Nitrogen oxides Lewis structure

The Lewis structures of the oxides of nitrogen are shown in Figure 21.6. Two of these species, NO and NO are paramagnetic, with one impaired electron. When nitrogen dioxide is cooled, it dimerizes the unpaired electrons combine to form a single bond between the two nitrogen atoms ... 

Similarly, if we treat the nitrogen in nitromethane as a trivalent atom, the index is 1, which is compatible with Figure 1.12. If we treat phosphorus in triphenylphosphine oxide as trivalent, the index is 12, which fits the Lewis structure in Figure 1.12. As an example, let us consider the molecular formula Ci3H9N204BrS. The index of hydrogen deficiency would be 13 - 10/2 + 2/2 + 1 = 10 and a consistent structure would be... 

Both nitrogen oxide (NO) and nitrogen dioxide (N02) are radicals. Show Lewis structures for these compounds. 

An oxide of nitrogen is 25.9% N by mass, has a molar mass of 108 g/mol, and contains no nitrogen-nitrogen or oxygen-oxygen bonds. Draw its Lewis structure, and name it. 

Oxidation State of Nitrogen Compound Formula Lewis Structure ... 

Write the molecular formula and Lewis structure for each of the following oxides of nitrogen [Section 22.7]... 

Write the Lewis structure for each of the following species, describe its geometry, and indicate the oxidation state of the nitrogen (a) HNO2,(b) Ns", (c) N2Hs, (d) NO3". 

Molecules with an uneven number of valence electrons. A typical example is nitric oxide, NO. Recall that the nitrogen atom has 5 valence electrons and the oxygen atom 6, so that NO must have 11, an uneven number. The Lewis structure of NO may be represented as one of the two following forms (these are resonance structures, which are discussed later in this section) ... 

Exception 1. You will have noticed that all our examples of correct Lewis structures contain an even number of electrons that is, aU are distributed as bonding or lone pairs. This distribution is not possible in species having an odd number of electrons, such as nitrogen oxide (NO) and neutral methyl (methyl radical, -CHs see Section 3-1). 

Figure 21.6 Lewis structures of the oxides of nitrogen. Many other resonance forms are possible.

Br0nsted acid sites depends on the structure of the amine. Chemisorption data for amorphous oxides (54) show that 2,6-dimethylpyridine (which contains methyl groups that hinder coordination of the nitrogen atom with Lewis acids) is a more selective reagent for the determination of Br0nsted acidity than an unhindered amine such as pyridine. Jacobs and Heylen (44) arrived at a similar conclusion on the basis of an infrared study of amines chemisorbed on Y zeolite. They also found that the poisoning effectiveness of 2,6-dimethylpyridine is much greater than that of pyridine for the catalytic titration of Y zeolite. 

A substantial portion of the early interest in MTO pertained to its use in alkene metathesis.12 Of more relevance to oxidation processes, much work has also involved examining Lewis base adducts of this electrophilic, (formally) 14-electron complex. Generally, nitrogen bases coordinate trans to the methyl group. Bidentate ligands such as bipyridyl lead to the fac-Me(N N)Re03 isomer of the octahedral complex. Table I summarizes some of the structural information from X-ray crystallographic and infrared studies. 

As noted previously, the formation of approximately tetrahedral bonds to nitrogen occurs principally in ammonium cations (R,N+), amine oxides (R3N+—O"), and Lewis add-base adducts (e.g., R3N+—B X3). In the amine oxides and these adducts, the bonds must have considerable polarity in the amine oxides, for instance, N — O donation cannot be effectively counterbalanced by any back-donation to N. In accord with this, the stability of amine oxides decreases as the R3N basidty decreases, since the ability of N to donate to O is the major factor. Similarly, R3N —> BX3 complexes have stabilities that are roughly parallel to R3N basicity for given BX3. When R is fluorine, basicity is minimal and F3N —> BX3 compounds are unknown. It is, therefore, curious that F3NO is an isolable compound. Evidently the extreme electronegativity of fluorine coupled with the availability otpir electrons on oxygen allows the structures in (9-V) to contribute to stability. 

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