• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Derivatives 7,7'-diazaisoindigo and its uses. Use of compounds derived from 7,7'-diazaisoindigo as components for the manufacture of solar cells, specifically organic photovoltaic cells. The invention also relates to novel compounds 7,7'-diazaisoindigo substituted in positions 5, 5 ', preferably by halogen atoms. (Machine-translation by Google Translate, not legally binding)
    公开号:ES2625021A1
    申请号:ES201531835
    申请日:2015-12-18
    公开日:2017-07-18
    发明作者:Eva María GARCÍA FRUTOS；Luis CAMACHO DELGADO；Gustavo DE MIGUEL ROJAS
    申请人:Consejo Superior de Investigaciones Cientificas CSIC；Universidad de Cordoba；
    IPC主号:
    专利说明:

    The present invention relates to the use of compounds derived from 7,7'diazaisoindigo as a component for the manufacture of solar cells, in particularof photovoltaic cells. In addition, the invention relates to derivative compounds7,7’-diazaisoindigo substituted in 5.5 ’positions. 10 STATE OF THE TECHNIQUE
    -conjugated organic molecules play a very important role both in the area of magnetism, photonics, and electronics due to -electronic communication between the different rings. During the last decades, the field of
    15 organic electronics have evolved rapidly and progressively due to their promising application in light emitting diodes (OLEDs) or photovoltaic cells (OPVs).
    Organic semiconductors offer high expectations in the development of
    20 devices not only for the low price, for the preparation of large flexible areas (properties difficult to achieve with conventional electronics), but also for the possibility of modulating key properties (luminescence, absorption, energy band and load transport). On the other hand, in recent years, global energy demand is growing rapidly. That's why the energies
    25 renewable and solar energy in particular, are the future of power generation. Renewable energies are those energies that come from natural resources that are not depleted. Solar energy is a renewable energy, obtained from the use of electromagnetic radiation from the Sun. In photovoltaic solar energy, electricity is obtained, directly from solar radiation
    30 through a semiconductor device called a photovoltaic cell. Among all photovoltaic cells, organic photovoltaic cells in which at least one active layer is composed of organic molecules have been extensively studied due to the low cost of organic semiconductors.
    35 Different kinds of materiales-conjugated organic materials both donors and


    Acceptors have caused great attraction in recent years, although the acceptors have been less studied due to their high reactivity and stability. Among all the acceptors described in the literature, the acceptors based on materials with amide / imide groups in the molecule are those that have excellent stability
    5 environmental. One of the acceptors with this most used imide / amide group has been the isoindigo (Romain Stalder et al. Chem. Mater 2014, 26, 664-678) although there have been very few variations or modifications of the central unit to date. DESCRIPTION OF THE INVENTION
    In the present invention, there are provided compounds derived from 7,7 diazaisoindigo whose photophysical experiments in different solvents have demonstrated a quenching of fluorescence with shorter life times in solvents with higher polarity or lower viscosity. These results are explained due to the
    The presence of a non-radiative deactivation mechanism that occurs through a conical intersection, as also occurs in the isoindigo molecule. In comparison with this last molecule, the deactivation process is much slower in the case of 7,7'-diazaisoindigo due to the adjustment of the energy of the orbitals when inserting the nitrogen atom. The clearest consequence of the different kinetics of
    20 deactivation for the isoindigo and 7,7'-diazaisoindigo is the absence of fluorescence in the case of the former and the measurement of a certain emission signal in the case of the latter. This deceleration of the deactivation kinetics of the excited state in the case of 7,7'-diazaisoindigo is what gives it an important advantage over the isoindigo for use in solar cells, both those sensitized by dye and
    25 polymer.
    In both cases, the 7,7'-diazaisoindigo molecule acts by absorbing the electromagnetic spectrum, which promotes the passage of an electron to an excited state that can return to the fundamental state but is trapped by a 30-electron acceptor molecule. The overall performance of a solar cell will depend on the efficiency of the transfer process of that excited electron to the acceptor molecule, which is inversely related to the kinetics of deactivation of the excited state. Therefore, because the deactivation process in the case of 7,7'-diazaisoindigo is slower than for the isoindigo, the efficiency of electron transfer to the
    The acceptor system will be greater in the case of 7,7'-diazaisoindigo and therefore the overall efficiency is greater.


    Therefore, a first aspect of the present invention relates to the use of a compound of general formula (I)
    (I)
    where: Y is selected from CH2, O, NH, C (O), S, S (O), NHC (O) and (O) CNH; R1 is a C1-C16 alkyl; Y
    10 R2 is selected from hydrogen, halogen and one of the following groups:
    where R is a C1-C16 alkyl group, preferably it is a C3-C11 alkyl,
    or any of its isomers, as an active component for the manufacture of solar cells, preferably organic photovoltaic cells.
    The solar cells and in particular the organic photovoltaic cells comprise in their structure at least one active layer that is composed of organic molecules, therefore as "active component" we refer in the present invention to a component, selected from at least one compound of general formula (I) of
    The present invention, comprised in said active layer.
    The term "alkyl" refers, in the present invention, to aliphatic, linear or branched chains, having 1 to 16 carbon atoms, for example, methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert. butyl, sec-butyl, pentyl, dodecyl, etc. Preferably the alkyl group has from 2 to 14 carbon atoms, more preferably from 3 to 11 carbon atoms. The alkyl groups may be


    optionally substituted by one or more substituents such as halogen, hydroxyl, azide, carboxylic acid or a substituted or unsubstituted group, selected from amino, amido, carboxylic ester, ether, thiol, acylamino or carboxamido.
    The term "halogen" refers, in the present invention, to a chlorine, bromine, fluorine or iodine atom, preferably it is bromine.
    The compounds of the present invention represented by the formula (I) may include isomers, including optical isomers or enantiomers, depending on the presence of chiral centers. The individual isomers, enantiomers or diastereoisomers and mixtures thereof fall within the scope of the present invention. The individual enantiomers or diastereoisomers, as well as mixtures thereof, can be separated by conventional techniques. Preferably the isomers are trans (E) enantiomers.
    In a preferred embodiment of the use of the compound of formula (I), R2 is hydrogen or halogen, more preferably R2 is hydrogen or bromine.
    In a preferred embodiment of the use of the compound of formula (I), Y is CH2.
    In another preferred embodiment of the use of the compound of formula (I), R 1 is a C 3 -C 11 alkyl.
    In another more preferred embodiment of the use of the compound of formula (I), the compounds are selected from: (E) -1,1'-dihexyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] - 2,2 '(1H, 1'H) -dione, (E) -1,1'-dibutyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2' (1H, 1 'H) -dione, (E) -1,1'-dioctyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2' (1H, 1'H) -dione and (E ) -5,5'-dibromo-1,1'-didodecyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H) -dione.
    A second aspect of the present invention relates to a compound of formula (I)
    or any of its isomers as defined above:


    (I)
    where: Y and R1 have been described above; YR2 is selected from halogen and one of the following groups:
    where R is a C1-C16 alkyl group.
    In a preferred embodiment of the compound of formula (I), R2 is a halogen, more preferably R2 is bromine.
    In another preferred embodiment of the compound of formula (I), Y is CH2.
    In another preferred embodiment of the compound of formula (I), R1 is a C3-C11 alkyl.
    In another more preferred embodiment of the compound of formula (I), the compound is (E) 5,5'-dibromo-1,1'-didodecyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2.2 '(1H, 1'H) -diona.
    A further aspect of the present invention relates to compounds (E) -1,1'20 dihexyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H ) -dione and (E) -1,1'-dibutyl- [3,3'bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H) -dione.
    Throughout the description and the claims the word "comprises" and its variants are not intended to exclude other technical characteristics, additives, components or steps. For those skilled in the art, other objects, advantages and features of the invention will be derived partly from the description and partly from the practice of the


    invention. The following examples and figures are provided by way of illustration, and are not intended to be limiting of the present invention. BRIEF DESCRIPTION OF THE FIGURES
    5FIG. 1 Optical microscope image of compound 4 obtained by slow evaporationof the compound in dichloromethane.
    FIG. 2 (A) Normalized absorption spectra (at λ = 284 nm) of the three molecules
    10 investigated, 3 (solid line), 2 (dashed line) and 1 (dotted line) in CCl4. (b) Excitation spectra (continuous line, λem = 650 nm) and 2 emission in CCl4 different excitation wavelengths, λexc = 475 nm (dashed line), λexc = 330 nm (dashed line) and λexc = 280 nm (dashed-dashed line).
    15 FIG. 3 (A) Emission spectra of 2 in different solvents: CCl4 (1), toluene (2), cyclohexanol (3), anisole (4), CH2Cl2 (5), EtOH (6) and ACN (7). λexc = 475 nm. (B) Standard emission spectra of 2 in different solvents: CCl4 (1), toluene (2), anisole (3), CH2Cl2 (4), EtOH (5) and ACN (6). λexc = 475 nm. (C) Stokes shift Δν versus Δf for the three molecules, 1 (triangles), 2 (circles) and 3
    20 (squares). The straight line is the best linear fit to the data points of 1. EXAMPLES
    The invention will now be illustrated by tests carried out by the inventors, which demonstrates the effectiveness of the product of the invention.
    Example 1: Synthesis of the compounds of formula (I)
    Compounds 1 to 3
    The synthesis of N, N-dialkyl 7,7'-diazaisoindigo (Scheme 1) was carried out by alkylating a mixture of 7,7'-diazaisoindigo (25 mg, 0.09 mmol), 1iodoalkane (0, 21 mmol) and K2CO3 (39.2 mg, 0.28 mmol) in 2 ml dimethylformide (DMF) was heated at 100 ° C between 16-18 hours. The red solution was dissolved in CH2Cl2, washed with water, and dried with anhydrous MgSO4. The solvent was evaporated and the residue
    35 was chromatographed on silica gel to give a red solid.

    Scheme 1
    Compound 1: R = C8H17 (E) -1,1'-dioctyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H) -dione (1) : Chromatographic column (hexane: acetone, 5: 1); yield: 65%, 1H NMR (200 MHz, CDCl3,)
    10  9.46 (dd, J = 8 Hz, J = 1.4 Hz, 2H) 8.24 (dd, J = 5.1Hz, J = 1.4 Hz, 2H), 7.02 (dd, J =
    5.1 Hz, J = 7.8 Hz, 2H), 3.90 (t, J = 7.5Hz, 4H), 1.76 (m, 4H), 1.24 (m, 20H), 0.87 (t, J = 6.5Hz, 6H); 13C NMR (50 MHz, CDCl3)  167.6, 157.7, 150.2, 137.5, 132.3, 118.4, 116.1, 39.4, 31.8, 29.2, 29.2, 27.8, 27.0, 22.6, 14.1; UV-vis (CH2Cl2, 25 ° C) max () 283 (30690), 327 (12034), 477 (5069); MALDI-TOF MS m / z 489 (M +); HRMS (MALDI-TOF)
    15 calculated for C30H40N4O2: 489.3224, found: 489.3240.
    Compound 2: R = C6H13 (E) -1,1'-dihexyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H) -dione (2) : Chromatographic column (hexane: acetone, 3: 1); yield: 55%, melting point: 124-126 ° C;
    20 1H NMR (200 MHz, CDCl3)  9.46 (dd, J = 8 Hz, J = 2Hz, 2H), 8.24 (dd, J = 5.1Hz, J =
    1.6 Hz, 2H), 7.02 (dd, J = 5.1 Hz, J = 7.8 Hz, 2H), 3.90 (t, J = 7 Hz, 4H), 1.76 (m, 4H),
    1.24 (m, 36H), 0.88 (t, J = 6.8Hz, 6H); 13C NMR (50 MHz, CDCl3)  167.6, 157.7, 150.2, 137.5, 132.3, 118.4, 116.1, 39.4, 31.85, 27.8, 26.7, 22.5, 14.01; UV-vis (CH2Cl2, 25 ° C) max () 283 (39478), 327 (15100), 477 (5943); MALDI-TOF MS m / z 433 (M +);
    HRMS (MALDI-TOF) calculated for C26H32N4O2: 433.2598, found: 433.2599.
    Compound 3: R = C4H9 (E) -1,1'-dibutyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H) -dione (3) : Column chromatography (hexane: acetone, 6: 1), yield: 60%, melting point: 176-179 ° C,
    30 1H NMR (200 MHz, CDCl3)  9.45 (dd, J = 8.0 Hz, J = 1.6 Hz, 2H), 8.23 (dd, J = 5.1


    Hz, J = 1.7 Hz, 2H), 7.0 (dd, J = 5.1 Hz, J = 7.9 Hz, 2H), 3.90 (t, J = 7 Hz, 4H), 1.76 (m, 4H), 1.24 (m, 36H), 0.88 (t, J = 6.8Hz, 6H); 13C NMR (50 MHz, CDCl3)  167.6, 157.7, 150.2, 137.5, 132.3, 118.4, 116.1, 39.2, 29.8, 20.2, 13.8; UV-vis (CH2Cl2, 25 ° C) max () 282 (41501), 328 (15861), 477 (6300); MALDI-TOF MS m / z 377 (M +); HRMS
    5 (MALDI-TOF) calculated for C22H25N4O2: 377.1972, found: 377.1988. Compound 4
    The synthesis of N, N-didodecyl 5,5'-dibromo-7,7'-diazaisoindigo (Scheme 2) was carried out by alkylation of 5,5'-dibromo-7,7'-diazaisoindigo (29 mg, 0.07
    10 mmol) by 1-iodododecane (0.04 ml, 0.10 mmol) in the presence of K2CO3 (28.2 mg, 0.20 mmol) in 2 ml of DMF was heated at 100 ° C for 20 h. The red solution was dissolved in CH2Cl2, washed with water, and dried with anhydrous MgSO4. The solvent was evaporated and the residue was chromatographed on silica gel (hexane: dichloromethane, 3: 1) to give a red solid (4) (14 mg, 56%):
    Scheme 2 (E) -5,5'-dibromo-1,1'-didodecyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H)
    20 dione (4): 1H NMR (200 MHz, CDCl3,)  9.65 (d, J = 2.2 Hz, 2H), 8.32 (d, J = 2.2 Hz, 2H), 3.88 (t, J = 7.3 Hz, 4H ), 1.73 (m, 4H), 1.25 (m, 36H), 0.87 (t, J = 6.4 Hz, 6H); 13C NMR (50 MHz, CDCl3)  167.0, 156.4, 151.1, 139.9, 132.2, 117.1, 113.9.39.6, 31.9, 29.6, 29.5, 29.3, 29.3, 27.6, 26.9, 22.7, 14.1; UV-vis (CH2Cl2, 25 ° C) max () 292 (30260), 334 (9963), 502 (2453); MALDI-TOF MS m / z 759 (M +); HRMS (MALDI-TOF)
    25 calculated for C38H55Br2N4O2: 759.2654, found: 759.2670.
    Example 2. Molecular geometries of the above compounds The molecular geometries of the different compounds (1 to 3) in the gas phase were optimized without symmetry restrictions using the functional theory of
    30 density (DFT) using functional B3LYP hybrids and a 6-311 + G ** base set.


    All point energy calculations were performed with the B3LYP / 6311 ++ G level (2d, p), while the vertical transition energies of 3 and N, N-dibutyl isoindigo were calculated with time-dependent DFT (TD -DFT) at the level of theory B3LYP / 6-311 ++ G (2d, p).
    5 The molecular geometry optimized for 3 and N, N-dibutyl isoindigo calculated at the B3LYP / 6-311 + G ** level of the theory, shows that the minimized structures differ in the dihedral angle value (torsion angle between the two fragments aza-oxindole), with 4o and 16o for 3y N, N-dibutyl isoindigo, respectively. The last value for the derivative
    10 of isoindigo is consistent with that observed in the literature for the unsubstituted isoindigo and N, N-dimethil, ~ 15o, indicating the small influence of the N-alkyl chain on the torsion angle (without steric hindrance ) (LA Estrada et al. Macromolecules 2013, 46, 8832-8844; EA Perpète et al. J. Phys. Chem A 2006, 110, 5629-5639.). In the diazaisoindigo compounds, the same behavior was observed,
    15 that is, an insignificant change in the torsion angle in compounds with longer N-alkyl chains, 3rd and 4th for 1 and 2, respectively. Therefore, the diaza substitution in 1 to 3 clearly imposes a flatter structure in the molecule, which is a relevant result due to the small change with respect to the isoindigo counterpart. The dihedral angle in this family of compounds is
    20 governed, basically, by the flattening effect of the πconjugated spine, and by the steric hindrance that forces the system to some rotation around the central double bond. However, the insertion of the N atom should not significantly affect the two previous factors. We are inclined to attribute the change in the dihedral angle to electrostatic attractions between the groups
    25 carbonyl and the H atoms attached to C at position 4 in each of the aza-oxindole moieties. Thus, from the greater electronegativity of the N vs C atom, it is inferred that a partial positive charge on the pyridine fragment must exist on the C atoms due to mesomeric and inductive effects. This behavior can be visualized on the electrostatic potential maps, which describe the energy of
    30 interaction of molecules with a positive point charge. Thus, it was observed in the H atom attached to the C atom in position 4, a more positive potential in 3 compared to N, N-dibutyl isoindigo. So this extra positive charge in 3 must generate an electrostatic attraction with the partial negative charge of the carbonyl group favoring the flat structure of the molecule.


    The isodensity surfaces (0.032 e / bohr3) and the energies of the 3 and N boundary molecular orbitals, N-dibutyl isoindigo, calculated at the B3LYP / 6-311 ++ G level (2d, p) of the theory were determined. The same surfaces were calculated for 1 and 2 where the aza substitution leads to some variation in the energies of the 5 border orbitals (FOEs): thus, both the HOMO or LUMO orbital are stabilized with similar energies, ~ 0.35 eV . This effect is attributed entirely to the electron-giving character of the N atom of the aza-oxindole group, since similar results have been reported in pyridine structures, where no significant changes in the separation between the energies of the HOMO and LUMO orbitals are observed ( D. 10 Chen, et al. J. Mater. Chem. C 2014, 2, 9565-9578). A detailed examination of the CLOA coefficients of the HOMO and LUMO orbitals reveals that the location of these orbitals is almost identical in both molecules. The HOMO orbital is distributed homogeneously over the π-conjugated region (stilbene unit), while the LUMO orbital is preferably located in the oxo-pyrrolidine groups. This configuration denotes a certain intramolecular charge transfer character for the HOMO → LUMO transition, as indicated above for the isoindigo. In 7,7'-diazaisoindigo derivatives, the greater electron donor character of the pyridine group may reinforce the charge transfer nature of the lower energy transition. Finally, the dipole moments of the states were calculated
    20 fundamentals. Interestingly, the 7,7'-diazaisoindigo molecule has an almost zero dipole moment (~ 0.02 D) as opposed to the value obtained for N, N-dibutyl isoindigo (0.6 D), which coincides well with the reported for N, N-dimethyl isoindigo (~ 0.5 D). This result is explained by the different dihedral angle in the two molecules.
    25 Calculations were made using TD-DFT at the level B3LYP / 6-311 ++ G (2d, p) of the theory, to investigate vertical transitions to excited states. 3 presents two vertical transitions centered at 3.85 and 2.59 eV with oscillator forces of 0.51 and 0.16, respectively. The transition of less energy is fundamentally HOMO
    → LUMO (89%), while the one with the highest energy is HOMO-2 → LUMO (70%).
    30 In the case of N, N-dibutyl isoindigo, there are three vertical transitions at 3.48, 3.18 and 2.47 eV with oscillator forces of 0.54, 0.12 and 0.10, respectively. While the transition of lower energy is clearly HOMO → LUMO (85%) as for 3, the other two are mixed configurations with transitions of an electron from HOMO-2
    → LUMO and HOMO-3 → LUMO. The results for N, N-dibutyl isoindigo coincide very well with those reported for N, N-dimethyl isoindigo.


    Example 3. Photophysical studies A. Absorption and emission in steady state
    The 7,7'-diazaisoindigo compounds of the invention have a rich photophysical activity characterized by strong absorption in the UV-visible region. Then,
    5 The photophysics of the 7,7'-diazaisoindigo compounds, in particular of the compounds 1 to 3, is analyzed in different solvents by means of the use of stationary and temporal resolution spectroscopic techniques, making a rational comparison with the behavior of isoindigo .
    10 FIG. 2A shows the normalized UV-vis absorption spectra (at λ = 284 nm) of the three molecules studied in CCl4 (5x10-5 M). The spectra clearly resemble being the same for all three molecules - the same occurs in solvents with increasing polarity CH2Cl2, EtOH (ethanol) and ACN (acetonitrile) - which demonstrates that the length of the secondary alkyl chains does not influence the absorption properties of the
    15 π-conjugate system. In the spectra, three absorption bands are observed, centered at λmax = 284, 329 and 477 nm, the latter being wider than the other two. The isoindigo also has three absorption peaks in similar positions, although the second peak is more displaced towards higher wavelengths, λ ~ 395 nm
    (P. W. Sadler et al. Spectrochim. Acta, 1960, 16, 1094-1099). The coefficients of
    20 extinction (ε) for absorption peaks in CCl4 are ε = 2700, 6700 and 17600 L · mol1 · cm-1 at the values of λmax, in the sense of low to high energy, values that are comparable to those obtained for the isoindigo. Calculations using the theory of functional time-dependent density (TD-DFT) correctly predict the position and strength of the two low energy absorption peaks (λmaxteor = 322 and 479
    25 nm), with the broadband, shifted towards red and exhibiting load transfer character, and the central band assigned to local electronic transitions. On the other hand, the absorption spectra for the three molecules in different solvents were also measured, where it was observed that there are almost no changes in the shape and in the maximum of the absorption peaks with the increase of the
    30 polarity of solvents: CCl4 (ε = 2.24), toluene (ε = 2.38), CH2Cl2 (ε = 8.93), cyclohexanol (ε = 15.0), EtOH (ε = 24.5) and ACN (ε = 37.5). Only 4 nm blue shifts were found for the low energy peak in EtOH and ACN, which coincides perfectly with the almost zero value of the dipole moment of these molecules in the fundamental state. This behavior is comparable to that of
    35 isoindigo and derivatives, although slightly more intense changes were observed in


    its absorption spectra due to the higher value of the dipole moment (0.5-0.6 D)
    (S. Lunák Jr et al. Dyes and Pigments 2010, 85, 171-176).
    FIG. 2B shows the emission spectra of 2 in CCl4 under excitation in the
    5 maxima of the three absorption peaks, λexc = 280, 330 and 475 nm. The shape of the emission band is the same independent of the excitation wavelength and is centered at λmax = 645 nm. The same behavior (λmax and shape) was observed for the other two molecules with shorter and longer N-alkyl chains, 1 and 3, which again indicates the small influence of the side chains on the photophysics of the
    10 molecules It is noteworthy that, as opposed to the evident emission band in our molecules, the isoindigo is not fluorescent. However, the quantum fluorescence yield is rather low (lufluor = 0.003 for 2 in CCl4), which reveals that this radiative process is not the main deactivation mechanism of the excited state. Recently, it has been reported that the 6,6'-isoindigo derivative
    15 has weak emission peaks around 675 nm in toluene (lufluor <0.001). These last peaks are very wide, confirming that both emission signals (1-3 and 6,6'-isoindigo) can develop from similar excited states and share similar deactivation pathways. Fig. 2B also shows the excitation spectrum of 2 at λem = 650 nm, where three peaks are observed that
    20 fit perfectly those observed in the absorption spectrum. The latter indicates that the highest excited states (S2 and S3) associated with the two high energy absorption peaks (λabs = 284 and 329 nm) are deactivated through internal conversion to the state of charge transfer (S1). However, the relative intensity of the peaks in the excitation spectrum is different from that found in the spectrum of
    25 absorption, with a lower intensity of the two high energy peaks. This behavior indicates that the quantum yield for internal conversion is not 100% and that the higher excited states are partially deactivated through other mechanisms.
    In order to investigate the deactivation mechanism of the first excited singlet state (S1), emission spectra were also measured in solvents with increasing polarity. FIG. 3A shows these spectra for 2 in seven solvents, after excitation in the maximum of the low energy band, λexc = 475 nm. It is noteworthy that there is a good correlation between signal strength and polarity
    35 of the solvent. The higher the dielectric constant of the solvent, the lower the emission peak. The same relationship was also found with the other two molecules,


    1 and 3. However, one of the solvents used had a higher viscosity compared to the others, cyclohexanol (η = 57.5 cP). The emission spectrum in this solvent did not follow the pattern of correlation with the polarity of the solvent. Indeed, the intensity of the emission spectrum of 2 in cyclohexanol is greater than in anisole, despite the fact that the dielectric constant is ~ 4 times smaller for the second solvent (ε = 15.0 vs. 4.33). This behavior suggests the presence of a deactivation step (non-radiative process) that is influenced by the high viscosity solvents. The molecular structure of these compounds, and that of their isoindigo counterparts, resemble that of trans-stilbene, which is a model system (along with 10 ethylene) in the study of cis-trans photoisomerization. The relaxation dynamics of trans-stilbene can provide us with some indications that explain the extinction of fluorescence in the 7,7'-diazaisoindigo derivatives. In particular, the main route of deactivation of the excited state in trans-stilbene is a non-radiant process through a conical intersection (CI) that involves twisting the double bond, followed by the pyramidalization of one of the carbon atoms ethylenic (J. Quennville et al. J. Phys. Chem A 2003, 107, 829-837). Therefore, the improvement of the fluorescence signal from 1 to 3 in cyclohexanol could be explained how because the high viscosity slows the rearrangement of the bonds (non-radiative deactivation). On the other hand, the sharp decrease in the fluorescence signal at
    20 increasing the polarity of the solvent can be attributed to the existence of intramolecular electron transfer processes linked to the rearrangement of the bonds. The energy barrier required to achieve IC is reduced by increasing the polarizability of solvents, accelerating this non-radiant process.
    In addition to the decrease in intensity with solvent polarity, the emission spectra show a wavelength shift of the maximum absorption (λmax). FIG. 3B shows the normalized emission spectra for 2 illustrating the spectral shifts of this molecule as a function of the solvent. It is worth noting that the shape of the spectra is maintained in all
    30 solvents, which rules out the appearance of a new spectral component. A thorough inspection of the spectra shows a redshift of λmax as polarity increases, from λmax = 650 to λmax = 719 nm, when switching from toluene to ACN. The same trend is observed in the other two molecules, 1 and 3. The Lippert-Mataga equation was used to explain the general interactions between fluorophore and
    35 the solvent, representing the displacement of Stokes (∆ν) vs. to the orientation of polarizability (∆f), which is a factor that includes changes in the index of


    refraction and in the dielectric constant of the solvents. FIG. 3C shows a good linear correlation of these two parameters (correlation coefficient, r = 0.94 for 2). On the other hand, the slope of the adjustment (3.9 ± 0.8 x 103 cm-1 for 2) is relatively high, indicating a strong change in the dipole moment after the
    5 excitation. Thus, if it is assumed that the radius of the cavity is, a = 4 Å, which is reasonable considering the dimensions of the molecules, it is possible to calculate the dipole moment of the excited state, μe ≈ 5.0 D. In fact , theoretical calculations showed the intramolecular charge transfer character of the first excited state (S1), which explains the great value of the dipole moment in the excited state. B. Fluorescence with temporary picosecond resolution
    To obtain more information on the photophysics of the three previous molecules, the kinetics of the different deactivation states have been studied by emission spectroscopy with temporal resolution of PS. Table 1 shows the times
    15 fluorescent life ( obtained from monoexponential adjustments of the emission signal for the three molecules in the seven solvents used.
    Table 1. Fluorescence life times obtained by monoexponential adjustments of the experimental data for the three molecules studied in the seven
    20 solvents λexc = 440 nm. The parameters of the solvents are also provided (Dielectric constant, , Lippert-Mataga solvent polarity parameter f, and viscosity at 20 ° C).
    2nd 2b2 CSolvent propertiesof the
    Solvent ps / ps / psf / cp
    CCl4 1051171142.240.0110.91
    Toluene 7086842.380.0130.56
    Anisole 6359564.330,1101.05
    CH2Cl2 <40<40<408.930.2170.41
    Cyclohexanol 535254fifteen0.23057.5
    EtOH <40<40<4024.50.2891.07
    ACN <40<40<4037.50.3050.37


    There is a good correlation between life times and the polarizability orientation parameter (∆f). For example, in 2, credecreases from 117 to 86 and 59 ps, in CCl4, toluene and anisole, respectively. In the more polar solvents, CH2Cl2, EtOH and ACN, the life times are much shorter (<40 ps), below the limit of detection of the instrument. In addition, in cyclohexanol the values of  are similar to those obtained in anisole (for example 54 vs. 56 ps for 3), although ∆f is double. This is attributed again to the high value of the viscosity of cyclohexanol (η = 57.5 vs. 1.05 cp in anisole), which hypothetically slows the twisting of the double bond after excitation. With all these arguments in mind, it is understood that there are 10 two main mechanisms for deactivating the excited state (S1): the deactivation of radiation through fluorescence emission and internal conversion through a reorganization of the bonds, possibly to through a twist of the double bond. The possibility of crossing between systems has been explored by conducting experiments with singlet oxygen, but the
    15 phosphorescence emission at 1270 nm. Thus, the kinetic velocity constants for both deactivation pathways (kfl and kIC), are determined using the classical equations (1) and (2), and are shown in Table 2. = ∅� (1)
    = −� (2)
    20 Table 2. Photophysical properties of 2 in the 7 solvents analyzed. Tª = 25ºC.
    Solvent Φfl104 / pskfl10-7 / s-1kIC10-10 / s-1
    CCl4 281172.40.8
    Toluene 14861.61.2
    Anisole 6.6591.11.7
    CH2Cl2 4.6<40> 1.1> 2.5
    Cyclohexanol 8.4521.31.9
    EtOH 3.1<40> 0.8> 2.5
    ACN 2.3<40> 0.6> 2.5


    First, instead, the kfl values are very similar for the different solvents, which confirms that the properties of the solvent do not affect the radiative deactivation. Secondly, there is a clear increase in the kfl value by increasing the polarity of the solvent which can be explained how due to the decrease in the activation energy, since the polar solvents stabilize the torsion state of charge transfer. In stilbene, the rearrangement of the bonds causes a photoisomerization of the molecule, which ultimately ends in the more stable trans photoisomer. On the other hand, it has been reported as similar indole-based molecules, capable of rotating through a central double bond, they can undergo photoisomerization, analyzing inverse kinetics with transient absorption techniques (G by Miguel et al. Phys. Chem Chem. Phys. 2012, 14, 1796-1805). Thus, flash photolysis measurements were made for the three 7,7'-diazaisoindigo molecules, in order to investigate the formation of long-lived species, in particular, the photoisomers. However, no signal was detected in the time range of the
    15 nano to the millisecond, which indicates that the torsion state must be quickly deactivated to the fundamental state through the possible conical intersection.
    Next, a particular analysis was carried out to compare the lifetime of the emissions in the 7,7-diazaisoindigo molecules with those observed in the isoindigo and derivatives. The absence of fluorescence emission in the isoindigo was provisionally attributed to a particularly rapid non-radiative deactivation pathway due to the analogy with trans-stilbene (fl = 79 ps in hexane). In 1 to 3, the existence of fluorescence with relatively long life times is a key factor that differentiates it from isoindigo. From a structural point of view, and due to
    25 that N-alkyl chains do not alter the time of life, it is inferred that aza groups must exert a significant influence on the non-radiant process, assuming constants of similar velocity for the radiative process.
    Finally, the deceleration of the non-radiative process in the 7,7'-diazaisoindigo is
    30 relevant to the applications of the chromophores of the isoindigo family. For example, in dye-sensitized solar cells, the quantum performance of the electron injection reaction is strongly dependent on the kinetics of non-radiative processes, since electron injection (PS time scale) competes with other mechanisms of deactivation. It has been shown a
    35 longer fluorescent life in the 7,7'-diazaisoindigo derivatives, due to the fine adjustment of the energies of the orbitals through the insertion of the aza structure


    in the isoindigo nucleus. In this way, the slower non-radiative process in 1, 2 and 3 would facilitate electron separation reactions in organic solar cells compared to isoindigo-based devices.

    权利要求:
    Claims (11)
    [1]
    1. Use of a compound of general formula (I)
    (I)
    where: Y is selected from CH2, O, NH, C (O), S, S (O), NHC (O) and (O) CNH; R1 is a C1-C16 alkyl; and 10 R2 is selected from hydrogen, halogen and one of the following groups:
    where R is a C1-C16 alkyl group,
    or any of its isomers, as a component for the manufacture of solar cells.
    [2]
    2. Use according to claim 1, wherein R2 is hydrogen.
    [3]
    3. Use according to claim 1, wherein R2 is a halogen. twenty
    [4]
    Four. Use according to claim 3, wherein R2 is bromine.
    [5]
    5. Use according to any one of claims 1 to 4, wherein Y is CH2.
    Use according to any one of claims 1 to 5, wherein R1 is a C3-C11 alkyl.

    [7]
    7. Use according to claim 1, wherein the compounds are selected from: (E) -1,1'-dihexyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H , 1'H) -dione, (E) -1,1'-dibutyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H) -dione, (E) -1,1'-dioctyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H) -dione and
    5 (E) -5,5'-dibromo-1,1'-didodecyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H) -dione.
    [8]
    8. Use according to any of claims 1 to 7, wherein the solar cells are organic photovoltaic cells.
    10 9. Compound of general formula (I)
    (I)
    where: Y is selected from CH2, O, NH, C (O), S, S (O), NHC (O) and(O) CNH;R1 is a C1-C16 alkyl; YR2 is selected from halogen and one of the following groups:
    Where R is a C1-C16 alkyl group,
    or any of its isomers.
    [10]
    10. Compound according to claim 9, wherein R2 is a halogen. 11. A compound according to claim 10, wherein R2 is bromine.
    [12]
    12. Compound according to any of claims 9 to 11, wherein Y is CH2.

    [13]
    13. Compound according to any of claims 9 to 12, wherein R1 is a C3-C11 alkyl.
    14. A compound according to claim 9, wherein the compound is (E) -5,5'-dibromo1,1'-didodecyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 ' (1H, 1'H) -diona.
    [15]
    15. Compound of general formula (I) as described in claim 1
    selected from (E) -1,1'-dihexyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H) 10 dione and (E) -1, 1'-dibutyl- [3,3'-bipyrrolo [2,3-b] pyridinylidene] -2,2 '(1H, 1'H) -dione.

    FIG. one
     Wavelength / nm
    300 400 500 600 700
     Wavelength / nm
     FIG. 2

    Emission intensity / u.a.
     0.00
     Wavelength / nm

    g
     0.0 0.1 0.2 0.3
    f
    FIG. 3 (cont.)
    类似技术:
    公开号 | 公开日 | 专利标题
    ES2625021B1|2018-05-03|DERIVATIVE COMPOUNDS 7,7`-DIAZAISOINDIGO AND ITS USES
    Li et al.2015|From Dark TICT State to Emissive quasi-TICT State: The AIE Mechanism of N-| phenyl)-4-tert-butylbenzamide
    Huckaba et al.2016|Molecular Design Principles for Near‐Infrared Absorbing and Emitting Indolizine Dyes
    US6207831B1|2001-03-27|Fluorescent dyes | for solid phase and solution phase screening
    Nayak2012|Synthesis, characterization and optical properties of aryl and diaryl substituted phenanthroimidazoles
    Zhan et al.2016|Aggregation-induced emission and reversible mechanochromic luminescence of carbazole-based triphenylacrylonitrile derivatives
    de Miguel et al.2016|7, 7′-Diazaisoindigo: a novel building block for organic electronics
    CN108780852B|2020-12-15|Luminescent compounds
    Espinoza et al.2016|Nitropyrene photoprobes: making them, and what are they good for?
    Gong et al.2014|Balanced π–π interactions directing the self-assembly of indolocarbazole-based low molecular mass organogelators
    Dos Santos et al.2017|Theoretical-experimental photophysical investigations of the solvent effect on the properties of green-and blue-light-emitting quinoline derivatives
    Singh et al.2019|The design and synthesis of 2, 3-diphenylquinoxaline amine derivatives as yellow-blue emissive materials for optoelectrochemical study
    Zhang et al.2019|BODIPY parent compound: fluorescence, singlet oxygen formation and properties revealed by DFT calculations
    Jiang et al.2018|J-Aggregation induced emission enhancement of a thienyl substituted bis |-1, 2-bis | methylene) hydrazine | dye
    Guzow et al.2013|Photophysical properties of 3-[2-| benzoxazol-5-yl] alanine derivatives—experimental and theoretical studies
    Huang et al.2021|A facile design of azaanthracene derivatives: ACQ–AIE conversion and blue-shifted mechanofluorochromic emission
    Zhou et al.2020|Bicarbazole‐based oxalates as photoinitiating systems for photopolymerization under UV–Vis LEDs
    Yuan et al.2012|Symmetrical and asymmetrical | branched truxene compounds: Structure and photophysical properties
    Zhang et al.2018|Two-photon absorption and mechanofluorochromic properties of 1, 4-diketo-2, 5-dibutyl-3, 6-bis | phenyl) pyrrolo [3, 4-c] pyrrole
    Qiu et al.2021|Vibratile Dihydrophenazines with Controllable Luminescence Enabled by Precise Regulation of π-Conjugated Wings
    Kurdyukova et al.2017|Synthesis and spectral properties of near-IR polymethine dyes derived from tris |-9H-fluorene-2, 4, 7-trisulfonate
    Komskis et al.2019|Suppression of Charge Transfer States in Aryl-Substituted 9, 9′-Bianthryl Derivatives
    Hao et al.2014|Synthesis, optical, and electrochemical properties of 2, 3-diphenyl-10H-indeno [1, 2-g] quinoxaline, 15H-dibenzo [a, c] indeno [1, 2-i] phenazine, and 15H-indeno [1, 2-i] phenanthro [4, 5-abc] phenazine derivatives
    Hwang et al.2019|Fluorescence Quenching of 4, 4′-Dimethoxytriphenylamine-Substituted Diketopyrrolopyrrole via Intramolecular Photoinduced Electron Transfer
    Wang et al.2021|Precise Regulation of Distance between Associated Pyrene Units and Control of Emission Energy and Kinetics in Solid State
    同族专利:
    公开号 | 公开日
    ES2625021B1|2018-05-03|
    WO2017103318A1|2017-06-22|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    CN103159926A|2011-12-09|2013-06-19|海洋王照明科技股份有限公司|Isoindigo based co-polymer organic semiconductor material, and preparation method and application thereof|
    KR20150002216A|2013-06-28|2015-01-07|광주과학기술원|Isoindigo derivative based compounds, methods for manufacturing the same, and soluble-processed organic photovolatic devices comprising the same|ES2600305B1|2015-07-06|2017-11-24|Consejo Superior De Investigaciones Científicas |ORGANOGEL BASED ON MOLECULES DERIVED FROM 7,7'-DIAZAISOINDIGO|
    CN107739374B|2017-10-27|2019-12-17|武汉工程大学|Organic solar cell receptor material and preparation method thereof|
    ES2718418B2|2017-12-29|2019-10-31|Consejo Superior Investigacion|DERIVATIVES OF 7,7'-DIAZAINDIGO AND ITS USES|
    法律状态:
    2018-05-03| FG2A| Definitive protection|Ref document number: 2625021 Country of ref document: ES Kind code of ref document: B1 Effective date: 20180503 |
    优先权:
    申请号 | 申请日 | 专利标题
    ES201531835A|ES2625021B1|2015-12-18|2015-12-18|DERIVATIVE COMPOUNDS 7,7`-DIAZAISOINDIGO AND ITS USES|ES201531835A| ES2625021B1|2015-12-18|2015-12-18|DERIVATIVE COMPOUNDS 7,7`-DIAZAISOINDIGO AND ITS USES|
    PCT/ES2016/070905| WO2017103318A1|2015-12-18|2016-12-16|7,7'-diazaisoindigo derivative compounds and uses thereof|
    [返回顶部]