Next Article in Journal
Studies of the Structure and Optical Properties of BaSrMgWO6 Thin Films Deposited by a Spin-Coating Method
Next Article in Special Issue
The Growth of Extended Melem Units on g-C3N4 by Hydrothermal Treatment and Its Effect on Photocatalytic Activity of g-C3N4 for Photodegradation of Tetracycline Hydrochloride under Visible Light Irradiation
Previous Article in Journal
A Novel Ca-Modified Biochar for Efficient Recovery of Phosphorus from Aqueous Solution and Its Application as a Phosphorus Biofertilizer
Previous Article in Special Issue
Synthesis and Characterization of Cu2ZnSnSe4 by Non-Vacuum Method for Photovoltaic Applications
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Physical Mechanisms of Intermolecular Interactions and Cross-Space Charge Transfer in Two-Photon BDBT-TCNB Co-Crystals

1
College of Science, Liaoning Petrochemical University, Fushun 113001, China
2
Institute of Clean Energy Chemistry, Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials of Liaoning Province, College of Chemistry, Liaoning University, Shenyang 110036, China
*
Authors to whom correspondence should be addressed.
These authors contributed equally to this work.
Nanomaterials 2022, 12(16), 2757; https://doi.org/10.3390/nano12162757
Submission received: 18 July 2022 / Revised: 6 August 2022 / Accepted: 9 August 2022 / Published: 11 August 2022
(This article belongs to the Special Issue Performance of Nanocomposite for Optoelectronic Applications)

Abstract

:
Co-crystal materials formed by stacking different molecules with weak interactions are a hot research topic. In this work, we theoretically investigate the intermolecular interactions and charge transfer properties of the supramolecular BDBT-TCNB co-crystal (BTC). The π-π bonds, hydrogen bonds, and S-N bonds in the BTC bind the BDBT and TCNB molecules together to form a highly ordered co-crystal and lead to the co-crystal’s excellent two-photon absorption (TPA) properties. The intermolecular interactions of the BTC are discussed in detail by the independent gradient model based on Hirshfeld partition (IGMH), atoms in molecules (AIM), electrostatic overlay diagram, and symmetry-adapted perturbation theory (SAPT) energy decomposition; it is found that there is a strong interaction force along the stacking direction. The charge transfer properties of the one-photon absorption (OPA) and TPA of the BTC were investigated by charge density difference (CDD) and transition density matrix (TDM). It is found that the dominant charge transfer mode is the cross-space charge transfer along the stacking direction. Therefore, strong intermolecular interactions will promote intermolecular cross-space charge transfer. This work is of great significance for the design of organic optoelectronic supramolecular materials.

1. Introduction

TPA is a third-order nonlinear optical process in which two photons excite from a medium to an intermediate state and then to an excited state. TPA has many potential applications in chemistry, life sciences, and physics. The excitation density of two photons is proportional to the square of the intensity; therefore, compared with the single photon, the two-photon excitation volume is smaller, which can improve the resolution of the microscope. This advantage has been applied to fluorescence microscopy [1,2,3]. Two-photon dyes can be used as labels to track the intracellular migration of non-fluorescent drugs [4]. Since long-wavelength lasers can minimize the damage of the light source to the catalytic substrate, TPA has a good application in the field of non-destructive photocatalysis [5,6,7].
Ordered structures formed by weak interactions between two or more molecules are called co-crystals. Co-crystals hold great promise in optics and electronics, such as light-emitting diodes and photovoltaic cells [8,9]. Co-crystals can be designed and constructed by π-π stacking structures instead of traditional π-conjugated structures. The properties of co-crystals are determined by their structure, and different packing structures lead to different intermolecular interactions in the system. Electron delocalization or charge interactions in π-π stacking systems have important effects on the optoelectronic properties [10], absorption, emission [11,12], stability [13], and photoluminescence quantum efficiency of co-crystals. Yang et al. demonstrated that the electrostatic and dispersive interactions of conjugated carbon materials relative to other materials are critical to the performance of photovoltaic devices [14,15,16].
The BTC is composed of benzo [b] naphtho [1,2-d] thiophene (BDBT) and 1,2,4,5-tetracyanobenzene (TCNB) stacked on each other, which have excellent TPA properties [17]. In this work, we chose BTC to study intermolecular interactions and two-photon transition properties. Conjugated structures are widely used in optoelectronic materials due to their high charge transfer ability. Strong intermolecular interactions will be more favorable for charge transfer, and this work also proves that charge transfer is more inclined to transfer along the direction of strong interactions. This provides the necessary theoretical basis for designing other optoelectronic materials.

2. Materials and Methods

All structures in this work were derived from the crystallographic information file (CIF) of the BTC. Electron excitation calculations were performed by the Gaussian program [18] combined with the density functional theory (DFT) [19], CAM-B3LYP functional [20], and the 6–31 g(d) basis set [21]. The energy decomposition was calculated by the psi4 program [22], combining sSAPT0 levels and jun-cc-pVDZ. The interaction energy obtained from this combination has been shown to be very close to the experimentally measured results [23]. All wave function analyses (IGMH, AIM, electrostatic potential overlay, CDD, and TDM) were carried out by the Multiwfn program [24]. The TPA spectrum was calculated based on a script we wrote ourselves [25]. All 3D structure diagrams in this work were drawn by the VMD program [26].
IGMH [27] is a method that can visualize the interactions in chemical systems in a graphical way. It is defined as:
δ g r = g I G M r g r
g r = i ρ i r
g I G M r = i ρ i r
where g I M G is the sum of the absolute values of the electron density gradients; g is the sum of the electron density gradients; ρ i represents the electron density of the i atom; r is a coordinate vector; and δ g inter and δ g intra are defined to reflect inter- and intra-fragment interactions, respectively.
δ g inter r = g IGM , inter r g inter r
g inter r = A i A ρ i r
g IGM , inter r = A i A ρ i r
δ g i n t r a r = δ g r δ g i n t e r r
The two-photon molar absorptivity [25] is defined as:
δ t p = 8 j g j f f μ j 2 j μ g 2 ω j ω f / 2 2 + Γ f 2 1 + 2 cos 2 θ j + 8 Δ μ f g 2 f μ g 2 ω f / 2 2 + Γ f 2 1 + 2 cos 2 ϕ
where g , j , and f are the wave functions of the ground state, intermediate state, and final state during the TPA process, respectively; j μ g and f μ j are the transition dipole moments from the ground state to the intermediate state and the intermediate state to the final state, respectively; θ j is the angle between the two transition dipole moments; Δ μ f g is the difference in permanent dipole moments between the ground state and the final state; ϕ is the angle between Δ μ f g and f μ g ; ω j and ω f are the energies of the intermediate state and the final state, respectively; and Γ f is the lifetime of the ground state.

3. Results and Discussion

BTC (Figure 1) is an excellent two-photon material. The BTC can well preserve the two-photon properties of the donor BDBT, and there are obvious charge transfer interactions in the BTC. Intermolecular interactions are crucial for the optical properties of co-crystals. In this section, we firstly study the intermolecular interactions of the BTC in detail and then visualize the OPA and TPA charge transfer of the co-crystals.

3.1. Intermolecular Interactions in the BTC

Intermolecular interactions are crucial for the charge transfer properties of the co-crystals. In this section, the interactions between dimers of four different configurations of BDBT and TCNB in the BTC were investigated by IGMH, AIM, and SAPT energy decomposition.
IGMH is a method that can visualize the interactions in chemical systems in a graphical way. Dimer 1 and dimer 3 are composed of BDBT and TCNB stacked on each other, and a large-scale green interaction isosurface is formed between the molecules (Figure 2a,c); this indicates that there is a significant π-π stacking interaction between BDBT and TCNB. Grimme had effectively demonstrated that the dispersive interactions of π electrons in the packing direction in unsaturated molecules is the essence of the π-π stacking effect [28]. Therefore, there are strong dispersive interactions in dimer 1 and dimer 3. Dimers 2 and 4 are connected laterally by N-H and S-N bonds to BDBT and TCNB (Figure 2b,d). The intermolecular green isosurfaces also represent van der Waals interactions. Electrostatic interactions are also the main source of intermolecular attraction. The electrostatic potential overlay map can clearly show the region of intermolecular electrostatic interaction [29]. The larger the overlap of the electrostatic potentials between the two molecules in the opposite sign, the stronger the electrostatic attraction. It can be seen that in dimer 1 and dimer 3 (Figure 3a,c), the areas with opposite signs of electrostatic potential overlap greatly, while dimer 2 and dimer 4 only have a small overlap (Figure 3b,d); this suggests that the electrostatic interactions in dimers 1 and 3 also contribute significantly to the mutual attraction of the molecules. The electrostatic interaction in dimer 4 is stronger than in dimer 2 because of the large overlap of electrostatic potentials in dimer 4 (Figure 3b,d).
AIM [30,31,32] is an important wave function analysis method and one of the most popular methods used for analyzing chemical bonds. AIM mainly obtains the relevant properties of chemical bonds by analyzing bond critical points (BCPs). When studying the interactions between atoms, it is natural to think of starting from the electronic structure characteristics of the interactions between atoms. In AIM theory, BCPs are considered to be the most representative points in the interatomic interaction region. So, the properties of BCPs can be used to study the properties of the corresponding chemical bonds, including the strengths and properties. The orange lines between the molecules in Figure 2 are the interaction paths between atoms, and the red spheres in the paths are the BCPs. The electron density and the energy density (Figure 4a) at all BCPs are very low (electron density < 0.01 a.u. and energy density < 0.002 a.u.). Both the electron density and the energy density reflect the very typical characteristics of non-covalent interactions. At the same time, more real-space functions of BCPs are calculated (Table S1), which will be more helpful in understanding the intermolecular interactions in the BTC.
Finally, we performed energy decomposition calculations for the intermolecular interactions of the four dimers to better understand the nature of the interactions. SAPT is a very popular method used to decompose weak interactions [33,34,35,36]. Energy decomposition can decompose the inter-fragment interaction energy into different physical components (dispersive, electrostatic, induced, and exchange interactions) and then gain a deeper understanding of the nature of the interaction from the energy perspective. It can be seen from Figure 4b that the total interaction energy of dimer 1 and dimer 3 is significantly stronger than that of dimer 2 and dimer 4; this suggests that dimer 1 and dimer 3 are more stable. The energy decomposition results show that, among the four configurations, exchange interactions play a repulsive role, and electrostatic, dispersive, and induced interactions play an attractive role. Among them, dispersive interactions play a major contribution in the binding of molecules. However, electrostatic interactions are also not negligible. Among them, dimer 1 and dimer 3 have stronger electrostatic interactions, and dimer 2 has the smallest electrostatic interactions; this is consistent with the conclusion obtained from the electrostatic potential overlay diagrams. The numerical values of the energy decomposition results are shown in Table S2. In all configurations, dispersive interactions contributed to more than 50% of the total attraction, dominating the intermolecular binding.

3.2. Cross-Space Charge Transfer in the BTC

3.2.1. The OPA and TPA Spectrum

Figure 5a shows the OPA spectrum of the BTC. After comparing this with the spectrum measured by the experiment [17], it is found that the calculated spectrum is accurate. There is an absorption peak mainly contributed by S2 (432.99 nm), S4 (411.59 nm), S6 (405.95 nm), and S7 (400.93 nm) in the range of 350–450 nm. Figure 5b shows the TPA spectrum of the BTC. There is a strong absorption peak and a weak absorption peak in the range of 700–900 nm; the strong absorption peak is contributed by S5 (813.10 nm), S7 (802.98 nm), and S8 (802.93 nm), and the weak absorption peak is mainly contributed by S10 (754.17 nm). The two absorption peaks were both determined by one-step transition and two-step transition.

3.2.2. Electronic Transition Properties of OPA

CDD and TDM are currently popular methods used to visualize the electron transfer process [37,38,39,40], which can clearly reflect where the electrons come from and where they go. The atomic number corresponding to the TDM is shown in Figure S1. There are four main excited states in the OPA spectrum, namely S2, S4, S6, and S7. In this section, we qualitatively analyze the electronic transition properties of each excited state by CDD and TDM. At the same time, we also quantitatively analyze the excited states by the transition indexes. Overall, the four one-photon excited states are all electron transfer excited states (Figure 6), and the electrons are all transferred from BDBT (donor) to TCNB (acceptor). The isosurfaces of the electrons and holes of S2 converge on the four molecules in the middle of the system, and the electrons are transferred from BDBT to TCNB (Figure 6a,b). The centroid distance (D) of the electrons and holes in S2 is only 0.043 Å (Table 1) because the electron and hole isosurfaces have the same center of symmetry; this does not mean that the electrons and holes of S2 are not separated. The electron transfer process of S4 is obviously different from that of S2. The electron and hole isosurfaces of S4 are located on the four molecules on both sides of the system, and the electrons are also transferred from BDBT to TCNB (Figure 6c,d); the electron and hole isosurfaces on the right side of the system are significantly larger than those on the left side. The average distribution breadth (H) of the electrons and holes in S4 reaches 12.196 Å (Table 1), which is caused by the distribution of electrons and holes on both sides of the system. The electron transfer process of S6 is very similar to that of S4 (Figure 6e,f), and the isosurfaces of the electrons and holes are located on both sides of the system; the H of S6 is 11.674 Å (Table 1). S7 has only one set of electron–hole isosurfaces (Figure 6g,h), which is why the D of S7 is significantly larger than the other three excited states. The electron–hole overlap index (Sr), hole delocalization index (HDI), and electron delocalization index (EDI) of the four excited states are all very close (Table 1); this shows that the degree of overlap and delocalization of the electrons and holes in the four excited states is very close. The electron–hole separation index (t) can also measure the separation degree of the electrons and holes (Table 1). The electrons and holes are sufficiently separated when t > 0, and vice versa when t < 0. The electron–hole densities of S2, S4, and S6 are all well separated, but t is negative. This is because the three excited states have two groups of electron–hole isosurfaces; as a result, t cannot effectively reflect the degree of separation of the electrons and holes.

3.2.3. Electronic Transition Properties of TPA

Two-photon materials are widely used in 3D optical imaging, lithographic micromachining, and optical data storage. In this section, we investigate the electronic transition mechanism of the excited states with a large cross-section in the BTC. S5, S7, S8, and S10 have larger two-photon cross-sections in the TPA spectrum of the BTC (Figure 5b). We visualized the first and second transitions in the two-photon transition processes by CDDs and TDMs. S5 has one transition channel (S0→S4→S5). S4 in OPA is an excited state with strong oscillator strength, so S4 is likely to become an intermediate state in the TPA processes (S2, S6, and S7 may also become intermediate states). The electronic transition process of S0→S4 is the same as that of S4 in OPA (Figure 7c,d). The electrons and holes isosurfaces of S4→S5 are located at the four BDBTs at the corners of the system (Figure 7a,b), and electrons are transferred from one BDBT across the TCNB to the other BDBT; this reflects the strong charge transfer ability of the BTC. S8 has the strongest two-photon cross-section in the TPA spectrum, with only one transition channel, and the intermediate state is S7 (S0→S7→S8). The electronic transition process of S0→S7 is the same as that of S7 in OPA (Figure 7g,h). The electrons transfer of S7→S8 is upward as a whole (Figure 7e,f), which is reflected as the blue isosurfaces representing the holes are below the red isosurfaces representing the electrons. The wavelength of S7 is very close to that of S8, but the two-photon cross-section is lower than that of S8. S7 has two transition channels (Figure 8), S0→S2→S7 and S0→S6→S7, respectively. The first-step transition of the two channels is the same as the transition of the corresponding excited state in the OPA. The second transition (S2→S7) of S0→S2→S7 is the charge transfer excitation of six molecules located in the middle of the system (Figure 8a,b). The electrons are transferred from the upper and lower sides to the middle, which is reflected in the red isosurfaces representing the electrons located in the middle of the system. The electron and hole isosurfaces of the second transition (S6→S7) of S0→S6→S7 are mainly located in the four molecules on the left side of the system (Figure 8e,f), and the transfer direction of electrons is downward. S10 dominates a weak absorption peak; it has two transition channels, S0→S6→S10 and S0→S9→S10, respectively. The second-step transition (S6→S10) of S0→S6→S10 is a charge transfer excitation located on both sides of the system (Figure 9a,b), and the electrons are transferred downward as a whole. The electronic excitation process of S0→S9→S10 (Figure 9e–h) is similar to that of S0→S6→S10, which can be seen from the CDDs and TDMs. From the size of the isosurface, it can be seen that the electron transfer intensity of the second channel is stronger than that of the first channel. Finally, we give the transition dipole moments of the individual transitions during the two-photon excitation (Table 2). The numerical values of the transition dipole moments are closely related to the strength of the two-photon cross-section.
In summary, we find that electrons are mostly transferred along the π-π stacking direction because the intermolecular interactions along the stacking direction are stronger. This will provide guidance for designing materials with excellent charge transfer capabilities.

4. Conclusions

In this work, we investigated the intermolecular interactions and optical properties of the BTC with a packing structure using first-principles calculations and wave function analysis. We discussed the two main driving forces for molecular binding, dispersive and electrostatic forces, through the IGMH and electrostatic overlay diagrams and give regions for the dispersive and electrostatic interactions. A series of real-space functions such as electron density and energy density at the intermolecular interactions were calculated by AIM. The energy dissociation of dimers with different binding modes was calculated using the SAPT theory, which helps us understand the nature of intermolecular interactions. BDBT and TCNB formed the BTC through π-π stacking, and abundant intermolecular interactions such as ππ bonds, hydrogen bonds, and N-S bonds were formed in the co-crystals. Strong intermolecular interactions will promote charge transfer between molecules. Charge transfer in the co-crystals is mainly achieved by cross-space charge transfer. We performed a visual study of the electron transfer in the OPA and TPA of the BTC by CDDs and TDMs and clarified the charge transfer mechanism in the co-crystals. We explained why the excited state with large oscillator strength in single-photon absorption is more likely to be the intermediate state in the TPA. Electrons tend to transfer in the direction of strong interactions. This work will provide the necessary theoretical basis for designing luminescent materials with a large two-photon cross-section.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/nano12162757/s1, Table S1: Real space functions of BCPs; Table S2: Numerical values for the energy decomposition of the four dimers; Figure S1: BTC’s atomic number.

Author Contributions

Conceptualization, Y.J. and Y.S.; methodology, Y.J.; software, C.L. and N.L.; validation, J.W., C.L., and N.L.; formal analysis, Y.J.; investigation, C.L.; resources, Y.J.; data curation, N.L.; writing—original draft preparation, C.L. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Talent Introduction project of Liaoning Petrochemical University and Liaoning Provincial Natural Science Foundation Project (2022-MS-363).

Data Availability Statement

Data can be available upon request from the authors.

Acknowledgments

This research was funded by the Talent Introduction project of Liaoning Petrochemical University.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Denk, W.; Strickler, J.H.; Webb, W.W. Two-photon laser scanning fluorescence microscopy. Science 1990, 248, 73–76. [Google Scholar] [CrossRef] [PubMed]
  2. Zipfel, W.R.; Williams, R.M.; Webb, W.W. Nonlinear magic: Multiphoton microscopy in the biosciences. Nat. Biotechnol. 2003, 21, 1369–1377. [Google Scholar] [CrossRef] [PubMed]
  3. Helmchen, F.; Denk, W. Deep tissue two-photon microscopy. Nat. Methods 2005, 2, 932–940. [Google Scholar] [CrossRef] [PubMed]
  4. Wang, X.; Krebs, L.J.; Al-Nuri, M.; Pudavar, H.E.; Ghosal, S.; Liebow, C.; Nagy, A.A.; Schally, A.V.; Prasad, P.N. A chemically labeled cytotoxic agent: Two-photon fluorophore for optical tracking of cellular pathway in chemotherapy. Proc. Natl. Acad. Sci. USA 1999, 96, 11081–11084. [Google Scholar] [CrossRef]
  5. Li, H.; Yang, Y.; He, C.; Zeng, L.; Duan, C. Mixed-ligand metal–organic framework for two-photon responsive photocatalytic c–n and c–c coupling reactions. ACS Catal. 2018, 9, 422–430. [Google Scholar] [CrossRef]
  6. Glaser, F.; Kerzig, C.; Wenger, O.S. Multi-photon excitation in photoredox catalysis: Concepts, applications, methods. Angew. Chem. Int. Ed. 2020, 59, 10266–10284. [Google Scholar] [CrossRef]
  7. Kerzig, C.; Guo, X.; Wenger, O.S. Unexpected hydrated electron source for preparative visible-light driven photoredox catalysis. J. Am. Chem. Soc. 2019, 141, 2122–2127. [Google Scholar] [CrossRef]
  8. Cui, L.S.; Nomura, H.; Geng, Y.; Kim, J.U.; Nakanotani, H.; Adachi, C. Controlling singlet–triplet energy splitting for deep-blue thermally activated delayed fluorescence emitters. Angew. Chem. Int. Ed. 2017, 56, 1571–1575. [Google Scholar] [CrossRef]
  9. Liu, W.; Xu, X.; Yuan, J.; Leclerc, M.; Zou, Y.; Li, Y. Low-bandgap non-fullerene acceptors enabling high-performance organic solar cells. ACS Energy Lett. 2021, 6, 598–608. [Google Scholar] [CrossRef]
  10. Jagtap, S.P.; Mukhopadhyay, S.; Coropceanu, V.; Brizius, G.L.; Brédas, J.-L.; Collard, D.M. Closely stacked oligo (phenylene ethynylene) s: Effect of π-stacking on the electronic properties of conjugated chromophores. J. Am. Chem. Soc. 2012, 134, 7176–7185. [Google Scholar] [CrossRef]
  11. Hassan, Z.; Spuling, E.; Knoll, D.M.; Lahann, J.; Bräse, S. Planar chiral [2.2]paracyclophanes: From synthetic curiosity to applications in asymmetric synthesis and materials. Chem. Soc. Rev. 2018, 47, 6947–6963. [Google Scholar] [CrossRef]
  12. Mullin, W.J.; Pawle, R.H.; Sharber, S.A.; Müller, P.; Thomas, S.W. Programmed twisting of phenylene–ethynylene linkages from aromatic stacking interactions. J. Mater. Chem. C 2019, 7, 1198–1207. [Google Scholar] [CrossRef]
  13. Shen, P.; Zhuang, Z.; Jiang, X.-F.; Li, J.; Yao, S.; Zhao, Z.; Tang, B.Z. Through-space conjugation: An effective strategy for stabilizing intramolecular charge-transfer states. J. Phys. Chem. Lett. 2019, 10, 2648–2656. [Google Scholar] [CrossRef]
  14. Chen, H.-Y.; Hou, J.; Zhang, S.; Liang, Y.; Yang, G.; Yang, Y.; Yu, L.; Wu, Y.; Li, G. Polymer solar cells with enhanced open-circuit voltage and efficiency. Nat. Photonics 2009, 3, 649–653. [Google Scholar] [CrossRef]
  15. Zhou, H.; Chen, Q.; Li, G.; Luo, S.; Song, T.-B.; Duan, H.-S.; Hong, Z.; You, J.; Liu, Y.; Yang, Y. Interface engineering of highly efficient perovskite solar cells. Science 2014, 345, 542–546. [Google Scholar] [CrossRef]
  16. You, J.; Chen, C.C.; Dou, L.; Murase, S.; Duan, H.S.; Hawks, S.A.; Xu, T.; Son, H.J.; Yu, L.; Li, G. Metal oxide nanoparticles as an electron-transport layer in high-performance and stable inverted polymer solar cells. Adv. Mater. 2012, 24, 5267–5272. [Google Scholar] [CrossRef]
  17. Zhang, Y.; Wu, H.; Wang, Y.; Sun, L.; Li, S.; Ren, Y.; Sun, Y.; Yang, F.; Zhang, X.; Hu, W. Cocrystal engineering for constructing two-photon absorption materials by controllable intermolecular interactions. J. Mater. Chem. C 2022, 10, 2562–2568. [Google Scholar] [CrossRef]
  18. Frisch, M.; Trucks, G.; Schlegel, H.; Scuseria, G.; Robb, M.; Cheeseman, J.; Scalmani, G.; Barone, V.; Petersson, G.; Nakatsuji, H. Gaussian 16 Revision c. 01. 2016; Gaussian Inc.: Wallingford, CT, USA, 2016; Volume 421. [Google Scholar]
  19. Kohn, W.; Sham, L.J. Self-consistent equations including exchange and correlation effects. Phys. Rev. 1965, 140, A1133. [Google Scholar] [CrossRef]
  20. Yanai, T.; Tew, D.P.; Handy, N. A new hybrid exchange–correlation functional using the coulomb-attenuating method (cam-b3lyp). Chem. Phys. Lett. 2004, 393, 51–57. [Google Scholar] [CrossRef]
  21. Hehre, W.J.; Ditchfield, R.; Pople, J.A. Self—consistent molecular orbital methods. Xii. Further extensions of gaussian—type basis sets for use in molecular orbital studies of organic molecules. J. Chem. Phys. 1972, 56, 2257–2261. [Google Scholar] [CrossRef]
  22. Parrish, R.M.; Burns, L.A.; Smith, D.G.; Simmonett, A.C.; DePrince III, A.E.; Hohenstein, E.G.; Bozkaya, U.; Sokolov, A.Y.; Di Remigio, R.; Richard, R.M. Psi4 1.1: An open-source electronic structure program emphasizing automation, advanced libraries, and interoperability. J. Chem. Theory Comput. 2017, 13, 3185–3197. [Google Scholar] [CrossRef]
  23. Burns, L.A.; Marshall, M.S.; Sherrill, C.D. Appointing silver and bronze standards for noncovalent interactions: A comparison of spin-component-scaled (scs), explicitly correlated (f12), and specialized wavefunction approaches. J. Chem. Phys. 2014, 141, 234111. [Google Scholar] [CrossRef]
  24. Lu, T.; Chen, F. Multiwfn: A multifunctional wavefunction analyzer. J. Comput. Chem. 2012, 33, 580–592. [Google Scholar] [CrossRef]
  25. Mu, X.; Wang, J.; Sun, M. Visualization of photoinduced charge transfer and electron–hole coherence in two-photon absorption. J. Phys. Chem. C 2019, 123, 14132–14143. [Google Scholar] [CrossRef]
  26. Humphrey, W.; Dalke, A.; Schulten, K. Vmd: Visual molecular dynamics. J. Mol. Graph. 1996, 14, 33–38. [Google Scholar] [CrossRef]
  27. Lu, T.; Chen, Q. Independent gradient model based on hirshfeld partition: A new method for visual study of interactions in chemical systems. J. Comput. Chem. 2022, 43, 539–555. [Google Scholar] [CrossRef]
  28. Grimme, S. Do special noncovalent π–π stacking interactions really exist? Angew. Chem. Int. Ed. 2008, 47, 3430–3434. [Google Scholar] [CrossRef]
  29. Liu, Z.; Lu, T.; Chen, Q. Intermolecular interaction characteristics of the all-carboatomic ring, cyclo[18]carbon: Focusing on molecular adsorption and stacking. Carbon 2021, 171, 514–523. [Google Scholar] [CrossRef]
  30. Bader, R.F. A quantum theory of molecular structure and its applications. Chem. Rev. 1991, 91, 893–928. [Google Scholar] [CrossRef]
  31. Cremer, D.; Kraka, E. Chemical bonds without bonding electron density—Does the difference electron-density analysis suffice for a description of the chemical bond? Angew. Chem. Int. Ed. Engl. 1984, 23, 627–628. [Google Scholar] [CrossRef]
  32. Espinosa, E.; Lecomte, C.; Molins, E. Experimental electron density overlapping in hydrogen bonds: Topology vs. Energetics. Chem. Phys. Lett. 1999, 300, 745–748. [Google Scholar] [CrossRef]
  33. Lu, C.; Chen, P.; Li, C.; Wang, J. Study of intermolecular interaction between small molecules and carbon nanobelt: Electrostatic, exchange, dispersive and inductive forces. Catalysts 2022, 12, 561. [Google Scholar] [CrossRef]
  34. Patkowski, K. Recent developments in symmetry-adapted perturbation theory. Wiley Interdiscip. Rev. Comput. Mol. Sci. 2020, 10, e1452. [Google Scholar] [CrossRef]
  35. Hohenstein, E.G.; Sherrill, C.D. Wavefunction methods for noncovalent interactions. Wiley Interdiscip. Rev. Comput. Mol. Sci. 2012, 2, 304–326. [Google Scholar] [CrossRef]
  36. Szalewicz, K. Symmetry-adapted perturbation theory of intermolecular forces. Wiley Interdiscip. Rev. Comput. Mol. Sci. 2012, 2, 254–272. [Google Scholar] [CrossRef]
  37. Lu, C.; Yu, J.; Sheng, H.; Jiang, Y.; Zhao, F.; Wang, J. Linear and nonlinear photon-induced cross bridge/space charge transfer in stc molecular crystals. Nanomaterials 2022, 12, 535. [Google Scholar] [CrossRef]
  38. Lu, C.; Jiang, F.; Wang, J. [6,6]CNB with controllable external electric field deformation: A theoretical study of the structure-function relationship. Mater. Res. Express 2022, 9, 064001. [Google Scholar] [CrossRef]
  39. Chen, X.; Lu, C.; Wang, L.; Wang, J. Angle-resolved one and two-photon absorption spectrum in twisted bilayer graphene quantum dots. Spectrochim. Acta Part A Mol. Biomol. Spectrosc. 2022, 271, 120894. [Google Scholar] [CrossRef]
  40. Mu, X.; Wang, X.; Quan, J.; Sun, M. Photoinduced charge transfer in donor-bridge-acceptor in one-and two-photon absorption: Sequential and superexchange mechanisms. J. Phys. Chem. C 2020, 124, 4968–4981. [Google Scholar] [CrossRef]
Figure 1. The structural diagrams of (a) BDBT, (b) TCNB, and (c) BDBT–TCNB co-crystals. Gold, blue, yellow, and white spheres represent carbon, nitrogen, sulfur, and hydrogen atoms, respectively.
Figure 1. The structural diagrams of (a) BDBT, (b) TCNB, and (c) BDBT–TCNB co-crystals. Gold, blue, yellow, and white spheres represent carbon, nitrogen, sulfur, and hydrogen atoms, respectively.
Nanomaterials 12 02757 g001
Figure 2. IGMH diagrams for (a) dimer 1, (b) dimer 2, (c) dimer 3, and (d) dimer 4. The orange lines are interaction paths, and the red spheres are bond critical points.
Figure 2. IGMH diagrams for (a) dimer 1, (b) dimer 2, (c) dimer 3, and (d) dimer 4. The orange lines are interaction paths, and the red spheres are bond critical points.
Nanomaterials 12 02757 g002
Figure 3. Electrostatic potential overlay diagrams for (a) dimer 1, (b) dimer 2, (c) dimer 3, and (d) dimer 4.
Figure 3. Electrostatic potential overlay diagrams for (a) dimer 1, (b) dimer 2, (c) dimer 3, and (d) dimer 4.
Nanomaterials 12 02757 g003
Figure 4. (a) The electron density and energy density at the BCPs. (b) The total interaction energy of dimers and their components.
Figure 4. (a) The electron density and energy density at the BCPs. (b) The total interaction energy of dimers and their components.
Nanomaterials 12 02757 g004
Figure 5. (a) The one-photon absorption spectrum and (b) the two-photon absorption spectrum of the BTC.
Figure 5. (a) The one-photon absorption spectrum and (b) the two-photon absorption spectrum of the BTC.
Nanomaterials 12 02757 g005
Figure 6. CDDs and TDMs of (a,b) S2, (c,d) S4, (e,f) S6, and (g,h) S7 in one-photon absorption. The red and blue isosurfaces represent the electrons and holes, respectively.
Figure 6. CDDs and TDMs of (a,b) S2, (c,d) S4, (e,f) S6, and (g,h) S7 in one-photon absorption. The red and blue isosurfaces represent the electrons and holes, respectively.
Nanomaterials 12 02757 g006
Figure 7. CDDs and TDMs of (a,b) S4→S5, (c,d) S0→S4, (e,f) S7→S8, and (g,h) S0→S7 in two-photon absorption. The red and blue isosurfaces represent the electrons and holes, respectively.
Figure 7. CDDs and TDMs of (a,b) S4→S5, (c,d) S0→S4, (e,f) S7→S8, and (g,h) S0→S7 in two-photon absorption. The red and blue isosurfaces represent the electrons and holes, respectively.
Nanomaterials 12 02757 g007
Figure 8. CDDs and TDMs of (a,b) S2→S7, (c,d) S0→S2, (e,f) S6→S7, and (g,h) S0→S6 in two-photon absorption. The red and blue isosurfaces represent the electrons and holes, respectively.
Figure 8. CDDs and TDMs of (a,b) S2→S7, (c,d) S0→S2, (e,f) S6→S7, and (g,h) S0→S6 in two-photon absorption. The red and blue isosurfaces represent the electrons and holes, respectively.
Nanomaterials 12 02757 g008
Figure 9. CDDs and TDMs of (a,b) S6→S10, (c,d) S0→S6, (e,f) S9→S10, and (g,h) S0→S9 in two-photon absorption. The red and blue isosurfaces represent the electrons and holes, respectively.
Figure 9. CDDs and TDMs of (a,b) S6→S10, (c,d) S0→S6, (e,f) S9→S10, and (g,h) S0→S9 in two-photon absorption. The red and blue isosurfaces represent the electrons and holes, respectively.
Nanomaterials 12 02757 g009
Table 1. Transition indices of S2, S4, S6, and S7 in one-photon absorption.
Table 1. Transition indices of S2, S4, S6, and S7 in one-photon absorption.
D (Å)SrH (Å)t (Å)E (eV)HDIEDI
S20.0430.2025.700−2.5972.8634.465.51
S40.4750.21912.196−2.4083.0123.865.57
S61.1040.26411.674−3.2843.0544.185.89
S72.6410.2394.8990.1933.0925.056.56
Table 2. Transition dipole moments of the first-step transition and the second-step transition of each excited state in two-photon absorption.
Table 2. Transition dipole moments of the first-step transition and the second-step transition of each excited state in two-photon absorption.
TPA StatesProcessTransition Dipole Moment
S5 ϕ S 0 μ ϕ S 4 ϕ S 4 μ ϕ S 5 1.135→24.263
S7 ϕ S 0 μ ϕ S 2 ϕ S 2 μ ϕ S 7 0.596→0.143
ϕ S 0 μ ϕ S 6 ϕ S 6 μ ϕ S 7 0.786→0.054
S8 ϕ S 0 μ ϕ S 7 ϕ S 7 μ ϕ S 8 1.422→28.729
S10 ϕ S 0 μ ϕ S 6 ϕ S 6 μ ϕ S 10 0.786→0.291
ϕ S 0 μ ϕ S 9 ϕ S 9 μ ϕ S 10 0.079→3.477
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Lu, C.; Li, N.; Jin, Y.; Sun, Y.; Wang, J. Physical Mechanisms of Intermolecular Interactions and Cross-Space Charge Transfer in Two-Photon BDBT-TCNB Co-Crystals. Nanomaterials 2022, 12, 2757. https://doi.org/10.3390/nano12162757

AMA Style

Lu C, Li N, Jin Y, Sun Y, Wang J. Physical Mechanisms of Intermolecular Interactions and Cross-Space Charge Transfer in Two-Photon BDBT-TCNB Co-Crystals. Nanomaterials. 2022; 12(16):2757. https://doi.org/10.3390/nano12162757

Chicago/Turabian Style

Lu, Chen, Ning Li, Ying Jin, Ying Sun, and Jingang Wang. 2022. "Physical Mechanisms of Intermolecular Interactions and Cross-Space Charge Transfer in Two-Photon BDBT-TCNB Co-Crystals" Nanomaterials 12, no. 16: 2757. https://doi.org/10.3390/nano12162757

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop