Quasi-fluid state in gabbro

Usually, the matter state is divided into three kinds: solid state, fluid state and gas state. But under the normal temperature and pressure, the phenomenon of natural oscillation, similar to fluid property, happening on the surface of the solid-state materials, such as steel, Cu-Zn-Al alloy, and silicon single crystal, can be observed[1—3]. In the metal materials of the Cu-Zn-Al alloy and pure silver, the natural oscillation may lead to generation of alloy nanostructure as shown in fig. 1,…     

"Extra stabilisation" of a pyrene based molecular couple by γ-cyclodextrin in the excited electronic state

Two thiosemicarbazide and semicarbazide functionalized pyrene labeled Schiff base compounds have been synthesized. The pyrene moieties in the compounds result in formation of π-π coupled complexes in aqueous medium in the excited electronic state. Added γ-cyclodextrin allows incorporation of the pyrene head inside its less polar core and promotes hydrogen bonding of the thio and oxo groups of the compounds with its rim hydroxyl groups to "stabilise" the monomers. This is confirmed by FT-IR and absorption spectroscopy. The stabilised monomers lead to formation of stabilised excimers as monitored by steady state and time-resolved fluorescence spectroscopy through varying the experimental conditions. The proposed model for the stabilisation of the Schiff base monomers has been evidenced by comparing with the fluorescence spectroscopic changes of two control compounds. The present work reports a step ahead toward proposing a simple host-guest method to extra stabilise the pyrene based excimers that can be biologically utilised.     

Solid state reaction of aromatic ketones with heteroaromatics

The solid state reactions of p-nitroacetophenone,acetyl-ferrocene with indole were catalyzed by anhydrous zinc chloride or aluminum chloride,and gave exclusively the 1:2 condensation products.The solid state condensation of aromatic ketones with l-phenyl-3-methyl-5-pyrazolone was also investigated,and the 1:1 and 2:1 condensation products were obtained.The structures of eleven new products were determined by IR,MS,1H NMR and elemental analysis.     

Solid state reactions of nitrogenous heterocyclic compounds (Ⅱ)——Solid state reactions of indole with carbonyl compounds

Solid state Michael addition reaction of indole with α,β-unsaturaled carbonyl compounds was carried out,by which a series of compounds containing three different heterocyclic groups binding to one carbon atom were obtained.In the presence of Lewis acid,indole could undergo the solid state condensation reaction with aromatic ketones and aldehydes or quinones.The solid state reaction showed higher selectivity and yield than solution reaction The structures of products were identified by IR,1H NMR,MS,elemental analysis and X-ray crystal analysis.The reaction mechanism was also proposed.     

Solid state reaction between α-naphthol and p-benzoquinone

The solid state reaction between α-naphthol and p-benzoquinone yields a red crystalline 1 : 1 adduct; in very concentrated solutions the red color can be seen, but it may be due either to Mulliken charge transfer or hydrogen bonding interactions. Kinetic studies of the solid state reaction by a capillary technique indicate that p-benzoquinone is the diffusing species, and that either surface migration or vaporphase diffusion plays an important role in the rate of complex formation. Microscopic examination of a single crystal of α-naphthol in the presence of p-benzoquinone vapor suggests that the reaction occurs only at defect centers on the α-naphthol surface. Since the reaction in the solid state goes to completion, it is suggested that cracks and crevices are formed, through which p-benzoquinone can diffuse easily into the lattice of the complex.     

Studies on solid state reactions of coordination compounds

A series of tetranuclear Mo(W)-Ag mixed-metal clusters have been synthesized by makinguse of the solid state reactions of[NH_4]_2[MYS_3](M=Mo,W;Y=O,S),AgX(X=Cl,Br,I)and(n-Bu)_4NX'(X'=Cl,Br),two of which[(n-Bu)_4N]_3[MoOS_3Ag_3Br_4](1)and[(n-Bu)_4N]_3[WS_4Ag_3Cl_4](2)have been structurally characterized by X-ray analysis.The crystal data:1,cubic,P 3m,a=12.093(4) ,Z=1,R=0.076;2,cubic,P 3m,a=12.059(2) ,Z=1,R=0.075.The clusteranion core[Ag_3MS_3X']of the two compounds can be viewed as a cube in which the four metal atomsand the four non-metal atoms are statistically distributed,respectively.Substitution reaction withPPh_3 ligand is also discussed for this type of tetranuclear clusters.     

Rotational state specific dissociation dynamics of HOD → H + OD via two-photon excitation to the C̃ electronic state

The dissociation dynamics of HOD via two-photon excitation to the C? state have been investigated using the H-atom Rydberg tagging time-of-flight (TOF) technique. The H-atom action spectrum for the C? ← X? transition shows resolved rotational structure. Product translational energy distributions and angular distributions have also been recorded for the H + OD channel for three excited levels each with k(a)′ = 2. From these distributions, quantum state distributions and angular anisotropy parameters (β2 and β4) for the OD product were determined. These results are consistent with the nonadiabatic predissociation picture illustrated in the one-photon dissociation process for H2O. The heterogeneous dissociation pathway via Coriolis coupling is the dominant dissociation process in the present study. A high proportion of the total available energy is deposited into the rotational energy of the OD product. The anisotropic recoil distributions reveal the distinctive contributions from the alignment of the excited states and the dissociation process. Comparisons are also made between the results for HOD and H2O via the equivalent rotational transitions. The OH bond energy, D(o)(H?OD), of the HOD molecule is also determined to be 41283.0 ± 5 cm(-1).     

A theoretical form of the Martin-Hou equation of state

A new equation of state is derived from the Barker-Henderson hard-sphere perturbation theory. It has the form similar to the Martin-Hou equation of state. The numerical values of the characteristic constants in the equation can be calculated by the method of Martin and Hou. The equation can be used to predict P-V-T properties accurately for fluids when the critical parameters (T_c, P_c and V_c) and one point on the vapor pressure cure are given. By using the functional relationships between the characteristic constants and the microscopic parameters, the molecular microscopic parameters of the substance can be obtained.     

What is the unperturbed state in polymer solutions?

We report theoretical results about amphiphilic random copolymers in a quasi‐ideal conformation with an overall size very close to that of the analogue homopolymers. We found that a few states may coexist with about the same free energy and a similar radius of gyration, but with different intramolecular conformations. We also argue that, in most cases, amphiphilic copolymers may never achieve the unperturbed Θ state, defined thermodynamically by a vanishing second virial coefficient. Thus, we suggest that such copolymers usually show neither an unperturbed conformation nor an unperturbed state from the thermodynamic viewpoint. We also briefly discuss star homopolymers, which show a depression of the Θ temperature with respect to linear chains and a significant, though finite, Θ swelling, as well as linear chains in the Θ state and in the melt. The main general conclusion is that interactions between chain segments do not cancel each other and are non‐negligible. Accordingly, we suggest that the word "unperturbed" be used only with reference to solution thermodynamics and not for the chain size or conformation.     

Joule-Thomson inversion curve prediction by using equation of state

In this paper five equations of state are tested for checking their ability to predict the Joule-Thomson inversion curve.These five equations of state are:Mohsennia-Modarres-Mansoori(MMM),Ji-Lemp(JL),modified Soave-Redlich-Kwang(SRK)equation of state by Graboski(MSRK1),modified SRK equation of state by Peneloux and Rauzy(MSRK2),and modified Peng-Robinson (PR)equation of state by Rauzy(PRmr).The investigated equations of state give good prediction of the low-temperature branch of the inversion curve,except for MMM equation of state.The high-temperature branch and the peak of the inversion curve have been observed,in general,to be sensitive to the applied equation of state.The values of the maximum inversion temperature and maximum inversion pressure are calculated for each component used in this work.     

How to make the Cassie wetting state stable?

Wetting of rough hydrophilic and hydrophobic surfaces is discussed. The stability of the Cassie state, with air trapped in relief details under the droplet, is necessary for the design of true superhydrophobic surfaces. The potential barrier separating the Cassie state and the Wenzel state, for which the substrate is completely wetted, is calculated for both hydrophobic and hydrophilic surfaces. When the surface is hydrophobic, the multiscaled roughness of pillars constituting the surface increases the potential barrier separating the Cassie and Wenzel states. When water fills the hydrophilic pore, the energy gain due to the wetting of the pore hydrophilic wall is overcompensated by the energy increase because of the growth of the high-energetic liquid-air interface. The potential barrier separating the Cassie and Wenzel states is calculated for various topographies of surfaces. Structural features of reliefs favoring enhanced hydrophobicity are elucidated.     

Are steady state diffusion layer thicknesses potential independent?

The required conditions are considered for the potential-independence of steady state diffusion layer thickness in an electrochemical experiment. Such conditions are illustrated by numerical solution of the mass transport equations for an electroactive species at the microdisc and tubular flow electrodes. Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 1, pp. 134–141. The text was submitted by the authors in English.     

Mechanism of 1,2-shift through π-complex transition state

A systematic calculation of the potential curves or surfaces for 1,2-shift has been realized by using MNDO or other models in MOPAC programs. By referring to the previous authors' viewpoints, the 1,2-shift can be divided into two categories. 1,2-electron-deficient shift is that the electronic configuration of the atom which accepts the migrating group is a cation or an electron-deficient atom, and 1,2-anion shift is the one that the accepted atom of the migration group is a negative ion. In terms of the experimental facts and the calculation of the potential surfaces, in electron-deficient shift such as Beckmann or Baeyer-Villiger rearrangement, the migration occurs through a transition complex formed between the 7i-bond and the cation or electron-deficient migrating group, but in anion shift such as Wittig or Stevens rearrangement, the electron pair in it-orbit excites at first to π* orbit, and then the migration occurs through the new formed complex between the anion migration group and the vacant rc     

Intruder state avoidance multireference Møller-Plesset perturbation theory

A new perturbation approach is proposed that enhances the low‐order, perturbative convergence by modifying the zeroth‐order Hamiltonian in a manner that enlarges any small‐energy denominators that may otherwise appear in the perturbative expansion. This intruder state avoidance (ISA) method can be used in conjunction with any perturbative approach, but is most applicable to cases where small energy denominators arise from orthogonal‐space states—so‐called intruder states—that should, under normal circumstances, make a negligible contribution to the target state of interests. This ISA method is used with multireference Møller–Plesset (MRMP) perturbation theory on potential energy curves that are otherwise plagued by singularities when treated with (conventional) MRMP; calculation are performed on the 1³Σ state of O₂; and the 2¹Δ, 3¹Δ, 2³Δ, and 3³Δ states of AgH. This approach is also applied to other calculations where MRMP is influenced by intruder states; calculations are performed on the ³Π_u state of N₂, the ³Π state of CO, and the 2¹A′ state of formamide. A number of calculations are also performed to illustrate that this approach has little or no effect on MRMP when intruder states are not present in perturbative calculations; vertical excitation energies are computed for the low‐lying states of N₂, C₂, CO, formamide, and benzene; the adiabatic ¹A₁–³B₁ energy separation in CH₂, and the spectroscopic parameters of O₂ are also calculated. Vertical excitation energies are also performed on the Q and B bands states of free‐base, chlorin, and zinc–chlorin porphyrin, where somewhat larger couplings exists, and—as anticipated—a larger deviation is found between MRMP and ISA‐MRMP. © 2002 Wiley Periodicals, Inc. J Comput Chem 10: 957–965, 2002     

Solid state reactions of nitrogenous heterocyclic compounds(Ⅰ)——Solid state reactions of 3-methyl-l-phenyl-5-pyrazolone with carbonyl compounds

The solid state reaction of 3-methyl-1-phenyl-5-pyrazolone (MPP) with aromatic aldehydes and ke-tones benzil derivatives and imides,and the solid state Michael addition reaction of MPP with 4-arylidene-3-methyl-1-phenyl-5-pyrnzolone 2 were investigated.Some new solid state reactions between the reactants were found,from which a series of new compounds were obtained The structures of the products were identified by IR,1H NMR,MS,elemental analyses and also by X-ray crystal analysis,and the reaction mechanism of MPP with aromatic aldehydes and ketones was proposed     

Does bimolecular charge recombination in highly exergonic electron transfer afford the triplet excited state or the ground state of a photosensitizer?

The investigations were made on photoinduced electron transfer (ET) from the singlet excited state of rubrene (1RU*) to p-benzoquinone derivatives (duroquinone, 2,5-dimethyl-p-benzoquinone, p-benzoquinone, 2,5-dichloro-p-benzoquinone, and p-chloranil) in benzonitrile (PhCN) by using the steady state and time-resolved spectroscopies. The photoinduced ET produces solvent-separated type charge-separated (CS) species and the charge-recombination (CR) process between RU radical cation and semiquinone radical anions obeys second-order kinetics. Not only the CS species but also the triplet excited state of RU (3RU*) is seen in the transient absorption spectra upon laser excitation of a PhCN solution of RU and p-benzoquinone derivatives. The comparison of their time profiles clearly suggests that the CR process between RU radical cation and semiquinone radical anions to the ground state is independent from the deactivation of 3RU*. This indicates that the CR in a highly exergonic ET occurs at a longer distance with a large solvent reorganization energy, which results in faster ET to the ground state than to the triplet excited state that is lower in energy than the CS state. Photoinduced ET from 3RU* in addition from 1RU* also occurs when p-benzoquinone derivatives with electron-withdrawing substituents were employed as electron acceptors.     

Is the HCCS radical linear in the excited state?

The A (2)Pi-X (2)Pi 415 nm band system of the linear HCCS radical has been known since 1978, but the vibronic structure in this complex spectrum, which has both spin-orbit and Renner-Teller complications, has never been satisfactorily assigned, despite serious experimental and theoretical efforts. In a further attempt to understand the spectrum, we have studied the laser-induced fluorescence spectra of jet-cooled HCCS and DCCS, produced from thiophene precursors using the discharge jet technique. The 0(0) (0) bands of HCCS and DCCS have been rotationally analyzed, providing precise ground and excited state spin-orbit splittings. The energy levels of the v(')=0 (2)Pi(3/2) component of DCCS are found to be perturbed by a very low-lying (2)Sigma vibronic level, indicating that the HCC bending mode Renner-Teller effect is much larger than predicted by ab initio calculations with a linear excited state geometry. With this observation, the vibronic bands in the spectra of both isotopomers have been consistently assigned for the first time. Model calculations show that the large Renner-Teller effect and substantially different HCCS and DCCS excited state zero-point spin-orbit splittings can be explained with the assumption of a quasilinear excited state geometry.     

Aggregation state and neurotoxic properties of alzheimer β-amyloid peptide

Alzheimer's disease (AD) represents the most common form of senile dementia and represents a tremendous health problem as the world population is aging. AD is characterized by the accumulation of amyloid β-peptide (Aβ) in the brain and the loss of cholinergic neurons in the basal forebrain. Accumulation of soluble and insoluble assemblies of Aβ in the brain is a crucial event in AD pathogenesis and the presence of amyloid plaques in the brain is required for definitive identification of AD. Yet, there is no correlation between amyloid plaques and the degree of dementia. In the past two decades researchers have devoted their effort to study and explain the mechanisms involved in the pathology of this devastating disease. Studies from different areas of the natural and medical sciences have provided important information towards the elucidation of some of the pathological processes that take place in AD. An aspect of crucial importance is the aggregation state of Aβ peptide and its role in neuropathology. Here, we discuss recent studies aimed at the identification of Aβ protein aggregates, the characterization of their toxic potential and the development of therapeutic strategies that target Aβ aggregation.     

On the thermodynamics of the McMillan–Mayer state function

The osmotic second virial coefficient is a key parameter in light scattering, protein crystallisation, self-interaction chromatography, and osmometry. The interpretation of the osmotic second virial coefficient depends on the solution theory. On the macroscopic level an expansion of the osmotic pressure is employed. A common statistical interpretation of the osmotic second virial coefficient of the expansion employs the McMillan–Mayer framework and the potential of mean force to characterise the solute–solute interaction. Supplementary to the statistical interpretation, it may be advantageous to develop the McMillan–Mayer framework in a classical thermodynamic context for which we develop the relationship between the state function of the McMillan–Mayer framework and the Helmholtz state function.     

Phase state of iron system colloidal catalyst in butadiene polymerization

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