Structures bicapped trigonal prism

Other Nd—O distances are Nd—0(3) =2.35 A and Nd—0(4) =2.33 A (129). The separation between two neod miiums is 4.234 A. However, the ultraphosphates (P5O14) of Nd(HI) and Sm(HI) containing MOg units have a different structure (129,130). The coordination polyhedra is best described as being bicapped trigonal prism (see next section). 

Dianion [Co8(CO)i8C)] is isoelcctronic with Rh8(CO)i9C but presents a very different stereochemistry as shown in structure XX (Fig. 8) (13). Its geometry can be described as a deformed square antiprism with a carbide atom in the center of the polyhedron. This structure can be derived from that of the bicapped trigonal prism by stretching the common edge of the two capped square faces, as indicated in Fig. 8 by the dotted line. In such a process the loss of an M—M bond formally generates a square face. The idealized symmetry of a tetragonal antiprism is Did. However,... 

The species is fluxional in solution119 . The energy separation between the three related structures, dodecahedron D2d, bicapped trigonal prism C2V and square antiprism D4d has been shown to be very small by UB NMR spectroscopy. 

Structure type La4Ag2ln4Si3 (Gulay et ah, 2008d) (Figure 106, Table 56). SG Pham, Z = A, a = 2.0523, h = 2.5118, c = 0.40241 nm. All four independent lanthanum atoms are located in bicapped trigonal prisms made of sulfur, and the shortest La-S distance is 0.2933 nm. The silver atoms... 

Trivalent. The trichlorides, AnCb, are stable across the series, and two structure types have been observed nine-coordinate UCI3 (tricapped trigonal prism) and eight-coordinate PuBrs (bicapped trigonal prism). The early actinides favor the former structure type, while Bk and Cr are found in the latter. A variety of synthetic routes can be used to access the trihalides, including metathesis, reduction, oxidation, and so on (equations 14 19). 

Trigonal prism coordination is very rare in finite complexes (for example, the chelates M(S2C2R2)3 of Mo, W, Re, V, and Cr, p. 940, and the Er chelate listed in Table 3.5) and not common in 3D structures other than NiAs, M0S2, AIB2 and related structures, and a few ionic crystals. Mono- or bicapped trigonal prism coordination is also not very common, and the following are examples in chemically related compounds ... 

Other structures with higher coordination of the metal ions include those of the two forms of YCl(OH)2, in both of which there is 8-coordination of Y (bicapped trigonal prism). 

The salts [MinI2L6]I (L = CNBu ) resulted from the oxidation of [M-I(CO)6] with I2 in the presence of L in dry thf.550,551 The structures may be described as bicapped trigonal prisms with ligands I capping two of the tetragonal planes (236). In wet thf, protons induced formation of... 

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