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Crown‐Annelated 9,10‐Bis(1,3‐dithiol‐2‐ylidene)‐9,10‐dihydroanthracene Derivatives as Cation Sensors: Synthesis, X‐ray Crystal Structures, Voltammetric and Spectroscopic Monitoring of Metal Complexation
Author(s) -
Bryce Martin R.,
Batsanov Andrei S.,
Finn Terry,
Hansen Thomas K.,
Moore Adrian J.,
Howard Judith A. K.,
Kamenjicki Marta,
Lednev Igor K.,
Asher Sanford A.
Publication year - 2001
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/1099-0690(200103)2001:5<933::aid-ejoc933>3.0.co;2-a
Subject(s) - chemistry , moiety , dithiol , crystallography , metal , electrochemistry , steric effects , crystal structure , reagent , stereochemistry , organic chemistry , electrode
The synthesis of O 4 S 2 ‐crown annelated derivatives of 9,10‐bis(1,3‐dithiol‐2‐ylidene)‐9,10‐dihydroanthracene using the novel Horner−Wadsworth−Emmons reagent 7 is reported. The bis‐ and mono‐crown systems 9 and 12 function as efficient ligands in the voltammetric and UV/Vis spectroscopic recognition of Na + and Ag + . Solution electrochemical studies reveal that metal complexation to the crown unit(s) leads to a significant positive shift in the potential of the first, two‐electron oxidation wave of 9 and 12 [maximum shift E 1 ox = 115 mV for 9 in the presence of Ag + (ca. 10 molar equivalents)]. Considerably smaller shifts (< 30 mV) were observed for complexation of Li + , K + and Ba 2+ . UV/Vis spectrophotometric studies of metal binding (Na + and Ag + ) to 9 are consistent with the simultaneous formation of 1:1 and 1:2 complexes. The X‐ray crystal structures of compounds 10 and 12· CH 2 Cl 2 are reported. The anthracenediylidene moiety of 12 is U‐shaped due to the boat conformation of the central (quinodimethane) ring and folding of both 1,3‐dithiole rings, providing an overall saddle conformation. The folding in 10 is reduced as steric crowding is relieved by removal of one of the 1,3‐dithiole units.