Weak pi hydrogen-bonded solute/solvent complexes are studied with ultrafast two-dimensional infrared (2D-IR) vibrational echo chemical exchange spectroscopy, temperature-dependent IR absorption spectroscopy, and density functional theory calculations. Eight solute/solvent complexes composed of a number of phenol derivatives and various benzene derivatives are investigated. The complexes are for...

A regioselective acylation series of methyl α-D-glucopyranoside (1), methyl 3-O-benzoyl-4,6-O-benzylidene-α-D-mannopyranoside (1A), and methyl 4,6-O-benzylidene-2-O-(3,5-dinitrobenzoyl)-α-D-mannopyranoside (1B) has been carried out by the direct acylation method and afforded the 2,6-di-O-glucopyranoside and 2 or 3-O-mannopyranoside derivatives in an excellent yield. In order to obtain newer pro...

Compound K is one of the active metabolites of Panaxnotoginseng saponins, which could attenuate the formation of atherosclerosis in mice modelsvia activating LXRα. We synthesized and evaluated a series of ginsenoside compound K derivatives modified with short chain fatty acids. All of the structures of this class of ginsenoside compound K derivative exhibited comparable or better biological act...

A set of hexasubstituted benzene derivatives with three thiol groups in the 1, 3, 5 positions and varied aliphatic substituents in the 2, 4, 6 positions (Me3-BTMT, Et3-BTMT, ODe3-BTMT) has been synthesized and self-assembled on Au(111). The resulting self-assembled monolayers (SAMs) are characterized by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and electrochem...

This tutorial presents several misconceptions related to the use the General Linear Model (GLM) in functional Magnetic Resonance Imaging (fMRI). The goal is not to present mathematical proofs but to educate using examples and computer code (in Matlab). In particular, I address issues related to (1) model parameterization (modeling baseline or null events) and scaling of the design matrix; (2) h...

New photographs of the far ultra-violet spectrum of benzene are presented. The absorption from 2000 to 1800A (Amlx, c. 1980A) is regarded not as a part of the much stronger absorp­ tion of peak at 1790 A but as due to a separate transition. Sharp bands lying at 1790 A represent the first member of a previously reported Rydberg series. The spectra of toluene, xylene, monochloroando-dichlorobenze...

Here we describe the metathesis reactions of a strained eight-membered ring that contains both alkene and alkyne functionality. We find that the alkyne metathesis catalyst produces polymer through a ring-opening alkyne metathesis reaction that is driven by the strain release from the monomer. The strained monomer provides unusual reactivity with ruthenium-based alkene metathesis catalysts. We i...

The effect of the excitation wavelength on the charge recombination (CR) dynamics of several donor-acceptor complexes (DACs) composed of benzene derivatives as donors and of tetracyanoethylene or pyromellitic dianhydride as acceptors has been investigated in polar solvents using ultrafast time-resolved spectroscopy. Three different wavelength effects have been observed. (1) With complexes exhib...

A detailed investigation has been made into the antiaromaticity and chemical reactivity of a planar cyclooctatetraene (COT) molecule fully annelated with bicyclo[2.1.1]hexane units 2. In spite of its planar 8pi-electronic structure, theoretical calculations have indicated that the antiaromaticity of COT 2 is considerably decreased in comparison with a planar COT 16 with D 4h symmetry. This beha...