Editing Lithium (section)

=== Organic chemistry ===
{{Main|Organolithium reagent}}
[[File:Butyllithium-hexamer-from-xtal-3D-balls-A.png|thumb|right|Hexameric structure of the [[N-Butyllithium|''n''-butyllithium]] fragment in a crystal]]
[[Organolithium compound]]s are numerous and useful.  They are defined by the presence of a [[covalent bond|bond]] between [[carbon]] and lithium. They serve as metal-stabilized [[carbanion]]s, although their solution and solid-state structures are more complex than this simplistic view.<ref>{{Cite book |url={{google books |plainurl=y |id=z76sVepirh4C |page=16}} |title=Lithium chemistry: a theoretical and experimental overview |author=Sapse, Anne-Marie |author2=von R. Schleyer, Paul |date=1995 |publisher=Wiley-IEEE |isbn=978-0-471-54930-7 |pages=3–40 |archive-url=https://web.archive.org/web/20160731221323/https://books.google.com/books?id=z76sVepirh4C&pg=PA16 |archive-date=31 July 2016 |url-status=live |name-list-style=amp}}</ref> Thus, these are extremely powerful [[base (chemistry)|bases]] and [[carbon nucleophile|nucleophiles]]. They have also been applied in asymmetric synthesis in the pharmaceutical industry. For laboratory organic synthesis, many organolithium reagents are commercially available in solution form. These reagents are highly reactive, and are sometimes [[pyrophoricity|pyrophoric]].

Like its inorganic compounds, almost all organic compounds of lithium formally follow the [[duet rule]] (e.g., [[N-Butyllithium|BuLi]], [[Methyllithium|MeLi]]). However, it is important to note that in the absence of coordinating solvents or ligands, organolithium compounds form dimeric, tetrameric, and hexameric clusters (e.g., BuLi is actually [BuLi]<sub>6</sub> and MeLi is actually [MeLi]<sub>4</sub>) which feature multi-center bonding and increase the coordination number around lithium. These clusters are broken down into smaller or monomeric units in the presence of solvents like [[dimethoxyethane]] (DME) or ligands like [[tetramethylethylenediamine]] (TMEDA).<ref>{{Cite journal |last1=Nichols |first1=Michael A. |last2=Williard |first2=Paul G. |date=1993-02-01 |title=Solid-state structures of n-butyllithium-TMEDA, -THF, and -DME complexes |journal=Journal of the American Chemical Society |volume=115 |issue=4 |pages=1568–1572 |doi=10.1021/ja00057a050 |bibcode=1993JAChS.115.1568N |issn=0002-7863}}</ref> As an exception to the duet rule, a two-coordinate lithate complex with four electrons around lithium, [Li(thf)<sub>4</sub>]<sup>+</sup>[((Me<sub>3</sub>Si)<sub>3</sub>C)<sub>2</sub>Li]<sup>–</sup>, has been characterized crystallographically.<ref>{{Cite book |title=Organometallic chemistry: a unified approach. |last=Mehrotra |first=R. C. |year=2009 |publisher=New Age International Pvt |isbn=978-81-224-1258-1 |oclc=946063142}}</ref>