Trigonal antiprismatic structures

Synthesis of the pale yellow dimer [Rh2 P(OMe)3 8] has been reported via ligand displacement from [CpRh(C2H4)2] (Cp = cyclopentadienyl) using excess P(OMe)3 at 60°C.115 Its 31P n.m.r. spectrum at room temperature indicates the non-fluxional bicapped trigonal antiprismatic structure (26). However, at 100 °C the spectrum is... 

Rh2[P(OMe)3]8, which has a bicapped trigonal antiprismatic structure at room temperature, undergoes a specific equatorial intermolecular ligand exchange rather than any intramolecular type of exchange (48). 

A hypothetical ion MXg has a trigonal antiprismatic structure (Dsd symmetry). Deduce the possible hybridization (a only) schemes for the central metal ion. In addition, choose one of the schemes to derive the explicit linear combinations for the hybrid j orbitals. Adopt the system of coordinates shown on the right. 

The influence of electron-count on cluster geometry has been very elegantly shown by a crystallographic study of the deep-red compound [K(ctypt)]g [Ge9]- [Ge9] .2.5en, prepared by the reaction of KGe with cryptand in ethylenediamine. [Ge9] has the C4, unicapped square-antiprismatic structure (10.10c) whereas [Ge9]- , with 2 less electrons, adopts a distorted Dit, structure which clearly derives from the tricapped trigonal prism (p. 153).The field is one of... 

X-ray results are available for numerous tris chelate complexes, however, we will be primarily concerned with the three classes mentioned above. The most striking feature of the structural results is the adherence to D3 symmetry even in complexes which are severely distorted from the octahedral or trigonal antiprismatic D3(jn) limit. Muetterties and Guggenberger75) have recently pointed out that with the exception of about six tris(dithiolate) complexes, 18, that are close to the D3h (trigonal prismatic) limit, all structurally established tris chelates have D3 or near... 

The X-ray structure analysis of compound 2 has shown that the bismuth center is surrounded by six sulfur atoms to form a trigonal antiprismatic geometry. All three dithiocarboxylate ligands are non-equivalent and the Bi-S bonds can be divided into two types short (2.617(2), 2.626(1) and 2.647(1) A) and long (2.963(2), 3.040(1) and 3.108(2) A). One of the sulfur atom coordinates weakly to the neighboring bismuth center (3.689 A) to form a dimeric structure in the solid state [87IC1453]. 

The transition metal dichalcogenides of groups 14, 15, and 16 have layered structures in which the transition metal (M) occupies either octahedral (trigonal antiprismatic, TAP) or trigonal prismatic see Trigonal Prism) sites between two layers of chalcogen atoms (X). Each chalcogen layer... 

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