Trigonal bipyramid molecule structure

In many respects the chlorine oxyfluorides resemble the chlorine fluorides. For example, they exhibit little or no self-ionization, but are amphoteric. With strong Lewis acids or bases they can form stable adducts. The tendency to form adducts was found (64) not to be so much a function of the relative acidity of the parent chlorine oxyfluoride but rather to depend on the structure of the amphoteric molecule and of that of the anion or the cation formed. The preferred structures are the energetically favored tetrahedron and octahedron. Consequently, a trigonal bipyramidal molecule, such as CIF3O (64), exhibits a pronounced tendency to form either a stable pseudotetrahedral cation or a pseudo-octahedral anion ... 

The crystal structure of antimony pentachloride, SbCls, is hexagonal (D (, P63 jmmc, a0 = 7.49, and c0 = 8.01 A) with two molecules in the cell. The molecules are hep giving the simple notation 2P(h). In Figure 4.26, we see that the trigonal bipyramidal molecules have their C3 axes parallel to c0, the packing direction. The axial Sb—Cl distance is 2.34 A and that in the equatorial plane is 2.29 A. The closest Cl—Cl distances (3.33 A) are between axial Cl atoms between adjacent molecules. 

Crystallization may in rare cases result in chemical transformation of the constituents of a chemical compound. For example, PCI5 is a trigonal bipyramidal molecule, but its crystal structure is composed of a packing of tetrahedral PCl and octahedral PClg ions. In contrast, PBrs in the crystalline state comprises PBr and Br ions formation of the PBr ion is precluded by steric repulsion between the bulky peripheral bromide ions. 

According to X-ray structural investigations, the two apical positions in these trigonal bipyramidal molecules are occupied by two sulfur atoms, one from each of the two xanthate groups2. 

The traditional Lewis structure for PC15 is shown in the margin. Five pairs of electrons around the phosphorus atom require a trigonal bipyramidal arrangement (see Table 13.8). When the chlorine atoms are included, a trigonal bipyramidal molecule results. 

X-ray structural investigations of diphenyl tellurium bis[0,0 -diethyl dithiophosphate] revealed the two dithiophosphates to be monodentate and located at the two apical positions of the trigonal bipyramidal molecule . ... 

SF4 It has trigonal bipyramidal in structure. However, due to the presence of a lone pair of electrons, there is distortion in the molecule and the bond angles are 89° and 177° instead of normal bond angles of 90° and 180°, respectively. 

The only binary halide of vanadium(V) is VF5 (equation 21.13) it is a volatile white solid which is readily hydrolysed and is a powerful fluorinating agent. In the gas phase, VF5 exists as trigonal bipyramidal molecules but the solid has a polymeric structure (21.4). The salts K[VFg] and [Xe2Fii][VF5] are made by reacting VF5 with KF or XeFg (at 250 K) respectively. 

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