TY - JOUR
T1 - Rigid Molecular Tweezers
T2 - Preorganized Hosts for Electron Donor-Acceptor Complexation in Organic Solvents
AU - Zimmerman, Steven C.
AU - VanZyl, Craig M.
AU - Hamilton, Gregory S.
PY - 1989/2
Y1 - 1989/2
N2 - Novel nonmacrocyclic receptor molecules 1 and 7 have been synthesized which are capable of acting as molecular tweezers. These molecules are 7-aryl-2,12-bis(9-acridinyl)dibenz[c,h]acridines, which when unsymmetrically substituted exhibit atropisomerism. In addition to being rigid and providing a ca. 7 Å interchromophore distance, the dibenz[c,h]acridine spacer is the first to enforce a syn cofacial orientation of the complexing chromophores. 1H NMR studies indicate that 1 and 7 have open clefts. These preorganized clefts form highly oriented inclusion complexes with 2,4,7-trinitrofluorenone (TNF) in CDCl3 as monitored by 1H NMR. The complexation has a strong electron donor-acceptor component. As such, the association constants for TNF are dependent on the π-basicity of the host and range from 149 M-1 for tert-butyl-substituted 7b to 697 M-1 for dimethylamino-substituted 7f (CDCl3). Monoacridines and a flexible diacridine, under identical conditions, bind TNF very weakly (Kassoc < 5 M-1).
AB - Novel nonmacrocyclic receptor molecules 1 and 7 have been synthesized which are capable of acting as molecular tweezers. These molecules are 7-aryl-2,12-bis(9-acridinyl)dibenz[c,h]acridines, which when unsymmetrically substituted exhibit atropisomerism. In addition to being rigid and providing a ca. 7 Å interchromophore distance, the dibenz[c,h]acridine spacer is the first to enforce a syn cofacial orientation of the complexing chromophores. 1H NMR studies indicate that 1 and 7 have open clefts. These preorganized clefts form highly oriented inclusion complexes with 2,4,7-trinitrofluorenone (TNF) in CDCl3 as monitored by 1H NMR. The complexation has a strong electron donor-acceptor component. As such, the association constants for TNF are dependent on the π-basicity of the host and range from 149 M-1 for tert-butyl-substituted 7b to 697 M-1 for dimethylamino-substituted 7f (CDCl3). Monoacridines and a flexible diacridine, under identical conditions, bind TNF very weakly (Kassoc < 5 M-1).
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U2 - 10.1021/ja00186a035
DO - 10.1021/ja00186a035
M3 - Article
AN - SCOPUS:0000619957
SN - 0002-7863
VL - 111
SP - 1373
EP - 1381
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 4
ER -