15th group elements

An interesting related feature shown by several alloys of the more basic metals (alkali, alkaline earths) with many /5-block (13th, 14th, 15th groups) elements, and,... 

The 15th group elements a summary of their atomic and physical properties See Tables 5.72-5.74. 

Notes on the crystal chemistry of selected alloys and compounds of the 15th group elements. Among the pnictides, several series of numerous isostructural compounds are found. The 1 1 compounds with Sc, Y, lanthanides and actinides, having the NaCl-type structure, generally correspond to very stable phases, strongly... 

Figure 5.39. Compound formation capability in the binary alloys of the 15th group elements.

Nowotny phases, chimney-ladder structures. The Nowotny chimney-ladder phases are an example in alloy field chemistry of composite structures. They are a series of intermetallic T X , compounds formed by transition metals T from the 4th to 9th groups with p-block elements X from the 13th to the 15th groups. 

A review about the Zintl phases has been published by Sevov (2002) from the introduction of this publication we quote a few remarks. It was preliminary observed that the number of Zintl phases has increased many-fold since Zintl s time and that the definition of a Zintl phase has never been very exact often compounds that include non-metals have been considered in this family. The paper by Sevov is mainly dedicated to clearly intermetallic Zintl phases (that is phases containing main group metals, semi-metals or semiconductors only). Attention has therefore been dedicated to compounds of alkali metals with the elements of the 13th, 14th and 15th groups (without B, Al, C, N and P). To this end the following definitions and statements have been considered. 

Moving from one element to the other down the group we notice a decrease in the compound formation elements according to a scheme similar to those observed in the 12th, 14th and 15th groups. 

ALLOYS OF THE ELEMENTS OF THE 15TH GROUP OF THE PERIODIC TABLE... 

Nitrides. Among the elements of the 15th group, the particular behaviour of nitrogen is notable. Several are the analogies with carbon in the formation, for instance, of interstitial compounds. A number of these phases, such as the refractory solid solution MeN. phases, have been described in 3.8.4 ff. 

Typical structures of elements of the 15th group (As, Sb, Bi). A typical structure shown by various elements of this group is the hR6-As type structure, corresponding to the stable grey (rhombohedral, metallic) oAs modification. 

Figure 7.17. The As-hR6 structure (a) a puckered layer of As atoms is viewed along the c axis of the hexagonal cell and (b) lateral view of two superimposed layers. Notice the coordination 3 of the atoms, characteristic for the element of the 15th group (five valence electrons).

Antimony and bismuth lie at the fifth and sixth rows of the 15th group in the periodic table, and a variety of trivalent and pentavalent organic compounds derived from these elements have been reported. As shown in Table 1, antimony and bismuth have relatively small ionization potentials and electronegativities as well as large orbital radii. Due to these properties, elemental antimony and bismuth behave as metals, and the respective organic compounds possess relatively weak and polarized element-carbon bonds. These characteristics of antimony and bismuth have been... 

The very high thermal stability of compounds with the elements representative of the 15th to 16th groups such as the antimonides, tellurides, etc. may be underlined. 

Elements of the 15th and 16th groups. We notice, in comparison with the precedent groups, and especially for the light elements, a substantial increase of the compound formation regions which (for O to Te) practically cover the entire Periodic Table. 

Many ternary alloys MeT2X2 (Me = Th, U, alkaline earth, rare earth metal, etc., T = Mn, Cr, Pt family metal, X = element of the 15th, 14th and occasionally 13th group) have been systematically prepared and investigated (Rossi cl al., 1979, Parthe and Chabot 1984). A few hundreds of them resulted in the ThCr2Si2 (or... 

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