6.7: In-Text References
- Page ID
- 354432
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)
- \(\mathrm{NaH}\) is synthesized by the reaction of sodium with hydrogen—a redox reaction. It is an ionic compound consisting of \(\mathrm{Na}^{+}\) and \(\mathrm{H}^{-}\) (hydride) ions; hydride cannot be produced by deprotonating \(\mathrm{NaH}_{2}\). ↵
- The \(\mathrm{pK}_{a}\) of \(\mathrm{NaH}_{3}\) (the conjugate acid of \(\mathrm{NaH}_{2} {}^{-}\)) is \(33\) ↵
- To use the oxidation number method, we must remember that \(\mathrm{H}\) is less electronegative than \(\mathrm{C}\); so in \(\mathrm{CH}_{4}\), the ON ofcarbon is –4 and each \(\mathrm{H}\) is +1. (This is confusing since we usually consider \(\mathrm{C-H}\) bonds as non-polar). In \(\mathrm{CO}_{2}\), each \(\mathrm{O}\) is –2 and the \(\mathrm{C}\) is +4. Therefore, in \(\mathrm{CO}_{2}\) the carbon is in a higher oxidation state than in CH4↵
- For more information about green chemistry see: https://www.epa.gov/greenchemistry ↵
- It is not necessary here to provide a long list of such reagents since many of them are complex, but it is important to know that there are alternatives should you ever need to oxidize an alcohol. ↵
- The formation of the analogous peroxide \(\mathrm{O-O}\) bond (Bond Dissociation Energy \(140 \mathrm{~kJ} / \mathrm{mol}\)) is even less likely, this bond is even weaker than \(\mathrm{S-S}\) (BDE \(230 \mathrm{~kJ} / \mathrm{mol}\)). ↵
- \(\mathrm{NaBH}_{4}\) and \(\mathrm{LiAlH}_{4}\) both contain a group III element (\(\mathrm{B}, \(\mathrm{Al}\)) here found in the form of the Lewis acid-base complex \(\mathrm{BH}_{4}\) or \(\mathrm{AlH}_{4}\). They are sources of Hydride ion, as shown above. \(\mathrm{LiAlH}_{4}\) is more reactive than \(\mathrm{NaBH}_{4}\). ↵
- Victor Grignard won a Nobel prize for this discovery: https://en.Wikipedia.org/wiki/Victor_Grignard. ↵
- The reaction mechanism is a little more complex than this—actually occurring via one electron transfer—but the result is the same. ↵