Out-of-plane movements

A molecular model shows that, irrespective of the ground state conformation, an attempt to perform a ring expansion in phenylcarbene by means of an overlap between the vacant carbene p-orbital and a ring-p-orbital in an out-of-plane movement of the carbene, will ipso facto lead to interaction between the carbene lone-pair and the ring. The success or failure of the reaction depends on whether this interaction is attractive or repulsive, that is, on the ring-LUMO. 

Puncture impact behavior ISO 6603-2 60 X 60 X 2 Record maximum force and energy at 50% decrease in force after the maximum Striker velocity 4.4 m/s striker diameter 20 mm specimen clamped suffrciently to prevent any out-of-plane movement striker lubricated. 

A mechanism for this solvolytic decomposition reaction has been postulated (Liu and Eick 1991). The reaction is topochemical with the structure of the product controlled by symmetry and size considerations. Since the R Cl2 +1 vernier structures are closely related to the fluorite structure (Haschke 1979), synthesis of fluorite-type modifications upon leaching is not surprising. However, when the M14X33 phase is leached either the fluorite or the anti-Fc2P-type structure is obtained. If M represents Sm or Eu, and X = Cl, the fluorite modification is obtained. If M = Ba and La or Nd and X = Br, the anti-FejP-type modification is obtained. The Mj4X33 and the fluorite structures both contain layers of cations and anions perpendicular to the three-fold axes. The anti-FejP structure contains both cations and anions in the layers. Thus conversion of the M 34013 3 structure to the fluorite modification requires only in-layer movement of the unsolvated M ions in the planes perpendicular to the three-fold axis. On the other hand, conversion to the anti-Fc2P-type structure requires both in-plane and out-of-plane movement of the M and Br ions. The latter motion results with larger cations which cannot fit easily in the planes. Reaction behavior is... 

Figure 13. A view perpendicular to the z-axis, of the middle three residues in the d(G)y M.D. average structures, along with neighbouring Na ions and water, (a) In the M.D. average structure with intercalated ions, the G-tetrads remain planar, (b) Without intercalated ions, the G-tctrads undergo some out of plane movements.

Positional corrections (in- and out-of-plane movements) were also permitted for peripheral carbon atoms on rings II and IV of both dimer halves (see fig. 1). The positions of these atoms are particularly crucial for the hfc s of non-methyl /5-protons (two bonds away from the T-system) ... 

Table 1 presents the characteristics of the potential wells. The largest potential wells are observed in SiC>2, for movements related with bond length changes. The smallest is observed for the Ba atom in BaTiC>3. The anisotropy of the well is particularly high for the oxygen in quartz, with a factor of 10 between the direction parallel to the Si-Si nearest neighbour line and the out-of-plane direction. This anisotropy is about 2...3 for the oxygen in stishovite or BaTiC>3. The potential well of other atoms is rather isotropic. 

While the isolated allyl anion is calculated to have a planar structure 42), interaction with lithium results in movement of the three of the hydrogens markedly out-of-plane (43-45). The ab initio (3-21G basis set) allyllithium geometry is shown in 25c the central hydrogen is bent toward and the two inner hydrogens at C(l) and C(3) are bent away from the lithium. 

Occupation of the orbital in the high-spin porphyrin may result in an expanded porphinato core or in the movement of the iron out of the plane in five-coordinate complexes. In both cases values of Fe—Np are larger than the low-spin complex, as are the Fe-axial ligand bond lengths. The out-of-plane high-spin Fe is not prevented from being in-plane by its larger size. 

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