Pnicogen structure

Fig. 4. Model of filled skutterudite structure that emphasizes the pnicogen-pnicogen bonding that results in nearly square pnicogen rings. The transition metal atoms (small white spheres) form a simple cubic lattice as shown. The lines connecting the transition metal atoms have been added for clarity and do not correspond to a chemical bond. The only chemical bonds shown in this model are those that form the pnicogen rings. The lanthanide atoms (large dark spheres) occupy the two voids without a pnicogen ring.

The nucleophilic carbene (112) has been shown to react with pnicogen pentafluorides (113a-c) to form adducts (114ac) with octahedral geometry at P (P N = 1.898 A), As (As-N = 1.999 A) and Sb (Sb-N = 2.175 A). The structures are therefore those of internal zwitterions with an imidazolium cation and a pnictogen anion. The strong nature of the bonds to the carbene... 

Keywords Structures and binding energies Intennolecular interactions 0—0 and o—ir pnicogen bonds Charge-transfer energies P— p EOM-CCSD spin—spin coupling constants J(P—P)... 

Keywords Clathrates Cage compounds Crystal structure Thermoelectric materials Tin Germanium Silicon Pnicogens... 

Del Bene JE, Alkorta I, Sanchez-Sanz G, Elguero J (2011) Structures, energies, bonding, and NMR properties of pnicogen complexes H2XP NXH2 (X = H, CH3, NH2, OH, F, Cl). J Phys Chem A 115 13724-13731... 

Fig. 3. Model of the filled skutterudite structure. The transition metal atoms (Fe, Ru, or Os - small light blue spheres) are at the center of distorted octahedra formed by the pnicogen atoms (P, As, Sb - green spheres). The lanthanide atoms (red spheres) are located at the center of a cage formed by 12 pnicogen atoms. The skut-terudile structure results if the lanthanide atoms are removed fiom the structure and the transition metals (Fe, Ru or Os) are replaced by transition metals with one more outer shell electron (Co, Rh or Ir).

Mixed pnicogen systems such as these are likely to show disorder in their structures. Crystallographic data are listed in table 26. 

In the next work Alkorta and co-workers explored equilibrium structures with P- Cl pnicogen bonds or halogen bonds on the potential... 

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