Group 15 Compounds

A book entitled Group III Condensed Matter Volume 35 Nuclear Magnetic Resonance (NMR) Data, Subvolume A Chemical Shifts and Coupling for Boron-11 and Phosphorus-31 has been published. Four reviews have 

Group III Condensed Matter Volume 35 Nuclear Magnetic Resonance (NMR) 

A review has appeared entitled Analytical methodologies for aluminium speci-ation in environmental and biological samples - a review , which contains Al NMR data.120  

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The reaction of zirconacydopentadienes with Group 14 compounds such as Me2SiCl2, Me2GeCl2, and Me2SnCl2 should be discussed here. GeCl4 readily reacts with both mono-cyclic and bicyclic zirconacydopentadienes (Eq. 2.20) [26],... 

In contrast, methyl-for-chlorine substitution is decidedly nonlinear, a feature also displayed by the lighter Group 14 compounds. This curvature is not an artifact of the BAC-MP4 predictions, since it is observable in the (admittedly limited) experimental data for these compounds (Fig. 10). In fact, the deviations from linearity are even greater in the experimental data. Such behavior is also observed in the analogous Si compounds and is related to the negative hypercongugation (anomeric) effect, in which electron density from... 

The relative weakness of the Sn - Cl bond in this case reflects a trend observed in all Group 14 compounds, in which bond dissociation energies (BDE) in a series MX n = 2-4) follow the order MX4 > MX3 and MX2 > MX3 [93]. For example, the bond energies in SnCU, SnCls, and SnCl2 are 84.2,42.9, and 91.1 kcalmoD based on our combined BAC-MP4 and coupled-cluster results. The relatively weak bond in SnCls makes the rate of Eq. 58 fast relative to Eq. 54, and thus not rate Hmiting. 

FIGURE 33. Schematic representation of the divalent group-14 compounds studied by Scholler et al. The calculated bond lengths and angles are given in Table 32. Reproduced by permission of Wiley-VCH from Reference 146... 

TABLE 32. Optimized bond lengths (A) and angles (deg) of divalent group-14 compounds shown in Figure 33 ... 

Negatively charged species of group-14 compounds have also been calculated by Anane et al. at the G2 level185. The authors optimized the donor-acceptor complexes of the... 

TABLE 8. Bond distances of metallated group-14 compounds... 

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