Xenon tetrafluoride structure

In many expanded-octet molecules, one or more of the electron pairs around the central atom are unshared. Recall, for example, the Lewis structure of xenon tetrafluoride, XeF4 (Example 7.4). 

I Self-Test 2.10B Write the lewis structure for the l ion and give the number of 25 Xenon tetrafluoride, XeF4 I electrons in the expanded valence shell. 

The starting point for the synthesis of xenon compounds is the preparation of xenon difluoride, XeF2, and xenon tetrafluoride, XeF4, by heating a mixture of the elements to 400°C at 6 atm. At higher pressures, fluorination proceeds as far as xenon hexafluoride, XeFfi. All three fluorides are crystalline solids (Fig. 15.27). In the gas phase, all are molecular compounds. Solid xenon hexafluoride, however, is ionic, with a complex structure consisting of XeF< + cations bridged by F anions. 

Let s work two examples illustrating the steps necessary to produce a good Lewis structure. We will take HN02 and XeF4 for these examples. The first molecule is nitrous acid. It is an example of an oxyacid. (Oxyacids are compounds containing hydrogen, oxygen, and one other element.) The other compound is xenon tetrafluoride. 

Self-Test 2.10A Write the Lewis structure for xenon tetrafluoride, XeF4, and give the number of electrons in the expanded octet. 

Because the noble gases have filled s and p valence orbitals, they are not expected to be chemically reactive. In fact, for many years these elements were called inert gases because of this supposed inability to form any compounds. However, in the early 1960s several compounds of krypton, xenon, and radon were synthesized. For example, a team at the Argonne National Laboratory produced the stable colorless compound xenon tetrafluoride (XeF4). Predict its structure and determine whether it has a dipole moment. 

Xenon is a noble gas that will form a few compounds with nonmetals that strongly attract electrons. Draw the correct Lewis structure for xenon tetrafluoride (Xep4). 

Fig. 5a—c. Molecular Geometries of Xenon Tetrafluoride-Metal Pentafluoride Adducts, a A perspective view of the XeF SbF structural unit b The [XeF3+][Sb2F1 J structural unit c The pteFJ-[BiFJ structural unit... 

Draw a Lewis structure of the noble gas compound xenon tetrafluoride (Xep4) in which all F atoms are bonded to the central Xe atom. 

Is xenon tetrafluoride, Xep4, tetrahedral or square planar IR and Raman spectra each show three vibrations. Use the GOT and analyses like those in Examples 14.19 and 14.22 to propose a structure for this molecule. 

Draw the Lewis structure of xenon tetrafluoride (XeF4). 

Argonne National Laboratory produced the stable colorless compound xenon tetrafluoride (XeF4). Predict its structure and whether it has a dipole moment. 

On the basis of simple electron pair repulsion theory the difluoride should be linear, with the fluorine atoms at the poles of a trigonal bipyramidal arrangement of electron pairs. The tetrafluoride should be a square planar arrangement of fluorine atoms about the xenon atom, there being a non-bonding electron pair both above and below the plane. The hexafluoride, since it possesses a nonbonding electron pair, should show some deviation from octahedral symmetry. The structural evidence has so far been in accord with all of these expectations. Table 10 contains some of the structural data obtained from X-ray and neutron diffraction studies of the di and tetra-... 

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