Mixture Of CHCl3 Research Articles

Preferential solvation studies using the solvatochromic dicyanobis(1,10-phenanthroline)iron(II) complex

Solvent effects on the electronic spectra of dicyanobis(1,10-phenanthroline)iron(II) have been investigated in thirteen pure solvents and twenty binary solvent mixtures. In pure solvents, the shifts of the νmax values are found to depend on more than one of the known solvent parameters (AN, α, β, DN and π*). AN, α and π* are found to be the most important solvent parameters, exerting a considerable effect on the solvatochromic shifts of the title complex. The preferential solvation of dicyanobis(1,10-phenanthroline)iron(II) in binary solvent mixtures has been investigated by monitoring the metal–ligand charge transfer band of the indicator complex. Organic solvents are preferred near the indicator complex in aqueous binary solvent mixtures (negative deviation), except in regions rich in MeCN, Me2CO and 1,4-dioxane, where water molecules are preferred over the organic component (dual behavior). However, the indicator complex is preferentially solvated by the component which has the higher acceptor number in non-aqueous binary solvent mixtures. Negative deviation was observed in binary mixtures of CHCl3 and Me2CO with alcohols and positive deviation in mixtures of CHCl3 with THF, DMSO and Me2CO. Different criteria were considered to evaluate the extent of preferential solvation in different solvent mixtures, iz., the local molar fraction (XAL), the excess function (ΔX), the iso-solvation point (XBiso) and the preferential solvation constant (KA/B). The preferential solvation data have been linearly correlated with the different solvent parameters.

Thermodynamics of mixtures with strongly negative deviations from Raoult's law Part 2. Application of the DISQUAC model to mixtures of CHCl3 or CH2Cl2 with oxaalkanes. Comparison with Dortmund UNIFAC results

Binary mixtures of linear and cyclic oxaalkanes and CHCl3 or CH2Cl2 are characterized in the framework of the DISQUAC model. The interaction parameters for the corresponding O/Cl contacts are reported. The enthalpic quasichemical interchange coefficients are negative, as in other mixtures which also show strong negative deviations from Raoult's law. There are proximity effects on both dispersive and quasichemical interaction parameters of diethers and acetals. DISQUAC represents fairly well the thermodynamic properties examined: vapor–liquid equilibria (VLE), molar excess enthalpies (HE), molar excess heat capacities at constant pressure (CpE) or natural logarithms of activity coefficients at infinite dilution (ln γi∞). DISQUAC provides much better results than the Dortmund version of UNIFAC using the published geometrical and interaction parameters. From this comparison, it seems that one should distinguish, at least, between linear monoethers, polyethers or acetals. Each cyclic molecule should be treated separately. A short comparison between DISQUAC and the ideal associated solution theory is also included. Both models yield similar results.

Detection of hydrogen-bonded adenine-thymine base-pair complexes by electrospray mass spectrometry

Abstract Bibracchial lariat ether compounds having three-carbon sidearms terminated in either adenine or thymine have the potential to form a molecular box in which the “ends” are crown ethers and the “sides” are hydrogen-bonded base pairs. Previous solution studies relying upon NMR and vapor pressure osmometry confirmed the formation of complexes. In the present study, four diaza-18-crown-6 derivatives having either one or two sidearms each terminated in either adenine or thymine have been studied in a mixture of CHCl3 and CH3OH. Either acetic acid or sodium chloride was added to the solutions. For the two-armed systems, the preferred complex was the dimer involving adenines on one monomer and thymines on the other. Homodimers and other complexes were detected as well. The preferred single-armed complex was that occurring between the monomer whose sidearm was terminated in thymine and either H+ or Na+.

Helix‐sense‐selective polymerization of phenyl[bis(2‐pyridyl)]methyl methacrylate and chiral recognition ability of the polymer

AbstractA novel monomer, phenyl[bis(2‐pyridyl)]methyl methacrylate (PB2PyMA), was synthesized. The solvolysis rate of PB2PyMA measured in CDCl3–CD3 OD [1/1 (v/v)] by 1H‐NMR spectroscopy at 35°C was much smaller than those of triphenylmethyl methacrylate (TrMA) and diphenyl‐2‐pyridylmethyl methacrylate (D2PyMA). PB2PyMA was anionically polymerized with the complexes of organolithiums with (−)‐sparteine (Sp), (S,S)‐(+)‐and (R,R)−(‐)‐2,3‐dimethoxy‐1,4‐bis(dimethylamino)butanes[(+)‐and (−) ‐DDB], and (S)‐(+)‐1‐(2‐pyrrolidinylmethyl) pyrrolidine (PMP) in toluene at low temperature. The polymers obtained with Sp and DDB complexes showed low optical activity. PMP complexes, particularly that with N,N′‐diphenylethylenediamine monolithium amide, were effective in synthesizing a polymer of high optical rotation ([α]25365 ∼ +1350°) which was comparable to those of poly(TrMA) and poly(D2PyMA) with one‐handed helical structure. The optical rotation of poly(PB2PyMA) in a mixture of CHCl3 and 2,2,2‐trifluoroethanol (9/1, v/v) slowly decreased with time. Optically active poly(PB2PyMA) coated on macroporous silica gel was able to resolve racemic compounds as a chiral stationary phase for high‐performance liquid chromatography. © 1993 John Wiley & Sons, Inc.

In vitro mutagenicity of water contaminants in complex mixtures.

Trihalomethanes, Carbon tetrachloride and trichloroethylene were tested in single, binary and multi-complex mixtures using standard tester strains TA1535, TA1537, TA98 and TA100 of Salmonella typhimurium with and without addition of an in vitro metabolizing fraction S-9. Chloroform (CHCl3) was found to be mutagenic in all strains without S-9 activation. However, when tested with Bromoform (15%), which was nonmutagenic singly, the combined effect of the mixture was nonmutagenic. CCl4 was a direct mutagen (without S-9) in all strains except TA 1535. When combined with 85% CHCl3, only strains TA1535 and TA1537 were mutagenic. When tested with mammalian activation (S-9), CCl4 was mutagenic in all strains. However, when tested with CHCl3 (CHCl3 and CCl4-85:15), the mutagenic capability was lost. With or without S-9 Activation multi-complex mixture of CHCl3, CCl4 and TCE (85:8:7) was mutagenic for a narrow range of doses in all strains.

Reduction of CCl4, CHCl3, and ArCH(OH)CCl3 by isopropanol with initiation by iron, molybdenum, and manganese carbonyls

1. Carbon tetrachloride is selectively reduced by isopropanol to CHCl3 in the presence of Fe(CO)5 and is nonselectively reduced to a mixture of CHCl3 and CH2Cl2 in the presence of Mn2(CO)10 or Mo(CO)6. 2. α-Trichloromethylarylcarbinols are effectively reduced by isopropanol to α-dichloromethylarylcarbinols when the reaction is initiated by Fe(CO)5. 3. The reduction of p-CH3OC6H4CH(OH)CCl3 by isopropanol in the presence of Fe(CO)5, Mo(CO)6, or Mn2(CO)10 results in the formation of p-CH3OC6H4CH(OH)CHCl2 and p-CH3OC6H4CH(CHCl2)OCH(CH3)2 in a ratio which depends on the nature of the metal carbonyl.

Reduction of polychloromethanes and?,?,?,?-tetrachloroalkanes with silicon hydrides in the presence of Fe(CO)5 OR H2PtCI�6H2O

1. In the presence of Fe(CO)5 or H2PtCl6·6H2O triethylsilane reduces CHCl3 to CH2Cl2 and CCl4 to a mixture of CHCl3 and CH2Cl2. 2. The presence of a single chlorine atom in the α-position to the CCl3 group prevents its reduction by triethylsilane in the presence of Fe(CO)5.