Ring centroids

In addition, mention may be made of more recent electrostatic calculations due to Voitlander and his coworkers 110,177). Qualitatively the results are very similar to those of Robertson and McConnell 30), although the latter contain erroneous numerical values (177), but the choice of R as the metal to ring centroid distance, rather than the metal to carbon distance, leads to much better agreement with experiment. Thus, for Fe(Cp)2, the latter choice predicts 6 < n < o, but the former yields 5 o < ir, with a total splitting of some 18000 cm-1, in quite good agreement with experiment. 

Distance from central atom to ring centroid. bAveraged El-C distances. 

Two supramolecular features predominate (1) the formation in one direction of the continuous zigzag chains of 7t-stacked C60 units with a C5—C6 ring centroid—ring centroid separation of 3.39 A, and (2) the formation in another direction of continuous -C60-pz-C60-pz- zigzag sandwiches (Fig. 34). 

A above and below the inner N4 plane, respectively (which is coplanar to within 0.03 A). The molecules pack to form stepped polar stacks with a mean interplanar separation of 4.05 A, the adjacent pz ring centroids being separated by 6.27 A (Fig. 37). 

In the solid state, both 46 and 47 exist as bent monomeric sandwich complexes with ring centroid-lead-ring centroid angles of 152.2° in 46 and 144.2° in 47. Interestingly, if the reaction between PbCl2 and [Li(dme)2][/Bu2G2P3] is carried out in tmen rather than DME, the product formed is not a homoleptic plumbylene but rather the novel heterobimetallic compound 48.73... 

FIGURE 1.24 Histogram plots of intermolecular distances between dummy atoms placed at ring centroids of the DNB group of DNB-Leu and the quinoline of the 0-9-(fert-hutylcarhamoyl)-6 -neopentoxy-cinchonidine selector (chloroform environment), (a) I -complex and (h) 5-complex. (Reprinted from N.M. Maier et al., J. Am. Chem. Soc., 124 8611 (2002). With permission.)... 

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