Rational Design of Star-shaped Molecules with Benzene Core and Naphthalimide Derivatives End Groups as Organic Light-emitting Materials

Li-Ping ZHANG Wan-Dong CHAI Rui-Fa JIN

Citation:  ZHANG Li-Ping, CHAI Wan-Dong, JIN Rui-Fa. Rational Design of Star-shaped Molecules with Benzene Core and Naphthalimide Derivatives End Groups as Organic Light-emitting Materials[J]. Chinese Journal of Structural Chemistry, 2016, 35(12): 1811-1818. doi: 10.14102/j.cnki.0254-5861.2011-1319 shu

Rational Design of Star-shaped Molecules with Benzene Core and Naphthalimide Derivatives End Groups as Organic Light-emitting Materials

    通讯作者: , Ruifajin@163.com

English

  • Organic light-emitting diodes (OLEDs) have received considerable interest in recent years due to their potentially low cost, light weight, capability of thin-film, large-area, flexible device fabrication, and wide selection of emission colors via molecular design of organic materials[1-3]. Unfortunately, most OLEDs emitters are still not satisfactory. The lower efficiency of OLEDs is a thorny obstacle to the application of efficient light-emitting devices. Therefore, the design and synthesis for new emitting materials with high efficiency and thermal stability remain one of the most active areas of studies. A number of studies demonstrate that the interplay between theory and experiment is capable of providing useful insights into the understanding of the nature of molecules[4-6]. Among various kinds of OLEDs materials, 1, 8-naphthalimide (NI) derivatives usually exhibit strong fluorescence and good photostability[7-9]. They have been widely used as the most important materials for the fabrication of OLEDs[10, 11]. Furthermore, a large variety of auxochromic groups in NI derivatives may be easily grafted to fine tune the absorption and emission wavelengths. Naphthalimides comprise a class of fluorophores whose electronic absorption and emission depend upon the properties of surrounding medium. The emission spectrum can be tuned by introducing different electron-donating substituent groups, such as N-substituted groups[12], C-substituted groups[13], and O-substituted groups[14]. Substitution of electron-donating groups usually increases the intensity of fluorescence emission, particularly when a methoxy or amino group at the C-4 position is used. Recently, some starburst amorphous molecules 1, 3, 5-tris (1, 8-naphthalimide-4- yl) benzenes have been reported[15]. It was found that the devices using these molecules performances are better than using the most prevalent tris (8-quinolinato) aluminum (Alq3) as a counterpart.

    With the above considerations, in this work, we investigated a series of star-shaped molecules with benzene as core and NI derivatives as end groups for OLEDs applications. An in-depth interpretation of the optical and electronic properties of these compounds has been presented. Several derivatives (1~6), as shown in Fig. 1, have been designed to provide a demonstration for the rational design of novel luminescent and charge transporting materials for OLEDs.

    Figure 1

    Figure 1.  Geometries of designed molecules 1~6

    All calculations have been performed using Gaussian 09 code[16]. Generally, the B3LYP method appeared notably adapted to the NI derivatives[17-19]. Therefore, the geometry optimizations of designed molecules in ground states (S0) were carried out by the B3LYP method using the 6-31G (d, p) basis set. The corresponding geometry in the first excited singlet state (S1) was optimized using TD-B3LYP with the 6-31G (d, p) basis set. The harmonic vibrational frequency calculations using the same methods as for the geometry optimizations were used to ascertain the presence of a local minimum. The absorption and fluorescent properties of 1~6 have been predicted using the TD-B3LYP/6-31G (d, p) method based on the S0 and S1 optimized geometries, respectively. To investigate the influence of solvents on the optical properties for the S0 and S1 states of the molecular systems in chloroform (dielectric constant: 2.0906) solvent, we performed the polarized continuum model (PCM)[20] calculations at the TD-DFT level.

    The stability is a useful criterion to evaluate the nature of devices for charge transport and luminescent materials. To predict the stability of 1~ 6 from a viewpoint of conceptual density functional theory, the absolute hardness, η, of 16 was calculated using operational definitions[21, 22] given by:

    $\eta =\frac{1}{2}\left( \frac{\partial \mu }{\partial N} \right)=\frac{1}{2}\left( \frac{{{\partial }.{2}}E}{\partial {{N}.{2}}} \right)=\frac{IP-EA}{2}$ $

    where μ is the chemical potential and N is the total electron number. In this work, the values for IP (adiabatic ionization potential) and EA (adiabatic electron affinity) were determined according to the equation IP = Ecr - Ep and EA = Ep - Ear, where p, cr, and ar indicate the parent molecule and the corresponding cation and anion radical generated after electron transfer.

    To characterize the optical transitions and the abilities of electron and hole transport, it is useful to examine the frontier molecular orbitals (FMOs) of the compounds under investigation. The origin of geometric difference introduced by excitation can be explained, at least in qualitative terms, by analyzing the change in bonding character of the orbitals involved in electronic transition for each pair of the bonded atoms. An electronic excitation results in some electron density redistribution that affects the molecular geometry[23]. We calculated the distribution patterns of FMOs for 1~6 in S0 (Fig. 2). The total and partial densities of states (TDOS and PDOS) on each fragment of the investigated molecules around the HOMO-LUMO gaps were calculated based on the current level of theory. The FMOs energies EHOMO and ELUMO, HOMO-LUMO gaps Eg, and the contributions of individual fragments (in %) to the FMOs of 1~6 are given in Table 1. As shown in Fig. 2, the S0S1 excitation process can be mainly assigned to the HOMOs → LUMOs and HOMOs-1 → LUMOs transitions, which correspond to a π-π* excited singlet state. For 1, 2, and 5, the HOMOs are distributed on the NI moieties, with minor contributions from benzene (BZ) and N-substituent groups (SG). The contributions of NI fragments of HOMOs are larger than 83.8%, while the corresponding sum contributions of BZ and SG fragments are within 16.2%, respectively. For 3 and 6, the HOMOs are mainly localized on the SG fragments with only minor contributions from NI and BZ fragments. The contributions of SG fragments of HOMOs are larger than 95%, while the corresponding sum contributions of NI and BZ fragments are within 4.9%, respectively. For 4, the HOMOs are distributed on the NI and SG fragments, with minor contributions from the BZ fragment. However, the LUMOs of 1~ 6 are mainly composed of contributions of NI, with minor contributions from SG and BZ fragments. The contributions of NI fragments of LUMOs are larger than 92.6%, while the corresponding sum contributions of SG and BZ fragments are within 7.4%, respectively.

    Figure 2

    Figure 2.  Electronic density contours of the frontier molecular orbitals for investigated derivatives

    The distribution patterns of FMOs also provide a remarkable signature for the charge-transfer character of vertical S0S1 transition. Analysis of FMOs indicates that the excitation of electron from HOMOs to LUMOs leads the electronic density to flow mainly from the SG and BZ fragments to the NI fragments for 1, 2, 4, and 5. The percentages of charge transfer are the differences between the contributions of fragments for LUMOs and the corresponding contributions for HOMOs in the compounds under investigation. The percentages of charge transfer from SG and BZ fragments to the NI fragments of 1, 2, 4, and 5 are 7.2, 8.2, 39.2, and 9.1%, respectively. On the contrary, for 3 and 6, the excitation of the electron from HOMOs to LUMOs causes the electronic density to flow mainly from SG fragments to the BZ and NI fragments. The percentage of charge transfer of 3 and 6 is 95.1 and 98.1%, respectively.

    Another way to understand the influence of optical and electronic properties is to analyze the EHOMO , ELUMO, and Eg values. From Table 1, one can find that the EHOMO values of 2, 4, and 5 decrease, while the corresponding values of 3 and 6 increase compared with that of 1. The HOMOs energies are in the order of 3 > 6 > 1 > 2 > 5 > 4. It suggests that the localization of HOMOs mainly on the SG fragments leads to larger EHOMO values, while the corresponding localization of HOMOs mainly on the NI fragments has smaller EHOMO values than that of 1, respectively. However, the values of EHOMO for 26 decrease compared with that of 1. The sequence of EHOMO values is 1 > 2 > 5 > 3 > 6 > 4. One can find that the contributions of NI fragments of LUMOs for molecules under investigation are larger than that of 1 except the corresponding contribution of 2 is almost equal to that of 1. It indicates that the localization of LUMOs mainly on the NI fragments has smaller EHOMO values than that of 1. Thus, the Eg values for 36 decrease compared with that of 1 while the Eg value of 2 is larger than that of 1 slighly. The Eg values are in the order of 2 > 1 > 5 > 4 > 3 > 6. It implies that the introduction of different donor groups to 1 leads to the change of EHOMO , ELUMO, and Eg values for its derivatives. The absorption and fluorescence spectra can be tuned by donor groups, providing a powerful strategy for the prediction of optical properties of novel electroluminophores.

    Table 1

    Table 1.  Calculated EHOMO , ELUMO, Eg (All in eV), and HOMOs and LUMOs Co ntributions (%) of 1~6
    DownLoad: CSV
    SpeciesHOMOLUMOELUMONIaBZbSGcELUMONIBZSGEg1–6.53585.514.40.1–2.68692.77.303.8496–6.4401.90.198.1–2.86692.97.103.574
    2–6.54084.414.21.4–2.68792.67.403.853
    3–6.4104.9095.1–2.77493703.636
    4–6.81153.68.537.9–3.02492.86.90.23.787
    5–6.59083.813.42.8–2.74292.96.90.23.848
    a NI: 1, 8-naphthalimide moieties; b BZ: benzene moieties; c SG: substituent groups

    The absorption λabs and fluorescence λfl wavelengths, main assignments, and the oscillator strength f for the most relevant singlet excited states in each molecule are listed in Tables 2 and 3, respectively. The λabs and λfl values of 1 are all in agreement with the experimental results[15]. The deviations are 5 and 25 nm, respectively. The Stokes shift of 1 is 36 nm, which is comparable to the experimental 66 nm. Thus, this result credits to the computational approach, so appropriate electronic transition energies can be predicted at these levels for this kind of system.

    Table 2

    Table 2.  Absorption Wavelengths λabs (in nm), the Oscillator Strength f, and Main Assignments (CI Expansion Coefficient) of 1~6 in Chloroform, along with Available Experimental Data
    DownLoad: CSV
    SpeciesλabsfAssignment13650.85HOMO–1→LUMO(0.70)Expa360
    HOMO–1→LUMO+2(0.12)
    23650.62HOMO→LUMO(–0.31)
    HOMO→LUMO+1(–0.32)
    HOMO–1→LUMO(0.43)
    33650.52HOMO→LUMO(0.60)
    HOMO→LUMO+2(0.14)
    43700.6HOMO→LUMO(0.59)
    HOMO→LUMO+2(0.12)
    53650.57HOMO→LUMO(0.58)
    HOMO→LUMO+1(0.17)
    63680.59HOMO→LUMO(0.45)
    HOMO→LUMO+1(0.20)
    HOMO→LUMO+2(0.22)
    a Experimental data for 1 in chloroform were taken from ref. [15].

    Table 3

    Table 3.  Fluorescence Wavelengths λfl (in nm), the Oscillator Strength f, and Main Assignments (CI Expansion Coefficient) of 1~6 in Chloroform, along with Available Experimental Data
    DownLoad: CSV
    SpeciesλflfAssignment14010.76LUMO+1→HOMO(0.55)Expa426
    LUMO→HOMO–1(–0.43)
    23990.83LUMO+1→HOMO(–0.49)
    LUMO→HOMO–1(0.49)
    34060.52LUMO→HOMO–1(0.67)
    LUMO→HOMO–2(0.14)
    44280.59LUMO+4→HOMO(0.47)
    LUMO+3→HOMO(0.34)
    54090.7LUMO+5→HOMO(0.56)
    LUMO→HOMO–1(–0.40)
    64540.5LUMO+1→HOMO(–0.41)
    LUMO→HOMO–1(0.67)
    a Experimental data for 1 in chloroform were taken from ref. [15].

    For the absorption spectra, the excitation to the S1 state corresponds mainly to the HOMO-1 → LUMO for 1, while the corresponding excitations for 2~6 correspond mainly to the HOMOs → LUMOs and HOMOs → LUMOs+1 and/or HOMOs → LUMOs+2. From Table 2, one can find that the λabs values of 2~6 are almost equal to that of 1. It suggests that the substituent effects do not significantly affect the absorption spectra of 2~6 compared with that of 1. Moreover, 2~6 have nearly equal values of oscillator strengths, being smaller slightly than that of 1. The oscillator strength for an electronic transition is proportional to the transition moment[24]. In general, larger oscillator strength corresponds to larger experimental absorption coefficient or stronger fluorescence intensity. This implies that these bipolar molecules show large absorption intensity.

    For the fluorescence spectra, the LUMO+1→ HOMO and LUMO → HOMO-1 excitations play a dominant role for 1. The fluorescence peaks of 2, 3, and 5 mainly correspond to LUMOs → HOMOs-1 excitations. As shown in Table 3, the λfl value of 2 is almost equal to that of 1, while the λfl values of 3~6 show bathochromic shifts of 5, 27, 8, and 53 nm compared with that of 1, respectively. The Stokes shifts of 3~6 are 41, 58, 44, and 86 nm, respectively. Furthermore, the f values for 2~6 are almost equal to that of 1, corresponding to strong fluorescence spectra. This implies that 2~6 have large fluorescent intensity and they are promising luminescent materials for OLEDs. As shown in Table 3, it clearly shows that the substituent groups can affect the fluorescence spectra of these molecules. The emission color of the molecules can be tuned by the N-substituent groups. Furthermore, all the substituted derivatives show stronger fluorescence intensity.

    The charge transfer rate can be described by Marcus theory[25, 26] via the following equation:

    $K=\left( {}.{{{V}.{2}}}\!\!\diagup\!\!{}_{\eta }\; \right){{\left( {}.{\pi }\!\!\diagup\!\!{}_{\lambda {{K}_{B}}T}\; \right)}.{{}.{1}\!\!\diagup\!\!{}_{2}\;}}\exp \left( {}.{-\lambda }\!\!\diagup\!\!{}_{4{{K}_{B}}T}\; \right)$ $

    where T is the temperature, kB is the Boltzmann constant, λ represents the reorganization energy due to the geometric relaxation accompanying charge transfer, and V is the electronic coupling matrix element (transfer integral) between the two adjacent species dictated largely by orbital overlap. It is clear that two key parameters are the reorganization energy and electronic coupling matrix element, which have a dominant impact on the charge transfer rate, especially the former.

    where T is the temperature, kB is the Boltzmann constant, λ represents the reorganization energy due to the geometric relaxation accompanying charge transfer, and V is the electronic coupling matrix element (transfer integral) between the two adjacent species dictated largely by orbital overlap. It is clear that two key parameters are the reorganization energy and electronic coupling matrix element, which have a dominant impact on the charge transfer rate, especially the former.

    For the reorganization energy λ, they can be divided into two parts: external reorganization energy (λext) and internal reorganization energy (λint). λext represents the effect of polarized medium on charge transfer, which is quite complicated to evaluate at this stage. λint is a measure of structural change between ionic and neutral states[27, 28]. Our designed molecules are used as charge transport materials for OLEDs in the solid film; the dielectric constant of the medium for the molecules is low. The computed values of the external reorganization energy in pure organic condensed phases are not only small but also much smaller than their internal counterparts[29, 30]. Moreover, there is a clear correlation between λint and charge transfer rate in literature[31, 32]. Therefore, we mainly study the λint of the isolated active organic π-conjugated systems owing to ignoring the environmental changes and relaxation in this work. Hence, the λe and λh can be defined by equations (3) and (4)[33]:

    ${{\lambda }_{e}}=\left( E_{0}.{-}-E_{-}.{-} \right)+\left( E_{-}.{0}-E_{0}.{0} \right)$ $

    ${{\lambda }_{H}}=\left( E_{0}.{+}-E_{+}.{+} \right)+\left( E_{+}.{0}-E_{0}.{0} \right)$ $

    where E0+ ( E0- ) is the energy of the cation (anion) calculated with the optimized structure of the neutral molecule. Similarly, E++ ( E-- ) is the energy of the cation (anion) calculated with the optimized cation (anion) structure, and E0+ ( E0- ) is that of the neutral molecule calculated at the cationic (anionic) state. Finally, E00 is the energy of the neutral molecule in the ground state. For comparison with the interested results reported previously[34, 35], the reorganization energies for electron (λe) and hole (λ h) of the molecules were calculated at the B3LYP/6-31G (d, p) level on the basis of the single point energy.

    The calculated reorganization energies for hole and electron are listed in Table 4. It is well-known that the lower the reorganization energy values, the higher the charge transfer rate[25, 26]. The results displayed in Table 4 show that the calculated λ e values of 1~6 (0.110~0.180 eV) are larger than that of tris (8-hydroxyquinolinato) aluminum (III) (Alq3) (λ e = 0.276 eV), a typical electron transport material[34]. It indicates that their electron transfer rates might be higher than that of Alq3, suggesting that 1~6 could be good electron transfer materials from the stand point of the λ e values. On the other hand, the calculated λ h values of 2~6 (0.292~ 0.328 eV) are larger than that of N, N′-diphenyl- N, N′-bis (3-methylphenyl)-(1, 1′-biphenyl)-4, 4′-diamine (TPD), which is a typical hole transport material ( λ h = 0.290 eV)[35]. It indicates that their hole transfer rates might be lower than that of TPD. It indicates that 1~6 can be used as promising electron transport materials in OLEDs from the stand point of the smaller reorganization energy.

    Table 4

    Table 4.  Calculated Molecular λ e, λ h, IP, EA, and η (All in eV) of 1~6 at the B3LYP/6-31G (d, p) Level
    DownLoad: CSV
    SpeciesλhλeIPEAη10.1420.156.6571.0022.82760.2840.1226.1760.4442.866
    20.3280.186.3510.6782.837
    30.2920.1567.6032.0232.79
    40.3150.2166.1330.7942.67
    50.3040.116.5340.7492.893

    As the stability is a useful criterion to evaluate the nature of devices for charge transport and luminescent materials, the absolute hardness η is the resistance of the chemical potential to change in the number of electrons. As expected, inspection of Table 4 reveals clearly that the η values of 2~6 are almost equal to that of 1. These results show that different π-conjugated bridges do not significantly affect the stability of these bipolar molecules.

    In this paper, a series of star-shaped molecules with benzene core and naphthalimide derivatives end groups have been systematically investigated. The FMOs analyses have turned out that the vertical electronic transitions of absorption and emission are characterized as intramolecular charge transfer (ICT). The calculated results show that their optical and electronic properties are affected by their substituent groups in N-position of 1, 8-naphthalimide. The study of substituent effects suggest that the λabs values of 2~6 are almost equal to that of the parent compound 1, while the λfl of 2~6 show bathochromic shifts compared with that of 1. Furthermore, 2~6 have large fluorescent intensity. The different substituent groups do not significantly affect the stability of these molecules. Our results suggest that 2~6 are expected to be promising candidates for luminescent materials and electron transport materials for OLEDs.

    1. [1]

      Müllen K, Scherf U. Organic Light-emitting Devices, Synthesis, Properties, and Applications[J]. Wiley-VCH, Weinheim, 2006, :  .

    2. [2]

      Minaev B, Baryshnikov G, Agren H. Principles of phosphorescent organic light emitting devices[J]. Phys. Chem. Chem. Phys, 2014, 16:  1719-1758. doi: 10.1039/C3CP53806K

    3. [3]

      Sasabe H, Kido J. Development of high performance OLEDs for general lighting[J]. J. Mater. Chem. C, 2013, 1:  1699-1707. doi: 10.1039/c2tc00584k

    4. [4]

      Che W. L, Liang W. D, Wang J, Lin G. X, Li G. F, Han C, Cui X. J, Zhu D. X. Synthesis, crystal structure and photoluminescence of triphenylamin derivative[J]. J. Mol. Sci, 2013, 29:  259-264.

    5. [5]

      Han L. Z, Wang C. T, Ren A. M, Liu Y. L, Liu P. J. Structural and optical properties of triphenylamin-substitutef anthracene derivatives[J]. J. Mol. Sci, 2013, 29:  146-151.

    6. [6]

      Jin R, ·Irfan A. Theoretical study on photophysical properties of multifunctional star-shaped molecules with 1,8-naphthalimide core for organic light-emitting diode and organic solar cell application[J]. Theor. Chem. Acc, 2015, 134:  89. doi: 10.1007/s00214-015-1693-8

    7. [7]

      Ramachandram B, Saroja G, Sankaran N. B, Samanta A. Unusually high fluorescence enhancement of some 1,8-naphthalimide derivatives induced by transition metal salts[J]. J. Phys. Chem. B, 2000, 104:  11824-11832. doi: 10.1021/jp000333i

    8. [8]

      Ivanov I. P, Dimitrova M. B, Tasheva D. N, Cheshmedzhieva D. V, Lozanov V. S, Ilieva S. V. Synthesis, structural analysis and application of a series of solid-state fluorochromes-aryl hydrazones of 4-hydrazino-N-hexyl-1,8-naphthalimide[J]. Tetrahedron, 2013, 69:  712-721. doi: 10.1016/j.tet.2012.10.093

    9. [9]

      Li Y, Xu Y, Qian X, Qu B. Naphthalimide-thiazoles as novel photonucleases: molecular design, synthesis, and evaluation[J]. Tetra. Lett, 2004, 45:  1247-1251. doi: 10.1016/j.tetlet.2003.11.145

    10. [10]

      Grabchev I, Chovelon J. M, Qian X. A copolymer of 4-N,N-dimethylaminoethylene-N-allyl-1,8-naphthalimide with methylmethacrylate as a selective fluorescent chemosensor in homogeneous systems for metal cations[J]. J. Photochem. Photobiol. A, 2003, 158:  37-43. doi: 10.1016/S1010-6030(03)00100-X

    11. [11]

      Morgado J, Gruner J, Walcott S. P, Yong T. M, Cervini R, Moratti S. C, Holmes A. B, Friend R. H, 4-AcNI—a new polymer for light-emitting diodes. Synth[J]. Met, 1998, 95:  113-117.

    12. [12]

      Islam A, Cheng C. C, Chi S. H, Lee S. J, Hela G. P, Chen I. C, Cheng C. H. Aminonaphthalic anhydrides as red-emitting materials: electroluminescence, crystal structure, and photophysical properties[J]. J. Phys. Chem. B, 2005, 109:  5509-5517.

    13. [13]

      Yang J. X, Wang X. L, Wang X. M, Xu L. H. The synthesis and spectral properties of novel 4-phenylacetylene-1,8-naphthalimide derivatives[J]. Dyes Pigm, 2005, 66:  83-87. doi: 10.1016/j.dyepig.2004.07.015

    14. [14]

      Magalhaes J. L, Pereira R. V, Triboni E. R, Berci Filho P, Gehlen M. H, Nart F. C. Solvent effect on the photophysical properties of 4-phenoxy-N-methyl-1,8-naphthalimide[J]. J. Photochem. Photobiol. A, 2006, 183:  165-170. doi: 10.1016/j.jphotochem.2006.03.012

    15. [15]

      Liu Y, Niu F, Lian J, Zeng P, Niu H. Synthesis and properties of starburst amorphous molecules: 1,3,5-tris(1,8-naphthalimide-4-yl)benzenes[J]. Synth. Met, 2010, 160:  2055-2060. doi: 10.1016/j.synthmet.2010.07.020

    16. [16]

      Frisch , M. J, Trucks , G. W, Schlegel , H. B, Scuseria , G. E, Robb M. A, Cheeseman J. R, Scalmani G, Barone V, Mennucci B, Petersson G. A, Nakatsuji H, Caricato M, Li X, Hratchian H. P, Izmaylov A. F, Bloino J, Zheng G, Sonnenberg J. L, Hada M, Ehara M, Toyota K, Fukuda R, Hasegawa J, Ishida M, Nakajima T, Honda Y, Kitao O, Nakai H, Vreven T, Montgomery J. A, Peralta Jr. J. E, Ogliaro F, Bearpark M, Heyd J. J, Brothers E, Kudin K. N, Staroverov V. N, Kobayashi R, Normand J, Raghavachari K, Rendell A, Burant J. C, Iyengar S. S, Tomasi J, Cossi M, Rega N, Millam J. M, Klene M, Knox J. E, Cross J. B, Bakken V, Adamo C, Jaramillo J, Gomperts R, Stratmann R. E, Yazyev O, Austin A. J, Cammi R, Pomelli C, Ochterski J. W, Martin R. L, Morokuma K, Zakrzewski V. G, Voth G. A, Salvador P, Dannenberg J. J, Dapprich S, Daniels A. D, Farkas O, Foresman J. B, Ortiz J. V, Cioslowski J, Fox D. J. Gaussian, Inc., Wallingford CT, 2009, Gaussian 09, Revision A[J]. , , :  .

    17. [17]

      Mancini G, Zazza C, Aschib M, Sannaa N. Conformational analysis and UV/Vis spectroscopic properties of a rotaxane-based molecular machine in acetonitrile dilute solution: when simulations meet experiments[J]. Phys. Chem. Chem. Phys, 2011, 13:  2342-2349. doi: 10.1039/C0CP01773F

    18. [18]

      Li H, Li N, Sun R, Gu H, Ge J, Lu J, Xu Q, Xia X, Wang L. Dynamic random access memory devices based on functionalized copolymers with pendant hydrazine naphthalimide group[J]. J. Phys. Chem. C, 2011, 115:  8288-8294.

    19. [19]

      Li Z, Yang Q, Chang R, Ma G, Chen M, Zhang W. N-Heteroaryl-1,8-naphthalimide fluorescent sensor for water: molecular design, synthesis and proper[J]. Dyes. Pigm, 2011, 88:  307-314. doi: 10.1016/j.dyepig.2010.07.009

    20. [20]

      Gudeika D, Michaleviciute A, Grazulevicius J. V, Lygaitis R, Grigalevicius S, Jankauskas V, Miasojedovas A, Jursenas S, Sini G. Structure properties relationship of donor-acceptor derivatives of triphenylamine and 1,8-naphthalimide[J]. J. Phys. Chem. C, 2012, 116:  14811-14819. doi: 10.1021/jp303172b

    21. [21]

      Pearson R. G. Absolute electronegativity and absolute hardness of Lewis acids and bases[J]. J. Am. Chem. Soc, 1985, 107:  6801-6806. doi: 10.1021/ja00310a009

    22. [22]

      Start M. S. Epoxidation of alkenes by peroxyl radicals in the gas phase: structure-activity relationships[J]. J. Phys. Chem. A, 1997, 101:  8296-8301. doi: 10.1021/jp972054+

    23. [23]

      Forés M, Duran M, Solà M, Adamowicz L. Excited-state intramolecular proton transfer and rotamerism of 2-(2′-hydroxyvinyl)benzimidazole and 2-(2′-hydroxyphenyl)imidazole[J]. J. Phys. Chem. A, 1999, 103:  4413-4420. doi: 10.1021/jp9844765

    24. [24]

      Schleyer P, Von R, Allinger N. L, Clark T, Gasteiger J, Kollman P. A, III Schaefer H. F, Schreiners P. R. The Encyclopedia of Computational Chemistry[J]. Wiley, UK, Chichester, 1998, :  .

    25. [25]

      Marcus R. A. Electron transfer reactions in chemistry. theory and experiment[J]. Rev. Mod. Phys, 1993, 65:  599-610. doi: 10.1103/RevModPhys.65.599

    26. [26]

      Marcus R. A. Chemical and electrochemical electron-transfer theory[J]. Annu. Rev. Phys. Chem, 1964, 15:  155-196. doi: 10.1146/annurev.pc.15.100164.001103

    27. [27]

      Lemaur V, Steel M, Beljonne D, Brédas J. L, Cornil J. Photoinduced charge generation and recombination dynamics in model donor/acceptor pairs for organic solar cell applications: a full quantum-chemical treatment[J]. J. Am. Chem. Soc, 2005, 127:  6077-6076. doi: 10.1021/ja042390l

    28. [28]

      Hutchison G. R, Ratner M. A, Marks T. J. Hopping transport in conductive heterocyclic oligomers: reorganization energies and substituent effects[J]. J. Am. Chem. Soc, 2005, 127:  2339-2350. doi: 10.1021/ja0461421

    29. [29]

      Martinelli N. G, Idé J, Sánchez-Carrera R. S, Coropceanu V, Brédas J. L, Ducasse L, Castet F, Cornil J, Beljonne D. Influence of structural dynamics on polarization energies in anthracene single crystals[J]. J. Phys. Chem. C, 2010, 114:  20678-20685. doi: 10.1021/jp105843t

    30. [30]

      McMahon D. P, Trois A. Evaluation of the external reorganization energy of polyacenes[J]. J. Phys. Chem. Lett, 2010, 1:  941-946. doi: 10.1021/jz1001049

    31. [31]

      K?se M. E, Long H, Kim K, Graf P, Ginley D. Charge transport simulations in conjugated dendrimers[J]. J. Phys. Chem. A, 2010, 114:  4388-4393.

    32. [32]

      Sakanoue K, Motoda M, Sugimoto M, Sakaki S. A molecular orbital study on the hole transport property of organic amine compounds[J]. J. Phys. Chem. A, 1999, 103:  5551-5556. doi: 10.1021/jp990206q

    33. [33]

      K?se M. E, Mitchell W. J, Kopidakis N, Chang C. H, Shaheen S. E, Kim K, Rumbles G. Theoretical studies on conjugated phenyl-cored thiophene dendrimers for photovoltaic applications[J]. J. Am. Chem. Soc, 2007, 129:  14257-14270. doi: 10.1021/ja073455y

    34. [34]

      Lin B. C, Cheng C. P, You Z. Q, Hsu C. P. Charge transport properties of tris(8-hydroxyquinolinato)aluminum(III): why it is an electron transporter[J]. J. Am. Chem. Soc, 2005, 127:  66-67. doi: 10.1021/ja045087t

    35. [35]

      Gruhn N. E, da Silva Filho D. A, Bill T. G, Malagoli M, Coropceanu V, Kahn A, Brédas J. L. The vibrational reorganization energy in pentacene: molecular influences on charge transport[J]. J. Am. Chem. Soc, 2002, 124:  7918-7919. doi: 10.1021/ja0175892

  • Figure 1  Geometries of designed molecules 1~6

    Figure 2  Electronic density contours of the frontier molecular orbitals for investigated derivatives

    Table 1.  Calculated EHOMO , ELUMO, Eg (All in eV), and HOMOs and LUMOs Co ntributions (%) of 1~6

    SpeciesHOMOLUMOELUMONIaBZbSGcELUMONIBZSGEg1–6.53585.514.40.1–2.68692.77.303.8496–6.4401.90.198.1–2.86692.97.103.574
    2–6.54084.414.21.4–2.68792.67.403.853
    3–6.4104.9095.1–2.77493703.636
    4–6.81153.68.537.9–3.02492.86.90.23.787
    5–6.59083.813.42.8–2.74292.96.90.23.848
    a NI: 1, 8-naphthalimide moieties; b BZ: benzene moieties; c SG: substituent groups
    下载: 导出CSV

    Table 2.  Absorption Wavelengths λabs (in nm), the Oscillator Strength f, and Main Assignments (CI Expansion Coefficient) of 1~6 in Chloroform, along with Available Experimental Data

    SpeciesλabsfAssignment13650.85HOMO–1→LUMO(0.70)Expa360
    HOMO–1→LUMO+2(0.12)
    23650.62HOMO→LUMO(–0.31)
    HOMO→LUMO+1(–0.32)
    HOMO–1→LUMO(0.43)
    33650.52HOMO→LUMO(0.60)
    HOMO→LUMO+2(0.14)
    43700.6HOMO→LUMO(0.59)
    HOMO→LUMO+2(0.12)
    53650.57HOMO→LUMO(0.58)
    HOMO→LUMO+1(0.17)
    63680.59HOMO→LUMO(0.45)
    HOMO→LUMO+1(0.20)
    HOMO→LUMO+2(0.22)
    a Experimental data for 1 in chloroform were taken from ref. [15].
    下载: 导出CSV

    Table 3.  Fluorescence Wavelengths λfl (in nm), the Oscillator Strength f, and Main Assignments (CI Expansion Coefficient) of 1~6 in Chloroform, along with Available Experimental Data

    SpeciesλflfAssignment14010.76LUMO+1→HOMO(0.55)Expa426
    LUMO→HOMO–1(–0.43)
    23990.83LUMO+1→HOMO(–0.49)
    LUMO→HOMO–1(0.49)
    34060.52LUMO→HOMO–1(0.67)
    LUMO→HOMO–2(0.14)
    44280.59LUMO+4→HOMO(0.47)
    LUMO+3→HOMO(0.34)
    54090.7LUMO+5→HOMO(0.56)
    LUMO→HOMO–1(–0.40)
    64540.5LUMO+1→HOMO(–0.41)
    LUMO→HOMO–1(0.67)
    a Experimental data for 1 in chloroform were taken from ref. [15].
    下载: 导出CSV

    Table 4.  Calculated Molecular λ e, λ h, IP, EA, and η (All in eV) of 1~6 at the B3LYP/6-31G (d, p) Level

    SpeciesλhλeIPEAη10.1420.156.6571.0022.82760.2840.1226.1760.4442.866
    20.3280.186.3510.6782.837
    30.2920.1567.6032.0232.79
    40.3150.2166.1330.7942.67
    50.3040.116.5340.7492.893
    下载: 导出CSV
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  • 收稿日期:  2016-06-13
  • 接受日期:  2016-08-16
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