetylene coupling reactions (oxidative acetylene coupling and Cadiot-Chodkiewicz coupling). The aggregation properties in chloroform of SPMs 1-6 were investigated by concentration- and temperature-dependent 1H-NMR investigations and by vapour pressure osmometry studies. Aggregation constants and thermodynamic data of the process were obtained by least-squares fitting of the NMR data and by van't Hoff analysis respectively. Aggregation was only observed for SPMs 2-6 comprising electron deficient tetrafluorobenzene corner units. While dimerization was the major aggregation process for SPMs 3-6, the formation of larger aggregates in solution was only observed for SPM 2. The formation of aggregates is in all cases enthalpically driven. As the largest and the smallest enthalpic contribution and entropic loss in the series of aggregating SPMs were found for the two SPMs 3 and 4, each comprising two fluorinated corner units, the spatial arrangement of these subunits within the macrocycle seems to be at least equally important as the ratio of tetrafluorobenzene and benzene moieties. Interestingly, micro-scaled hexagonal rods were formed from SPM 3 upon heating in toluene, presumably consisting of mixtures of oligomers arising from covalently interlinked macrocycles.

Ab initio modeling of competitive drug–drug interactions: 5‐fluorouracil dimers in the gas phase and in solution

Abstract5‐Fluorouracil (FU) is a halogen derivative of the uracil nucleoside widely used for treatment of solid tumors and in combination drug regimens for cancer chemotherapy. In drug delivery by biodegradable poly(ester‐ether‐ester)s, drug–drug interactions are competitive with respect to the drug–copolymer ones. The potential energy and free energy of association for a variety of FU–FU dimers (either H‐bonded or stacked) were therefore studied in the gas phase to shed some light on their absolute and relative strength, because competition between these two kinds of interactions was recently proposed [McCarthy et al. Mol Phys 1997, 91, 513] and examined with a combination of methods [Hobza et al. J Phys Chem A 1998, 102, 6921] for uracil dimers. The effect of the computational level [Hartree–Fock/second order Møller–Plesset (HF/MP2) or B3LYP, including or not counterpoise corrections to the basis set superposition error] was examined as well as that of the use of polarization functions more diffuse than usual 6‐31G*(0.25) more diffuse than usual. The MP2 level is necessary to describe stacking interactions, because B3LYP is inadequate for them, giving results very similar to the HF ones. The 6‐31G*(0.25) basis set produces very favorable interaction energies, but it is prone to basis set superposition error (BSSE). The binding free energy is noticeably less favorable than the potential energy, due to the increase in vibrational entropy for the association process. There is a good linear relationship between Svib and the binding energy for the HF/6‐31G* optimized structures. Estimates of the incidence of thermal corrections at the MP2 level were carried out on the MP2/3‐21G and B3LYP/6‐31G* structures, where possible. The solvation properties in chloroform or in water of the dimers kept rigid at their in vacuo geometries were examined in the polarizable continuum model framework. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 128–142, 2001

'My Beloved Chloroform'. Attitudes to Childbearing in Colonial Queensland:: A Case Study

In 1847 the anaesthetic and analgesic properties of chloroform were discovered. This technology generated a new era for midwifery: mothers could be relieved of pain in childbirth. The introduction of chloroform for childbirth saw increasing medical dominance in obstetrics, traditionally in the hands of the midwife. At the same time the use of chloroform sparked a medical and moral controversy which lasted for several decades. On the one hand women were destined by the 'curse of Eve' to experience pain during childbirth; on the other, medical humanitarians and practitioners believed that there were technical and moral reasons for alleviating pain in childbirth. In concentrating on the debate historians have largely ignored the reactions of mothers to the introduction of the technology. This paper explores changing attitudes to childbearing within the context of colonial Queensland society, 1860-90, by examining the correspondence of an upper-class mother. Her education and liberal outlook, and a certain ambivalence towards motherhood, all influenced her attitude to the use of chloroform and the process of childbirth.

Influence of intramolecular hydrogen-bonding on the conformation of 3-deoxy-3-thioureido sugars

3-Deoxy-3-thioureido derivatives of 1,2:5,6- di-O- isopropylidene-α- d- allofuranose and 1,2:5,6- di-O- isopropylidene-α- d- glucofuranose were prepared, and their conformational properties in chloroform- d solutions were studied by temperature variable 1H NMR spectroscopy. The whole results, which include temperature coefficient data for the exchangeable pseudoamide protons, support that the presence of the sugar NHC( S) E-rotamer for d- gluco N, N′-disubstituted derivatives can be essentially ascribed to the existence of an intramolecular hydrogen bond analogous to that characteristic of peptide γ-turns.

Adsorption of polar solutes in reversed-phase liquid-liquid chromatography

The properties of chloroform as a liquid stationary phase in reversed-phase liquid chromatography have been investigated. Stable systems and complete pore filling of the support were obtained. Uncharged acids were slightly adsorbed by the support. Amines in the cationic form showed tailing, which can be attributed to adsorption on the support material. The influence of several reversed-phase supports on retention and peak symmetry has been studied. Little difference was found for uncharged acids, but retention and peak shape of the cations was dependent on the specific support. Also on the poly(styrene-divinylbenzene) copolymer PRP-1 cations gave tailing peaks. The results indicate that the surface of reversed-phase supports is heterogeneous. From this and other studies it can be concluded that only certain reversed-phase silicas, such as μ-Bondapak, are suitable supports for cationic solutes. In liquid-liquid chromatography polar solutes only obey a liquid-liquid distribution model if the liquid stationary phase molecules contains a hydrophobic group, as well as a polar function.

Conformational analysis of organic carbonyl compounds. Part 8. Conformational properties of aroyl derivatives of thiophene and benzo[b]thiophene studied by X-ray crystallography, nuclear magnetic resonance lanthanide-induced shifts spectroscopy, and MO ab initio calculations

An investigation of the conformational properties in the solid state and in solution of 2- and 3-p-anisoyl derivatives of thiophene and of benzo[b]thiophene, compounds (1b) and (2b), and (3) and (4) respectively, is reported. X-Ray analysis of the compounds gave the following crystal data: (1b) space group Pbca, a= 18.479(2), b= 11.450(1), c= 9.874(1)Å, Z= 8, R= 0.0438 for 1 611 observed reflections; (2b) space group Pbca, a= 46.245(25), b= 7.393(4), c= 6.195(3)Å, Z= 8, R= 0.0435 for 1 153 observed reflections; (3) space group P212121, a= 14.039(2), b= 12.469(2), c= 7.457(1)Å, Z= 4, R= 0.0697 for 1 871 observed reflections; (4) space group P21/a, a= 11.138(5), b= 14.698(6), c= 7.764(5)Å, Z= 4, R= 0.0556 for 1 983 observed reflections. In each of the molecules the rings are twisted with respect to the carbonyl plane, the heterocyclic ring is less twisted than the phenyl ring, and this deviation from planarity is particularly evident in the 2-substituted derivatives (1b) and (3). The orientation of the carbonyl group is of the S,O-cis and S,O-trans type in the 2-substituted and 3-substituted compounds; the former derivatives show the presence of attractive interactions between the sulphur and oxygen atoms. The conformational properties in chloroform were studied with the n.m.r. lanthanide-induced shifts (LIS) method (1H and 13C nuclei were employed). The preferred conformation (ca. 70%) found for derivatives (1b) and (3) is of the S,O-cis type, with the thiophene ring nearly coplanar with the carbonyl plane and the phenyl ring twisted. For derivative (2b) the preferred conformation in the equilibrium mixture is the S,O-trans type, yet in derivative (4) this conformation is almost exclusive. The heterocyclic and aryl rings show nearly the same degree of twist relative to the carbonyl plane. The conformational situation of derivatives (1)–(4) is compared with that of the corresponding furan and benzo[b]furan derivatives, and close conformational behaviour is found for the 3-substituted compounds. MO Ab-initio calculations in the minimal STO-3G basis set were also performed on the 2- and 3-benzoyl derivatives of thiophene, chosen as model compounds of those under investigation, and the conformations of minimum energy were located in the potential energy surface. For the 2-substituted compound (1a) the conformation of S,O-cis type was found to be the more stable conformer and a lower degree of twisting was found for the heterocycle than for the phenyl ring, in agreement with the experimental findings relative to compound (1b). For the 3-substituted derivative (2a) the results of calculations showed that the two conformers of the S,O-cis and S,O-trans type differ only slightly in energy content, the former being predicted to be more stable, in contrast with the experimental behaviour found for derivative (2b).

Susceptibility of Male and Female Mice to the Nephrotoxic and Hepatotoxic Properties of Chlorinated Hydrocarbons.

SummaryMale and female mice were tested for their susceptibility to the nephro-toxic properties of chloroform and 1,1,2-trichloroe thane. Renal dysfunction, as determined by phenolsulfonephthalein excretion was demonstrated in male mice with chloroform at 0.078 ml/kg and 0.17 ml/kg for 1,112-trichloroethane. Renal dysfunction could not be produced in female mice with chloroform and 1,1,2-trichloroethane, even at lethal doses. Male and female mice were also tested for their susceptibility to the hepatotoxic properties of carbon tetrachloride. Liver dysfunction, as determined by elevated serum glu-tamic-pyruvic transaminase activity, could be demonstrated in both male and female mice at 0.009 ml/kg. No sex difference was observed in the 24-hour LD50 values for the three agents tested. This indicates that with these agents nephrotoxicity is not an important contributing factor in the deaths occurring during the first 24 hours.

Discovery of Chloroform Anæsthesia

The discovery of the use of chloroform as an anæsthetic, made by Sir James Young Simpson in Edinburgh in 1847, was marked by a graduation ceremony at the University at which the honorary degree of LL.D. was conferred on Dr. H. W. Feather-stone, founder-president of the Association of Anæsthetists of Great Britain, and Mr. T. B. Simpson, a grand-nephew of Simpson. A meeting to discuss the present-day use of chloroform was also held, at which Prof. R. R. Macintosh (Oxford) and Drs. D. S. Middleton and John Gilles (Edinburgh) read papers. Dr. Douglas Guthrie, lecturer on the history of medicine in the University of Edinburgh, gave an address at a reception in the Upper Library, where an exhibition of Simpson relics had been arranged. Dr. Guthrie said that the discovery of chloroform anæsthesia was one of the most dramatic episodes in the history of medicine, and with antiseptics had revolutionized surgery; it was remarkable that it had been delayed until the middle of last century. After graduating M.D. at Edinburgh in 1832, Simpson became assistant to Prof. John Thomson, professor of pathology, who advised him to specialize in midwifery. He was appointed professor of midwifery in the University in 1840, a post which he held until his death at the early age of fifty-nine in 1870. Since the discovery by Simpson of the anæsthetic properties of chloroform, there have been great advances in the technique of its administration, to which he himself contributed; and in spite of the introduction of many new substances, it still holds its place as a general anæsthetic.

On the Purification and Properties of Chloroform

On the Purification and Properties of Chloroform

3. Notes on the Purification and Properties of Chloroform.

Chloroform has been prepared both from alcohol and from wood-spirit. The latter has been used for the sake of cheapness; but as it is a mixture of several liquids, all of which do not yield chloroform, it gives an impure product, in a proportion which varies much, but is always below that obtained from alcohol. There is therefore not only no advantage, but the contrary, in using woodspirit, which is not, after all, much cheaper than alcohol.