Bond length tables

Tire calculated Ca-N" bond lengths, Table III, of these pyridinium cations [as well as the bond orders, BO, and the reaction energies, zIT/r, for a hypothetical dissociation to give the corresponding carbenium ion 44 and pyridine (Scheme 13)] indicate that these bonds are significantly weakened... 

The X—O distances in both the nitrate and phosphite sets (Tables 4-8) are on the long side compared to the other X—O bonds reviewed here. The differences are smallest for X = C in the nitrate. The X... Op interaction should tend to lengthen X—O. The C—O(N) bond should be better described than C—O(P) because of the latter s higher O—P ionic character. For the same reason, the other X—O(P) bonds should be shorter in the phosphite compounds compared to the nitrates. These expectations are realized in the calculated relative X—O bond lengths (Tables 4-9) except for the lead compounds. 

The complex [Fe(acea)2]BPh4 exhibits a gradual, almost complete spin crossover [131]. The Fe-donor atom bond lengths (Table 3) are consistent with high spin Fe(III) at room temperature. 

The observed B—O bond lengths are 1.47 0.01 A for the BO tetrahedron and 1.37 0.01 A for the BOs triangle. The B—O single-bond length (Table 7-5) is 1.43 A. The experimental values suggest that the bonds in B04 have bond number a little smaller than 1, and in BO3 a little larger than 1 (about 20 percent of double-bond character, with use of the fourth boron orbital). 

The dihedral angles between the two interlocking trapezoids in the two independent units are very close to the 90° required for D2d symmetry (89.8, 87.8°). Slightly shorter Ti—SB bond lengths are observed compared to the Ti-SA bond lengths (Table XII) (Fig. 15). 

E = Ge 37, E = Sn) (see Fig. 13), and formally contain Ge(IV) and Sn(IV), respectively. Moreover, a formal double bond exists between the main-group element and the symmetry-unique tungsten atom, which factor is reflected in the X-ray-derived bond lengths (Table II). Reactions involving 37 with THF... 

The chromium complexes are proved to be silanediyl complexes, as shown by the silicon-transition metal bond lengths (Table 5) and by the extreme low field shift of the 29Si NMR signals (124.9 and 121.2) at 22 °C for R = H and CH2NMe2, respectively (Table 6). The 29Si NMR shifts of these complexes are temperature-dependent due to the hindered rotation of the phenyl ring and dynamic coordination of the nitrogens to the Si atom. 

The structures of the simple, tetrahedral, symmetrical tetraorganogermanes serve both as the best measures of Ge—C bond lengths (Table II) unperturbed by the influence of atoms of varying electronegativity bonded to germanium, and also to assess the available theoretical models for the prediction of molecular packing in the solid state. It is somewhat surprising therefore that relatively few compounds of this... 

The reaction product of ytterbium metal with benzophenone in a 1 1 molar ratio could be determined by an X-ray structure [278]. The benzophenone dianion unsymmetrically bridges the ytterbium atoms in the HMPA solvate [Yb(OCPh2)2(HMPA)2]2. The aryl oxygen forms a Yb-O bond with a typical terminal bond length (Table 18), but also donates to the other ytterbium. A Yb-C a-bond involving the a-C-atom (2.59(5) A) balances the charge at Yb (II). Reaction of the dianionic complex with four equivalents of phenol HOC6H3tBu2-2,6-Me-4 afforded the mononuclear aryloxide complex Yb(OAr)2(HMPA)2 (Sect. 4.2) [72],... 

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