Vibrational spectra of two new organic semiconductors: tetrathiafulvalene (TTF) and tetramethyltetraselenafulvalene (TMTSF) salts of paranitrophenylmalononitrile (PNMA)

1991 ◽  
Vol 69 (5) ◽  
pp. 901-907 ◽  
Author(s):  
K. D. Truong ◽  
A. D. Bandrauk ◽  
J. ZAUHAR ◽  
C. Carlose
Keyword(s):  
Raman Spectroscopy ◽  
Charge Transfer ◽  
Organic Semiconductors ◽  
Vibrational Spectra ◽  
Electron Distribution ◽  
Charge Transfer Complexes ◽  
Strong Electron ◽  
Ir And Raman ◽  
Degree Of Charge Transfer ◽  
Ftir And Raman Spectroscopy

Two new complexes of stoichiometry 2:1 are reported for the donors tetrathiafulvalene (TTF) and tetramethyltetraselenafulvalene (TMTSF) with the acceptor paranitrophenylmalononitrile (PNPMA). Both compounds are semiconductors with a resistivity of about 4 × 10−4 Ω m for (TMTSF)2PNPMA and 0.58 Ω m for (TTF)2PNPMA. The larger conductivity of the first complex can be attributed to the disorder of the PNPMA anions. Vibrational spectra were obtained by FTIR and Raman spectroscopy, in order to determine the degree of charge transfer in these systems. Both complexes have the electron distribution (D+0.4)2A−0.8. As a result the donors D stack in tetramerized units and exhibit vibronic activation of certain symmetric monomer modes, thus indicating the presence of strong electron–vibrational interactions in the donor stacks. Key words: TTF and TMTSF salts, charge transfer complexes, IR and Raman spectra, degree of charge transfer, paranitrophenylmalononitrile (PNPMA).

Crystal growth and characterization of solvated organic charge-transfer complexes built on TTF and 9-dicyanomethylenefluorene derivatives

CrystEngComm ◽  
2015 ◽  
Vol 17 (32) ◽  
pp. 6227-6235 ◽  
Author(s):  
Amparo Salmerón-Valverde ◽  
Sylvain Bernès
Keyword(s):  
Charge Transfer ◽  
Crystal Growth ◽  
Charge Transfer Complexes ◽  
Organic Complexes ◽  
Donor Acceptor ◽  
Degree Of Charge Transfer

A series of solvated donor–acceptor organic complexes were shown to slowly release the lattice solvent while the degree of charge transfer decreases steadily. This behavior is not observed in the case of a hydrate.

Schwingungs-und Elektronenspektren der bindungsisomeren Hexakis(thiocyanato(N)-thiocyanato(S))-osmate(III) und (IV) / Vibrational and Electronic Spectra of Bond-Isomeric Hexakis(thiocyanato(N)-thiocyanato(S))osmates(III) and (IV)

1988 ◽  
Vol 43 (4) ◽  
pp. 371-381 ◽  
Author(s):  
K. Bütje ◽  
W. Preetz
Keyword(s):  
Charge Transfer ◽  
Vibrational Spectra ◽  
Near Infrared ◽  
Bathochromic Shift ◽  
Infrared Region ◽  
Hypsochromic Shift ◽  
Linkage Isomers ◽  
Near Infrared Region ◽  
Ir And Raman ◽  
Metal Ligand

AbstractWell-resolved IR and Raman spectra of the two sets of all 10 isomeric complexes [Os(NCS)n(SCN)6-n]3-/2-, n = 0-6, have been recorded. For both series, νCS(N) > νCS(S) and δNCS > δSCN; for the Os(III) complexes, vCN(N) ~ vCN(S) and vOsN ≥ vOsS while for the Os(IV) compounds, vCN(N) < vCN(S) and vOsN ~ vOsS. The vibrational spectra of the n = 0 and n = 6 members of both sets are assigned according to D3d and Oh point symmetry, respectively. For the mixed linkage isomers the band pattern is strongly influenced by pseudo-octahedral coupling wherever frequencies of N- and S-bonded groups coincide. The metal-ligand stretching region is therefore assigned according rather to pseudo-Oh, pseudo-D3d and pseudo-D4h symmetry than to D4h, C4v, C3v and C2v microsymmetry. The charge-transfer spectra of both series are similar, showing a parallel hypsochromic shift with increasing n value. Upon oxidation, a bathochromic shift of the CT bands by an average of 5400 cm-1 is observed, and the intensity increases by a factor 2-2.5. Weak absorptions in the near infrared region are assigned to intraconfigurational transitions.

Gelification Effects on the Structure and Birefringence of Charge Transfer Complex Terthiophene Bisililated – TCNQ Hybrid Materials

2006 ◽  
Vol 517 ◽  
pp. 257-261
Author(s):  
N. Kancono ◽  
H.B. Senin
Keyword(s):  
Charge Transfer ◽  
Detection Limit ◽  
Hybrid Materials ◽  
Vibrational Spectra ◽  
Lamellar Structure ◽  
Radical Anion ◽  
Charge Transfer Complex ◽  
Visible Spectrum ◽  
Charge Transfer Complexes

Charge transfer complexes (CTC) can be readily introduced into materials by cohydrolysis-copolymerisation of bis-silylated ter-thiophenes as precursors with TMOS and TEOS in the presence of TCNQ. CTC formation is shown in the visible spectrum of the xerogel by the band at 850 nm characteristic of the TCNQ·- radical anion. Vibrational spectra have shown that strong vibration of C≡N bond at 2184, 2120 and 1595 cm-1 as peaks characteristics of CTC. The CTC bands are weak and the complex is easily destroyed by washing with acetone, which removes the TCNQ. The gelification effect of the charge transfer complexes on the hybrid materials of 2,5’’- bis(trime thoxysilyl)terthiophene/TCNQ/ TMOS showed that the peak with distance of more than 11.68 Å, formed by precursors and matrices, as a lamellar structure. The birefringence of xerogel BTS3T in presence of alkoxysilane showed that the value is near the detection limit of 0.1 – 0.4 x 10-3, which is weaker than BTS3T / THF with the birefringence value of 4.5 x 10-3.

scholarly journals Molecular Doping in Multi-Molecule Polymer-Dopant Complexes Shows Reduced Coulomb Binding

2020 ◽  
Author(s):  
Chuanding Dong ◽  
Stefan Schumacher
Keyword(s):  
Charge Transfer ◽  
Organic Semiconductors ◽  
Positive Charge ◽  
Charge Carriers ◽  
Mechanistic Study ◽  
Charge Transfer Complexes ◽  
Mobile Charge ◽  
Molecular Doping ◽  
Gap States ◽  
P Type

<p>The mechanistic study of molecular doping of organic semiconductors (OSC) requires</p><p>an improved understanding of the role and formation of integer charge transfer complexes</p><p>(ICTC) on a microscopic level. In the present work we go one crucial step beyond</p><p>the simplest scenario of an isolated bi-molecular ICTC and study ICTCs formed of</p><p>up to two (poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b,3,4-b”]dithiophene)-alt-4,7-(2,1,3-</p><p>benzothiadiazole)](PCPDT-BT) oligomers and up to two CN6-CP molecules. We find that depending</p><p>on geometric arrangement, complexes containing two conjugated oligomers and two</p><p>dopant molecules can show p-type doping with double integer charge transfer, resulting in either</p><p>two singly doped oligomers or one doubly doped oligomer. Interestingly, compared to an individual</p><p>oligomer-dopant complex, the resulting in-gap states on the doped oligomers are significantly</p><p>lowered in energy. Indicating that, already in the relatively small systems studied here, Coulomb</p><p>binding of the doping-induced positive charge to the counter-ion is reduced which is an elemental</p><p>step towards generating mobile charge carriers through molecular doping.</p>

scholarly journals Molecular Doping in Multi-Molecule Polymer-Dopant Complexes Shows Reduced Coulomb Binding

2020 ◽  
Author(s):  
Chuanding Dong ◽  
Stefan Schumacher
Keyword(s):  
Charge Transfer ◽  
Organic Semiconductors ◽  
Positive Charge ◽  
Charge Carriers ◽  
Mechanistic Study ◽  
Charge Transfer Complexes ◽  
Mobile Charge ◽  
Molecular Doping ◽  
Gap States ◽  
P Type

<p>The mechanistic study of molecular doping of organic semiconductors (OSC) requires</p><p>an improved understanding of the role and formation of integer charge transfer complexes</p><p>(ICTC) on a microscopic level. In the present work we go one crucial step beyond</p><p>the simplest scenario of an isolated bi-molecular ICTC and study ICTCs formed of</p><p>up to two (poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b,3,4-b”]dithiophene)-alt-4,7-(2,1,3-</p><p>benzothiadiazole)](PCPDT-BT) oligomers and up to two CN6-CP molecules. We find that depending</p><p>on geometric arrangement, complexes containing two conjugated oligomers and two</p><p>dopant molecules can show p-type doping with double integer charge transfer, resulting in either</p><p>two singly doped oligomers or one doubly doped oligomer. Interestingly, compared to an individual</p><p>oligomer-dopant complex, the resulting in-gap states on the doped oligomers are significantly</p><p>lowered in energy. Indicating that, already in the relatively small systems studied here, Coulomb</p><p>binding of the doping-induced positive charge to the counter-ion is reduced which is an elemental</p><p>step towards generating mobile charge carriers through molecular doping.</p>

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