Binary covalent compound defined

The description of bonding within these compounds has been treated by several different approaches that come to the same conclusion. The (8 — N) rule that is generahzed by Mooser and Pearson uses a covalent model with collective counting of electrons. The generahzed 8 — N rule can be easily defined for simple binary compounds of the general formula, as 8x electrons are required in order... 

How well can we tell the difference between an ionic bond and a polar covalent bond The only honest answer to this question is that there are probably no totally ionic bonds between discrete pairs of atoms. The evidence for this statement comes from calculations of the percent ionic character for the bonds of various binary compounds in the gas phase. These calculations are based on comparisons of the measured dipole moments for molecules of the type X—Y with the calculated dipole moments for the completely ionic case, X+Y. We performed a calculation of this type for HF in Section 13.3. The percent ionic character of a bond can be defined as... 

Fluorination of graphite at elevated temperature yields covalent layered C—F compounds with variable fluorine content. The compositions and properties of these preparations depend on particle size and orientation of the pristine carbon material and on the conditions of fluorination. Nevertheless, graphite fluorides are better defined than graphite oxides, and there are at least three different binary graphite fluorides polyfmonocarbon monofluoride), poly(dicarbon monofluoride) and polyftetracarbon monofluoride). 

RIs of elemental solids are listed in Table SI 1.2 and those of binary compounds in Tables S11.3-S11.7. For substances with the same structure, RI increases with the covalence and metallicity of bonding, as follows from Eq. 11.3 as on transition from ionic to covalent and then to metallic substances the absorption frequency (Vi) decreases and approaches v, the denominator of Eq. 11.3 approaches 0, hence n 00. Later we shall make use of this circumstance to define atomic polarizabilities... 

---