Charge transfer complexes of diquat and paraquat with halide anions

1987 ◽  
Vol 65 (10) ◽  
pp. 2425-2427 ◽  
Author(s):  
S. G. Bertolotti ◽  
J. J. Cosa ◽  
H. E. Gsponer ◽  
C. M. Previtali
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Band ◽  
Association Constants ◽  
Charge Transfer Complexes ◽  
Ion Selective Electrodes ◽  
Halide Ions ◽  
Ultraviolet Spectrophotometry ◽  
A Charge ◽  
Difference Absorption ◽  
Absorption Measurements

The association of methylviologen, 1,1′-dimethyl-4,4′-bipyridynium (PQ2+), with halide and pseudo-halide ions was studied in water at 25 °C by ultraviolet spectrophotometry. A charge transfer band could be observed in the region around 300 nm. From difference absorption measurements the first association constant (K1,) was obtained as 1.7 (Cl−), 3.3 (Br−), 3.9 (I−), 0.7 (CN−), and 2.0(SCN−) M−1. Similar results were obtained for the dication, 6,7-dihydrodipyrido[1,2-a:2′,1′-c]pyrazinium (DQ2+), with first association constants 3.3 (Cl−), 4.1 (Br−) and 4.6 (I−) M−1. First and second (K2) association constants were also determined by a potentiometric technique using ion selective electrodes: K1 = 2.0 M−1; K2 = 0.4 M−1 for the system PQ2+–Cl− and K1 = 5.3 M−1; K2 = 0.3 M−1 for DQ2+Br−.

Chemical behavior of charge-transfer complexes. VII. Solvolysis of alkyl arenesulfonate donors in the presence of aromatic acceptors

1978 ◽  
Vol 56 (4) ◽  
pp. 585-590 ◽  
Author(s):  
Allan K. Colter ◽  
Robert E. C. Turkos
Keyword(s):  
Acetic Acid ◽  
Charge Transfer ◽  
Kinetic Data ◽  
Association Constants ◽  
Charge Transfer Complexes ◽  
Chemical Behavior ◽  
Measurable Rate ◽  
Leaving Groups

Rates of solvolysis of several ethyl and 2-propyl arenesulfonates having π donor leaving groups were measured in the absence of accepter and in the presence of the π acceptors 1,3,5-trinitrobenzene (TNB) and 2,4,7-trinitrofluorenone (TNF). With four of the nine combinations investigated, added accepter produced small but measurable rate enhancements. Ester–TNF 1:1 association constants were measured spectrophotometrically at 20, 30, and 40 °C in acetic acid for 2-propyl 4-methoxy-1-naphthalenesulfonate (3b), 4,8-dimethoxy-1-naphthalenesulfonate (4), 3,7-dimethyl-1-naphthalenesulfonate (5), and 1-pyrenesulfonate (6). From the equilibrium and kinetic data, the reactivity of the 1:1 ester–TNF complex relative to that of the uncomplexed ester (kc/ku) in acetolysis at 85.73 °C was estimated to be lessthan 4.2 and 1.4 for 3b and 4, respectively, 4.4 ± 2.0 for 5, and 2.8 ± 0.4 for 6. The value of kc/ku for 6 determined from analysis of the kinetic data alone is 2.7 ± 0.8.

Spectra of the 1:1 and 3:1 solid complexes of coronene-TCNQ

1977 ◽  
Vol 55 (21) ◽  
pp. 3712-3716 ◽  
Author(s):  
Kim Doan Truong ◽  
André D. Bandrauk
Keyword(s):  
Charge Transfer ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Ground State ◽  
Electronic Absorption Spectra ◽  
Charge Transfer Band ◽  
Out Of Plane ◽  
The Individual ◽  
A Charge ◽  
Solid Complexes

Two new solid TCNQ complexes have been isolated, coronene–TCNQ 1:1 and 3:1. The infrared and electronic absorption spectra are presented for the two different stoichiometries. From these spectra we infer that the complexes are covalent in the ground state with a charge transfer band appearing at 730 nm. The out of plane vibrations of the individual molecules are noticeably perturbed upon complexation.

scholarly journals Water-Soluble Visible Light Sensitive Photoinitiating System Based on Charge Transfer Complexes for the 3D Printing of Hydrogels

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3195
Author(s):  
Hong Chen ◽  
Mehdi Vahdati ◽  
Pu Xiao ◽  
Frédéric Dumur ◽  
Jacques Lalevée
Keyword(s):  
Charge Transfer ◽  
3D Printing ◽  
Visible Light ◽  
Water Solubility ◽  
Charge Transfer Complex ◽  
Water Soluble ◽  
Charge Transfer Complexes ◽  
Free Radical Photopolymerization ◽  
Potential Applications ◽  
A Charge

The development of visible-light 3D printing technology by using water-soluble initiating systems has attracted widespread attention due to their potential applications in the manufacture of hydrogels. Besides, at present, the preparation of water-soluble photoinitiators suitable for visible light irradiation (such as LEDs) still remains a challenge. Therefore, this work is devoted to developing water-soluble photoinitiators (PI)/photoinitiating systems (PIS) upon irradiation with a LED @ 405 nm. In detail, a new water-slightly-soluble chalcone derivative dye [(E)-3-(4-(dimethylamino) phenyl)-1-(4-(2-(2-(2-methoxyethoxy) ethoxy) ethoxy) phenyl) prop-2-en-1-one] was synthesized here and used as a PI with a water-soluble coinitiator, i.e., triethanolamine (TEA) which was also used as an electron donor. When combined together, a charge transfer complex (CTC) formed immediately which exhibited excellent initiating ability for the free radical photopolymerization of poly(ethyleneglycol)diacrylate (PEG-DA). In light of the powerful CTC effect, the [dye-TEA] CTC could not only exhibit enhanced water solubility and mechanical properties but could also be effectively applied for 3D printing. This CTC system is environmentally friendly and cost-saving which demonstrates a great potential to prepare hydrogels via photopolymerization.

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