HCl Complex Research Articles

Stability and structure of the 1:2 hydrogen bonded complex of dimethyl ether and HCl

Abstract SCF-MO calculations for the 1:2 hydrogen-bonded complex Me2O..(HCl)2 predict a structure where both HCl molecules are bonded to the oxygen in a roughly tetrahedral arrangement. Agreement between calculated and observed energy changes is very satisfactory. Population analysis is used to investigate the electron reorganization on complex formation.

Structure of the complexes of HCl with pyrixine and trimethylamine, isolated in an ar matrix

Structure of the complexes of HCl with pyrixine and trimethylamine, isolated in an ar matrix

The Reaction of Ethylbenzene with Methylbenzene–AlCl3–HCl Complex

Abstract Toluene, m-xylene, and mesitylene complexes prepared with AlCl3 and HCl, were separated from the upper hydrocarbon layer and allowed to react with ethylbenzene at 2 and 30 °C. The proton exchange between methylbenzenium ions and ethylbenzene, and the transalkylation of ethylbenzene were investigated by 13C NMR spectroscopy.

Internal dynamics of van der Waals complexes. I. Born–Oppenheimer separation of radial and angular motion

An efficient method has been developed for calculating ground state properties of atom–diatomic van der Waals complexes. The wide amplitude bending motion is decoupled from the radial motion in a way analogous to the Born–Oppenheimer separation of electronic and nuclear motion. The treatment furnishes rigorous upper and lower bounds to the ground state energy that are typically ±3 cm−1 for the Ar–HCl surfaces considered. Extensive comparison of this technique with the close-coupling method of Dunker and Gordon [J. Chem. Phys. 64, 354 (1976)] using intermolecular potentials for the Ar HCl complex indicates excellent agreement in the prediction of angular expectation values and rotational constants for the ground state, while realizing an approximate 700-fold reduction in computation time.

HCl and HBr Complexes with oxygen bases

Abstract Investigation of the formation constants, infra-red absorption spectra and dipole moments of HCl and HBr complexes with oxygen bases (sulphoxides, phosphine oxides, N-oxides) in CCl4 has been carried out. Low formation constants are probably due to an entropy effect connected with a freezing of free rotation of HCl molecules in CCl4. A plot of hydrogen bond polarity Δ μ versus basicity of oxides shows a characteristic inversion range in which sharp increase of the dipole moment due to the proton transfer equilibrium takes place. Complexes from the inversion range show continuous absorption in the infra-red region 600 to 3000 cm−1, the highest value of the shift of short wavelength maximum ascribed to protonic stretching vibration, and lowest value of the isotopic effect νHCl/νDCl, which is 1.30 (1.36 for weak complexes). A plot of relative values of the stretching vibration band shifts versus basicity of oxides is similar to the hydrogen bond polarity curve.

Argon hydrochloride, Ar⋅HCl, bond energy by infrared spectroscopy

The infrared absorption of argon (200–760 torr) and hydrogen chloride (2–6 torr) mixtures has been re-examined in the spectral region 2860–3010 cm−1 (the missing Q branch region) over the temperature range 195–298°K. The temperature dependence of two absorption features of the Ar⋅HCl complex, at 2887 and 2879 cm−1, lead to a bond energy estimate that depends upon the assumptions made about the internal degrees of freedom of the complex. Agreement with experiment can be reached for well depths near 1.2 kcal/mole, a result that is relatively insensitive to the choices of the vibrational frequencies and anharmonicities but which does depend upon the extent to which the energy level manifolds are truncated to avoid molecular excitation in excess of the bond energy. This bond energy contrasts with the commonly accepted value of 0.4 kcal/mole; the possible origin of the disparity is considered.

The i.r. spectra of matrix isolated water species—II. The characterisation of non-rotating monomer water species in an argon matrix by xenon doping: The matrix isolated spectra of H 2O·HCl and (CH 3) 2O·H 2O as model compounds for water dimer spectra

Non-rotating monomer lines of H 2O, D 2O and HDO in an argon matrix have been characterised by addition of xenon which enhances the intensity of lines ascribed in Part I of this series to non-rotating monomers on the basis of their concentration dependence and behaviour on annealing. Spectra of the matrices H 2O(D 2O, HDO)/HCl or (CH 3) 2O/H 2O have been obtained. The added HCl or (CH 3) 2O results in an enhancement of the non-rotating water monomer lines as well as giving new lines due to bimolecular complexes between water and HCl or (CH 3) 2O. Assignments for the water stretching and bending modes in the complexes of H 2O, D 2O, HDO with HCl or (CH 3) 2O are proposed. The frequencies assigned are closely related to those assigned to the water dimer in Part I and provide support for the open structure of the water dimer. Anomalies connected with υ 3 water modes in non-rotating monomers and in the H 2O·HCl complex are noted.

Ir spectra of complexes of HCL and HBR with tetramethylethylene, isolated in solid argon

1. In an argon matrix at 25°K, HCl and HBr form complexes with tetramethylethylene. 2. The degree of charge transfer in these systems is 0.2–0.3, which is somewhat less than in the same complexes in the solid state.

IR spectra of complexes of HCl and HBr with olefins at low temperatures

1. At low temperatures HCl and HBr form molecular complexes with olefins, and as the number of-alkyl substituents at the C =C bond increases, the basic properties of the olefins increase sharply. 2. In the system hydrohalide-olefin, a significant role is played by the forces of charge transfer.

Bromination of calf thymus chromatin

Calf thymus chromatin and its components were brominated with different concentrations of aqueous bromine reagent. The following samples were brominated: chromatin, histone-free chromatin, DNA-residual protein complex obtained from chromatin by extraction with 4 M guanidine · HCl and heat-denatured DNA-residual protein complex. The bromine content of the brominated DNAs, determined by X-ray fluorescence analysis, showed that the structural changes of chromatin as well as the presence or absence of histone protein were important factors in bromination of DNA when the bromine concentration was low (0.32 mole Br 2 per mole of deoxynucleotide). The structure of chromatin and the associated proteins, e.g. histone and residual protein, afforded protection to DNA against bromination. When a high concentration of bromine (2.54 moles Br 2 per mole of deoxynucleotide) was used, no such modifying effect of proteins on bromination of DNA was observed. The protection of DNA by proteins was virtually eliminated in the presence of excess bromine.

The energy of the hydrogen bond in complexes of HBr, HCl and HF with organic bases

The energy of the hydrogen bond in complexes of HBr, HCl and HF with organic bases

Reaction between hydrogen chloride, tetra-n-butylammonium chloride, and trimethylchlorosilane in benzene solutions

1. The dipole moments of TBAC, TBAB, and TMCS in benzene and of TBAC and TBAB inp-xylene have been measured. 2. Complexes are formed between TBAC and HCl in benzene. 3. The interaction between TMCS and the complex of HCl and TBAC is weak.

Studies on the behaviour of Cuprous chloride in hydrochloric acid and potassium chloride solution. II. Conductometric and potentiometric Measurements for determining complex ion formation

AbstractThe formation of complexes of HCl and KCl with CuCl in solution has been studied by measurements of the conductivity and the electromotoric force.