Molecular Marriage via Charge Transfer Interaction ... - ACS Publications

Subscriber access provided by UB + Fachbibliothek Chemie | (FU-Bibliothekssystem)

Article

Molecular Marriage via Charge Transfer Interaction in Organic Charge Transfer Co-crystals toward Solid-state Fluorescence Modulation Arshad Khan, Mingliang Wang, Hao Sun, Rabia Usman, Man Du, and Chunxiang Xu Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.6b01636 • Publication Date (Web): 18 Jan 2017 Downloaded from http://pubs.acs.org on January 22, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Crystal Growth & Design is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

Molecular Marriage via Charge Transfer Interaction in Organic Charge Transfer Co-crystals toward Solid-state Fluorescence Modulation

Arshad Khan a, Mingliang Wang*a, Rabia Usmana , Hao Sun a, Man Du a, Chunxiang Xu b*

† School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, P. R. China ‡ State Key Laboratory of Bioelectronics, Southeast University, Nanjing 210096, P. R. China

*Corresponding author. Tel.: +862585092237. E-mail address: (M.W.) [email protected]; (C.X.) [email protected]

ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Abstract: A set of three new binary-component charge transfer (CT) complexes (Ia, Ib and Ic) based on anthracene derivatives, 1-acetyl-3-naphthyl--(9-anthryl)-2-pyrazoline (ANNP)/1acetyl-3-(4-methoxyphenyl)-5-(9-anthryl)-2-pyrazoline

(AMAP)/1-acetyl-3-thiophene-5-(9-

anthryl)-2-pyrazoline (ATAP) as donors (D) and 1,2,4,5-tetracyanobenzene (TCNB) as acceptor (A) were fabricated via molecular self-assembly and comprehensively characterized. Crystal structural analysis revealed that acceptor molecules become sandwiched in a face to face manner between the anthracene units through charge transfer, hydrogen bond and π···π interactions forming CT organic co-crystals with the unique mixed stacking of D··A··D··A··D (Ib and Ic) and DAD···DAD (Ia) arrangement. All these crystals displayed significant enhancement and red-shift in fluorescence and color tunable emission such as blue to orange in solid state. Remarkably, the solid state luminescence efficiency of these CT co-crystals has been improved in comparison to pristine donors. Based on structural analysis, the mixed stacking mode between π-stacked donors and acceptor result in CT transition state which should be responsible for these behaviors of crystals. The present study demonstrates that using co-crystal strategy could provide these unique mixed stacking CT assemblies, which may have high potential in optoelectronic applications considering their high solid-state luminescence efficiency.


Page 2 of 23

Page 3 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Introduction Research on the organic solid-state fluorescent materials is gaining remarkable attention in the view of their appealing applications in various fields1-5. Recent studies on the properties of organic solid functional materials for example, optical and electronic: demonstrate that these characteristics are not only determined by the chemical structure of molecular components but also by their relative molecular packing toward the design of a fantastic library of luminescent materials6. Perhaps most remarkable is the effect of adjusting different supramolecular interactions in the solid state on the bulk properties of the organic fluorescent compounds that eventually result in obtaining target materials with promising tunable characteristics

7, 8

. To date, it has been well established that

altering the luminance properties of organic solid involve the modulation of supramolecular interactions, but most important is how to realize such materials is another issue that modern materials scientists are facing. Several strategies have been discovered to obtain tunable luminescent materials since; research on single component materials saw limited success through traditional structural tailoring techniques9. In this respect, self-assembly of two components systems offers a unique alternative approach to develop molecular crystals (more properly Co-crystal) through different non-covalent routes namely Charge transfer (CT) interactions, hydrogen bond and π···π interactions10-13. Among various different noncovalent interactions, CT interactions have been used to achieve various tailor-made molecular organic co-crystals with tunable fluorescence that has wide application in optoelectronics14-17. At the same time to obtain these molecular solids is not without a challenge since effective co-crystallization is not easy approach owing to the different solubility behavior of the two components. Hence, it is of great importance to have



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 23

proper knowledge about various supramolecular interactions for the rational design of the desired molecular solids with fantastic photo-physical properties. Anthracene containing fluorophores present an exciting class of compounds that has been widely explored owing to their excellent optical and electronic properties18-20. In our previous work, we investigated structure-property relationship by regulating the stacking modes of anthracene to obtain co-crystals with interesting properties8, 21. Herein, we demonstrate successful illustration of obtaining high solid state fluorescence efficiency through modulation of molecular packing structures involving different anthracene derivatives 1-acetyl-3-naphthyl-5-(9-anthryl)-2-pyrazoline (ANNP), 1acetyl-3-(4-methoxyphenyl)-5-(9-anthryl)-2-pyrazoline thiophene-5-(9-anthryl)-2-pyrazoline

(ATAP)

as

(AMAP), donors

(D)

and and

1-acetyl-31,2,4,5-

tetracyanobenzene (TCNB) as acceptor (A) (scheme 1) via classical solution cocrystallization process displaying tunable emission from blue to orange. The choice of the acceptor is based on the fact that it can form CT superstructures with electron rich aromatic donors to achieve tunable emission, which has recently been employed to obtain D-A mixed stacking CT assemblies exhibiting excellent properties15, 20, 22. Thus using cocrystal strategy, we regulate the stacking modes of anthracene derivatives in solid state upon the introduction of acceptor towards tuning and modifying the physicochemical properties of molecular solid properties to obtain mixed stacking CT structures with promising properties.

Experimental Material synthesis Three types of anthracene derivatives were synthesized as electron rich components for this study by a known protocol23 (1H NMR figure S1-S3 of the supporting information).


Page 5 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1,2,4,5-tetracyanobenzene (CAS: 712-74-3) and solvents were purchased commercially and used directly without further purification. Co-crystal preparation Cocrystal Ia. ANNP (0.1 mmol) and TCNB (0.1 mmol) were dissolved in ethanol/ethyl acetate (1:1) mixed solvents in a glass vial. After two weeks of slow evaporation at room temperature, orange color crystals appeared in the mother solution which was isolated prior to complete evaporation of the solution. Cocrystal Ib. AMAP (0.1 mmol) and TCNB (0.1 mmol) were dissolved in ethanol/ethyl acetate (1:1) mixed solvents in a glass vial. After two weeks of slow evaporation at room temperature orange color crystals appeared in the mother solution which was isolated prior to complete evaporation of the solution Cocrystal Ic. ATAP (0.1 mmol) and TCNB (0.1 mmol) were dissolved in ethanol/DCM (1:1) mixed solvents in a glass vial. After two weeks of slow evaporation at room temperature orange color crystals appeared in the mother solution which was isolated prior to complete evaporation of the solution. Measurement Studies PXRD patterns for the solids were recorded using a 18KW advance X-ray diffractometer with Cu Kα radiation (λ=1.54056 Å). Single X-ray diffraction data for crystals Ia, Ib and Ic were collected on Nonius CAD4 diffractometer with Mo Kα radiation (λ= 0.71073 Å). The structures were solved by direct methods using the SHELXL-2014/7 program and refined anisotropically using full-matrix least-squares procedure24. All non-hydrogen atoms were refined anisotropically and were inserted at their calculated positions and fixed at their positions. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) patterns were recorded with a Mettler-Toledo TGA/DSC Thermogravimetric Analyzer



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

with the temperature scanned from 50 to 300 °C at 10 °C /min under a dry nitrogen purge (20 mL/min). Spectroscopic Measurements. 1H NMR spectra were recorded at 303 K on a Bruker Avance 500 MHz NMR spectrometer using CDCl3 as a solvent and TMS as an internal standard. UV-Vis absorption spectra were collected on a Shimadzu UV-3600 spectrometer. Fluorescence spectra were obtained on a Horiba FluoroMax 4 spectrofluorometer. Infrared spectra were collected on a Bruker Tensor 27 FT-IR spectrometer with KBr pellets. Fluorescence microscopy images. Fluorescence microscopy images were collected on Olympus BX51 imaging system excited at 365 nm. Solid fluorescent quantum yields were performed using Quanta-φ accessory with excitation wavelength at 320 nm. Fluorescence lifetime measurements for the crystals were undertaken by the timecorrelated single-photon counting technique (TCSPC) using a TemPro Fluorescence Lifetime System (Horiba Jobin Yvon) equipped with a NanoLed excitation source of 340 nm.

Results and discussion Co-crystal structures Single-Crystal X-Ray Diffraction (SCXRD) allows us to identify supramolecular interactions and self-assembly fashion in the solid state. Co-crystal Ia comprises of one donor and half molecule of the acceptor in 2:1 ratio while Ib and Ic crystalize in 1:1 stoichiometric ratio of donor and acceptor in an asymmetric unit. All the crystallographic data of these crystals are documented in Table 1. In the CT co-crystal, Ia each acceptor molecules is sandwiched in a face to face manner between two anthracene units (DAD···DAD) while in Ib and Ic, acceptor molecules aligned alternatively forming typical mixed stack (D···A···D···A···D) arrangement


Page 6 of 23

Page 7 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


through charge transfer interactions which can be verified by their interplanar (dπ-π) and closest centroid distance (dc-c) (Table 3). Co-crystal Ia crystallized in monoclinic crystal system with the space group of P21/c and comprises of one molecule of donor and half molecule of the acceptor in the asymmetric unit.

In the crystal structure, acceptor molecules adopt two kinds of

orientations between the two heterochiral molecules of donors via hydrogen bonds (CH···N and C-H···O) and charge transfer interactions (Table 2 and 3) generating racemic 1D hydrogen bond chain extending along a axis. The parallel stacked chains associate together via weak C-H··· π interactions (Table 4) between the two adjacent ANNP molecules along the b axis (fig 1). Co-crystal 1b forms columnar framework established via charge transfer interactions, hydrogen bonds (C-H···N and C-H···O) and π···π interactions (Table 2 and 3) (see fig 2) between the homochiral donor molecules to form a 2D structure. Acceptor molecules act as a bridge to connect two neighboring AMAP molecules with opposite chirality. Moreover, C-H··· π and π···π interactions (Table 4) contribute to stack neighboring AMAP units to extend further the network along b axis. Co-crystal Ic structure consists of alternate mixed stacking of donor and acceptor molecules bonded by hydrogen bonds (C-H···N and C-H···O) and CT interactions (Table 2 and 3) to make column structure. The acceptor (TCNB) and the donor (ATAP) molecules are arranged alternately in a face to face stacking geometry with a nonuniform interplanar separation distance of 3.391 Å and 3.469 Å, to form two homochiral chains (fig 3). The two homochiral chains with different chirality further stacked together through weak C-H··· π and π ··· π to (Table 4) to form 2D structure along c axis.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 23

Powder X-ray diffraction analysis To affirm the phase purity and homogeneity, the samples were subjected to X-ray powder diffraction (XRPD) analysis. The findings of the PXRD analysis are depicted in fig 4, indicating peaks positions are in agreement with that simulated values from their single crystal data, confirming their highly crystalline structure Thermal analysis Differential scanning calorimetry (DSC) and Thermogravimetric (TGA) analysis were performed to appraise the potential formation of CT co-crystals and to investigate thermal characteristic of the solids. The method identifies establishment of co-crystals by the appearance of a unique single endothermic peak owing to the melting of the cocrystals. TGA profile depicts (fig 5) that all these co-crystals exhibit the starting point of decomposition from around 220°C and they are 86.65%, 95.09% and 90.52% for Ia, Ib, and Ic respectively. DSC thermogram illustrates single phase transition endothermic peaks centered at 230oC, 225oC and 224oC for Ia, Ib and Ic respectively, corresponding to the melting and decomposition enthalpy of these co-crystals.

Spectroscopic Measurement Vibration spectra In order to identify the existence of the D-A interactions within the co-crystals, vibration spectra was undertaken. Examination of the IR spectra (fig 6) reveals distinct changes in the frequency shifts of main bands in the co-crystals compared to the parent components. The occurrence of C≡N stretching peak of free TCNB appear to be similar in all three complexes with a small red shift of 1-2 cm−1. It is interesting to note that, the C-H stretching bands (3049 cm−1 and 3113 cm−1) of free TCNB

shown a decrease in

frequency shift upon co-crystals formation with donor molecules (Ia: 3040-3105, Ib: 3036-3101, Ic: 3038-3105) owing to CT effect which could explain the different π-π


Page 9 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


distance in these crystals. These changes in the vibration spectra are consistent with the previous literature 15 and encourage us to further affirm the presence of CT state.

Photo-physical characteristics The CT interaction and photo-physical properties for the as obtained three co-crystals are completely revealed by solid-state UV and fluorescence measurement. As illustrated in fig. 7 all the three co-crystals showed a new distinct broad red shifted bands in between 419-535 nm, reflecting CT interaction between donor-acceptor in these crystals25 relative to the pristine donors which did not show such bands. In fact, these CT absorption bands and color difference of the crystals are noticeable features of CT interaction co-crystals. This phenomenon can be further verified by observing the solid materials under the UV light exhibit different color from blue to orange which can be facilely be detected by the naked eye (fig. 8). Remarkably, emission spectra (fig. 9) of the as-prepared crystals showed bathochromic shifts with a broad structureless emission peaks (Ia; 566nm, Ib; 591nm, Ic; 603nm) appear in the visible region relative to their single components, which implies the formation of typical CT transition state in these solids 26. In contrast, all the co-crystals retain the emission peaks of two components in solution state suggesting no CT interaction between D-A (figure S4-S6 of the supporting information). From the above results a conclusion can be drawn that tunable emission can be accomplished via formation of the binary component system rather than monomeric one and different noncovalent interactions between D-A trigger the self-assembly. Moreover, based on the preceding of structural analysis, because the co-crystals exhibit unlike emission bands and color changes from blue to orange may be related to different CT interactions between the D-A molecules (Table 3).



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

To get further insight into the optical-physical properties of these CT complexes, emission quantum yields (ΦF) and fluorescence lifetimes (τF) were measured. For the CT complexes, it is found that emission takes place with highest ΦF of 41.38% for Ia, 38.85% for Ib and 34.06% for Ic co-crystal in the solid state (Table 5). Moreover, fluorescence life time of these CT solids improved compared to pristine donors summarized in table 5 and the corresponding decays curves are presented in fig 10. This increase in fluorescence life time is attributed to the fact that the CT state generated by TCNB is much more stable than the S0-S126.

Conclusion In summary, we have developed mixed CT solid state fluorescent materials based on two components system showing blue to orange light emissions upon UV irradiation. Crystal structural investigation establishes that molecular recognition between D-A results in adjusting the stacking modes of the donor molecules upon introduction of the acceptor. Due to the unique mixed stacking of D··A··D··A··D (Ib and Ic) and DAD···DAD (Ia) in the crystalline state, where CT state has been achieved leading to enhance

improvement in optical photo-physical properties, therefore such packing arrangement is beneficial for the development of efficient solid state materials for the next-generation luminescent materials27. ASSOCIATED CONTENT Supporting Information 1

H NMR for the donors compounds, fluorescence spectra in solution and X-ray

crystallographic information files (CIF) for Ia, Ib and Ic; This information is available free of charge via the Internet at http://pubs.acs.org. AUTHOR INFORMATION Corresponding Authors


Page 10 of 23

Page 11 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


*E-mail: [email protected]. Tel: +862585092237. Notes The authors declare no competing financial interest. ACKNOWLEDGMENT This project gets the supports of the National Basic Research Program of China (2011CB302004).

References (1)

Kang, S. J.; Ahn, S.; Kim, J. B.; Schenck, C.; Hiszpanski, A. M.; Oh, S.; Schiros,

T.; Loo, Y.-L.; Nuckolls, C., Using Self-Organization To Control Morphology in Molecular Photovoltaics. Journal of the American Chemical Society 2013, 135, (6), 2207-2212. (2)

Zhang, Y.; Jiang, M.; Han, G.-C.; Zhao, K.; Tang, B. Z.; Wong, K. S., Solvent

Effect and Two-Photon Optical Properties of Triphenylamine-Based Donor–Acceptor Fluorophores. The Journal of Physical Chemistry C 2015, 119, (49), 27630-27638. (3)

Strassert, C. A.; Chien, C.-H.; Galvez Lopez, M. D.; Kourkoulos, D.; Hertel, D.;

Meerholz, K.; De Cola, L., Switching On Luminescence by the Self-Assembly of a Platinum(II) Complex into Gelating Nanofibers and Electroluminescent Films. Angewandte Chemie International Edition 2011, 50, (4), 946-950. (4)

Schmidtke, J.; Stille, W.; Finkelmann, H.; Kim, S. T., Laser Emission in a Dye

Doped Cholesteric Polymer Network. Advanced Materials 2002, 14, (10), 746-749. (5)

Yan, D.; Lu, J.; Ma, J.; Wei, M.; Evans, D. G.; Duan, X., Reversibly

Thermochromic, Fluorescent Ultrathin Films with a Supramolecular Architecture. Angewandte Chemie International Edition 2011, 50, (3), 720-723. (6)

Chung, J. W.; Yoon, S.-J.; Lim, S.-J.; An, B.-K.; Park, S. Y., Dual-Mode

Switching in Highly Fluorescent Organogels: Binary Logic Gates with Optical/Thermal Inputs. Angewandte Chemie International Edition 2009, 48, (38), 7030-7034. (7)

Yan, D.; Delori, A.; Lloyd, G. O.; Friščić, T.; Day, G. M.; Jones, W.; Lu, J.; Wei,

M.; Evans, D. G.; Duan, X., A Cocrystal Strategy to Tune the Luminescent Properties of Stilbene-Type Organic Solid-State Materials. Angewandte Chemie International Edition 2011, 50, (52), 12483-12486.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(8)

Dong, B.; Wang, M.; Xu, C.; Feng, Q.; Wang, Y., Tuning Solid-State

Fluorescence of a Twisted π-Conjugated Molecule by Regulating the Arrangement of Anthracene Fluorophores. Crystal Growth & Design 2012, 12, (12), 5986-5993. (9)

Blackburn, A. K.; Sue, A. C. H.; Shveyd, A. K.; Cao, D.; Tayi, A.; Narayanan,

A.; Rolczynski, B. S.; Szarko, J. M.; Bozdemir, O. A.; Wakabayashi, R.; Lehrman, J. A.; Kahr, B.; Chen, L. X.; Nassar, M. S.; Stupp, S. I.; Stoddart, J. F., Lock-Arm Supramolecular Ordering: A Molecular Construction Set for Cocrystallizing Organic Charge Transfer Complexes. Journal of the American Chemical Society 2014, 136, (49), 17224-17235. (10)

Park, S. K.; Varghese, S.; Kim, J. H.; Yoon, S.-J.; Kwon, O. K.; An, B.-K.;

Gierschner, J.; Park, S. Y., Tailor-Made Highly Luminescent and Ambipolar Transporting Organic Mixed Stacked Charge-Transfer Crystals: An Isometric Donor– Acceptor Approach. Journal of the American Chemical Society 2013, 135, (12), 47574764. (11)

Nguyen, H. L.; Horton, P. N.; Hursthouse, M. B.; Legon, A. C.; Bruce, D. W.,

Halogen Bonding: A New Interaction for Liquid Crystal Formation. Journal of the American Chemical Society 2004, 126, (1), 16-17. (12)

Morimoto, M.; Irie, M., A Diarylethene Cocrystal that Converts Light into

Mechanical Work. Journal of the American Chemical Society 2010, 132, (40), 1417214178. (13)

Pan, F.; Wong, M. S.; Gramlich, V.; Bosshard, C.; Günter, P., A Novel and

Perfectly Aligned Highly Electro−Optic Organic Cocrystal of a Merocyanine Dye and 2,4-Dihydroxybenzaldehyde. Journal of the American Chemical Society 1996, 118, (26), 6315-6316. (14)

Zhu, W.; Zheng, R.; Zhen, Y.; Yu, Z.; Dong, H.; Fu, H.; Shi, Q.; Hu, W.,

Rational Design of Charge-Transfer Interactions in Halogen-Bonded Co-crystals toward Versatile Solid-State Optoelectronics. Journal of the American Chemical Society 2015, 137, (34), 11038-11046. (15)

Zhu, W.; Zhu, L.; Zou, Y.; Wu, Y.; Zhen, Y.; Dong, H.; Fu, H.; Wei, Z.; Shi, Q.;

Hu, W., Deepening Insights of Charge Transfer and Photophysics in a Novel Donor– Acceptor Cocrystal for Waveguide Couplers and Photonic Logic Computation. Advanced Materials 2016, 28, (28), 5954-5962. (16)

Imai, Y.; Kamon, K.; Kido, S.; Harada, T.; Tajima, N.; Sato, T.; Kuroda, R.;

Matsubara, Y., Formation and crystal structure of the chiral charge-transfer complex


Page 12 of 23

Page 13 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


with

axially

chiral

1,1[prime

or

minute]-bis-2-naphthol

derivatives

and

tetracyanobenzene. CrystEngComm 2009, 11, (4), 620-624. (17)

Liu, G.; Liu, J.; Liu, Y.; Tao, X., Oriented Single-Crystal-to-Single-Crystal

Phase Transition with Dramatic Changes in the Dimensions of Crystals. Journal of the American Chemical Society 2014, 136, (2), 590-593. (18)

Feng, Q.; Wang, M.; Xu, C.; Khan, A.; Wu, X.; Lu, J.; Wei, X., Investigation of

molecular arrangements and solid-state fluorescence properties of solvates and cocrystals of 1-acetyl-3-phenyl-5-(9-anthryl)-2-pyrazoline. CrystEngComm 2014, 16, (26), 5820-5826. (19)

Wu, C.-H.; Chien, C.-H.; Hsu, F.-M.; Shih, P.-I.; Shu, C.-F., Efficient non-doped

blue-light-emitting diodes incorporating an anthracene derivative end-capped with fluorene groups. Journal of Materials Chemistry 2009, 19, (10), 1464-1470. (20)

Danel, K.; Huang, T.-H.; Lin, J. T.; Tao, Y.-T.; Chuen, C.-H., Blue-Emitting

Anthracenes with End-Capping Diarylamines. Chemistry of Materials 2002, 14, (9), 3860-3865. (21)

Khan, A.; Wang, M.; Usman, R.; Lu, J.; Sun, H.; Du, M.; Zhang, R.; Xu, C.,

Organic charge-transfer complexes for the selective accommodation of aromatic isomers using anthracene derivatives and TCNQ. New Journal of Chemistry 2016, 40, (6), 52775284. (22)

Lei, Y.-L.; Jin, Y.; Zhou, D.-Y.; Gu, W.; Shi, X.-B.; Liao, L.-S.; Lee, S.-T.,

White-Light Emitting Microtubes of Mixed Organic Charge-Transfer Complexes. Advanced Materials 2012, 24, (39), 5345-5351. (23)

Wang, M.-L.; Dong, B.-L.; Li, Y.-H., 1-[5-(Anthracen-9-yl)-3-phenyl-4,5-

dihydro-1H-pyrazol-1-yl]ethanone. Acta Crystallographica Section E: Structure Reports Online 2011, 67, (Pt 1), o94-o94. (24)

Sheldrick,

G.,

Crystal

structure

refinement

with

SHELXL.

Acta

Crystallographica Section C 2015, 71, (1), 3-8. (25)

Zhu, W.; Zheng, R.; Fu, X.; Fu, H.; Shi, Q.; Zhen, Y.; Dong, H.; Hu, W.,

Revealing the Charge-Transfer Interactions in Self-Assembled Organic Cocrystals: Two-Dimensional Photonic Applications. Angewandte Chemie International Edition 2015, 54, (23), 6785-6789. (26)

Li, S.; Lin, Y.; Yan, D., Two-component molecular cocrystals of 9-

acetylanthracene with highly tunable one-/two-photon fluorescence and aggregation induced emission. Journal of Materials Chemistry C 2016, 4, (13), 2527-2534.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(27)

Page 14 of 23

Yu, W.; Wang, X.-Y.; Li, J.; Li, Z.-T.; Yan, Y.-K.; Wang, W.; Pei, J., A

photoconductive

charge-transfer

crystal

with

mixed-stacking

donor-acceptor

heterojunctions within the lattice. Chemical Communications 2013, 49, (1), 54-56.


Page 15 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Captions of scheme, figures and Tables Scheme 1. Chemical structures of acceptor and donor molecules and b) Co-crystal

structures of the studied D–A complexes Crystal stacking fashion of Co-crystal Ia. The turquiose and lavender color molecules present two kinds of chiral molecules of donor. Figure 2. View of the columnar structure of crystal 1b. The pink and gray color molecules present two kinds of chiral molecules of donor Figure 3. a) Non uniform interplaner separation distance between acceptor and donor molecules b) CT and hydrogen bonded columns in co-crystal Ic. The Pink and orange color molecules present two kinds of chiral molecules of donor. Figure 4. PXRD pattern of CT co-crystals simulated (black) and experimental (red). Figure 5. DSC and TGA profile of crystals Figure 1.

Figure 6.

FT-IR spectra of CT crystals

Figure 7.

Solid state absorption spectra of CT complexes

Figure 8.

Fluorescence microscopy images of CT co-crystals (λex=365nm).

Figure 9.

Fluorescence spectra of CT crystals (λex=365nm).

Figure 10. Fluorescence decay curves for the three crystals Table 1.

Details of Crystallographic Data for the CT co-crystals

Table 2.

Intermolecular Hydrogen Bonds Parameters in CT crystals

Table 3.

Face-to-face π-stacking interactions between acceptor and anthracene moieties

Table 4.

C-H···π and π-π interactions in the crystals

Table 5.

Optical-physical property data of crystals



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Scheme 1

Figure 1


Page 16 of 23

Page 17 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 2

Figure 3



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Figure 4

Figure 5

Figure 6


Page 18 of 23

Page 19 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 7

Figure 8

Figure 9



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 23

Figure 10

Table 1

Crystal

Ia

Ib

Ic

Formula

C34H23N4O

C36H24N6O2

C33H20N6OS

Temperature/K

293

293

293

Crystal size/mm3

0.30×0.20×0.10

0.20×0.10×0.10

0.20×0.20×0.10

Morphology

Block

Block

Rod

Crystal system

Monoclinic

Triclinic

Monoclinic

Space group

P21/c

Pī

P21/c

a/ Å

15.821(3)

7.6650(15)

19.549(4)

b/ Å

17.653(4)

9.4610(19)

7.3430(15)

c/ Å

9.6890(19)

20.649(4)

19.666(4)

α/deg

90

95.22(3)

90

β/deg

93.57(3)

97.82(3)

93.12(3)

γ/deg

90

94.54(3)

90

V/ Å3

2700.8(9)

1471.0(5)

2818.8(10)

Z

4

2

4

ρ (calcd)/Mg m-3

1.238

1.293 1.293

θ Range for data

1.29-25.41

1.043-25.38 1.00-25.38

collection/°

1052

1136 596

F(000) Ref collected/unique

4960/4960

5412/ 5412

5183/ 5183

R1, wR2(I >2σ(I))

0.0702, 0.1219

0.0888, 0.1734

0.0805, 0.1136

R1, w R2 (all data)

0.1650, 0.1469

0.1814, 0.2071

0.1964, 0.1427

Goodness-of-fit,S

1.026

1.023

1.014

CCDC

1515448

1515449

1515450

Table 2 Crystal

D-H (Å)

H···A (Å)

D···A (Å)


∠D-H···A (°)

Page 21 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Ia C30-H30A···O

0.929

2.151

2.934

141

C4-H4A···N4

0.930

2.651

3.480

148

C3-H3A…N3

0.930

2.653

3.414

139

C26-H26A···N3

0.931

2.703

3.629

173

C32-H32A···N4

0.930

2.533

3.528

135

C10-H10A···N6

0.959

2.628

3.541

144

C15-H15A···O1

0.931

2.538

3.357

147

C29-H29A···O2

0.931

2.103

2.931

148

C27-H27A···O

0.929

2.087

2.926

149

C24-H24A···N4

0.930

2.615

3.326

134

C4-H4A···N6

0.930

2.625

3.416

143

Ib

Ic

Table 3 Crystal

Interaction

dπ-π, dc-c(Å)[a]

Angle (°) [b]

Ia

TCNB ···anthracene

3.485, 3.970

7.80

Ib

TCNB··· anthracene

3.447, 3.779

3.11

Ic


3.392, 3.889

4.53


3.468, 4.206

4.53

[a] The interplanar separation (dπ-π) and the closest centroid distance (dc-c) and [b] the angles were measured between the mean planes of TCNB and anthracene rings (for π-π interaction) respectively.

Table 4 Crystal

interaction

distance (Å)[d]

Angle (°) [e]

Ia

C10-H10A···anthracene

2.900

145.74

C23-H23A···anthracene

2.913

157.55

C2-H2C···anthracene

2.968

165.95

benzene···pyrazoline

3.352

6.85

C3-H3A···thiophene

3.051

135.57

Ib

Ic



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 23

pyrazoline···thiophene

3.492

12

C23-H23C···thiophene

3.021

156.27

d

The distances were measured from the hydrogen atom to the center of the aromatic ring (for C −H···π or π ···π interactions). eThe angles were measured between C −H −c (for C −H···π interactions)

Table 5 Crystals

ANNP

AMAP

ATAP

Ia

Ib

Ic

PLQY ΦF (%)

3.5

4.0

2.8

41.4

38.9

34.0

Fluorescence lifetime τF (ns)

3.4

3.3

4.2

342

290

422


Page 23 of 23

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


For table of content use only

Molecular Marriage via Charge Transfer Interaction in Organic Charge Transfer Co-crystals toward Solid-state Fluorescence Modulation

Arshad Khan a, Mingliang Wang*a, Rabia Usmana , Hao Sun a, Man Du a, Chunxiang Xu b* † School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, P. R. China ‡ State Key Laboratory of Bioelectronics, Southeast University, Nanjing 210096, P. R. China

We Report here three mixed Charge Transfer D-A co-crystals that show tunable emission from blue to orange. Due to the unique mixed stacking of D··A··D··A··D (Ib and Ic) and DAD···DAD (Ia) arrangement in the crystalline state, where CT state has been

achieved leading to enhance improvement in optical photo-physical properties.


Molecular Marriage via Charge Transfer Interaction ... - ACS Publications

Recommend Documents