Typing of strains

Based on this calculation, if the product can tolerate this type of strain without affecting performance, then the dimensional requirements are met. 

That the high degree of torsional and other types of strain inherent in the triplet states or trans conformers of cyclohexene and cycloheptene may be responsible for their photochemical behavior is suggested by the reactions of compound (50), a moderately twisted olefin according to molecular models. Compound (50) quantitatively yields bicyclo[3.3.1]non-l-yl acetate (51) within 15 sec after being dissolved in glacial acetic acid(83> ... 

Part 2. Two-Network Method. Different Types of Strain. 

The two-network method has been carefully examined. All the previous two-network results were obtained in simple extension for which the Gaussian composite network theory was found to be inadequate. Results obtained on composite networks of 1,2-polybutadiene for three different types of strain, namely equibiaxial extension, pure shear, and simple extension, are discussed in the present paper. The Gaussian composite network elastic free energy relation is found to be adequate in equibiaxial extension and possibly pure shear. Extrapolation to zero strain gives the same result for all three types of strain The contribution from chain entangling at elastic equilibrium is found to be approximately equal to the pseudo-equilibrium rubber plateau modulus and about three times larger than the contribution from chemical cross-links. 

These studies confirmed that Taft s values are truly a measure of the steric effect of the alkyl group R. DeTar further suggested to use the Eg value as a measure of the van der Waals type of strain in hydrocarbons (242). 

Quotient of strain and stress where the type of strain and stress is defined by the type of deformation employed. 

The reaction is useful for the synthesis of certain types of strained alkenes. 

Steric effects can also be caused by other types of strain, 1,8-Bis(diethylamino)-2.7-dimethoxynaphthalene (1) is an extremely strong base for a tertiary amine (p/f of the... 

Because of the scarcity of data in other types of deformation than unilateral extension, the variability of Cx and C2 with the type of strain has escaped the attention of several authors involved in molecular explanations of the C2 term. Quite recently Bobear (15) and in greater detail Blokland (14) have given this matter further consideration. We will return to Blokland s work in Chapter IV, Section 3. 

Electrical output transducers exist in many forms and consist simply of elastic elements coupled with suitable displacement transducers such as capacitance, inductance and reluctance pick-ups, certain types of strain gauge, piezoelectric elements, potentiometers and eddy current probes. A selection of these is described in the following paragraphs. 

The smaller bond angles prevent normal overlap along the intemuclear axis (dotted line). Overlap occurs outside the intemuclear axis and a bent bond is formed (also referred to as a r bond). The r bond is weaker than a a bond due to nonoptimal overlap and thus is of higher energy. This type of strain is termed angle strain (sometimes called Baeyer strain). It comes about because normal bond angles are not possible and thus nonoptimal overlap results. Angle strain... 

Build a model of cyclobutane. Examine the various types of strain present in the planar and nonplanar geometries. 

Like the chair conformation, all of the C—C—C bond angles of the boat conformation are 109.5°, so it has no angle strain. However, it does have other types of strain. The two red hydrogens, called flagpole hydrogens, approach each other too closely and cause some sceric strain. In addition, the conformations about the green bonds are eclipsed. This can be seen more easily in the Newman projection down these bonds ... 

Discuss the geometry and the types of strain present in these compounds ... 

Build a handheld model of bicyclo[2.2.1]heptane and discuss the types of strain that are present in this compound. 

Transannular strain (Section 6.6) A type of strain that occurs in larger rings because of steric crowding of atoms on the opposite sides of the ring. Also called cross-ring strain. 

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