Nitrogen, Phosphorus, Arsenic, Antimony, and Bismuth

Although nitrogen is in a similar position to carbon in being more a ligand atom than a central atom, there are a number of structures which have particular relevance to the stereochemistry of nitrogen and are worthy of discussion in this section. 

An interesting situation has been found in the crystal structures of 

The structure of diphenylmethyleneaminodimesitylborane confirms the presence of the expected w-bonding, 5C=N K , which gives the molecule an allenic structure. The C=N and N—B distances are 1.31 and 1.40 A, respectively. 

Compounds containing phosphorus in the form of a phosphine ligand bonded to a metallic atom are omitted from this section, since these are discussed in the chapters relevant to the metal. In spite of this reduction in coverage, the number of structures published, and the range of types described, is still large. 

The atomic parameters of phosphorus pentachloride in the solid state have been refined. The PCI4+ cation has 4 symmetry and a unique P-Cl bond length of 1.90 A. In the PCI - anion, which has a four-fold axis only, the equatorial bonds are 2.11(1) A and the axial 2.12(1) and 2.16(1) A. 

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Oxoacid Salts of Nitrogen, Phosphorus, Arsenic, Antimony, and Bismuth... 

Other chemists then showed that the elements could be classified into groups coi sisiing of hiore than three similar elements. Fluorine was added to the tri ad of "chlorine, bromine, and iodine, and magnesium to the triad calcium, strontium, barium. Oxygen, sulfur, selenium, and tellurium had been classed as one family, and nitrogen, phosphorus, arsenic, antimony, and bismuth as another family ot elements by 1854. 

The Group VA is the nitrogen family. The group consists of nitrogen, phosphorus, arsenic, antimony, and bismuth. Nitrogen is a diatomic, colorless, and odorless gas, and is not a very reactive element. The Group VA elements have a valence shell configuration of os np ... 

Phosphorus, symbol P, atomic number 15, atomic weight 30.974, is a non-metallic p-block element which belongs to Group VA (Group 15) of the periodic table. The elements of this group, namely, nitrogen, phosphorus, arsenic, antimony and bismuth, are sometimes known as pnicogens,... 

Like nitrogen, phosphorus, arsenic, antimony and bismuth usually bond to silicon in the III valence state. NMR and vibrational spectra indicate a pyramidal structure... 

Although obscure and not officially accepted, just the existence of a group name indicates that we have started back toward more uniform properties within a group. Still, there is a great deal of diversity among nitrogen, phosphorus, arsenic, antimony, and bismuth. 

COMPOUNDS OF NITROGEN, PHOSPHORUS, ARSENIC, ANTIMONY AND BISMUTH... 

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