Intramolecular charge-transfer compounds

Azobenzene-linked amphiphile C180AZOSN employed for our experiments (Fig.4.) is an intramolecular charge-transfer compound with donor (alkoxy) and... 

S. Tazuke, R. K. Guo, and T. Ikeda, Time-resolved fluoresence spectroscopy of a twisted intramolecular charge transfer compound bonded to polymers, /. Phys. Chem. 94, 1408(1990). 

Intramolecular Charge-Transfer Compound Bonded to Poly (methyl methacrylate)... 

RD Schulte, JF Kauffman. Fluorescence from the twisted intramolecular charge transfer compound bis(4,4 -dimethylaminophenyl)sulfone in ethanol/C02 a probe of local solvent composition. Appl Spectrosc 49 31, 1995. 

During the last decade one paper concerning the use of ESCA on heterocyclic compounds has appeared. The observed effects are interpreted in terms of intramolecular charge-transfer transitions between a donor and an acceptor group of the molecule.41... 

All compounds were measured at room temperature in air between Au electrodes inside a Faraday cage. IVT = maximum of the optical InterValence Transfer or intramolecular charge transfer band. RR Rectification Ratio. Survives cycling means RR does not decrease with cycling of IV measurements. AR or anti-AR indicates whether electron flow is from A to D (AR) or from D to A (anti-AR)... 

Compounds undergoing photoinduced intramolecular charge transfer (ICT) and internal rotation... 

The desulphurization of disulphides by tervalent phosphorus compounds has been the subject of a review.70 The light-induced desulphurization of benzylic sulphides by phosphites has found further use in the synthesis of cyclophanes which exhibit the formation of intramolecular charge-transfer complexes, e.g. (61) and (62).71... 

Figure 2,7. Absorption and fluorescence spectra of DCM-crown and its complexes with perchlorate salts in acetonitrile. DCM-H is the compound in which the crown is replaced by a hydrogen atom this compound cannot undergo intramolecular charge transfer and its fluorescence quantum yield is very low (3 x 1(C) (adapted from Ref, 40.)...

J. Bourson and B. Valeur, Ion-responsive fluorescent compounds. 2. Cation-steered intramolecular charge transfer in a crowned merocyanine,/. Phys. Chem, 93, 3871 (1989). 

K. A. Al-Hassan and T. Azumi, The role of free volume in the twisted intramolecular charge transfer (TICT) emission of dimethylaminobenzonitrile and related compounds in rigid polymer matrices. Chem. Phys. Lett. 146, 121 (1988). 

Electronic absorption studies were performed on compounds 90 and 91 in dimethylformamide (DMF) the longest wavelength maxima at 503-567 nm arising from intramolecular charge transfer (ITC) are shifted bathochromically with an increase in the sum of the nucleophilic constant btt-attached to the fluorene ring. An equation to enable calculation of this effect was devised <2001MM2232>. 

V,/V-Dimethylamino)benzonitrile (DMABN) and its derivatives, as a class of organic donor-acceptor compounds, exhibit dual fluorescence, one related to the local excited state ( B band) and the other ascribed to the twisted intramolecular charge transfer (TICT) state ( A band).17 As expected, compound 818 exhibits dual fluorescence, showing two fluorescence bands centered at 350 and 432 nm, which can be ascribed to the corresponding band (from the local excited state) and A band (from the TICT state), respectively. After oxidation of TTF unit in 8, the fluorescence intensity of A band decreases while that of band increases slightly. As expected, further reduction of TTF" + into neutral TTF unit leads to the restoration of the fluorescence spectrum of 8. Therefore, the dual fluorescence spectrum of 8 can be reversibly modulated by redox reactions of TTF unit in 8. 

They display intramolecular charge transfer [8.87] and marked second-harmonic generation. The determination of the hyperpolarizabilities of such compounds... 

Halophenyl)pyridazinium ylides have been found to act as strong carbon nucleophiles towards diazoaromatic compounds to yield stable carbanion disubstituted ylides for which the intense colour has been attributed to intramolecular charge transfers.88... 

Main Chain Polymers. Another system of dye attached polymers is a polyamic acid and a polyimide with a Tt-electron conjugation in the main chain. The Tt-electron conjugated system is not an intramolecular charge transfer system, unlike the azo and stilbene dye mentioned above. The polyamic acids (PAAs) were obtained through the reaction of a carboxylic acid anhydride and a diamine. A Tt-electron conjugated system exists in the diamine compound. These polyamic acids were soluble in conventional solvents and... 

Compounds 268a and 269a showed large Stokes shifts in polar solvents. Such large Stokes shifts have been observed in many TICT (twisted intramolecular charge transfer) molecules. Fluorescence decay time measurement indicated that there were two kinds of excited states, fast and slower decaying components, and the latter was the emission from the more polar state. 

Donor-acceptor 7i-conjuga ted (D-rc-A) compounds have led to numerous theoretical and experimental studies to explore the origin of intramolecular charge-transfer (ICT) fluorescence. This property can be used in order to have low bandgap materials. 

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