On characterization of organic structures - A highly discriminating molecular topological index

A new molecular topological index, EATI is proposed based on the extended adjacency matrix, It has a hitherto unheard of power of discrimination and can be applied to discriminate various kinds of organic compounds, such as structures containing heteroatoms, etc.. Thus EATI might be possibly used as supplementary reference for CAS Registry Numbers for structure documentation.

Study on computer perception of topological symmetry

A new algorithm for computer perception of topological symmetry is proposed. A node library containing various kinds of nodes is built, and the index number of the library is used as initial atom class identifier (CI) to discriminate the different types of non-hydrogen atoms. The path index (PI) and ringindex (RI) are calculated from the CI, and the global topological enviroment is defined as the sum of PIs and RIs. The topological symmetry can be detected by the iterative calculation of the global topological enviroment.

On highly discriminating molecular topological index

A highly discriminating molecular topological index, EAID, is proposed based on the extended adjacency matrix. A systematic search for degeneracy was performed for 3 807 434 alkane trees, 202 558 complex cyclic or polycyclic graphs, and 430 472 structures containing heteroatoms. No counterexamples (two or more nonisomorphic structures with the same EAID number) were found. This is a hitherto unheard of power of discrimination. Thus EAID might be possibly used as supplementary reference for CAS Registry Numbers for structure documentation.

Study on structure-property relationships between color reagents and sensitivity of color reactions with yttrium by topological indices

In this paper, three topological indices, Am-1, Am-2, and Am-3, multivariate analysis in structure-property studies. The topological indices of twenty asymmetrical phosphosphono bisazo derivatives of chromotropic acid have been calculated. The structure-property relationships between color reagents and molar absorptivity of color reactions with yttrium have been studied by A(m) indices and structure selective factors. Good results have been obtained by using correlation equation to predict the molar absorptivity of new color reagents.

A new topological index for the Changchun institute of applied chemistry C-13 NMR information system

A method to assign a single number representation for each atom (node) in a molecular graph, Atomic IDentification (AID) number, is proposed based on the counts of weighted paths terminated on that atom. Then, a new topological index, Molecular IDentification (MID) number is developed from AID. The MID is tested systematically, over half a million of structures are examined, and MID shows high discrimination for various structural isomers. Thus it can be used for documentation in the Changchun Institute of Chemistry C-13 NMR information system.

Studies on structure-property relationship between color reagents and contrast of their color reactions with cerium by topological indices

In this paper, three topological indices A(m1), A(m2) and A(m3) have been applied to multivariate analysis in structure property relationship studies. The topological indices oi fourty-three asymmetrical phosphono bisazo derivatives of chromotropic acid have been calculated, The structure-property relationship between color reagents and contrast of color reactions with cerium has been studied by A, indices and structure selective factors, Good results have been obtained.

STUDIES ON STRUCTURE-PROPERTY RELATIONSHIP BETWEEN COLOR REAGENTS AND SENSITIVITY OF THEIR COLOR-REACTIONS WITH YTTERBIUM BY TOPOLOGICAL INDEXES

In this paper A, topological indices and molecular connectivity inidces have been applied to multivariate analysis in structure-property studies. The topological indices of twenty asymmetrical phosphone bisazo derivatives of chromotropic acid have been calculated. The structure-property relationships between color reagents and molar absorptivity of color reactions with ytterbium have been studied by A(m) indices and molecular connectivity indices. Good results have been obtained.

NEW TOPOLOGICAL INDEX AND PREDICTION OF PHASE-TRANSFER ENERGY FOR PROTONATED AMINES AND TETRAALKYLAMINES IONS

The applications of new topological indices A(x1)-A(x3) suggested in our laboratory for the prediction of Gibbs energy values of phase transfer (water to nitrobenzene) of amine ions are described with satisfactory results. Multiple regression analysis and neural network were employed simultaneously in this study.

ON HALL AND KIERS TOPOLOGICAL STATE AND TOTAL TOPOLOGICAL INDEX

The topological state and the total topological index, tau, have been tested systematically. Counterexamples are provided proving that the topological state method cannot determine classes of symmetrically equivalent atoms in a molecule fully correct. The

ALGORITHM FOR COMPUTER PERCEPTION OF TOPOLOGICAL SYMMETRY

For the exhaustive and irredundant generation of candidate structures in ESESOC (Expert System for the Elucidation of the Structures of Organic Compounds), a new algorithm for computer perception of topological equivalence classes of the nodes (non-hydrog

PREDICTION OF THE GIBBS ENERGY OF ION TRANSFER ACROSS THE WATER NITROBENZENE INTERFACE USING 3 NEW TOPOLOGICAL INDEXES

Correlation analysis of the standard Gibbs energy for a series of tetraalkylammonium ions, protonated substituted ethylenediamine derivatives and protonated aromatic amine derivatives using three new topological indices Ax1, Ax2 and Ax has been studied. T

STUDY ON STRUCTURE-ACTIVITY-RELATIONSHIPS OF ORGANIC-COMPOUNDS - 3 NEW TOPOLOGICAL INDEXES AND THEIR APPLICATIONS

In this paper, three new topological indices, A(x1), A(x2), and A(x3), have been developed for use in multivariate analysis in structure-property relationship (SPR) and structure-activity relationship (SAR) studies. Good results have been obtained by using them to predict the physical and chemical properties and biological activities of some organic compounds.

A NEW TOPOLOGICAL INDEX FOR RESEARCH ON STRUCTURE-PROPERTY RELATIONSHIPS OF ALKANES

in this Raper, based on distance matrix and branch vertex of atomes in a molecule, a new topological index (Y(x)) has been developed to be used in research on physical and chemical properties of alkanes. It is concluded that this index bears good structure selectivity and relativity when the results from index were compared with that of other ones.

A NEWLY PROPOSED MOLECULAR TOPOLOGICAL INDEX FOR THE DISCRIMINATION OF CIS/TRANS ISOMERS AND FOR THE STUDIES OF QSAR/QSPR

A new topological index, the general a(N)-index (GAI), on quantum chemistry, is described in this paper. The GAI can be applied to molecules that contain heteroatoms and multiple bonds, and performs well in distinguishing cis/trans isomers. The relationships between the GAIs and physicochemical properties of olefins and neutral phosphorus compounds were observed with satisfactory results.

Tensile Tests Of Micro Anchors Anodically Bonded Between Pyrex Glass And Aluminum Thin Film Coated On Silicon Wafer

Micro anchor is a kind of typical structures in micro/nano electromechanical systems (MEMS/NEMS), and it can be made by anodic bonding process, with thin films of metal or alloy as an intermediate layer. At the relative low temperature and voltage, specimens with actually sized micro anchor structures were anodically bonded using Pyrex 7740 glass and patterned crystalline silicon chips coated with aluminum thin film with a thickness comprised between 50 nm and 230 nm. To evaluate the bonding quality, tensile pulling tests have been finished with newly designed flexible fixtures for these specimens. The experimental results exhibit that the bonding tensile strength increases with the bonding temperature and voltage, but it decreases with the increase of the thickness of Al intermediate layer. This kind of thickness effect of the intermediate layer was not mentioned in the literature on anodic bonding. (C) 2008 Elsevier Ltd. All rights reserved.