Ethane conjugate base

Ethyl anion 1-Hexyne Ethane Conjugate base of 1-hexyne... 

In this series, as the hybridization changes from sp2 in ethane to sp1 in ethene and to sp in ethyne, the acidity increases and the pATa decreases. This is because of the relative stability of the unshared electrons in the conjugate bases of each of these compounds. 

The conjugate bases formed by removing a proton from ethane, ethylene, and acetylene are each carbanions—species with a negative charge on carbon. 

There has been a number of recent reports on metal-catalyzed electrophilic activation of methane and ethane. For two reasons much of the work in the area has been carried out in strong acids. First, the conjugate bases of strong acids are... 

As expected based on the properties of acid—base conjugate pairs, an carbanion is the strongest base in a series based on carbon hybridization, and an sp carbanion (an alkynide) is the weakest base. This trend is illustrated here with the conjugate bases of ethane, ethene, and ethyne. 

Recall that a lower piT corresponds to a greater acidity. Therefore, acetylene (piT = 25) is significantly more acidic than ethane or ethylene. To be precise, acetylene is 19 orders of magnitude (10,000,000,000,000,000,000 times) more acidic than ethylene. The relative acidity of acetylene can be explained by exploring the stability of its conjugate base, called an acetylide ion (the suffix ide indicates the presence of a negative charge) ... 

The stability of an acetylide ion can be rationalized using hybridization theory, in which the negative charge is considered to be associated with a lone pair that occupies an s -hybridized orbital. Compare the conjugate bases for ethane, ethylene, and acetylene (Figure 10.3). 

The conjugate base of ethane exhibits a lone pair in an sp -hybridized orbital. The conjugate base of ethylene has the lone pair in an sp -hybridized orbital, and the conjugate base of acetylene has the lone pair in an sp-hybridized orbital. 

The conjugate base derived from ethanal (acetaldehyde) is more stable than the conjugate base of ethane. Explain why. 

The conjugate base derived from ethanal (acetaldehyde) is more stable than the conjugate base of ethane. Explain why. Answer The conjugate base of ethanal is resonance stabilized, and the conjugate base of ethane is not. 

The electron transfer dynamics of monolayers based on osmium polypyridyl complexes linked to an electrode surface through conjugated and non-conjugated bridges, e.g. frans-l,2-bis(4-pyridyl)ethylene (bpe) and 1,2-bis(4-pyridyl)ethane (p2p), respectively, have been explored [18]. The standard heterogeneous electron transfer rate constant, k°, depends on both a frequency factor and a Franck-Condon barrier, as follows [19-21] ... 

Why is the base more stable When a proton is removed from ethane, the electrons left behind reside solely on a carbon atom. Because carbon is not very electronegative, a carbanion is relatively unstable and therefore difficult to form. As a result, the pK of its conjugate acid is very high. 

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