Editing Charge-transfer complex (section)

===Electron donor-acceptor complexes ===
A number of organic compounds form charge-transfer complex, which are often described as '''electron-donor-acceptor complexes''' (EDA complexes).  Typical acceptors are nitrobenzenes or tetracyanoethylene (TCNE).  The strength of their interaction with electron donors correlates with the ionization potentials of the components.  For TCNE, the [[Stability constants of complexes|stability constant]]s (L/mol) for its complexes with benzene derivatives correlates with the number of methyl groups: [[benzene]] (0.128), [[mesitylene|1,3,5-trimethylbenzene]] (1.11), [[durene|1,2,4,5-tetramethylbenzene]] (3.4), and [[hexamethylbenzene]] (16.8).<ref>{{cite journal |doi=10.1021/j100454a006|title=Electron Donor-Acceptor Complexes|year=1980|last1=Foster|first1=R.|journal=The Journal of Physical Chemistry|volume=84|issue=17|pages=2135–2141}}</ref> A simple example for a prototypical '''[[Electron donor|electron-donor]]-acceptor complexes''' is [[nitroaniline]].<ref>{{Cite journal |last1=Vismarra |first1=Federico |last2=Fernández-Villoria |first2=Francisco |last3=Mocci |first3=Daniele |last4=González-Vázquez |first4=Jesús |last5=Wu |first5=Yingxuan |last6=Colaizzi |first6=Lorenzo |last7=Holzmeier |first7=Fabian |last8=Delgado |first8=Jorge |last9=Santos |first9=José |last10=Bañares |first10=Luis |last11=Carlini |first11=Laura |last12=Castrovilli |first12=Mattea Carmen |last13=Bolognesi |first13=Paola |last14=Richter |first14=Robert |last15=Avaldi |first15=Lorenzo |date=December 2024 |title=Few-femtosecond electron transfer dynamics in photoionized donor–π–acceptor molecules |journal=Nature Chemistry |language=en |volume=16 |issue=12 |pages=2017–2024 |doi=10.1038/s41557-024-01620-y |pmid=39322782 |issn=1755-4349|pmc=11611723 |bibcode=2024NatCh..16.2017V }}</ref>

1,3,5-Trinitrobenzene and related polynitrated aromatic compounds, being electron-deficient, form charge-transfer complexes with many arenes.  Such complexes form upon crystallization, but often dissociate in solution to the components.  Characteristically, these CT salts crystallize in stacks of alternating donor and acceptor (nitro aromatic) molecules, i.e. A-B-A-B.<ref name=Goetz>{{cite journal |doi=10.1039/C3TC32062F|title=Charge-Transfer Complexes: New Perspectives on an Old Class of Compounds |year=2014 |last1=Goetz |first1=Katelyn P. |last2=Vermeulen |first2=Derek |last3=Payne |first3=Margaret E. |last4=Kloc |first4=Christian |last5=McNeil |first5=Laurie E. |author5-link=Laurie McNeil |last6=Jurchescu |first6=Oana D.|author6-link=Oana Jurchescu |journal=J. Mater. Chem. C |volume=2 |issue=17 |pages=3065–3076}}</ref>