Meridional form

The other isomer is a meridional form. This has two A and two A combinations. The first set is with the rings as originally shown. The second set is seen after a clockwise C4 rotation about the axis through the top front and bottom rear nitrogens of the vertical diethylenetriamine. 

For the mixed ligand complex with l- or D-aspartic acid and L-2,4-diaminobutyric acid, [Co(l- or D-asp) (L-2,4-dba)], the possible isomers are shown in Fig. 3.11. Both of L- and D-series are composed of two meridional forms and one facial form about the [Co(N)3(0)3] chromophore. The two L-mer isomers are denoted by L-tranjOs-cisNs (with respect to oxygen) and L-cisOstronjNs. To investigate the H NMR spectra of those isomers, Watabeetal. prepared the complexes with Na3[Co(C03)3] 3 H2O... 

Meridional forms of the N3S quadridentate complexes of the type (18) with R = Me and NH2 are readily prepared from [Co(en)2(S(R)CH2CH2NH2)]" (with R = CH2COCH3 and CH2CN, respectively) in basic solution. X-ray crystallography of the complex with R = NH2 (monohydrate of the triflate salt) establishes the configuration of the quadridentate. 

If the earth did not rotate or if it rotated much more slowly than it does, a meridional (along meridians) circulation would take place in the troposphere (Fig. 17-24). Air would rise over the tropics, move poleward, sink over the poles forming a subsidence inversion, and then stream equa-... 

The three water ligands located at meridional positions of the J ,J -DBFOX/Ph aqua complexes may be replaced by another molecule of DBFOX/Ph ligand if steric hindrance is negligible. Based on molecular model inspection, the hetero-chiral enantiomer S,S-DBFOX/Ph looks like a candidate to replace the water ligands to form the heterochiral meso-2 l complex J ,J -DBFOX/Ph-S,S-DBFOX/... 

Tridentate amines come in a variety of forms. Diethylenetriamine (dien) (129) and its bis-trimethylene homolog ditn (130) may adopt either facial or meridional coordination modes. Furthermore, the /ao[Co(dien)2]3+ complex may exist as either the centrosymmetric meso or dissymmetric rac isomer where the secondary amines are trans or cis respectively.662 However,... 

The localized-valence halogen-bridged platinum(II)/platinum(IV) complexes (175) are of interest because of their highly anisotropic electrical and optical properties. The complexes are characterized by broad and intense intervalence bands in their electronic spectra.542 Partial oxidation of [PtCl(dien)]Cl with iodine yields the mixed valence species [PtI(dien)][PtI3(dien)]I2,543 but when 4Me-dien is used, the mixed valence compound is only obtained if it is trapped quickly, before isomerization of the meridional platinum(IV) complex to a facial form.544 Although these species nominally have localized valences, the extent of delocalization increases as the bridging halide... 

A A -coordi nation was found in the zinc complex of 2,2 -dipyridyl diselenide, [ZnLCl2].214 The tridentate ligand 6-(2-aminophenyl)-2,2 -bipyridine contains two pyridyl and one aniline donor ligand to form a complex of the form [ZnL2]2+. The X-ray structure shows a distorted octahedral metal center with each ligand twisting from planar to accommodate the meridional binding.215... 

Eqs. (40H41) are obtained from the analytical solution using the first two terms in the 0-series expansion of the concentration profile. As a result, they are accurate only for small values of meridional angle, 8. To correct for large values of 6, Newman [45] used Lighthill s transformation and Eq. (15) for the meridional velocity gradient to calculate the local mass transfer rate as Sc - oo. His numerical result is plotted in Fig. 5 in the form of Shloc/Re1/2 Sc1/3 vs. 8 as the thin solid line. The dashed line is... 

In addition to the crystal forms, X-ray scattering studies indicate that when unoriented PEN fiber was drawn at 120 °C ( 7 g), a mesophase is generated. In this form, the molecular chains are in registry with each other in the meridional direction but not fully crystallized in the equatorial direction. This conclusion was based on the presence of additional meridional peaks not accounted for by the crystal structure obtained by X-ray scattering. The mesophase is a intermediate phase and its existence is strongly dependent upon the processing conditions consequently, it could have implications with respect to the properties of commercially produced fibers and films, since it appears to be stable and not easily converted to the crystalline form, even at elevated temperature [25, 26], The mesophase structures of PET, PEN and poly(ethylene naphthalate bibenzoate) were compared by Carr et al. [27], The phase behavior of PEN and PEN blends with other polymers has also been studied [28-32],... 

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