Strain minimization

Reuther U, Brandmuller T, Donaubauer W, Hampel F, Hirsch A (2002) A highly regioselective approach to multiple adducts of Cm governed by strain minimization of macrocyclic malonate addends. Chem. Eur. J. 8 2261-2273. 

X-ray crystal structure analysis of 847 revealed the unusual conformation adopted by this molecule. Its two oxygen atoms are puckered toward the inner regions of the sphere in a manner which cau the methylene carbons to tilt outward from the cavity in order to achieve nonbonded strain minimization The high propensity of these molecules for structural rearrangement was again... 

There is little change in most values, particularly for the 5X isomer which has little tetrahedral twist. The increase in strain energy in the XX isomer is mainly due to a build up of torsional strain, van der Waals repulsion and twist angle strain. Minimization does not proceed as smoothly with larger values of the force constant. Thus, it may be advisable to increase the damping and/or to decrease the termination rms shift (Setup/Optimization Controls). 

Gong et al. (1998) assessed the effect of rat strain on susceptibility to anesthesia and convulsions produced by inhaled compounds in five different rat strains. Strain minimally influenced anesthetic and convulsant requirements of inhaled compounds in rats. 

Gong D, Fang Z, Ionescu P et al. (1998) Strain minimally influences anesthetic and convulsant requirements of inhaled compounds in rats. Anesth Analg 87 963-966 Hall RI, Murphy MR, Hug CC (1987) The enfluorane sparing effect of sufentanyl in dogs. Anesthesiol 67 518-525 Ide T, Sakurai Y, Aono M, Nishino T (1998) Minimum alveolar anesthetic concentrations for airway occlusion in cats A new concept of minimum alveolar anesthetic concentration-airway occlusion response. Anaesth Analg 86 191-197... 

In the case of strained cyclic structures, the exhaustive generation of 3D isomers usually requires looser geometric constraints. Thus, some of the conformers obtained could be distorted with respect to the reference geometric parameters. In this case an original strain minimization techniqne (PMM) is applied based on a simple energylike fnnction, where the electrostatic terms are omitted. 

Molecular Mechanics Model Builder. The three-dimensional molecular model builder routine interfaced to ADAPT (MOLMEC) is used to derive information on the special conformation of molecules. A molecule can be viewed as a collection of particles held together by simple harmonic or elastic forces. These forces can be defined by potential energy functions whose terms are functions of the atomic coordinates of the molecule. This function can then be minimized to obtain a strain-free three-dimensional model of the molecule. In the strain minimization section, the atom coordinates are systematically altered until a mlnlmun is found in the strain or potential energy function. 

If increased momentary performance does not contribute to increased total performance (e.g., if process parameters limit speed and quality criteria are fulfilled), operation strategies will be aimed at strain minimization. 

In this case, the anti diol 72 will have cyclized faster than the syn diol. If both torsional strain minimization and stereoelectronic arguments are involved, then the preferred transition states will be those in which the hydroxyl group is orthogonal (as in B, Fig. 7.20) to the r-system of the double bond (G and H, Fig. 7.21). In this scenario, transition state G should be higher in energy than H due to development of transannular diaxial interaction, and the syn diol will have reacted faster than the anti diol 72. 

Clark IT, Aldinger BS, Gupta A, Hines MA (2010) Aqueous etching produces Si(100) surfaces of near-atomic flatness strain minimization does not predict surface morphology. J Phys Chem C 114 423-428... 

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