A Novel Optical Sensor for Metal Ions Based on Ground-State Intermolecular Charge-Transfer Complexation

Abstract

A derivative of dipyridylethylene 2 was synthesized in order to study intermolecular coordination between the 18-crown-6 ether units of bis-crown stilbene 1 and the NH3 + groups of 2. In acetonitrile solution, the formation of a supramolecular complex is evidenced by a considerable upfield shift of the 1H NMR signals from the aromatic and olefinic protons. Emission quenching and the appearance of a new absorption band in the visible spectral region indicate the formation of a charge-transfer complex. The addition of Ba2+ to a solution of the complex leads to significant fluorescence enhancement and to the disappearance of the charge-transfer absorption band.

Stereoselective [2+2] photocycloaddition in bispseudosandwich complexes of bis(18-crown-6) stilbene with alkanediammonium ions

“…18 [(E) 2 (2,3,5,6,8,9,11,12,14,15 Decahydro 1,4,7,10,13,16 benzohexaoxacyclooctadecin 18 yl) 1 ethenyl] 2,3,5,6,8,9,11, 12,14,15 decahydro 1,4,7,10,13,16 benzohexaoxacycloocta decine ((E) 1) 17 and salts H 3 N + (CH 2 ) n NH 3 + 2ClO 4 -(C2-С6, C10, C12) 20,22,23 were synthesized according to known procedures.…”

Cooperative Recognition of C60–Ammonium Substrates by a Ditopic Oligophenylenevinylene/Crown Ether Host

“…[5c, 13] Moreover, a sizeable stabilization is also observed with respect to ground-state charge-transfer complexes formed by bis(crown)stilbene and alkyldiammonium or bis(ammonium)viologen substrates (1.13 < log K < 9.08). [14] A sum of secondary weak interactions like p-p stacking or hydrophobic associations between host 1 or 3 and guest 2 may be proposed to explain this stronger coordination.…”

Synthesis and Structure of Bis-crown-Containing Stilbenes

“…The most typical photochemical processes occurring in the above selforganized systems and accompanied by considerable variation of their properties are trans-cis isomerization of the double bonds, electrocyclic reactions, and [2 + 2]-cycloaddition. Crown ether-fused stilbenes were not studied in much detail [6][7][8], though these compounds might be expected to exhibit equally interesting photochemical behavior and pronounced ability to form complexes.We recently showed that bis(18-crown-6)-stilbene Id and a number of diammonioalkyl derivatives of viologen analogs in dilute solutions give rise to unusual bi-and trimolecular complexes with effective intermolecular charge transfer due to spatial preorganization of the donor and acceptor parts of the initial molecules via hydrogen bonding [9][10][11]. Such supramolecular systems were found to be very stable; therefore, they can be regarded as convenient models for studying photoinduced intermolecular electron transfer [12] and promising species with versatile electrochemical properties [13].…”

“…We recently showed that bis(18-crown-6)-stilbene Id and a number of diammonioalkyl derivatives of viologen analogs in dilute solutions give rise to unusual bi-and trimolecular complexes with effective intermolecular charge transfer due to spatial preorganization of the donor and acceptor parts of the initial molecules via hydrogen bonding [9][10][11]. Such supramolecular systems were found to be very stable; therefore, they can be regarded as convenient models for studying photoinduced intermolecular electron transfer [12] and promising species with versatile electrochemical properties [13].…”