Search results for " molecule"

First transformations of pyrano[3,4-b]indol-3-ones to salvadoricine and 2,3-diacylindoles

1992

The readily available methylated pyrano[3,4-b]indol-3-ones 1a and 1b were hydrolyzed to furnish the 2-acetylindol-3-alkanoic acids 2 and 4. Compound 2 was easily transformed selectively to 2-acetyl-3-methylindole (3, salvadoricine). Substrate 1b reacts with molecular oxygen from the air only in the presence of a catalyst to give 2,3-diacetylindole (5) while 1a reacts with nitrosobenzene via a proposed Diels-Alder step to yield 2-acetylindole-3-carbaldehyde (6). The latter product can also be obtained in low yield from the reaction of 1a with molecular oxygen from the air.

Effects of transdermal hormone replacement therapy on levels of soluble P- and E-selectin in postmenopausal healthy women

2002

Abstract Objective: To study the adhesion molecule pattern in postmenopausal women who were not receiving hormone replacement therapy (HRT), HRT users, and fertile women. Design: Case-control study. Setting: Second University of Naples, Naples, Italy. Patient(s): Fifty healthy naturally postmenopausal women and 20 fertile women. Intervention(s): Twenty-six women received no HRT and 24 received continuous transdermal 17β−estradiol, 0.05 mg/d, plus oral acetate nomegestrol, 5 mg/d. Main Outcome Measure(s): Levels of the soluble forms of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and P-selectin. Result(s): Women who did not received HRT …

The U(p+1) Formalism Applied to The Vibrational Hamiltonians of Nonlinear ABC Molecules

2000

Actinide and lanthanide molecules to search for strong CP-violation

2020

The existence of the fundamental CP-violating interactions inside the nucleus leads to the existence of the nuclear Schiff moment. The Schiff moment potential corresponds to the electric field localized inside the nucleus and directed along its spin. This field can interact with electrons of an atom and induce the permanent electric dipole moment (EDM) of the whole system. The Schiff moment and corresponding electric field are enhanced in the nuclei with the octupole deformation leading to the enhanced atomic EDM. There is also a few-order enhancement of the T,P-violating effects in molecules due to the existence of energetically close levels of opposite parity. We study the Schiff moment e…

Theoretical simulations of the radiation-induced defect processes in insulating materials

1994

Abstract The results of two basic kinds of computer simulations of radiation-induced processes in insulating materials, one based on quantum-mechanical and pair-potential (atomistic) approaches, and the other a phenomenological theory of diffusion-controlled reactions, are presented. It is shown that, by combining different techniques (atom-atom potentials and semi-empirical quantum chemical methods) the optimized geometry and the electronic structure of a family of hole centres in crystalline corundum (α-Al2O3) could be found. Their energetics are analyzed; V2−, V−V−Mg hole centres all have a common basic element, namely the diatomic molecule O23−, which is responsible for their similar ab…

Simple modeling of dipolar coupled 7Li spins and stimulated-echo spectroscopy of single-crystalline β-eucryptite

2004

Abstract Stimulated-echo spectroscopy has recently been applied to study the ultra-slow dynamics of nuclear spin-3/2 probes such as 7 Li and 9 Be in solids. Apart from the dominant first-order quadrupolar interaction in the present article also the impact of the homonuclear dipolar interactions is considered in a simple way: the time evolution of a dipole coupled pair of spins with I =3/2 is calculated in an approximation, which takes into account that the satellite transitions usually do not overlap. Explicit analytical expressions describing various aspects of a coupled quadrupolar pair subjected to a Jeener–Broekaert pulse sequence are derived. Extensions to larger spin systems are also …

Comparison of full-configuration interaction and coupled-cluster harmonic and fundamental frequencies for BH and HF

2001

The harmonic and fundamental frequencies are calculated for the potential-energy curves of BH and HF using the full-configuration interaction model and two hierarchies of coupled-cluster wavefunction models. The anharmonic contributions are also obtained using second-order vibrational perturbation theory. A consistent and systematic improvement is seen for both the harmonic and anharmonic contributions when increasing the level of the correlation treatment. The changes are largest for the harmonic contributions. This is also the case when including valence or diffuse functions in the basis set. Second-order perturbation theory gives a good approximation to the anharmonic contribution and in…

Heteronuclear NMR Applications (Y–Cd)*

1999

Fluorine and Gold: A Fruitful Partnership

2016

Gold-catalyzed reactions have witnessed an exponential growth in the past decade. When the unique modes of activation exhibited by gold species meet species with either fluorinated building blocks or fluorinating reagents, new opportunities arise for the development of new methodologies in fluoroorganic chemistry. Indeed, gold and fluorine truly formed a very fruitful partnership, and different types of reactivity emerged from their combination. This review gives an overview of such endeavors. The special properties imparted by fluorine to organic molecules have been exploited in gold-catalyzed processes, allowing for the generation of unprecedented fluorinated chemical entities. Thus, the …

ChemInform Abstract: Fluorine and Gold: A Fruitful Partnership

2016

Gold-catalyzed reactions have witnessed an exponential growth in the past decade. When the unique modes of activation exhibited by gold species meet species with either fluorinated building blocks or fluorinating reagents, new opportunities arise for the development of new methodologies in fluoroorganic chemistry. Indeed, gold and fluorine truly formed a very fruitful partnership, and different types of reactivity emerged from their combination. This review gives an overview of such endeavors. The special properties imparted by fluorine to organic molecules have been exploited in gold-catalyzed processes, allowing for the generation of unprecedented fluorinated chemical entities. Thus, the …