Intermolecular interactions of p-nitrophenol with butyl acetate,according to IR spectroscopic data

Infrared difference spectroscopy has been used to study the association of p-nitrophenol (NP) with butyl acetate (BA) in CCl₄ and in undiluted BA. It has been shown that in CCl₄, an associate is formed, [NP·BA] ·BA (Ia), in which one molecule of BA is linked to the NP by a hydrogen bond, and the second BA molecule is linked to the H-complex NP·BA by outer-sphere (dipole-dipole) interaction. In undiluted BA with low concentrations of NP, (Ia) is formed; with high concentrations of NP, an associate [(NP)₂BA] ·mBA is formed, in which two molecules of NP are bonded successively to each other and with a BA molecule; and the number of outer-sphere BA molecules may depend on the concentration of free BA molecules in the solutions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 593–599, March, 1991.     

Calibration of a basket option model applied to company valuation

Applying real options thinking to company valuation seems theoretically and intuitively appealing. However, the real option analogy of a single European option as well as the compound option proxy perform poorly when applied to company valuation. We therefore suggest to rework the building blocks of real option applications to corporate valuation.  We introduce a framework to delineate the distribution of the underlying asset in the risk neutral world, which is important in order to value any derivative. This is achieved by an algorithm to calibrate a basket option model using real world data of observed share prices. The fitting takes account of the class of stable distributions. The index of stability of asymmetric α stable distribution serves as an over-all parameter to characterise the specific distribution.     

Asymptotic expansions of integrals of two Bessel functions via the generalized hypergeometric and Meijer functions

Asymptotic expansions of certain finite and infinite integrals involving products of two Bessel functions of the first kind are obtained by using the generalized hypergeometric and Meijer functions. The Bessel functions involved are of arbitrary (generally different) orders, but of the same argument containing a parameter which tends to infinity. These types of integrals arise in various contexts, including wave scattering and crystallography, and are of general mathematical interest being related to the Riemann—Liouville and Hankel integrals. The results complete the asymptotic expansions derived previously by two different methods — a straightforward approach and the Mellin-transform technique. These asymptotic expansions supply practical algorithms for computing the integrals. The leading terms explicitly provide valuable analytical insight into the high-frequency behavior of the solutions to the wave-scattering problems.     

On the interpretation of the RHEED intensity oscillations during the growth of vicinal faces

A quantitative treatment of the crystallization kinetics in MBE growth of vicinal surfaces results the relation l ²=2D _sK between the surface diffusion coefficient D _s, the time for a monolayer deposition and the interstep distance l at which the RHEED intensity oscillations disappear. The correction factor K depends on the size and the energy of the two-dimensional critical nucleus and it is estimated to be smaller than 10^–2. The currently used interpretation of the RHEED intensity oscillations ignores the correction factor K and, therefore, the calculated values of D _s are several orders of magnitude smaller than its real values. The surface transport during the time of growth interruption is discussed in connection with the tendency to three dimensional growth at every second interface (where a deposition of the material with strong intermolecular bonds starts) of a small period superlattice.     

IN SITU IR SPECTROSCOPIC STUDIES OF HCOOH DECOMPOSITION OVER V-TI-O CATALYST

Decomposition of formic acid over V-Ti-O catalysts was studied by in situ IR spectroscopy. Four surface compounds, among which are H-bonded acid, one mono- and two bidentate formates (BF1 and BF2), were identified in the temperature range of 100-190°C. The activation energy and rate of the BF2 decomposition were found equal to those for the CO formation. This equality points to the involvement of BF2 in the HCOOH decomposition into carbon monoxide.     

Four cyclo­alkane­spiro‐4′‐imidazolidine‐2′,5′‐dithiones

The crystal structures of four cyclo­alkane­spiro‐4′‐imidazolidine‐2′,5′‐dithiones, namely cyclo­pentane­spiro‐4′‐imidazolidine‐2′,5′‐dithione {systematic name: 1,3‐diaza­spiro­[4.4]­nonane‐2,4‐dithione}, C₇H₁₀N₂S₂, cyclo­hexane­spiro‐4′‐imidazolidine‐2′,5′‐dithione {systematic name: 1,3‐diaza­spiro­[4.5]decane‐2,4‐dithione}, C₈H₁₂N₂S₂, cyclo­heptane­spiro‐4′‐imidazolidine‐2′,5′‐dithione {systematic name: 1,3‐diaza­spiro­[4.6]undecane‐2,4‐dithione}, C₉H₁₄N₂S₂, and cyclo­octane­spiro‐4′‐imidazolidine‐2′,5′‐dithione {systematic name: 1,3‐di­aza­spiro­[4.7]dodecane‐2,4‐dithione}, C₁₀H₁₆N₂S₂, have been determined. The three‐dimensional packing in all of the structures is based on closely similar chains, in which hydantoin moieties are linked through N—H⋯S hydrogen bonding. The size of the cyclo­alkane moiety influences the degree of its deformation. In the cyclo­octane compound, the cyclo­octane ring assumes both boat–chair and boat–boat conformations.     

2-Substituted imidazoles. 1. Reactions of 1-methyl-2-(2-furyl)imidazole with electrophiles

1-Methyl-2-(2-furyl)imidazole has been synthesized. Electrophilic attack (bromination, nitration, formylation, acylation, and hydroxymethylation) occurs in most cases at the free -position of the furan ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1396–1400, October, 1989.     

Acid-base interactions and adhesion capacity in the system constituted by an epoxy coating and a metal

Free surface energy and acidity parameter of solid surfaces of polyepoxides used as anticorrosive coatings were measured. Formulations of epoxy resins with various curing agents were studied. The adhesion capacity of epoxy films to various metallic surfaces was evaluated.     

Synthesis and photochemistry of Ru(II) complexes containing phenanthroline-based ligands with fused pyrrole rings

Hydrolysis of 1,10-phenanthrolinopyrrole ethyl ester leads to the acid derivative which is unstable at room-temperature releasing CO(2) and forming 1,10-phenanthrolinopyrrole (php). The ligand reacts with ruthenium(II) to form a series of complexes of the general formula [Ru(php)(n)(bpy)(3-n)](2+), where bpy = 2,2'-bipyridine and n = 1-3. The photochemical properties reveal that the complexes have longer-lived excited states than the standard complex, [Ru(bpy)(3)](2+). Their emission lifetimes range from 9.04 micros (n = 1) to 35.5 micros (n = 3) at 77 K compared to 7.57 micros for the standard. Similarly, at room-temperature, emission lifetimes range from 1.20 micros (n = 1) to 1.70 micros (n = 3) relative to the standard (0.56 micros). The emission quantum yields also have higher values than the standard [Ru(bpy)(3)](2+) under similar conditions. The temperature-dependent studies for the complexes establish the distribution among the radiative, nonradiative, and (3)MLCT to (3)d-d decay channels and are in agreement with the energy gap law.