KINETICS OF FORMATION AND STABILITY CONSTANTS OF MONO AND BIS l-TYROSINE COMPLEXES OF Cu(II), Co(II), AND Ni(II)

Abstract

The kinetics and stability constants of l-tyrosine complexation with copper(II), cobalt(II) and nickel(II) have been studied in aqueous solution at 25° and ionic strength 0.1 M. The reactions are of the type M(HL)^(3-n)+ _n-1 + HL- ? M(HL)^(2-n)+_n(k_n, forward rate constant; k_-n, reverse rate constant); where M=Cu, Co or Ni, HL^? refers to the anionic form of the ligand in which the hydroxyl group is protonated, and n=1 or 2. The stability constants (K_n=k_n/k_-n) of the mono and bis complexes of Cu²⁺, Co²⁺ and Ni²⁺ with l-tyrosine, determined by potentiometric pH titration are: Cu²⁺, log K₁=7.90 ± 0.02, log K₂=7.27 ± 0.03; Co²⁺, log K₁=4.05 ± 0.02, log K₂=3.78 ± 0.04; Ni²⁺, log K₁=5.14 ± 0.02, log K₂=4.41 ± 0.01. Kinetic measurements were made using the temperature-jump relaxation technique. The rate constants are: Cu²⁺, k₁=(1.1 ± 0.1) × 10⁹ M ^?1 sec^?1, k_-1=(14 ± 3) sec^?1, k₂=(3.1 ± 0.6) × 10⁸ M ^?1 sec^?1, k^?2=(16 ± 4) sec^?1; Co²⁺, k₁=(1.3 ± 0.2) × 10⁶ M ^?1 sec^?1, k_-1=(1.1 ± 0.2) × 10² sec^?1, k₂=(1.5 ± 0.2) × 10⁶ M ^?1 sec^?1, k_-2=(2.5 ± 0.6) × 10² sec^?1; Ni²⁺, k₁=(1.4 ± 0.2) × 10⁴ M ^?1 sec^?1, k_-1=(0.10 ± 0.02) sec^?1, k₂=(2.4 ± 0.3) × 10⁴ M ^?1 sec^?1, k_-2=(0.94 ± 0.17) sec^?1. It is concluded that l-tyrosine substitution reactions are normal. The presence of the phenyl hydroxyl group in l-tyrosine has no primary detectable influence on the forward rate constant, while its influence on the reverse rate constant is partially attributed to substituent effects on the basicity of the amine terminus.     

The bond nature of alkaline-earth homonuclear metal clusters investigated with pseudopotential CI method

The electronic stucture of Be_l, Mg_m and Ca_n ( 1? 7, m and n ? 5) metal clusters has been investigated by means of an ab initio pseudopotential method followed by multireference double-excitation configuration interaction (PP MRD CI). Two completely different situations arise on going from Be to heavier alkaline metals. The sp hybridization, which is effective in the Be case, completely disappears when aggregates of Mg and Ca are considered. The potential energy curves relative to Be, Mg and Ca clusters exhibit a very shallow minimum at large distances while a second deeper minimum is characteristic of some Be clusters. This inner minimum is generated by the large interaction of atomic p orbitals at an internuclear separation close to the BeBe distance present in the Be crystal. The bond in Be clusters largely depends on the geometrical arrangement which directly influences the possible sp hybridisation. Very small Be planar structures are always less favored with respect to clusters containing the tetrahedral unit as a part of the whole structure. However, this situation is changed when larger planar clusters are considered, and the highest binding energy per atom (12.0 kcal/mole) from all clusters considered in this work was found for the triplet ground state of the planar Be₇(D_6h) cluster.     

The direct l-type resonance spectrum of CF3CCH in the vibrational state v10=3: Extension of the theory of reduction to H6n terms

The direct l-type resonance spectrum of CF₃CCH has been measured in the v₁₀=3 vibrational state by means of waveguide microwave Fourier transform spectroscopy in the range 8–26 GHz. Three types of direct l-type resonance transitions induced by the (Δk=Δl=±2) interaction could be observed: 140 transitions following the ΔJ=0, Δk=Δl=±2, Δ|l|=0, selection rule covering values of J=17–61 and G=|k−l| from 1 to 7, 94 transitions following the ΔJ=0, Δk=Δl=±2, Δ|l|=±2, selection rule covering values of J=26–57 and G from 15 to 24, 90 transitions following the ΔJ=0, Δk=Δl=±4 selection rule covering values of J=34–80 and G from 3 to 12 and 13 transitions following the ΔJ=0, Δk=Δl=±6, k=∓1, l=∓1⇔k=±5, l=±3 selection rule for J=71-83. 14 A₁–A₂ splitting transitions with kl=+1 were measured from J=33 to 49. Strong perturbations due to Δ(k−l)=±3 interactions made possible the observation of perturbation-allowed transitions with selection rule k=±4, l=±3⇔k=±3, l=∓1. Furthermore, the rotational transitions J=2–1, 3–2 and 4–3 have been measured. To make use of the multiple fitting concept, the theory of reduction developed for the v_t=2 vibrational state by Sarka and Harder [K. Sarka, H. Harder, J. Mol. Spectrosc. 197 (1999) 254] has been extended to the v_t=3 vibrational state including terms up to H₆₂. Owing to problems in the reproduction of data with low K and A₁–A₂ symmetry, two types of fits have been performed using five reduced forms of the effective Hamiltonian. The first type of fit used a reduced data set for which part of the transitions has been omitted. The unitary equivalence of the determined parameter sets has been demonstrated including newly derived relations for parameters in v₁₀=3. In the second type of fit, the complete data set has been included, yielding satisfactory results only in one reduction. In both type of fits, parameters up to sixth order have been determined including the axial rotational constant A and the Coriolis constant Aζ for both values of l. General features of the direct l-type resonance spectrum in a v_t=3 level are discussed.     

Evaluation of behaviour of linear monoamines CH3-(CH2)n−1-NH2 (n=1-6) in ion chromatography

This paper reports the results on a study of ion chromatography (IC) behaviour on strong cationic exchange column of CH₃-(CH₂)_n−1-NH₂ (n=1-6) type linear monoamines. The eluents were mixtures of HCl-NaCl, HNO₃-NaNO₃, HClO₄-NaClO₄, H₂SO₄-Na₂SO₄, HClO₄-NaClO₄-CH₃CN. Amines were revealed with an amperometric detector. The influence of different counter-ions on retention factors, k′, is discussed. Relationships between k′ and pE (E=sum of Na⁺ and H⁺ concentrations), and length of alkylic chain, and sensitivity coefficient S, are reported and discussed. The addition of acetonitrile (ACN) in the eluent was also taken into account. Suitable considerations are derived from these data. An example of monoamines separation is given.     

Retardation (Casimir) energy shifts for Rydberg helium-like low-Z ions

The development of storage rings and electromagnetic traps for heavy charged particles is opening up new regimes of atomic physics, including, in particular, spectroscopic studies of Rydberg helium-like ions — with nuclear chargeZ, one electron in the 1s state, and one electron in a near-hydrogenic state of highn andl <n, withn andl the principal and orbital quantum numbers, respectively. We consider the possibility of detecting energy shifts due to retardation, ΔE _ret (n,l), Casimir-like effects. These are quantum electrodynamic (QED) retardation effects associated with the finite speed of light. (As opposed to basically kinematic and dynamic QED effects for small quantum numbersn andl, the appropriate expansion parameter forn andl large for retardation QED corrections is notZ(e ²/?c) but [(Z ? 1)/n ² Z ²](?c/e ²).) We wish to provide some orientation to those planning experiments in the area, with regard to the choices ofn,l, andZ most likely to be able to generate a high-precision confirmation of a retarded interaction. To do so, we provide extensive tables of estimates, for 1s,nl states, of ΔE _ret(n,l), of radiative widths, and ofE, the spin-independent (“electric” fine structure) energy in the absence of retardation shifts, for (nuclear spin zero) ions withZ=2, 6, 8, 16 and 20. These ions might be experimentally accessible in storage rings, and theZ's are low enough that virtual pair production effects may not yet be significant. There is also a brief survey of possible experimental techniques.     

Description of phenomenological process during thermal formation of an epoxy system in presence of metal nanoparticles using advanced kinetics analysis

The curing process of diglycidyl ether of bisphenol A (DGEBA)–isophoronediamine (IPDA) system filled with different contents of Fe nanoparticles (nano-Fe) has been investigated by differential scanning calorimetry and Fourier transform infrared spectroscopy analysis in order to understand the effect of nano-Fe. These studies revealed that high percentage of the nanofiller, i.e. 10 %, results in improved epoxy matrix as evidenced by increasing in the reaction heat and conversion degree. Kinetics of DGEBA/IPDA/10 % nano-Fe cure was studied by calorimetry measurements at isothermal mode. Isothermal kinetic parameters, including k ₁, k ₂, m, and n were determined and it was shown that the reaction kinetics could be expressed well by dα/dt = (k ₁ + k ₂ α ^m)(1?α)ⁿ which called Kamal model. The results also showed that the diffusion control does not occur. The excellent fitting Kamal model with experimental data at the end of the isothermal cure process could be mentioned as evidences here. The dispersion of 10 % nano-Fe into epoxy matrix was analyzed by atomic force microscopy observations.     

Magnetic properties and exchange couplings of one-dimensionally arrayed 4f−3d heterometallic [Ln2Cu2]n compounds

Heterometallic polymeric coordination compounds [{Ln(hfac)₂(CH₃OH)}₂{Cu(dmg)(Hdmg)}₂]_n ([Ln₂Cu₂]_n; Ln = Tb, Ho, and Er; H₂dmg = dimethylglyoxime; Hhfac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione) were synthesized, and the X-ray crystallographic analysis shows that their structures are isomorphous to those of the known ferrimagnetic [Gd₂Cu₂]_n and [Dy₂Cu₂]_n analogs. The exchange couplings in [Tb₂Cu₂]_n, [Ho₂Cu₂]_n, and [Er₂Cu₂]_n were precisely evaluated by high-frequency EPR and pulsed-field magnetization studies, giving J_Tb?Cu/k_B = ?0.77(2) K, J_Ho?Cu/k_B = ?0.250(12) K and J_Er?Cu/k_B = ?0.149(15) K. They were comparable to those of the Gd and Dy analogs. The absolute value of the exchange coupling parameter monotonically decreases in the order of Gd, Tb, Dy, Ho, and Er.     

β-d-Xylosidase from Selenomonas ruminantium: Thermodynamics of Enzyme-Catalyzed and Noncatalyzed Reactions

β-d-Xylosidase/α-l-arabinofuranosidase from Selenomonas ruminantium is the most active enzyme known for catalyzing hydrolysis of 1,4-β-d-xylooligosaccharides to d-xylose. Temperature dependence for hydrolysis of 4-nitrophenyl-β-d-xylopyranoside (4NPX), 4-nitrophenyl-α-l-arabinofuranoside (4NPA), and 1,4-β-d-xylobiose (X2) was determined on and off (k _non) the enzyme at pH 5.3, which lies in the pH-independent region for k _cat and k _non. Rate enhancements (k _cat/k _non) for 4NPX, 4NPA, and X2 are 4.3?×?10¹¹, 2.4?×?10⁹, and 3.7?×?10¹², respectively, at 25 °C and increase with decreasing temperature. Relative parameters k _cat ^4NPX/k _cat ^4NPA, k _cat ^4NPX/k _cat ^X2, and (k _cat/K _m)^4NPX/(k _cat/K _m)^X2 increase and (k _cat/K _m)^4NPX/(k _cat/K _m)^4NPA, (1/K _m)^4NPX/(1/K _m)^4NPA, and (1/K _m)^4NPX/(1/K _m)^X2 decrease with increasing temperature.     

Cadmium ion reduction at mercury electrode in aqueous KCl solution in presence of adsorbed polyvinyl alcohol

The influence of polyvinyl alcohol on the kinetics of cadmium ion reduction in 1M aqueous KCl solution at the dropping mercury electrode was investigated using the impedance method. It was found that small additions of PVA did not change the diffusion coefficient much, but affected only the rate of charge transfer process. The electroreduction of cadmium in the presence of PVA became less reversible. The standard rate constant dependence on coverage degree is described by the following equation: k_s=k_s0(1?ν)ⁿ, where n=2.     

Formation and structural refinements of tunneled intergrowth phases in the Ga2O3-In2O3-SnO2-TiO2 system

Over 100 samples were prepared as (Ga,In)₄(Sn,Ti)_n−4O_2n−2, n=6, 7, and 9 by solid-state reaction at 1400 °C and characterized by X-ray diffraction. Nominally phase-pure beta-gallia-rutile intergrowths were observed in samples prepared with n=9 (0.17?x?0.35 and 0?y?0.4) as well as in a few samples prepared with n=6 and 7. Rietveld analysis of neutron time-of-flight powder diffraction data were conducted for three phase-pure samples. The n=6 phase Ga_3.24In_0.76Sn_1.6Ti_0.4O₁₀ is monoclinic, P2/m, with Z=2 and a=11.5934(3) Å, b=3.12529(9) Å, c=10.6549(3) Å, β=99.146(1)°. The n=7 phase Ga_3.24In_0.76Sn_2.4Ti_0.6O₁₂ is monoclinic, C2/m, with Z=2 and a=14.2644(1) Å, b=3.12751(2) Å, c=10.6251(8) Å, β=108.405(1)°. The n=9 phase Ga_3.16In_0.84Sn₄TiO₁₆ is monoclinic, C2/m, with Z=2 a=18.1754(2) Å, b=3.13388(3) Å, c=10.60671(9) Å, β=102.657(1)°. All of the structures are similar in that they possess distorted hexagonal tunnels parallel to the [010] vector.     

Excess molar quantities of (a halogenated n-alkane + an n-alkane) A comparative study of mixtures containing either 1-chlorobutane or 1,4-dichlorobutane

Excess molar volumes V_m^E at 298.15 K were obtained, as a function of mole fraction x, for series I: {x1-C₄H₉Cl + (1 ? x)n-C_lH_{2l + 2}}, and II: {x1,4-C₄H₈Cl₂ + (1 ? x)n-C_lH_{2l + 2}}, for l = 7, 10, and 14. 10, and 14. The instrument used was a vibrating-tube densimeter. For the same mixtures at the same temperature, a Picker flow calorimeter was used to measure excess molar heat capacities C_{p, m}^E at constant pressure. V_m^E is positive for all mixtures in series I: at x = 0.5, V_m^E/(cm³ · mol^?1) is 0.277 for l = 7, 0.388 for l = 10, and 0.411 for l = 14. For series II, V_m^E of {x1,4-C₄H₈Cl₂ + (1 ? x)n-C₇H₁₆} is small and S-shaped, the maximum being situated at x_max = 0.178 with V_m^E(x_max)/(cm³ · mvl^?1) = 0.095, and the minimum is at x_min = 0.772 with V_m^E(x_min)/(cm³ · mol^?1) = ?0.087. The excess volumes of the other mixtures are all positive and fairly large: at x = 0.5, V_m^E/(cm³ · mol^?1) is 0.458 for l = 10, and 0.771 for l = 14. The C_{p, m}^Es of series I are all negative and |C_{p, m}^E| increases with increasing l: at x = 0.5, C_{p, m}^E/(J · K^?1 · mol^?1) is ?0.56 for l = 7, ?1.39 for l = 10, and ?3.12 for l = 14. Two minima are observed for C_{p, m}^E of {x1,4-C₄H₈Cl₂ + (1 ? x)n-C₇H₁₆}. The more prominent minimum is situated at x′_min = 0.184 with C_{p, m}^E(x′_min)/(J · K^?1 · mol^?1) = ?0.62, and the less prominent at x″_min = 0.703 with C_{p, m}^E(x″_min)/(J · K^?1 · mol^?1) = ?0.29. Each of the remaining two mixtures (l = 10 and 14) has a pronounced minimum at low mole fraction (x_min = 0.222 and 0.312, respectively) and a broad shoulder around x = 0.7.     

Measurement of state-to-state rotational transfer rates in collision of I2*(B 0u+, υ = 15, j) with 3He, 4He,Ne, Ar,H2, D2 and I2

The selective laser excitation and induced fluorescence observation technique has been used to study rotationally inelastic collisions of I₂^*(B 0_u⁺, υ = 15,j) with I₂, ³He, ⁴He, Ne, Ar, H₂ and D₂. For each collision partner, several initial rotational levels ranging from j_i = 12 up to j_i = 146 have been excited. For purely rotational transfer within the υ = 15 level, our data are perfectly consistent with energy sudden (eventually corrected) scaling laws. Thus, any thermally averaged rate constant, k(j_i → j_f), can be expressed as a function of the basis rate constants k(l → 0). Furthermore, these k(l → 0) are found to follow simple empirical fitting laws. Consequently any k(j_i → j_f) can be predicted given a set of two or three fitting parameters. Collisions with relatively heavy particles (I₂, Ar and Ne) are well described by using the inverse power fitting law k(l → 0) = b[l(l+1)]^?γ, where b = 1.7, 1.2 and 1.2×10^?10 cm³ s^?1 and γ = 1.08, 1.02 and 1.17 for I₂^*-Ne, I₂^*-Ar and I₂^*-I₂ collisions respectively. For collisions with light particles (³He, ⁴He, H₂ and D₂), k(l → 0) shows a sharp decrease with l which can be accounted for by a hybrid power-exponential fitting law k(l → 0) = b[l(l+1)]^?γ exp[-l(l+1)/l^* (l^*+1)], where b = 0.84, 0.71, 2.77 and 2.78×10^?10 cm³ s^?1l⁺ = 20.6, 23.1, 18.8 and 31.4, and γ = 0.66, 0.66, 0.78 and 0.91 for I₂^*-³He, I₂^*-He, I₂^*-H₂ and I₂^*-D₂ collisions, respectively. We confirm that the rotational transfer dynamics in heavy molecules is mainly governed by angular momentum exchange.     

Theoretical study of H⋯P and X⋯P interactions of methylphosphines with HSX molecules

Ab initio calculations were used to analyze the interactions between thiohypohalous acids (HSX; X = F, Cl, Br, I) and methylphosphine derivatives (PH _n Me_3?n , n = 0–3) at the MP2/aug-cc-pVDZ level of theory. Interaction of HSX with PH _n Me_3?n leads to both hydrogen bond (HSX–PH _n Me_3?n –HB) as well as halogen bond (HSX–PH _n Me_3?n –XB) complexes. Stabilities of both HB and XB complexes increase with basicity of the phosphines. However, HB complexes of a phosphine molecule with different HSX have the same order of stabilities, but XB complexes of heavier thiohypohalous acids are more stable. Electron densities of complexes were characterized with the atoms in molecules methodology. The charge transfer within dimers was analyzed by means of natural bond orbitals.     

General properties of the electronic structure of alkali metal clusters and Ia-IIa mixed clusters

The results of the systematic ab-initio CI investigation of neutral and charged Li _n , Na _n , BeLi _k and MgNa _k clusters are summarized and analyzed. The general characteristic features of the electronic structure are pointed out:a) The participation of the atomic orbitals, which are empty in Ia and IIa metal atoms, allows for a higher valency of these atoms in clusters.b) Jahn-Teller and pseudo-Jahn-Teller effects strongly influence the electronic and geometric structure of clusters.c) Deformations of cluster geometry can lead to biradicaloid structures with higher spin multiplicity in their ground states.d) The peculiarities of the electronic structures of clusters can be deduced from the presence of many “surface” atoms. The theoretical results agree with experimental data presently available and they are useful for interpretation of the experimental findings.     

Isotropic C6, C8 and C10 interaction coefficients for CH4, C2H6, C3H8, n-C4H10 and cyclo-C3H6

The non-empirical generalized Kirkwood, Unsöld, and the single-Δ Unsöld methods (with double-zeta quality SCF wave-functions) are used to calculate isotropic dispersion (and induction) energy coefficients C_2n, with n ? 5, for interactions involving ground state CH₄, C₂H₆, C₃H₈, n-C₄H₁₀ and cyclo-C₃H₆. Results are also given for the related multipole polarizabilities α_l, multipole sums S₁/(0) and S₁(?1) which are evaluated using sum rules, and the permanent multipole moments. for l = 1 (dipole) to l = 3 (octupole). Estimates of the reliability of the non-empirical methods, for the type of molecules considered, are obtained by a comparison with accurate literature values of α₁S₁(?1) and C₆. This, and the asymptotic properties of the multipolar expansion of the dispersion energy, the use to discuss recommended representation for the isotropic long range interaction energies through R^?10 where R is the intermolecular separation.     

Modelling and experimental validation of enantioseparation of racemic phenylalanine via a hollow fibre-supported liquid membrane

This paper reports on the enantioseparation of racemic phenylalanine or D-phenylalanine and Lphenylalanine via a hollow fibre-supported liquid membrane (HFSLM) and the results are compared with the mathematical model. The enantioseparation results, of 80 % and 73 %, showed the highest extraction and stripping of l-phenylalanine from the feed phase and the enantiomeric excess (% ee) of 60 % from 6 mmol L^?1 of initial rac-phenylalanine in the feed solution. The optimum parameters were feed solution at pH 5, 6 mmol L^L?1 of O,O′-dibenzoyl-(2S,3S)-tartaric acid ((+)-DBTA) as the extractant in octanol as the liquid membrane, and deionised water as the stripping solution. Equal flow-rates of feed and stripping solutions of 100 mL min^L?1 were adjusted in a batch operation mode for 50 min at ambient temperature. From the calculation, the equilibrium constants of extraction (K _ex) and mass transfer coefficients in the feed phase (k _f) and in the liquid membrane phase (k _m) were found to be 1.81 L mmol^?2, 3.50 × 10^?2 cm s^?1, and 1.40 × 10^?2 cm s^?1, respectively. Finally, the change in concentrations of d,l-phenylalanine over time in the feed and stripping solutions by mathematical model were estimated and compared with the experimental results. The values thus calculated were in agreement with the experimental data with the average deviation of approximately 3 %.     

Molecular structures and supramolecular association of chlorodiorganotin(IV) complexes with bis- and tris-dithiocarbamate ligand

Two series of di and trinuclear chlorodiorganotin(IV) complexes derived from bis- and tris-dithiocarbamate ligands have been prepared and structurally characterized. The dinuclear complexes 1-2 of the composition {(R₂SnCl)₂(bis-dtc)} (1, R = Me; 2, R = ⁿBu) have been obtained from R₂SnCl₂ (R = Me, ⁿBu) and the triethylammonium salt of N,N′-dibenzyl-1,2-ethylene-bis(dithiocarbamate). The trinuclear complexes 3-9 with the general formula {(R₂SnCl)₃(tris-dtc)} 3, R = Me, tris-dtc = tris-dtc-Me; 4, R = Me, tris-dtc = tris-dtc-ⁱPr; 5, R = Me, tris-dtc = tris-dtc-Bn; 6, R = ⁿBu, tris-dtc = tris-dtc-Me; 7, R = ⁿBu, tris-dtc = tris-dtc- ⁱPr; 8, R = ⁿBu, tris-dtc = tris-dtc-Bn; 9, R = ^tBu, tris-dtc = tris-dtc-Me) were prepared from R₂SnCl₂ (R = Me, ⁿBu, ^tBu) and the potassium dithiocarbamate salts of (tris[2-(methylamino)ethyl]amine) (tris-dtc-Me), (tris[2-(isopropylamino)ethyl]amine) (=tris-dtc-ⁱPr) and (tris[2-(benzylamino)ethyl]amine) (=tris-dtc-Bn). Compounds 1-9 have been analyzed as far as possible by elemental analysis, FAB⁺ mass spectrometry, IR and NMR (¹H, ¹³C, ¹¹⁹Sn) spectroscopy, and single-crystal X-ray diffraction analysis. The solid state and solution studies showed that the dtc ligands are coordinated to the tin atoms in the anisobidentate manner. In all cases the metal centers are five-coordinate. The coordination geometry is intermediate between square-pyramidal and trigonal-bipyramidal coordination polyhedra with τ-values in the range of 0.32-0.53. For the members of each series characterized in the solid state by X-ray diffraction analysis, different molecular conformations were found. The crystal structures show the presence of C-H?Cl, C-H?S, C-H?π, S?Cl, S?S, Cl?Sn and S?Sn contacts.     

Copper diazine spin ladders: Synthesis,structure and magnetic analyses of Cu(2-methylthiopyrazine)Br2

The reaction of copper(II) bromide with 2-methylthiopyrazine (meSpz) in THF/CH₂Cl₂ gave crystals of [Cu(meSpz)Br₂]_n. The compound crystallizes in the monoclinic space group C2/m: a = 13.754(6) Å, b = 6.825(2) Å, c = 9.731(4) Å, β = 104.598(8)°. The structure comprises ladders where the rungs of the ladder are formed by bridging bromide ions and the rails are formed by bridging meSpz molecules. Magnetic susceptibility data over the range 1.8–325 K was fit to a strong-rung ladder model resulting in J/k_rung = ?39.79(17) K and J/k_rail = ?18.0(4) K.     

Analytical results for the classical and semiclassical coordinate probability distribution function of anharmonic oscillators

The classical and Wigner—Kirkwood semiclassical distribution functions for single and double-well anharmonic oscillators with ? = p?²/2m + k₂x?² + k_2nx?²ⁿ are given in closed form. Applications in the theory of electron diffraction are discussed briefly.     

Kinetic Studies on the Oxidation of Germanium(II) with Chlorate by Polarographic Analysis

The rate of oxidation of Ge(II) chloride by large excess of ClO₂^? ions in HCl, NaCl and Na₂SO₄ mixed solutions was polarographically observed at various H₂O⁺ and Cl^? ion concentrations. The observed rate constant, k_obs, is expressed by k_o=K_obs/(ClO₃^?)={k₁,(H⁺)+k₂K₁(Cl^?)²+ K₃K₂(SO₄^2?)} (H⁺)/{(H⁺)¹+K₁(Cl^-)2 +K₂(SO₄^2?)} for the following reaction processes, The values were obtained aa k₁=1.5410^-3liter² mole^2? sec^-1, k₂=5.00×10^-2liter² mole^2? sec^-2 and k₂=4.30×10^-3liter² mole^2? sec^-2, K₁=1.80× 10^-2, K₂= 2.43×10^-2 mole liter^-1 at constant ionic strength I=0.50 M at 30°C.