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In focusing mainly on Augustine’s De Doctrina Christiana, this paper discusses three major characteristics of his hermeneutics. First, he understands the Scriptures as signs that point to the transcendent reality of God. This understanding of the Scriptures anticipates today’s reader response theories and the hermeneutical concept, the ‘surplus of meaning’. It also rules out biblicism, by reminding us that the role of Scripture is provisional and instrumental. Second, Augustine’s hermeneutics has existential and moral tendencies. He emphasizes the essential connection between interpretation of Scripture and the interior attitude and moral quality of the interpreter. In this regard, Augustine’s hermeneutics anticipates and has influenced contemporary hermeneutical theory according to which a life-relation to the subject matter is essential to understanding. Third and finally, the rule of charity and the rule of faith are the most important criteria in Augustine’s hermeneutics. Such an emphasis on the rule of charity and the rule of faith is consonant with contemporary hermeneutics, which underscores that understanding takes place in a particular tradition.

Because organic molecules and materials are generally insensitive or weakly sensitive to magnetic fields, a certain means to enhance their magnetic responsiveness needs to be exploited. Here we show a strategy to amplify the magnetic responsiveness of self-assembled peptide nanostructures by synergistically combining the concepts of perfect α-helix and rod-coil supramolecular building blocks. Firstly, we develop a monomeric, nonpolar, and perfect α-helix (MNP-helix). Then, we employ the MNP-helix as the rod block of rod-coil amphiphiles (rod-coils) because rod-coils are well-suited for fabricating responsive assemblies. We show that the self-assembly processes of the designed rod-coils and disassembly of rod-coil/DNA complexes can be controlled in a magnetically responsive manner using the relatively weak magnetic field provided by the ordinary neodymium magnet [0.07 ~ 0.25 Tesla (T)]. These results demonstrate that magnetically responsive organic assemblies usable under practical conditions can be realized by using rod-coil supramolecular building blocks containing constructively organized diamagnetic moieties.

Nested Rollout Policy Adaptation (NRPA) is a Monte Carlo search algorithm that learns a playout policy in order to solve a single player game. In this paper we apply NRPA to the vehicle routing problem. This problem is important for large companies that have to manage a fleet of vehicles on a daily basis. Real problems are often too large to be solved exactly. The algorithm is applied to standard problem of the literature and to the specific problems of EDF (Electricité De France, the main French electric utility company). These specific problems have peculiar constraints. NRPA gives better result than the algorithm previously used by EDF.

Vesicles such as liposomes, polymersomes, and exosomes have been widely used as drug delivery carriers; however, peptide vesicles (peptidesomes) despite their potential utility are far less well developed. Peptidesomes are distinctive because peptides play dual roles as a self-assembly building block and a bioactive functional unit. In order for peptidesomes to become successful nanodrugs, the issues related to differences in nanostructural properties between

We demonstrate for the first time highly luminescent blue-emitting CdZnS/ZnS wurtzite core/shell nanorods (NRs) that show electric-field-induced fluorescence switching properties. Uniform CdZnS NRs were rapidly synthesized by injecting sulfur powder dissolved in 1-octadecene into a flask containing phosphonic acid ligands, and subsequently ZnS shells were coated using reagents consisting of sulfur powder, zinc sulfate heptahydrate, and oleylamine. The growth of high-quality ZnS shells resulted in a dramatically increased photoluminescence (PL) quantum yield (QY) of ∼40% with a minimal red-shift of the blue PL peak, which indicates that the combination of reagents successfully controlled a large number of defects appearing on the surface of the NR cores. By pre-annealing CdZnS cores before growing ZnS shells, we could achieve an additional increase in the maximum PL QY to 50%, decreases in both the full width at half maximum (FWHM) and the red-shift of the PL peak, and improved electric-field-induced fluorescence switching performance. Density functional theory calculations reveal that the effective relaxation of strain accumulating on the NR core during shell growth is the key to our successful synthesis of blue-emitting NRs, and that the additional improvement in performance obtained through the pre-annealing process results from the elimination of sulfur vacancies appearing at the surface of the NR core.

The real-time selective detection of disease-related markers in blood using biosensors has great potential for use in the early diagnosis of diseases and infections. However, this potential has not been realized thus far due to difficulties in interfacing the sensor with blood and achieving transparent circuits that are essential for detecting of target markers (e.g., protein, ions, etc.) in a complex blood environment. Herein, we demonstrate the real-time detection of a specific protein and ion in blood without a skin incision. Complementary metal-oxide-semiconductor technology was used to fabricate silicon micropillar array (SiMPA) electrodes with a height greater than 600 μm, and the surface of the SiMPA electrodes was functionalized with a self-assembling artificial peptide (SAP) as a receptor for target markers in blood, i.e., cholera toxin (CTX) and mercury(II) ions (Hg). The detection of CTX was investigated in both in vitro (phosphate-buffered saline and human blood serum, HBO model) and in vivo (mouse model) modes via impedance analysis. In the in vivo mode, the SiMPA pierces the skin, comes into contact with the blood system, and creates comprehensive circuits that include all the elements such as electrodes, blood, and receptors. The SiMPA achieves electrically transparent circuits and, thus, can selectively detect CTX in the blood in real time with a high sensitivity of 50 pM and 5 nM in the in vitro and in vivo modes, respectively. Mercury(II) ions can also be detected in both the in vitro and the in vivo modes by changing the SAP. The results illustrate that a robust sensor that can detect a variety of molecular species in the blood system in real time that will be helpful for the early diagnosis of disease and infections.

A WSe2 -based vertical graphene-transition metal dichalcogenide heterojunction barristor shows an unprecedented on-current increase with decreasing temperature and an extremely high on/off-current ratio of 5 × 10(7) at 180 K (3 × 10(4) at room temperature). These features originate from a trap-assisted tunneling process involving WSe2 defect states aligned near the graphene Dirac point.

The effective mass approximation (EMA) could be an efficient method for the computational study of semiconductor nanostructures with sizes too large to be handled by first-principles calculations, but the scheme to accurately and reliably introduce EMA parameters for given nanostructures remains to be devised. Herein, we report on an EMA approach based on first-principles-derived data, which enables accurate predictions of the optoelectronic properties of quantum nanostructures. For the CdS/ZnS core/shell quantum rods, for which we recently reported its experimental synthesis, we first carry out density functional theory (DFT) calculations for an infinite nanowire to obtain the nanoscopic dielectric constant, effective mass, and Kohn-Sham potential. The DFT-derived data are then transferred to the finite nanorod cases to set up the EMA equations, from which we estimate the photoluminescence (PL) characteristics. Compared with the corresponding method based on bulk EMA parameters and abrupt potential, we confirm that our EMA approach more accurately describes the PL properties of nanorods. We find that, in agreement with the experimentally observed trends, the optical gap of nanorods is roughly determined by the nanorod diameter and the PL intensity is reduced with increasing the nanorod length. The developed methodology is additionally applied to CdSe nanoplatelets, where reliable experimental data became recently available. Here, we again obtain excellent agreements between calculated and measured optical gap values, confirming the generality of our approach. It is finally shown that the abrupt confinement potential approximation most adversely affects the accuracy of EMA simulations., 14 pages, 6 figures, 3 tables

A series of mono-, di-, and tri-phosphine oxide substituted triarylboranes, Mes2BAr (1), MesBAr2 (2), and BAr3 (3) (Ar = 4-(Ph2PO)-2,6-Me2-C6H2) were prepared to investigate the effect of a phosphine oxide group (Ph2PO) on Lewis acidity enhancement of triarylboranes. The X-ray crystal structure of 3 revealed peripheral decoration of Ph2PO groups with a C3-axis perpendicular to the trigonal boron center. UV/Vis absorption and PL spectra indicated a significant contribution of π(Mes or phenylene) → pπ(B) charge transfer in the lower-energy electronic transition. The reduction potential measured by cyclic voltammetry showed apparent LUMO stabilization by introduction of phosphine oxide groups, the extent of which gradually increased with the increasing number of phosphine oxide groups. Lewis acidity enhancement was also supported by the gradual increase in fluoride ion affinity in the order 3 > 2 > 1. Theoretical calculations suggest that introduction of a Ph2PO group into a triarylborane significantly enhances the Lewis acidity of the boron center via an inductive electron-withdrawing effect and this effect is additive for multiple phosphine oxide groups.

We present an ab initio study of the structural, electronic, and quantum transport properties of B–N-complex edge-doped graphene nanoribbons (GNRs). We find that the B–N edge codoping is energetically a very favorable process and furthermore can achieve novel doping effects that are absent for the single B or N doping. The compensation effect between B and N is predicted to generally recover the excellent electronic transport properties of pristine GNRs. For the zigzag GNRs, however, the spatially localized B–N defect states selectively destroy the doped-side spin-polarized GNR edge currents at the valence and conduction band edges. We show that the energetically and spatially spin-polarized currents survive even in the fully ferromagnetic metallic state and heterojunction configurations. This suggests a simple yet efficient scheme to achieve effectively smooth GNR edges and graphene-based spintronic devices.

Background and Aim The outcomes of sorafenib therapy in patients with advanced hepatocellular carcinoma (HCC) and impaired liver function remain unresolved. Although Child–Pugh (CP) classification is widely used for patient categorization, heterogeneity within a given CP class makes outcomes less predictable. The aim was to investigate the prognostic significance of CP score elements on the outcome of sorafenib in patients with advanced HCC and impaired liver function. Methods Of 1385 consecutive patients with advanced HCC in our center between January 2007 and December 2010, we reviewed the medical records of 325 patients who received sorafenib monotherapy. Results Median duration of sorafenib was 2.0 months (range 0.4–24.2) and median follow-up was 4.9 months (range 0.5–43.4). Disease control rates were significantly higher in CP class A (CPA) than in CP class B (CPB) patients. Median overall survival (OS) was 5.8 months. Subgroups with different CP scores showed significantly different OS (months): CPA5, 8.4; CPA6, 5.1; CPB7, 3.5; CPB8–9, 2.6 (P

Molecular structures, molecular orbital characteristics, and electronic properties of salen–aluminum complexes in organic light emitting diodes have been investigated by quantum chemical calculations to elucidate emission properties. The first excited-state structures were optimized by CIS and TD-CAM-B3LYP and their emission wavelengths were obtained from TD-CAM-B3LYP. Absorption and emission wavelengths from TD-CAM-B3LYP reproduced experimental values. The TD-B3LYP method is not adequate to calculate the transition energies for the first excited-state of salen–aluminum complexes. The structural changes and electronic transition during the excitation process and the tendency in absorption and emission wavelengths have been interpreted by frontier molecular orbitals.

Although there has been substantial advancement in the development of nanostructures, the development of self-assembled nanostructures that can selectively recognize multivalent targets has been very difficult. Here we show the proof of concept that topology-controlled peptide nanoassemblies can selectively recognize and detect a multivalent RNA target. We compared the differential behaviors of peptides in a linear or cyclic topology in terms of peptide-gold nanoparticle hybrid nanostructure formation, conformational stabilization, monovalent and multivalent RNA binding in vitro, and multivalent RNA recognition in live cells. When the topology-dependent selectivity amplification of the cyclic peptide hybrids is combined with the noninvasive nature of dark-field microscopy, the cellular localization of the viral Rev response element (RRE) RNA can be monitored in situ. Because intracellular interactions are often mediated by overlapping binding partners with weak affinity, the topology-controlled peptide assemblies can provide a versatile means to convert weak ligands into multivalent ligands with high affinity and selectivity.

Treatment of AlMe3 with 2 equiv of 2-(2H-benzo[d][1,2,3]triazol-2-yl)-4,6-di-tert-pentylphenol (Lig1H) or 2-tert-butyl-6-(5-chloro-2H-benzo[d][1,2,3] triazol-2-yl)-4-methylphenol (Lig2H) and subsequent addition of ROH afford monomeric and heteroleptic (OR)AlL2 complexes [R = C6H5, L = Lig1, 1; R = p-C6H4Ph, L = Lig1, 2; R = C6H5, L = Lig2, 3; R = p-C6H4Ph, L = Lig2, 4]. The simple reaction between a quantitative amount of water and compound 1 gave the novel dimeric aluminum complex 5 bridged by an oxygen atom. The crystal structures of 1, 3, and 5 determined from X-ray diffraction studies reveal pentacoordination geometry around the Al center with the preference for the slightly distorted trigonal-bipyramidal geometry. Monomeric complexes 1−4 showed emissions of the blue region (475 nm) with broad emission areas (half-width of peak = 150 nm) in the emission spectrum with high quantum yield. Dimeric aluminum complex 5 with enhanced thermal stability has a similar absorption and emission pattern to complexe...

Reactions of the dilithium salt of aminosilylene-bridged ligands with (Me2N)2ZrCl2(THF)2 followed by the treatment of Me3SiCl are found to be an efficient synthetic route to aminosilylene-bridged ansa-zirconocenes, R2N(Me)Si(η5–C5H4)2ZrCl2 (R = Me (1), Et (2)) and Me2N(Me)Si(η5–C5H4)(η5–C5Me4)ZrCl2 (3). Crystal structure of 3 determined by X-ray diffraction study reveals the presence of π-bonding interaction between N and Si atoms, which is further supported by DFT calculation results. These complexes are very active (>1 × 103 Kg/(mol Cat.·atm·h)) for homopolymerization of ethylene in the presence of methylalumoxane (MAO) cocatalyst, generating polyethylenes that contain branches as well as bimodal molecular weight distribution (MWD). Methyl, ethyl, butyl, and other longer branches (n ≥ 6) are observed in the resulting polyethylenes. The polyethylenes from 1, 2 and 3/MAO show a broad MWD range (6.3–42.2, 3.5–4.0 and 2.6–3.4, respectively).

Structures and vibrational frequencies of group 17 fluorides EF 3 (E = I, At, and element 117) are calculated at the density functional theory (DFT) level of theory using relativistic effective core potentials (RECPs) with and without spin-orbit terms in order to investigate the effects of spin-orbit interactions and electron correlations on the structures and vibrational frequencies of EF 3 . Various tests imply that spin-orbit and electron correlation effects estimated presently from Hartree-Fock (HF) and DFT calculations with RECPs with and without spin-orbit terms are quite reasonable. Spin-orbit and electron correlation effects generally increase bond lengths and/or angles in both C 2v and D 3h structures. For IF 3 , the C 2v structure is a global minimum, and the D 3h structure is a second-order saddle point in both HF and DFT calculations with and without spin-orbit interactions. Spin-orbit effects for IF 3 are negligible in comparison to electron correlation effects. The D 3h global minimum is the only minimum structure for (117)F 3 in all RECP calculations, and the C 2v structure is neither a local minimum nor a saddle point. In the case of AtF 3 , the C 2v structure is found to be a local minimum in all RECP calculations without spin-orbit terms, and the D 3h structure becomes a local minimum at the DFT level of theory with and without spin-orbit interactions. In the HF calculation with spin-orbit terms, the D 3h structure of AtF 3 is a second-order saddle point. AtF 3 is a borderline case between the valence-shell-electron-pair-repulsion (VSEPR) structure of IF 3 and the non-VSEPR structure of (117)F 3 . Relativistic effects, including scalar relativistic and spin-orbit effects, and electron correlation effects together or separately stabilize the D 3h structures more than the C 2v structures. As a result, one may suggest that the VSEPR predictions agree very well with the structures optimized by the nonrelativistic HF level of theory even for heavy-atom molecules but not so well with those from more elaborate theoretical methods. Vibrational frequencies of AtF 3 and (117)F 3 are modified substantially and nonadditively by spin-orbit and electron correlation contributions. This is one of those rare cases for which vibrational frequencies of the closed-shell molecules are significantly affected by spin-orbit interactions. Spin-orbit interactions decrease all vibrational frequencies of EF 3 molecules considered.

Several fluorene copolymers containing isothianaphthene units (P1, P2, and P3) or similar derivatives (P4 and P5) have been synthesized by Pd-catalyzed Suzuki polymerization. The monomers containing isothianaphthene were prepared by a ring-closure reaction with Lawesson's reagent. Strong photoluminescence (PL) quenching in the film state was observed for P1 and P2, which was mainly due to the enhanced quinoid character formed by introducing the isothianaphthene unit. Their energy levels of the compounds were determined using cyclic voltammetry. Among the polymers tested, the polymer containing both an isothianaphthene and a selenophene unit, P2, showed the smallest band gap of 1.85 eV. The influence of structural variation on the band gap of the polymer chains was further investigated by optimizing the geometries of several model monomers. Our results based on the optical and electrochemical properties combined with theoretical calculations showed that polymers containing isothianaphthene have small band gaps, rigid conformations, and strong tendencies to aggregation. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3573–3590, 2008

We gratefully acknowledge financial support from the Center for Advanced Functional Polymers through Korea Science and Engineering Foundation (KOSEF) and BK21.

Based on density functional theory calculations, we here show that the formation of a fullerene C$_{60}$ carbon "nanobud" (CNB) on carbon nanotube (CNT) caps is energetically more favorable than that on CNT sidewalls. The dominant CNB formation mode for CNT caps is found to be the [2+2] cycloaddition reaction as in the conventional CNT sidewall case. However, it is identified to be exothermic in contrast to the endothermic reaction on CNT sidewalls. Computed reaction pathways further demonstrate that the formation (dissociation) barrier for the CNT cap-based CNB is slightly lower (significantly higher) than that of the CNT sidewall-based CNB, indicating an easier CNB formation as well as a higher structural stability. Additionally, performing matrix Green's function calculations, we study the charge transport properties of the CNB/metal electrode interfaces, and show that the C$_{60}$ bonding to the CNT cap or open end induces resonant transmissions near the Fermi level. It is also found that the good electronic linkage in the CNT cap-C$_{60}$ cycloaddition bonds results in the absence of quantum interference patterns, which contrasts the case of the CNB formed on an open-ended CNT that shows a Fano resonance profile., Comment: 7 pages, 5 figures, to be published in Nanoscale

It was recently shown that nitrogen-doped graphene (NG) can exhibit both p- and n-type characters depending on the C-N bonding nature, which represents a significant bottleneck for the development of graphene-based electronics. Based on first-principles calculations, we herein scrutinise the correlations between atomic and electronic structures of NG, and particularly explore the feasibility of converting p-type NG with pyridinic, pyrrolic, and nitrilic N into n- or bipolar type by introducing an additional dopant atom. Out of the nine candidates, B, C, O, F, Al, Si, P, S, and Cl, we find that the B-, Al-, and P-codoping can anneal even relatively large vacancy defects in p-type NG. It will be also shown that, while the NG with pyridinic N can be converted into n-type via codoping, only the bipolar type conversion can be achieved for the NG with nitrilic or pyrrolic N. The amount of work function reduction was up to 0.64 eV for the pyridinic N next to a monovacancy. The atomistic origin of such diverse type changes is analysed based on Mulliken and crystal orbital Hamiltonian populations, which provide us with a framework to connect the local bonding chemistry with macroscopic electronic structure in doped and/or defective graphene. Moreover, we demonstrate that the proposed codoping scheme can recover the excellent charge transport properties of pristine graphene. Both the type conversion and conductance recovery in codoped NG should have significant implications for the electronic and energy device applications., Comment: to be published in Nanoscale

Several theoretical studies have suggested that a spin–orbitinduced isomer may be found for a molecule of the as-yetunknow superheavy element 118, that is, (118)F4, [1] but there have been no reports of an experimentally observed molecule for which the inclusion of spin–orbit effects is essential for the correct identification of the ground state structure. We report here a molecular ion, [CH2ClI] , for which spin–orbit interactions are crucial for the identification of the structure and vibrational frequencies of the correct ground state. Theoretically, the spin–orbit interaction is part of the relativistic effect. The importance of relativity for the description of heavy atoms is well recognized. Scalar relativistic effects are routinely included in electronic-structure calculations of molecules containing heavy elements through the use of relativistic effective core potentials (RECP), but spin–orbit interactions are usually omitted when deriving optimized structures partly because of the assumption that their influence on the molecular structures is negligible and partly due to computational difficulties. Even when spin–orbit terms are available in RECPs, the usual treatment involves perturbational inclusion of these terms after the variational determination of orbitals and structures. Quantum chemical calculations employing RECPs and spin– orbit operators from the start have been available for some time. The spin–orbit density functional theory (DFT) method available in NWChem is particularly useful for the present purpose of demonstrating spin–orbit effects on geometries since the geometry can be optimized with both electron correlations and spin–orbit interactions included. We have been investigating the reactivity of mixed dihalomethane cations for some time. Hence, we have recorded the vibrational spectra of the cations by massanalyzed threshold ionization (MATI) spectrometry. Figure 1 shows the MATI spectrum of CH2ClI recorded by monitoring [CH2 ClI] in the electronic ground state. The most intense peak at around 78644 cm 1 corresponds to the 0–0 band. The distance of each peak from the 0–0 band in this spectrum corresponds to the vibrational frequency of the cation. CH2ClI has nine nondegenerate normal modes: modes 1–6, with a’ symmetry, and modes 7–9, with a’’ symmetry. All the fundamentals and overtones of the totally symmetric modes, a’, are dipole-allowed, while only the even-numbered overtones of the a’’modes are allowed. Utilizing the selection rule and the frequencies in the neutral species, plausible assignments can be made for the prominent peaks; these are listed in Table 1. Modes 2 and 3 are due to CH2 motion, modes 4 and 5 are C Cl and C I stretchings, respectively, and mode 6 is I C Cl bending. Other peaks in the spectrum are due to overtones and combinations. Our normal routine is to perform quantum chemical calculations for the vibrational frequencies, isotope shifts, and Franck–Condon factors to confirm, improve, or revise the phenomenological assignments. In particular, results from the DFT/B3LYP calculations have been found to be adequate in most cases. When we performed DFT/B3LYP calculations for [CH2ClI] + with Gaussian98, using a well-knownRECP for iodine such as LanL2DZ, we always obtained two distinct stationary states, A’ and A’’, formed by removal of an electron from in-plane and out-of-plane iodine nonbonding orbitals, respectively. Even though their energies are nearly the same, their geometries are noticeably different because of the partial antibonding characteristics contained in essentially iodine nonbonding orbitals. The vibrational frequencies in the two states are also noticeably different, suggesting that the observed spectrum would be a superposition of two spectra. The fact that a rather straightforward phenomenological assignment of the MATI spectrum was possible is not compatible with the calculated results. Moreover, the experimental frequencies could not be correlated with the calculated results with the accuracy expected for the DFT/B3LYP results ( 15 cm ). We thought that neglecting the spin–orbit effect could be one possible cause of this discrepancy, and we therefore performed the spin–orbit DFT calculations implemented in NWChem for neutral and cationic CH2ClI in the electronic ground states using RECPs with the effective spin– [*] M. Lee, Prof. M. S. Kim National Creative Research Center for Control of Reaction Dynamics and School of Chemistry, Seoul National University Seoul 151-742 (Korea) Fax: (+82)2-889-1568 E-mail: myungsoo@plaza.snu.ac.kr

The outcomes of sorafenib therapy in patients with advanced hepatocellular carcinoma (HCC) and impaired liver function remain unresolved. Although Child-Pugh (CP) classification is widely used for patient categorization, heterogeneity within a given CP class makes outcomes less predictable. The aim was to investigate the prognostic significance of CP score elements on the outcome of sorafenib in patients with advanced HCC and impaired liver function.Of 1385 consecutive patients with advanced HCC in our center between January 2007 and December 2010, we reviewed the medical records of 325 patients who received sorafenib monotherapy.Median duration of sorafenib was 2.0 months (range 0.4-24.2) and median follow-up was 4.9 months (range 0.5-43.4). Disease control rates were significantly higher in CP class A (CPA) than in CP class B (CPB) patients. Median overall survival (OS) was 5.8 months. Subgroups with different CP scores showed significantly different OS (months): CPA5, 8.4; CPA6, 5.1; CPB7, 3.5; CPB8-9, 2.6 (P 0.001). The presence of ascites was a significant prognostic factor in CPB7 patients (hazard ratio 2.262; P = 0.016). OS of CPB7 patients without ascites was similar to that of CPA6 patients (4.6 months) and was significantly longer than that of CPB7 patients with ascites (2.5 months; P = 0.027). OS of CPB7 patients with ascites was similar to that of CPB8-9 patients.CP score was more important than CP class in predicting the outcome of sorafenib therapy in patients with advanced HCC. Among the CP score components, presence of ascites was a significant prognostic factor, especially in CPB7 patients.

Showing their true colors? Full emission color tuning in the visible region can be achieved with salen-aluminum complexes that are electronically modulated at C5 of the phenoxide ring in the salen moiety. Emission spectra for various substituents R(5) are shown (EWG: electron-withdrawing group, EDG: electron-donating group).A series of salen-aluminum complexes, [{(R(5))(2)-salen(3-tBu)(2)}Al(OC(6)H(4)-p-C(6)H(5))] (salen=N,N'-bis(salicylidene)ethylenediamine; R(5)=H (1), tBu (2), Br (3), Ph (4), OMe (5), NMe(2) (6)) and [{5,5'-(NMe(3))(2)-salen(3-tBu)(2)}Al(OC(6)H(4)-p-C(6)H(5))][OTf](2) (7; OTf=CF(3)SO(3)) that are electronically modulated directly at C5 of the phenoxide ring in the salen moiety has been prepared. The crystal structures of 1, 4, 6, and 7 determined by X-ray diffraction reveal distorted square-pyramidal geometries around the Al atoms. Complexes 1-7 are all air-stable in both the solid and solution states and have high thermal stability (decomp 313-338 degrees C). Differential scanning calorimetric analyses show that they can form amorphous glasses with glass transition temperatures of 95-132 degrees C depending on the C5 substituent. UV/Vis absorption spectra of the complexes exhibit major bands at lambda=338-413 nm assignable to salen-centered pi-pi* transitions with a gradual red shift of the absorption maximum wavelengths as the substituent is varied from an electron-withdrawing (NMe(3)) to an electron-donating group (NMe(2)). The maxima in the emission spectra of 1-7 occur over the entire visible region, ranging from lambda=438 nm for 7 to lambda=599 nm for 6, with high fluorescence quantum efficiencies of up to Phi=0.40 for 4 in solution. DFT calculations suggest that the low-energy electronic transitions in 1-7 are characterized by HOMO(-i)-LUMO(+1) (i=1 for 1-6 or i=4 for 7) transitions localized on the salen moiety, with much involvement of the C5 position in the HOMO(-i). Thus, the electronic alteration at the C5 position of the phenoxide ring, which mainly affects the HOMO(-i) energy levels of salen-Al luminophores, is responsible for the observed emission color-tuning properties over the entire visible region.

One-photon mass-analyzed threshold ionization (MATI) spectrum of CH2BrI was obtained using coherent vacuum-ultraviolet radiation generated by four-wave difference-frequency mixing in Kr. Unlike CH2ClI investigated previously, a very extensive bending (Br-C-I) progression was observed. Vibrational frequencies of CH2BrI+ were measured from the spectra and the vibrational assignments were made by utilizing frequencies calculated by the density-functional-theory (DFT) method using relativistic effective core potentials with and without the spin-orbit terms. A noticeable spin-orbit effect on the vibrational frequencies was observed from the DFT calculations, even though its influence was not so dramatic as in CH2ClI+. A simple explanation based on the bonding characteristics of the molecular orbitals involved in the ionization is presented to account for the above differences between the MATI spectra of CH2BrI and CH2ClI. The 0-0 band of the CH2BrI spectrum could be identified through the use of combined data from calculations and experiments. The adiabatic ionization energy determined from the position of this band was 9.5944+/-0.0006 eV, which was significantly smaller than the vertical ionization energy reported previously.

A series of compounds consisting of 4'-oxybenzylidene-4-n-butylaniline, a mesogen, and a p-substituted phenoxyterephthaloyl structure a non-mesogen, interconnected through a central hexamethylene spacer were synthesized and their thermal behavior and liquid crystallinity were studied. p-Substituents included in this study are H, Cl, CN, and phenyl groups. The compounds having phenyl and substituents are enantiotropic and form smectic-A(SA) and nematic (N) phases. The compound with substituent is monotropic and forms only a nematic phase on heating the solid, whereas it forms nematic as well as phases on cooling the isotropic liquid. The rest compounds were found to be non-liquid crystalline. This is in great contrast to the fact that the monomesogenic model compound 4'-n-hexyloxybenzylidine-4-n-butylaniline forms and N phases enantiotropically.