Structural effect on properties

Structural effects on properties were also studied in detail by a group from Tohoku University, who prepared poly(methylphenylsilylene) (PMPS Mv = 3,120, Mw/Mn = 1.76) and poly(phenylsilyne) (131 poly(penfafluorophenylrilyne)(PPS) 4/w = 1,090, Mw/M = 1.30) by Wurtz-type coupling using sodium and 18-crown-6 in hot toluene and compared their optical and electrical properties.359,360... 

Through the recent developements in thiepin chemistry, many thiepin derivatives are now available for a detailed study of their properties. One of the most intriguing problems awaiting solution is the structural effects on the thermal stability of the thiepin system. 

In this chapter, we will explore the effect of various environmental conditions and the polymers5 chemical composition and structure on its stability. We will examine the mechanisms associated with degradation and will explore several well studied polymeric systems. Finally, we will discuss the role of additives and their effects on properties. 

In this work we present a description of the quantification of structural effects on reactivities and properties of polyene systems. 

Inter- and intramolecular forces (imf) are of vital importance in the quantitative description of structural effects on bioactivities and chemical properties. They can make a significant contribution to chemical reactivities and some physical properties as well. Types of intermolecular forces and their present parameterization are listed in Table 750. 

Examples of the application of correlation analysis to diene and polyene data sets are considered below. Both data sets in which the diene or polyene is directly substituted and those in which a phenylene lies between the substituent and diene or polyene group have been considered. In that best of all possible worlds known only to Voltaire s Dr. Pangloss, all data sets have a sufficient number of substituents and cover a wide enough range of substituent electronic demand, steric effect and intermolecular forces to provide a clear, reliable description of structural effects on the property of interest. In the real world this is not often the case. We will therefore try to demonstrate how the maximum amount of information can be extracted from small data sets. 

Methods have been presented, with examples, for obtaining quantitative structure-property relationships for alternating conjugated and cross-conjugated dienes and polyenes, and for adjacent dienes and polyenes. The examples include chemical reactivities, chemical properties and physical properties. A method of estimating electrical effect substituent constants for dienyl and polyenyl substituents has been described. The nature of these substituents has been discussed, but unfortunately the discussion is very largely based on estimated values. A full understanding of structural effects on dienyl and polyenyl systems awaits much further experimental study. It would be particularly useful to have more chemical reactivity studies on their substituent effects, and it would be especially helpful if chemical reactivity studies on the transmission of electrical effects in adjacent multiply doubly bonded systems were available. Only further experimental work will show how valid our estimates and predictions are. 

Yu JH, Park GW, Lee S, and Woo SK. Micro structural effects on the electrical and mechanical properties of Ni-YSZ cermet for SOFC anode. J Power Sources 2007 163 926-932. 

Protein Features of protein structure Effect on transcription Other properties In vivo expression and localization... 

Conflation analysis Is the most effective simple generally applicable method for the quantification of structural effects on chemical physical or biological properties. It was first successfully applied to biological activities by Hansoh and his ooworkers(X) In an equation of the form... 

They are explicative. SPQR can be used to explain structural effects on a measured property. In the case of chemical reactivity, they can provide information useful in determining reaction mechanism. 

They are archival. Information regarding structural effects on measurable properties can easily and concisely be stored in this way. 

Structural effects on reactivity and properties of oximes and hydroxamic acids... 

From some property of a reference set by definition (primary values). This method assumes that structural effects on the data set to be studied are a linear function of those which occur in the reference set. Secondary values of these parameters can be estimated by various methods. 

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