Rational plane

Co—Fe/Cu grew having inplane uniaxial aniso-tropy and easy axis parallel to the cube direction in the MgO(llO) plane satu-ration field (240 kA/m) at room temperature for... 

Localized 3-centre bond formalism can readily be used to rationalize the structure and bonding in most of the non-c/r>5r>-boranes. This is illustrated for some typical nido- and arachno-horanes in the following plane-projection diagrams which use an obvious symbolism for nonnal 2-centre bonds B-B O—O, B-Hc O— , (t = terminal). 

The transition state for disproportionation requires overlap of the p C—H bond undergoing scission and the p-orbital containing the unpaired electron.18 This requirement rationalizes the specificity observed in disproportionation of radicals 29 (Section 1.4,2) and provides an explanation for the persistency of the triisopropylmcthyl radical (33) and related species (Section 1.4.3.2).166 In the case of 33, the P-bydrogens are constrained to lie in the nodal plane of the p-orbital due to stcric buttressing between the methyls of the adjacent isopropyls. 

Pasoi in. .. F, Proc. Kov. Soc. A 182 (1943) 75. Eva X>ration from a plane free liquid surface into a turbulent air stream. 

Cooper et al. [30] were successful in rationalizing the striking variation in the S-S equihbrium bond lengths of FSSF (189.0 pm), ClSSCl (195.0 pm) and HSSH (205.5 pm) using the spin coupled (modern valence bond) theory. In the disulfur dihalides, but not for HSSH, incipient hypercoordinate character is observed at sulfur, with two partial t-like interactions in approximately perpendicular planes, and some antibonding character in the S-X (X=F or Cl) bonds. In other words, it is the form of t-like orbitals that is most rele-... 

Sp and sp-carbon atoms such as a carbonyl group and an alkene are reactive cent-ersl in many kinds of reactions. The n orbitals of a simple molecule such as ethylene or formaldehyde are symmetric in magnimde and antisymmetric in sign with respect to reflection in the molecular plane. Various attempts have been made to rationalize stereoselectivities, and several general ideas have emerged, including a steric basis and an orbital basis. 

The high enantioselectivity again can be rationalized by enantioface-selective alkene coordination in 63 (Fig. 35). The olefin moiety is expected to bind trans to the upper imidazoline moiety [70,73] thereby releasing the catalyst strain. Coordination at this position may, in principal, afford four different isomers assuming the stereoelectronically preferred perpendicular orientation of the alkene and the Pt(II) square plane. In the coordination mode shown, steric repulsion between both olefin substituents and the ferrocene moiety is minimized. Outer-sphere attack of the indole core results in the formation of the product s stereocenter. 

The rather confusing conformational dependences in Fig. 3.52 can be rationalized in a simple way. From the total of 7t-a and a-7t stabilizations at their respective coplanar alignments with the pi system, one can confirm that C—H bonds are better overall hyperconjugating groups than C—I bonds. The most favorable hyperconjugative alignment is therefore to place both C—H bonds maximally out-of-plane (i.e., C—F in-plane) at = 0°, whereas a secondary favorable alignment... 

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