Next Article in Journal
The Interplay between Various σ- and π-Hole Interactions of Trigonal Boron and Trigonal Pyramidal Arsenic Triiodides
Previous Article in Journal
Structural Aspects of Porphyrins for Functional Materials Applications
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Crystals
Volume 7
Issue 7
10.3390/cryst7070224
crystals-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Inorganic Anions Regulate the Phase Transition in Two Organic Cation Salts Containing [(4-Nitroanilinium)(18-crown-6)]+ Supramolecules

by
Yuan Chen
,
Yang Liu
*,
Binzu Gao
,
Chuli Zhu
and
Zunqi Liu
*
Chemical Engineering College, Xinjiang Agricultural University, Urumqi 830052, China
*
Authors to whom correspondence should be addressed.
Crystals 2017, 7(7), 224; https://doi.org/10.3390/cryst7070224
Submission received: 28 May 2017 / Revised: 30 June 2017 / Accepted: 6 July 2017 / Published: 15 July 2017
Browse Figures
Versions Notes

Abstract

:
Two novel inorganic–organic hybrid supramolecular assemblies, namely, (4-HNA)(18-crown-6)(HSO4) (1) and (4-HNA)2(18-crown-6)2(PF6)2(CH3OH) (2) (4-HNA = 4-nitroanilinium), were synthesized and characterized by infrared spectroscopy, single X-ray diffraction, differential scanning calorimetry (DSC), and temperature-dependent dielectric measurements. The two compounds underwent reversible phase transitions at about 255 K and 265 K, respectively. These phase transitions were revealed and confirmed by the thermal anomalies in DSC measurements and abrupt dielectric anomalies during heating. The phase transition may have originated from the [(4-HNA)(18-crown-6)]+ supramolecular cation. The inorganic anions tuned the crystal packings, and thus influenced the phase-transition points and types. The variable-temperature X-ray diffraction data for crystal 1 revealed the occurrence of a phase transition in the high-temperature phase with the space group of P21/c and in the low-temperature phase with the space group of P21/n. Crystal 2 exhibited the same space group P21/c at different temperatures. The results indicated that crystals 1 and 2 both underwent an iso-structural phase transition.

1. Introduction

From both theoretical and applied viewpoints, phase-transition compounds are popular and valuable in increasing the general understanding of structure–property relations and exploring functional materials with novel physical properties [1,2,3,4,5,6,7,8,9,10]. Phase-transition crystalline materials are usually accompanied by an abrupt change in some physical properties around the transition temperature. These materials show great applications in molecular sensors, switches, and data storage devices [11,12,13,14,15]. In particular, energy harvesting occurs during phase changes; thus, phase-transition materials may serve as energy-saving materials. Designing special inorganic-organic hybrid compounds with molecular dielectrics is an effective method for synthesizing ideal phase-transition materials [16,17,18,19].
Phase-transition inorganic–organic hybrid compounds display novel crystal structures and interesting physical properties, including ferroelectric, dielectric, optical, and piezoelectric properties [20,21,22,23,24]. Among them, 15-crown-5 or 18-crown-6 are good candidates, owing to their variable conformation, such as [(RNH3)(18-crown-6)][A], where R is an alkyl or aryl group, and A is an anion. The driving force of these phase-transition compounds can be ascribed to the motional changes in the R–NH3﹢ guest cation (R = aryl group) or/and anionic units. The use of the R group as a molecular rotor or pendulum unit produces desirable properties [25,26,27,28,29]. As a result, the motion of organic ammonium cations changes their dynamic state. This alteration further leads to dielectric changes and ferroelectricity through the phase transitions between the disordered high-temperature phase (HTP) and ordered low-temperature phase (LTP) [30,31,32,33]. On the contrary, the asymmetric unit of the supramolecular adduct also contains counter anions. These anions are primarily tetrahedral ions, such as BF4﹣, ClO4﹣, and IO4﹣. These anions easily change position with varied temperatures and weak interactions, because of their higher symmetry and relatively small volume [34,35]. In fact, inorganic anions (such as HSO4﹣) have rarely been explored. Given these findings, in this work we report the syntheses of (4-HNA)(18-crown-6)(HSO4) (1) and (4-HNA)2(18-crown-6)2(PF6)2(CH3OH) (2) to determine other suitable geometric anions that can regulate a potential phase transition. The structures, phase transitions, and dielectric properties of the two anions are revealed in Scheme 1.

2. Results and Discussion

2.1. Crystal Structure of 1

The crystal structure of 1 was characterized at different temperatures by X-ray diffraction to confirm whether the phase transition was associated with structural changes. Compound 1 crystallized in the monoclinic space group P21/c with a = 10.450 (6) Å, b = 18.453 (11) Å, c =13.466 (8) Å, β = 112.672 (7)°, and V = 2396 (2) Å3 in the HTP at 296 K. At the LTP (100 K), crystal 1 crystallized in the monoclinic space group P21/n with small changes in cell parameters, i.e., a = 10.3715 (18) Å, b = 18.235 (3) Å, c =13.384 (3) Å, β = 112.736 (2)°, and V = 2334.4 (8) Å3 (Table 1).
The crystal structures of 1 are similar between the LTP and HTP structures. This result reveals that the asymmetric unit was composed of one cationic [(4-HNA)(18-crown-6)]+ moiety and one anionic HSO4﹣(Figure 1a). The 4-HNA cations were connected to the 18-crown-6 ring to form a supramolecular rotator–stator structure through N–H⋯O interactions between the –NH3+ group and the six O (O1, O2, O3, O4, O5, and O6) atoms of 18-crown-6. The average hydrogen-bonding N–O distances of 2.874 and 2.888 Å at 100 K and 296 K, respectively, were almost the same to those of the standard NH3﹢⋯O distance for the crown ether molecular-based system (Table S1). The π-plane of the 4-HNA cation was nearly perpendicular to the mean plane of the oxygen atoms. The N1 atom of the 4-HNA cations was located higher than the best plane of the oxygen atoms of the crown ring, rather than in the nesting position (Figure 1a). The dihedral angles between the aromatic ring and the crown ether ring were 92.48° (100 K) and 93.47° (296 K). In Figure 1b, the packing diagram of complex 1 is located along the a+c axis. The packing diagram for the LTP (100 K) indicates that the dimer structure of the two HSO4﹣anions is linked by O–H⋯O hydrogen bonds that fill in the space to form four [(4-HNA)(18-crown-6)]+ supramolecular cations. In addition, the O–H⋯O hydrogen-bonding interaction becomes stronger than the N–H⋯O hydrogen bonds with bond distances of 2.647 Å and 2.657 Å at 100 K and 296 K, respectively. This finding indicates that the movement of H protons was more difficult between the donor (O11) and acceptor atoms (O10). The most significant differences between the structures at 296 K and 100 K were the distances of the two crown ether rings. Compared with the distances at 100 K, those at 296 K changed from 4.208 Å to 4.063 Å. C–H⋯π interactions were noted in the [(4-HNA)(18-crown-6)]+ complex cations. The aromatic rings formed two C–H⋯π interactions with distances of 3.195 Å at 100 K and 3.267 Å at 296 K (Figure 2).

2.2. Crystal Structure of 2

The crystal structure of 2 was analyzed in HTP (296 K) and LTP (100 K) forms. When the HSO4﹣anion was replaced with the PF6﹣anion, compound 2 at both 296 K and 100 K crystallized in the monoclinic system with the same space group P21/c. Although the temperature changed, the space group of crystal 2 remained unchanged. Hence, no structural symmetry breaking occurred in this temperature range. Crystallographic data and details on the collection and refinement for 296 K and 100 K are listed in Table 1.
The asymmetric unit of compound 2 consisted of two independent [(4-HNA)(18-crown-6)]+ supramolecular cations, two PF6﹣anions, and one methanol molecule at 296 K and 100 K (Figure 3a). In contrast to the ordered HSO4﹣anions in 1, the PF6−anions in 2 were disordered at both 100 K and 296 K. The molecular structure of 2 with atomic labeling is shown in Figure 3a. The disordered PF6﹣anion and methanol molecules filled the structure between neighboring supramolecular cations (Figure 3b).
The most striking structural features in the LTP and HTP forms were the distances of the two crown ether rings. The distances of crystal 2 from the neighboring [(4-HNA)(18-crown-6)]+ supramolecular cations were 8.877 Å (100 K) and 9.082 Å (296 K) (Figure 4). Interestingly, it was found that obvious disorder phenomena occur in the HTP phase of the –NO2 group. The O14, O15, O16, O17 atoms of –NO2 group in supramolecular cations are distinctly disordered and occupy two sites (O14A, O14B, O15A, O15B, O16A, O16B, O17A, O17B). The occupation factors of oxygen atoms of –NO2 group are displayed in Table S2, suggesting that biased –NO2 group orientation was achieved in compound 2 (Figure 4b). The –NH3﹢ group resided in a perching position, and attained a configuration similar to that of crystal 1; the group was linked by the oxygen atoms of the crown ethers through the six N–H⋯O hydrogen bonds. Apparent hydrogen bonding interactions occurred between the nitrogen and oxygen atoms with bond lengths of 2.821–2.956 Å and 2.816–2.966 Å at 100 K and 296 K, respectively (Table S3). In crystal 2, the distance between two adjacent crown ether rings was nearly twice as long as that in crystal 1 at 100 K and 296 K (Figure 4). In crystal 1, the dimer structure of two HSO4−anions occupied a larger space volume, resulting in a relatively closer packing pattern for the [(4-HNA)(18-crown-6)]+ supramolecular cation. Furthermore, no C–H⋯π interactions existed in the supramolecular cations. However, weak π⋯π interactions were found between the aromatic rings of the [(4-HNA)(18-crown-6)]+ supramolecular cations. These interactions stabilized the crystal packing and formed the alternated inorganic–organic hybrid structure in the bc plane (Figure S1).

2.3. Differential Scanning Calorimetry

Differential scanning calorimetry (DSC) is commonly used to detect whether a compound displays a phase transition triggered by temperature. This approach is also used to confirm the existence of a heat anomaly during heating and cooling. When a compound undergoes a structural phase transition with a thermal entropy change, reversible heat anomalies are detected during heating and cooling. In the DSC spectrum obtained from crystal 1, a main endothermic peak and a main exothermic peak were observed at heating of 257 K and cooling of 252 K, respectively, with a 5 K hysteresis width (Figure 5a). These exothermic and endothermic peaks clearly reveal the occurrence of a reversible phase transition. The entropy change (∆S) of the phase transition was too low to be estimated from the DSC. The wide heat hysteresis and peak shapes reflect the characteristics of a first-order phase transition. The driving force of the phase transition was confirmed by evaluating the crystal structure across varying temperatures. For example, apparent differences were observed for the distances of two crown ether rings, with values of 4.063 Å at 100 K and 4.208 Å at 296 K. Additionally, the dihedral angle between the aromatic ring and the crown ring slightly changed from 92.48° in the LTP form to 93.47° in the HTP form.
Compared with the DSC measurements for crystal 1, those for crystal 2 were conducted within the temperature range 240–320 K, and revealed two anomalies at 266 K (heating) and 261 K (cooling) (Figure 5b). The thermal hysteresis was about 5 K, and the entropy change (∆S) of the phase transition was also too low to be estimated from the DSC. The almost non-existent hysteresis and small heat anomalies clearly reflect the continuous characteristic of the phase transition and thus effectively show features of a second-order phase transition. The distances of neighboring [(4-HNA)(18-crown-6)]+ supramolecular cations were 8.877 Å (100 K) and 9.082 Å (296 K) for crystal 2. For these reasons, crystals 1 and 2 both revealed reversible phase transitions despite containing different anions. This finding implies that the phase transition may have originated from the [(4-HNA)(18-crown-6)]+ supramolecular cations, a finding observed in similar compounds.

2.4. Dielectric Property

The variable-temperature dielectric response is another common method for studying phase transitions, especially at relatively high frequency ranges. This method is useful for identifying phase transitions. The temperature-dependent dielectric constant of the powder samples of crystals 1 and 2 were presented at four selected frequencies, namely, 5 KHz, 10 KHz, 100 KHz, and 1 MHz. Strong and significant dielectric anomalies were observed around the Tc. For crystal 1, the dielectric constant slowly increased with rising temperature below 250 K (Figure 6a). Interestingly, when the temperature neared 255 K, the dielectric constant sharply increased to a maximum value of 22.5 at 5 KHz. Then, the dielectric constant abruptly decreased and achieved a minimum value of 11.91 at about 265 K. The sharp peak-like dielectric anomaly further confirms the phase transition in 1, which is consistent with the DSC result.
For crystal 2, the dielectric constant slowly increased, with an abrupt slope at around 265 K during heating (Figure 6b). The maximum dielectric constant value was about 8.14 at 5 KHz; this value corresponds to a high dielectric state. The dielectric constant of 2 achieved a sudden rapid increase at room temperature. Compound 2 attained small DSC and dielectric anomalies at about 265 K; this pattern is a feature of a second-order phase transition. The relatively weak dielectric anomaly of crystal 2 relative to that of 1 is presented in the temperature ranges. This finding is probably due to the unchanged electric polarizations of ions and molecules in the crystal lattice.
The temperature-dependent dielectric response of compound 1 and 2 both display one sharp peak-like anomaly upon heating at 255 K and 265 K, respectively. However, there is no distinct dielectric anomaly for 1 and 2 upon cooling. For the cooling and heating processes, the DSC curves for the two crystals exhibit relatively weak exothermic and endothermic peaks. Phase transition occurs in compound 1 and 2, thus leading to dielectric anomalies with the increase in temperature. Because crystal 1 and 2 have undergone phase transitions of temperature variation once with the structural changes, there is no distinct dielectric response with the decrease in temperature.
The variable-temperature crystal structures of 1 and 2 reveal that the phase transition and dielectric anomaly in the same temperature range may be caused by the structural interactions and different crystal packing patterns in the LTP and HTP forms. Crystals 1 and 2 achieved significant differences at 296 K and 100 K, i.e., the distances between the two adjacent crown rings of 2 were 8.877 Å (100 K) and 9.082 Å (296 K). These distances were larger than the values of 4.063 Å (100 K) and 4.208 Å (296 K) in 1. This finding suggests that the inorganic anion tunes the crystal and hence affects the phase-transition points and types.

3. Materials and Methods

3.1. Materials and Instrument

The chemicals and solvents employed in this work were commercially obtained as chemically pure and used without any further purification. Infrared (IR) spectra were obtained using an Affinity-1 spectrophotometer and KBr pellets in the 4000–400 cm−1 region. Thermogravimetric analyses (TGA) were performed with a SHIMADZU DTG-60 thermal analyzer in a nitrogen atmosphere from room temperature to 800 K with a heating rate of 10 K/min using aluminum crucibles (Figures S2 and S3). Elemental analyses were conducted using a Vario EL Elementar Analysensysteme GmbH at the TRW Research Collaboration Center, YanZhou, Shandong. DSC measurements were performed by heating and cooling the samples (16 mg) within the temperature range 210–280 K on a TA Q2000 DSC instrument under nitrogen. Meanwhile, the crystal dielectric constants were measured with a TH2828 Precision LCR meter within the frequency range of 500 Hz–1 MHz, applied voltage of 1.0 V, and temperature sweeping rate of approximately 2 K/min.
X-ray single crystal diffraction: X-ray diffraction experiments were conducted on crystals 1 and 2 using a Bruker CCD diffractometer with Moka radiation (λ = 0.71073 Å) at 100 K and 296 K. The structures of 1 and 2 were elucidated by direct methods and refined by the full-matrix method based on F2 using the SHELXL 97 software package. All non-hydrogen atoms were anisotropically refined, and the positions of all hydrogen atoms were geometrically generated. CCDC:1529205 (100 K), CCDC:1529207 (296 K) for 1 and CCDC:1529231 (100 K), CCDC:1529232 (296 K) for 2 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Center via www.ccdc.cam.ac.uk/data_request/cif.

3.2. Preparation of Compound (4-HNA)(18-crown-6)(HSO4) (1)

Yellow crystals 1 were obtained by evaporating an alcohol solution containing 4-nitroaniline (20 mg), H2SO4 (50 mg), and 18-crown-6 (200 mg) at room temperature for 5 days to a 52% yield (based on 4-nitroaniline). The calculated percentage compositions of C, H, and N for C18H32N2O12S were 43.19% C, 6.44% H, and 5.60% N, respectively, whereas the measured percentage compositions were 43.11%, 6.42% H, and 5.76% N, respectively. The IR spectrum of the single crystal 1 is given in Figure S4.

3.3. Preparation of Compound (4-HNA)2(18-crown-6)2(PF6)2(CH3OH) (2)

Single crystals of 2 were prepared by slowly evaporating a mixture of HPF6 (50 mg), 4-nitroaniline (20 mg), and 18-crown-6 (200 mg) in methanol solution (50 mL). The methanol solution was allowed to stand for approximately 5 days under room temperature. The single crystals of salt 2 were colorless transparent crystals obtained at 58% yield. The calculated percentage compositions of C, H, and N for C37H66F12N4O17P2 were 39.37% C, 5.89% H, and 4.96% N, respectively, whereas the measured percentage compositions were 39.35% C, 5.87% H, and 4.89% N, respectively. The IR spectrum (KBr) of the single crystal 2 is presented in Figure S5.

4. Conclusions

Two inorganic–organic hybrid crystals based on the [(4-HNA)(18-crown-6)]+ supramolecular cation were reported in this study. Variable-temperature crystal structure analyses and thermal measurements (DSC) showed that crystals 1 and 2 exhibited similar crystal packings and underwent reversible phase transitions at 255 K and 265 K, respectively. The dielectric anomalies of crystals 1 and 2 in the temperature–frequency ranges further confirmed the existence of such phase transitions. These results indicated that the phase transitions may be caused by the [(4-HNA)(18-crown-6)]+ supramolecular cations. The inorganic anions (PF6﹣and HSO4﹣) played an important role in the crystal packing and regulated the phase-transition points and types.

Supplementary Materials

The following are available online at https://www.mdpi.com/2073-4352/7/7/224/s1. Arrangement of the supramolecular cations of crystal 2 (Figure S1); TG data and IR spectra of crystals 1 and 2 (Figures S2–S5); Hydrogen bond geometry of crystals 1 (Table S1); The occupation factor of oxygen atoms in –NO2 group for 296K (Table S2); Hydrogen bond geometry of crystals 2 (Table S3);

Acknowledgments

The present work was supported by prophase-sustentation fund of Xinjiang Agricultural University (Contract grant number: XJAU201511).

Author Contributions

Zunqi Liu designed the method and wrote the manuscript; Yuan Chen synthesized the crystal materials. Yang Liu and Binzu Gao supported the dielectric constant and DSC measurements. Chunli Zhu analyzed the crystal data of 1 and 2. All authors have given approval the final version of the paper.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Fu, H.; Cohen, R. Polarization rotation mechanism for ultrahigh electromechanical response in single-crystal piezoelectrics. Nature 2000, 403, 281–283. [Google Scholar] [PubMed]
  2. Horiuchi, S.; Tokunaga, Y.; Giovannetti, G.; Picozzi, S.; Itoh, H.; Shimano, R.; Kumai, R.; Tokura, Y. Above-room-temperature ferroelectricity in a single-component molecular crystal. Nature 2010, 463, 789–793. [Google Scholar] [CrossRef] [PubMed]
  3. Liao, W.Q.; Zhang, Y.; Hu, C.L.; Mao, J.G.; Ye, H.Y.; Li, P.F.; Huang, S.D.; Xiong, R.G. A lead-halide perovskite molecular ferroelectric semiconductor. Nat. Commun. 2015, 6, 7338–7345. [Google Scholar] [CrossRef] [PubMed]
  4. Yangui, A.; Sy, M.; Li, L.; Abid, Y.; Naumov, P.; Boukheddaden, K. Rapid and robust spatiotemporal dynamics of the first-order phase transition in crystals of the organic-inorganic perovskite (C12H25NH3)2PbI4. Sci. Rep. 2015, 5, 16634. [Google Scholar] [CrossRef] [PubMed]
  5. Yangui, A.; Pillet, S.; Mlayah, A.; Lusson, A.; Bouchez, G.; Triki, S.; Abid, Y.; Boukheddaden, K. Structural phase transition causing anomalous photoluminescence behavior in perovskite (C6H11NH3)2[PbI4]. J. Chem. Phys. 2015, 143, 224201. [Google Scholar] [CrossRef] [PubMed]
  6. Yangui, A.; Pillet, S.; Garrot, D.; Triki, S.; Abid, Y.; Boukheddaden, K. Evidence and detailed study of a second-order phase transition in the (C6H11NH3)2[PbI4] organic-inorganic hybrid material. J. Appl. Phys. 2015, 117, 115503. [Google Scholar] [CrossRef]
  7. Horiuchi, S.; Ishii, F.; Kumai, R.; Okimoto, Y.; Tachiban, H.; Nagaosa, N.; Tokura, Y. Ferroelectricity near room temperature in co-crystals of nonpolar organic molecules. Nat. Mater. 2005, 4, 163–166. [Google Scholar] [CrossRef] [PubMed]
  8. Akutagawa, T.; Koshinaka, H.; Sato, D.; Takeda, S.; Noro, S.I.; Takahashi, H.; Kumai, R.; Tokura, Y.; Nakamura, T. Ferroelectricity and polarity control in solid-state flip-flop supramolecular rotators. Nat. Mater. 2009, 8, 342–347. [Google Scholar] [CrossRef] [PubMed]
  9. Guo, P.C.; Chen, T.Y.; Ren, X.M.; Ning, W.H.; Jin, W. A low-κdielectric metal-organic-framework compound showing novel three-step dielectric relaxations originating from orientational motion of dipolar guest molecules. New J. Chem. 2014, 38, 2254–2257. [Google Scholar] [CrossRef]
  10. Lv, X.H.; Liao, W.Q.; Wang, Z.X.; Li, P.F.; Mao, C.Y.; Ye, H.Y. Design and prominent dielectric properties of a layered phase transition crystal: (cyclohexylmethylammonium)2CdCl4. Cryst. Growth Des. 2016, 16, 3912–3916. [Google Scholar] [CrossRef]
  11. Yangui, A.; Pillet, S.; Lusson, A.; Bendeif, E.E.; Triki, S.; Abid, Y.; Boukheddaden, K. Control of the white-light emission in the mixed two-dimensional hybrid perovskites (C6H11NH3)2[PbBr4-xIx]. J. Alloy. Compd. 2017, 699, 1122–1133. [Google Scholar] [CrossRef]
  12. Zhang, Y.; Ye, H.Y.; Fu, D.W.; Xiong, R.G. An order-disorder ferroelectric host-guest inclusion compound. Angew. Chem. Int. Ed. 2014, 53, 2114–2118. [Google Scholar] [CrossRef] [PubMed]
  13. Ye, H.Y.; Li, S.H.; Zhang, Y.; Zhou, L.; Deng, F.; Xiong, R.G. Solid state molecular dynamic investigation of an inclusion ferroelectric:[(2,6-diisopropylanilinium)([18]crown-6)]BF4. J. Am. Chem. Soc. 2014, 136, 10033–10040. [Google Scholar] [CrossRef] [PubMed]
  14. Mei, G.Q.; Liao, W.Q. Structural phase transitions coupled with prominent dielectric anomalies and dielectric relaxation in a one-dimensional organic-inorganic hybrid compound [(C3H4NS)[CdCl3]. J. Mater. Chem. C 2015, 3, 8535–8541. [Google Scholar] [CrossRef]
  15. Liu, Z.Q.; Kubo, K.; Noro, S.I.; Akutagawa, T.; Nakamura, T. Design of crystalline spaces for molecular rotation in crystals. Cryst. Growth Des. 2014, 14, 537–543. [Google Scholar] [CrossRef]
  16. Chen, C.H.; Mu, R.; Zhang, L.; Xu, G.C. Synthesis, crystal structure and disorder-order phase transition of a new diamine template metal sulfate, (C3H12N2)2[Cu(H2O)4(SO4)2](HSO4)2. CrystEngComm 2016, 18, 2719–2724. [Google Scholar] [CrossRef]
  17. Tang, Y.Z.; Yu, Y.M.; Xiong, J.B.; Tan, Y.H.; Wen, H.R. Unusual high-temperature reversible phase-transition behavior, structure, and dielectric-ferroelectric properties of two new crown ether clathrates. J. Am. Chem. Soc. 2015, 137, 13345–13351. [Google Scholar] [CrossRef] [PubMed]
  18. Sato, D.; Akutagawa, T.; Takeda, S.; Noro, S.I.; Nakamura, T. Supramolecular rotor: Adamantylammonium([18]crown-6) in [Ni(dmit)2]− salt. Inorg. Chem. 2007, 46, 363–365. [Google Scholar] [CrossRef] [PubMed]
  19. Jin, Y.; Yu, C.; Wang, Y.; Li, S.; Zhang, W. Synthesis and structural phase transitions of Copper(II) and Iron(III) complexes containing [(C8H12NO)(18-crown-6)]+ supramolecular cations. Z. Anorg. Allg. Chem. 2014, 640, 1499–1505. [Google Scholar] [CrossRef]
  20. Yu, H.Y.; Ge, J.Z.; Tang, Y.Y.; Li, P.F.; Zhang, Y.; You, Y.M.; Xiong, R.G. Molecular ferroelectric with most equivalent polarization directions induced by the plastic phase transition. J. Am. Chem. Soc. 2016, 138, 13175–13178. [Google Scholar]
  21. Zhang, Y.; Zhang, W.; Li, S.H.; Ye, Q.; Cai, H.L.; Deng, F.; Xiong, R.G.; Huang, S.D. Ferroelectricity induced by ordering of twisting motion in a molecular rotor. J. Am. Chem. Soc. 2012, 134, 11044–11049. [Google Scholar] [CrossRef] [PubMed]
  22. Ye, H.Y.; Cai, H.L.; Ge, J.-Z.; Xiong, R.-G. Reversible structural phase transition of pyridinium-4-carboxylic acid perchlorate. J. Appl. Cryst. 2010, 43, 1031–1035. [Google Scholar] [CrossRef]
  23. Wang, W.-X.; Fu, X.Q. Reversible phase transition of 4-ethoxybenzenammonium iodide. Z. Anorg. Allg. Chem. 2013, 639, 471–474. [Google Scholar] [CrossRef]
  24. Nishihara, S.; Akutagawa, T.; Hasegawa, T.; Fujiyama, S.; Nakamura, T.; Nakamura, T. Two polymorphs of (anilinium)(18-crown-6)[Ni(dmit)2]: Structure and magnetic properties. J. Solid State Chem. 2002, 168, 661–667. [Google Scholar] [CrossRef]
  25. Zhang, S.Y.; Li, J.; Zhang, Y.; Wen, H.R.; Du, Z.-Y. Hydrogen-bond-directed assemblies of [La(18-crown-6)(H2O)4](BiCl6)3H2O and [Nd(18-crown-6)(H2O)4](BiCl6)3.5H2O regulated by different symmetries. J. Mol. Struct. 2016, 1125, 227–233. [Google Scholar] [CrossRef]
  26. Akutagawa, T.; Shitagami, K.; Nishihara, S.; Takeda, S.; Hasegawa, T.; Nakamura, T.; Hosokoshi, Y.; Inoue, K.; Ikeuchi, S.; Miyazaki, Y.; et al. Molecular rotor of Cs2([18]crown-6)3 in the solid state coupled with the magnetism of [Ni(dmit)2]. J. Am. Chem. Soc. 2005, 127, 4397–4402. [Google Scholar] [CrossRef] [PubMed]
  27. Wang, W.X.; Zhu, R.Q.; Fu, X.Q.; Zhang, W. Crystal structure and dielectric property of (p-CH3OC6H4NH3)+(18-crown-6)∙H2PO4−∙2H3PO4. Z. Anorg. Allg. Chem. 2012, 638, 1123–1126. [Google Scholar] [CrossRef]
  28. Liu, Z.Q.; Liu, Y.; Wang, J.F.; Yang, G.F. A novel proton transfer supramolecular compound induced by N-H⋯O hydrogen bond through 18-crown-6: Syntheses, structure, and dielectric properties. Inorg. Chem. Commun. 2015, 61, 109–112. [Google Scholar] [CrossRef]
  29. Han, X.-B.; Hu, P.; Shi, C.; Zhang, W. Structure phase transition and dielectric transitions in a 1,4-diazabicyclo[2,2,2]octane (dabco) based organic crystal. J. Mol. Struct. 2017, 1127, 372–376. [Google Scholar] [CrossRef]
  30. Shi, P.P.; Ye, Q.; Li, Q.; Wang, H.T.; Fu, D.W.; Zhang, Y.; Xiong, R.G. Crystal structures, phase transitions, and switchable dielectric behaviors: Comparison of a series of N-heterocyclic ammonium perchlorates. Dalton Trans. 2015, 44, 8221–8231. [Google Scholar] [CrossRef] [PubMed]
  31. Wang, D.Y.; Qin, L.L.; Hou, X.L.; Ye, H.Y. Temperature-triggered phase transition in pyridazine hexafluorophosphate. Chin. Chem. Lett. 2015, 26, 145–148. [Google Scholar] [CrossRef]
  32. Liu, Z.Q.; Liu, Y.; Chen, Y.; Zhao, W.Q.; Fang, W.N. Synthesis, characterization, and phase transition of an inorganic-organic hybrid compound, [(3-nitroanilinium+)(18-crown-6)][IO4−](CH3OH). Chin. Chem. Lett. 2017, 28, 297–301. [Google Scholar] [CrossRef]
  33. Wang, H.-T.; Li, Q.; Shi, P.-P.; Zhou, L.; Zhang, Y.; Ye, Q.; Fu, D.-W. The structures and dielectric properties of high temperature phase transition compounds with 4-(dimethylamino)(pyridinium). Inorg. Chem. Commun. 2015, 62, 85–90. [Google Scholar] [CrossRef]
  34. Ye, Q.; Akutagawa, T.; Ye, H.Y.; Hang, T.; Ge, J.Z.; Xiong, R.G.; Noro, S.I.; Nakamura, T. Two novel coordination polymers constructed from 2,2′-bipyridine-3,3′-dicarboxylic acid 1,1′-dioxide ligands. CrystEngComm 2011, 13, 6185–6191. [Google Scholar] [CrossRef]
  35. Ye, Q.; Shi, P.P.; Chen, Z.Q.; Akutagawa, T.; Noro, S.I.; Nakamura, T. Flexible cis-cyclohexane-1,4-diammonium ion in magnetic [Ni(dmit)2] crystals. Eur. J. Inorg. Chem. 2012, 23, 3732–3739. [Google Scholar] [CrossRef]
Crystals 07 00224 sch001 550
Scheme 1. Structural formulae of compounds 1 and 2.
Scheme 1. Structural formulae of compounds 1 and 2.
Crystals 07 00224 sch001
Crystals 07 00224 g001 550
Figure 1. Crystal structure of crystal 1 at 100 K. (a) Asymmetric unit for crystal 1, dashed lines indicate hydrogen bonds; (b) Unit cell of crystal 1 viewed along the a + c axis. Most hydrogen atoms on carbon atoms are omitted for clarity.
Figure 1. Crystal structure of crystal 1 at 100 K. (a) Asymmetric unit for crystal 1, dashed lines indicate hydrogen bonds; (b) Unit cell of crystal 1 viewed along the a + c axis. Most hydrogen atoms on carbon atoms are omitted for clarity.
Crystals 07 00224 g001
Crystals 07 00224 g002 550
Figure 2. Arrangement of the supramolecular cations in 1 at 100 K (a) and 296 K (b) viewed in the a+c plane; the dashed lines show the C–H⋯π interactions.
Figure 2. Arrangement of the supramolecular cations in 1 at 100 K (a) and 296 K (b) viewed in the a+c plane; the dashed lines show the C–H⋯π interactions.
Crystals 07 00224 g002
Crystals 07 00224 g003 550
Figure 3. Asymmetric unit (a) and packing diagram (b) of crystal 2 viewing along the a-axis at 100 K and 296 K. Most of the hydrogen atoms on the carbon atoms are omitted for clarity.
Figure 3. Asymmetric unit (a) and packing diagram (b) of crystal 2 viewing along the a-axis at 100 K and 296 K. Most of the hydrogen atoms on the carbon atoms are omitted for clarity.
Crystals 07 00224 g003
Crystals 07 00224 g004 550
Figure 4. Arrangement of the supramolecular cations in 2 at 100 K (a) and 296 K (b) viewed along the a-axis; the dashed lines show the distance of the adjacent two crown ether rings.
Figure 4. Arrangement of the supramolecular cations in 2 at 100 K (a) and 296 K (b) viewed along the a-axis; the dashed lines show the distance of the adjacent two crown ether rings.
Crystals 07 00224 g004
Crystals 07 00224 g005 550
Figure 5. DSC curves of crystal 1 (a) and crystal 2 (b) in a heating-cooling cycle.
Figure 5. DSC curves of crystal 1 (a) and crystal 2 (b) in a heating-cooling cycle.
Crystals 07 00224 g005
Crystals 07 00224 g006 550
Figure 6. Dielectric properties for crystal 1 (a) and 2 (b) measured as a function of temperature under a frequency of 5 KHz to 1 MHz.
Figure 6. Dielectric properties for crystal 1 (a) and 2 (b) measured as a function of temperature under a frequency of 5 KHz to 1 MHz.
Crystals 07 00224 g006
Table
Table 1. Crystallographic data and structural refinement details for 1 and 2.
Table 1. Crystallographic data and structural refinement details for 1 and 2.
1-LTP1-HTP2-LTP2-HTP
Chemical formulaC18H32N2O12SC18H32N2O12SC37H68F12N4O17P2C37H68F12N4O17P2
Formula weight500.52500.521130.881130.88
Temperature/K100296100296
Crystal size (mm3)0.21 × 0.20 × 0.190.21 × 0.20 × 0.190.316 × 0.223 × 0.1390.316 × 0.223 × 0.139
Crystal systemmonoclinicmonoclinicmonoclinicmonoclinic
Space groupP21/nP21/cP21/cP21/c
a (Å)10.3715 (18)10.450 (6)10.9491 (9)10.9429 (9)
b (Å)18.235 (3)18.453 (11)23.701 (2)23.687 (2)
c (Å)13.384 (3)13.466 (8)21.9038 (16)21.8926 (16)
α (°)90.0090.0090.0090.00
β (°)112.736 (2)112.672 (7)113.961 (4)113.962 (4)
γ (°)90.0090.0090.0090.00
V (Å3)2334.4 (8)2396 (2)5194.3 (7)5185.6 (7)
Z4422
Dcalc (g·cm−1)1.4241.3881.3511.167
F(000)1064106422221946
m (mm−1)0.2040.1980.1680.112
Measured 2 range (°)0.999–25.010.999–25.010.992–24.500.981–25.01
Rint0.03720.05110.09920.0998
R (I > 2 (I)) [a]0.04420.07380.18200.1871
WR (all data) [b]0.10660.16080.31840.2917
GOF1.0391.0151.0200.988

Share and Cite

MDPI and ACS Style

Chen, Y.; Liu, Y.; Gao, B.; Zhu, C.; Liu, Z. Inorganic Anions Regulate the Phase Transition in Two Organic Cation Salts Containing [(4-Nitroanilinium)(18-crown-6)]+ Supramolecules. Crystals 2017, 7, 224. https://doi.org/10.3390/cryst7070224

AMA Style

Chen Y, Liu Y, Gao B, Zhu C, Liu Z. Inorganic Anions Regulate the Phase Transition in Two Organic Cation Salts Containing [(4-Nitroanilinium)(18-crown-6)]+ Supramolecules. Crystals. 2017; 7(7):224. https://doi.org/10.3390/cryst7070224

Chicago/Turabian Style

Chen, Yuan, Yang Liu, Binzu Gao, Chuli Zhu, and Zunqi Liu. 2017. "Inorganic Anions Regulate the Phase Transition in Two Organic Cation Salts Containing [(4-Nitroanilinium)(18-crown-6)]+ Supramolecules" Crystals 7, no. 7: 224. https://doi.org/10.3390/cryst7070224

APA Style

Chen, Y., Liu, Y., Gao, B., Zhu, C., & Liu, Z. (2017). Inorganic Anions Regulate the Phase Transition in Two Organic Cation Salts Containing [(4-Nitroanilinium)(18-crown-6)]+ Supramolecules. Crystals, 7(7), 224. https://doi.org/10.3390/cryst7070224

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