Molecular structure organic compounds

Information on organic compounds, molecular structure, chemical reactivity and organic reactions, stereochemistry, and spectroscopy and structure... 

Pilhaja, K. (1987). Thermochemical Methods in the Structural Analysis of Organic Compounds. Molecular Structure and Energetics. Physical Measurements. Liebman,... 

Molecular descriptors may provide fundamental and scientific explanations of variations in the activity mechanism due to the structure of molecules. QSAR models can provide insight into kinetic mechanisms of organic compounds, and some of the design uncertainty associated with SCWO kinetics can be reduced. By using appropriate molecular descriptors, then, the results of QSAR models for SCWO could be used to determine the oxidation rate constants of organic compounds of structure similar to the training set chemicals of the QSAR model without experiments. 

These are molecular properties related to the effect of a substance produces on an organism or any biological target. Biological activity depends on peculiarities of compounds (molecular structure and physico-chemical properties), biological entity (species, gender, age, etc.), and mode of treatment (dose, route, exposure, etc.). 

A molecular organic compound whose structural formula reveals the presence of an asymmetric centre leads generally to a mixture of two possible enantiomers R and S in variable quantities. If such a mixture is chromatographed on a column packed with a chiral stationary phase (a phase that contains active sites corresponding to only one enantiomer, R for example), two peaks will be observed on the chromatogram (Figure 3.11). These peaks result from the reversible interactions R(compound)/R(stationary phase) and S(compound)/R(stationary phase) of which the stabilities are slightly different. The areas under the peaks are proportional to the abundance of each of the forms, R and S. 

One of the most important applications of Infrared spectroscopy in adhesion research concerns thin films formed on metal snbstrates. A wide variety of films may be studied, including air-formed oxides, anodic oxides, plasma-polymerized films, and films formed by adsorption of polymers or low molecular weight organic compounds. The structure and composition of the films may be determined, including that of the film/substrate interphase . 

A challenging task in material science as well as in pharmaceutical research is to custom tailor a compound s properties. George S. Hammond stated that the most fundamental and lasting objective of synthesis is not production of new compounds, but production of properties (Norris Award Lecture, 1968). The molecular structure of an organic or inorganic compound determines its properties. Nevertheless, methods for the direct prediction of a compound s properties based on its molecular structure are usually not available (Figure 8-1). Therefore, the establishment of Quantitative Structure-Property Relationships (QSPRs) and Quantitative Structure-Activity Relationships (QSARs) uses an indirect approach in order to tackle this problem. In the first step, numerical descriptors encoding information about the molecular structure are calculated for a set of compounds. Secondly, statistical and artificial neural network models are used to predict the property or activity of interest based on these descriptors or a suitable subset. 

A relatively small training set of 744 NMR chemical shifts for protons from 1 20 molecular structures was collected from the literature. This set was designed to cover as many situations of protons in organic structures as possible. Only data from spectra obtained in CDCl, were considered. The collection was restricted to CH protons and to compounds containing the elements C, H, N, 0, S, F, Cl, Br. or I. 

Gavezzotti A 1991. Generation of Possible Crystal Structures from the Molecular Structure for Low-polarity Organic Compounds, journal of the American Chemical Society 113 4622-4629. 

For pui e nonhydi ocai bon organics, the simplest accurate method for prediction of critical pressure is the method of Lydersen. Equation (2-7) requires the molecular weight (M) and the molecular structure of the compound. 

Molecular Orbital Theory of the Electronic Structure of Organic Compounds V Molecular Orbital Theoiy of Bond Separation W. J. Hehre, R. Ditchfield, L. Random and J. A. Pople Journal of the American Chemical Society 92 (1970) 4796... 

Organic chemists have found a way to draw complex molecular structures in a very simple way, by not showing the C and H atoms explicitly. A line structure represents a chain of carbon atoms by a zigzag line, where each short line indicates a bond and the end of each line represents a carbon atom. Atoms other than C and H are shown by their symbols. Double bonds are represented by a double line and triple bonds by a triple line. Because carbon almost always forms four bonds in organic compounds, there is no need to show the C—FI bonds explicitly. We just fill in the correct number of hydrogen atoms mentally compare the line structure of 2-chlorobutane, QT3C1TC1CF12C]T3 (3a), with its structural form (3b). Line... 

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