Synthesis, Characterization, and Fluorescence Properties of Two New Heterocyclic Compounds Containing 1,5-Dioxaspiro Group
MicroScale Science Institute, Department of Chemistry, Chemical Engineering and Environmental Engineering, Weifang University, Weifang 261061, China
*
Authors to whom correspondence should be addressed.
Crystals 2018, 8(7), 269; https://doi.org/10.3390/cryst8070269
Submission received: 21 May 2018
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Revised: 25 June 2018
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Accepted: 26 June 2018
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Published: 27 June 2018
(This article belongs to the Section Crystal Engineering)
Abstract
:A precursor, C21H29NO8 (A1) was prepared by reactions of 1,1-dimethoxy-N,N-dimethylmethanamine and 1,5-dioxaspiro[5.5]undecane-2,4-dione. The new N-containing heterocyclic compound, C19H19NO4 (B1) was obtained by adding A1 into ethanol solution of o-toluidine. The crystal structure determination of two compounds were both found to belong to the triclinic P-1 space group. The precursor includes one (C2H8N)+ cation and one (C19H21O8)− anion, which constituted a chained structure by N–H···O intra- and intermolecular interactions. The title compound (B1) formed a 3D-network structure by weak C–H···O intermolecular interactions and π···π stacking interactions. The fluorescent behaviors of A1 and B1 in ethanol solution were discussed. The result shows that they exhibit blue and purplish blue emission, respectively.
1. Introduction
Heterocyclic compounds and their derivatives have been widely used in agronomy and medicine because of their unique biological activity. For example, the CYP1B1 inhibitors with heterocyclic chalcones were useful to treat glaucoma and ischemia [1]. The cholinesterase inhibitors including pyrazolo[1,5-c]quinazolines showed anti-inflammatory and analgesic activity [2]. A novel insecticide with pyridine group had a strong effect on imidacloprid (IMI)-resistant rice pests [3]. The complexes with thiosemicarbazide motif possessed antimicrobial activity [4]. Three heterocyclic homoprostanoids derivatives showed antioxidant and anti-inflammatory activity [5]. Recently, fluorescence properties of heterocyclic compounds have also received much more attention. For example, dibenzo[a,c][1,2,5] tiadiazolo [3,4-i]phenazine [6], fluorimetric [7], hydroxyphenylquinazolinone [8], 3-hydroxyflavone derivative [9], carbazole schiff base [10], have been applied to fluorescence chemosensor or probe. Alkynylgold(III) complexes [11], pyrene-pyrazoline [12], piro-annulated benzimidazole host [13] have been used as organic light-emitting devices. Based on these reasons, different heterocyclic compounds were designed and synthesized by our group for ten years [14,15,16,17]. Considering that chemical property of compounds containing 1,5-dioxaspiro group will be different with other heterocyclic compounds, two new spiroheterocyclic compounds: C21H29NO8 (A1) and C19H19NO4 (B1) are designed and synthesized (Scheme 1). In comparison to our earlier work [17], the present route used 1,1-dimethoxy-N,N-dimethylmethanamine instead of trimethoxymethane as raw materials, which the reaction time was more faster and the purity was higher. Furthermore, to the best our knowledge, there is no report for the synthesis of heterocyclic compounds containing 1,5-dioxaspiro group with 1,1-dimethoxy-N,N-dimethylmethanamin and 1,5-dioxaspiro[5.5]undecane-2,4-dione.
2. Materials and Methods
2.1. Materials and Characterization
Elemental analyses were carried out on an Elementar Vario EL III elemental analyzer (Elementar, Hanau, Germany). IR data were determined on FT IR-650 spectrophotometer Nicolet Instrument Inc., Madison, WI, USA). NMR spectra were recorded on a Bruker Avance-500 spectrometer (Bruker, Elisabethhof, The Netherlands) with CD3COCD3 as the solvent. Photoluminescent (PL) spectra were recorded in a RF-5301PC spectrometer (Shimadzu, Kyoto, Japan).
2.2. Synthetic Procedures of A1 and B1
1,1-dimethoxy-N,N-dimethylmethanamine (1.19 g, 10 mmol) was added dropwise to a suspension of 1,5-dioxaspiro[5.5]undecane-2,4-dione (1.84 g, 10 mmol) of absolute ethanol (25 mL) at 22~25 °C. The mixture continued reacting 2 h, then 1,1-dimethoxy-N,N-dimethylmethan amine (0.119 g, 1 mmol) was added. The above solution continued stirring for another 1.5 h. Then the mixture was evaporated at room temperature. The yellow precipitate was filtered off and recrystallized from ethanol to afford intermediate A1 (1.73 g), Yield (41%). m.p.: 151.2~151.3 °C. Elemental analysis Calcd. (%), For C21 H29 N O8: C, 59.56; H, 6.90; N, 3.31. Found: C, 60.30; H, 6.71; N, 3.10. 1H-NMR (500 MHz, CD3COCD3): 8.53 (s, 1H, CH-anionic part), 8.14 (m, 2H, NH2+), 2.84 (s, 6H, –(CH3)2) 1.95~2.07 (m, 8H, cyclohexane–H), 1.46 (m, 12H, cyclohexane–H). 13C-NMR (500 MHz, CD3COCD3): δ = 22.38 (CH2, C3/C5/C16/C18, cyclohexane), 24.57 (CH2, C4/C17, cyclohexane), 28.48–29.38 (CH2, C2/C6/C15/C19, cyclohexane), 35.41 (CH3, C20/C21, N–(CH3)2), 94.44 (C, C1/C14, cyclohexane), 101.51 (C, C8/C10/C11, 1,3-dioxane ring), 149.86 (C, C7/C9/C12/C13, 1,3-dioxane ring).
A mixture of salt A1 (4.23 g, 10 mmol) and o-toluidine (1.07 g, 10 mmol) in absolute ethanol (15 mL) was stirred for 1.5 h. Then the solution was also evaporated at room temperature. The yellow precipitate was filtered off and recrystallized from ethanol to afford the compound B1 (1.053 g), Yield (35%). m.p.: 144.9~145.4 °C. Elemental analysis Calcd. (%), For C17 H19 N O4: C, 67.76; H, 6.36; N, 4.65; Found: C, 67.90; H, 6.28; N, 4.58. 1H-NMR (500 MHz, CD3COCD3): 8.65 (s, 1H, –NH), 8.51 (s, 2H, –CH–), 7.22 (t 1H, J = 6.2 Hz, Ar–H), 7.35 (t, 2H, J = 9.7 Hz, Ar–H) 7.65 (d, 1H, J = 3.2 Hz Ar–H), 2.42 (s, 1H, –CH3), 2.06~2.10 (m, 4H, cyclohexane–H), 1.46~1.69 (m, 6H, cyclohexane–H). 13C-NMR (500 MHz, CD3COCD3): δ = 16.32 (CH3, C17, Ar–CH3), 24.12 (CH2, C1/C3, cyclohexane), 28.87 (CH2, C2, cyclohexane), 35.45 (CH2, C4/C6, cyclohexane), 94.44 (CH2, C5, cyclohexane), 116.83 (C, C12, phenyl ring), 126.29 (C, C14, phenyl ring), 127.58 (C, C16, phenyl ring), 128.02 (C, C13, phenyl ring), 131.22 (C, C15, phenyl ring) 137.05 (C, C11, phenyl ring), 149.81(C, C8, 1,3-dioxane ring) 152.83 (CH, C10, 1,3-dioxane ring), 165.21(C, C7/C9, 1,3-dioxane ring).
2.3. Crystal Data and Structure Refinement
Yellow and block crystals of A1 and B1 were mounted on Spider area detector. Their structures were solved and expanded by SHELXL-2015 and SHELXT-2015 [18]. Crystallographic data of two compounds are listed in Table 1. The aromatic H atoms of A1 and B1 were refined with riding coordinates and the C–H distance is 0.93–0.97 Å, the Uiso(H) values were set to 1.2 Ueq(C). However, the methyl H atoms of A1 were refined as rotating groups and the C–H distance is 0.96 Å, the Uiso(H) values were 1.5 Ueq(C).
3. Results and Discussion
3.1. Crystal Structure Determination of A1 and B1
As shown in Figure 1 and Table 2, N-containing heterocyclic intermediate (C19H21O8)− (C2H8N)+ (A1) is a salt which containing one (C19H21O8)− anion and one (C2H8N)+ cation. Two 1,5-dioxaspiro moieties are bridged by the central C(10) atom, which forms conjugated system (C(8)=C(10)–C(11)). Bond lengths C(8)–C(10) (1.373(2) Å) and C(10)–C(11) (1.396(3) Å) are between C=C double bond and C–C single bond. The bond angle of C(8)=C(10)–C(11) 131.80(16)° resembles to our earlier report (131.19(1)°) [16]. 1,5-dioxaspiro moiety and (o-tolylamino)methylene moiety are also linked by the central C(10) atom in B1, which forms C(8)=C(10)–N(1). The bond lengths of C(8)=C(10) (1.380(2) Å) and N(1)–C(10) (1.314(2) Å) are little lager than similar structures (1.371(7), 1.308(7) [17]. The bond angle of C(8)=C(10)–N(1) (125.12(16)°) is in agreement to what was previously reported (127.0(5)°, 125.05(14)°) [17].
In A1, (C19 H21 O8)− anion connected with (C2 H8 N)+ cation by N(1)–H(1A)···O(5) intramolecular interaction, the distances of N(1)···O(5) is 2.750(2) Å and N(1)–H(1B)···O(6) intermolecular interaction, the distances of N(1)···O(6) is 2.776(2) Å (Table 3). The molecule of A1 forms a 1D-chained structure by above all hydrogen bonds (Figure 2). In B1, N–H···O intramolecular interaction, weak C–H···O intermolecular interactions are present (Table 3). The C(12) atom with O(1) atom forms weak C–H···O intermolecular interaction, the distance of which is 3.2265 Å. In the meantime, two types of π···π stacking interactions are also present in the packing diagram, with a centroid-centroid separation of 3.370 Å and 3.543 Å, respectively. Above weak C–H···O intermolecular interactions and π···π stacking interactions constitute a 3D-network structure of B1 (Figure 2 and Figure 3).
3.2. Spectroscopic Properties of A1 and B1
In A1, the sharp peaks at 1703, 1686, 1246, 1212 cm−1 are due to the C=O and C–O vibrations of (C19 H21 O8)− anion, as shown in Figure 4. In B1, the sharp peaks at 1717, 1678, 1250, 1200 cm−1 are due to the C=O and C–O vibrations of C19 H19 N O4, which resembles to our earlier report [16,17]. A similar peak at 1631 cm−1 and 1625 cm−1 is present, respectively, which indicting C=C stretching vibration of C(8)=C(10)–C(11) in (A1) and C(8)=C(10)–N(1) (B1). The difference of the two compounds is that B1 exhibits sharp peaks at 1597 cm−1 (C=C), 1436 cm−1 (C–C), 752 cm−1 (νC–H of the phenyl ring. These facts were in accordance with the X-ray diffraction results.
The emission spectra of two compounds in dilute ethanol solution were discussed, as shown in Figure 5. The intermediate A1 exhibits bright blue emission with peak at 484 nm (Figure 6), while the excitation wavelength is at 239 nm. A sharp emission band of B1 was observed at 508 nm, when the excitation wavelength is at 252 nm. Its luminescent emission lies in the purplish blue region. In addition, because of containing (o-tolylamino)methylene chromophore [19], the emission of B1 was red-shifted 24 nm than A1, and the relative intensity was increasing. These facts indicate that the two compounds are potential fluorescent materials.
4. Conclusions
Two new heterocyclic compounds: dimethylammonium(2,4-dioxo-1,5-dioxaspiro[5.5]undecan-3-yl)(2,4-dioxo-1,5-dioxaspiro[5.5]undecan-3-ylidene)methanide (A1) and 3- ((o-tolylamino) methylene)-1,5-dioxaspiro[5.5] undecane-2,4-dione (B1) were designed and prepared by a new route because of faster reaction time and higher purities. The results show that the two compounds both belong to the triclinic, P-1 space group. A chained structure of A1 was constituted by N–H···O hydrogen bonds. In B1, weak C–H···O intermolecular interactions and π···π stacking interactions form a 3D-network structure. A1 and B1 exhibit blue and purplish-blue emission, respectively, indicating that they are potential fluorescent materials.
Author Contributions
Y.L. and G.J. performed the experiments. J.J. and W.Z. analysed the data. W.Z. wrote the paper.
Funding
The authors acknowledge the support the Natural Science Foundation of Shandong Province (No. ZR2017BEE038) and Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green (No. 2017-K29).
Conflicts of Interest
The authors declare no conflict of interest.
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Scheme 1.
Preparation of A1 and B1.
Figure 1.
ORTEP drawing of A1 and B1 with thermal ellipsoids at 30% probability level.
Figure 2.
1D-chained structure of A1 and 3D-network structure of B1.
Figure 3.
The packing representation of A1 and B1.
Figure 4.
Infrared spectra of A1 and B1.
Figure 5.
Emission spectra of A1 and B1 in dilute ethanol solutions at room temperature (λex(max) = 239 nm, λem(max) = 484 nm; λex(max) = 252 nm, λem(max) = 508 nm).
Figure 5.
Emission spectra of A1 and B1 in dilute ethanol solutions at room temperature (λex(max) = 239 nm, λem(max) = 484 nm; λex(max) = 252 nm, λem(max) = 508 nm).
Figure 6.
The color coordinates of A1 and B1.
Table 1.
Crystallographic data and depository number for A1 and B1.
| Compounds | A1 | B1 |
|---|---|---|
| Formula | C21H29NO8 | C19H19NO4 |
| CCDC No. | 1843487 | 1489653 |
| Mr | 423.45 | 301.33 |
| Crystal System, Space group | Triclinic, P-1 | Triclinic, P-1 |
| a, b, c (Å) | 9.399 (3), 9.708 (3), 12.512 (4) | 6.9229 (14), 8.4594 (17), 13.795 (3) |
| α, β, γ (°) | 89.624 (5), 76.334 (5), 75.042 (5) | 104.19 (3), 90.29 (3), 101.27 (3) |
| Crystal Size (mm) | 0.35 × 0.31 × 0.23 | 0.25 × 0.16 × 0.14 |
| Wavelength (Å) | 0.71073 | 0.71073 |
| θ Ranges (°) | 3.170~27.485 | 3.00~27.480 |
| V (Å3) | 1069.9 (6) | 766.9 (3) |
| Z | 2 | 2 |
| F(000) | 452 | 320 |
| D/g·cm−3 | 1.314 | 1.305 |
| μ/ mm−1 | 0.101 | 0.097 |
| −h, h/−k, k/−l, l | −11: 12; −12: 12; −16: 16 | −8: 8; −10: 10; −17: 17 |
| Total, unique and [I > 2σ(I)] reflections | 9715, 4749, 2971 | 7496, 3490, 2171 |
| No. of reflections, restraints, parameters | 4749, 1, 273 | 3490, 0, 199 |
| R(int) | 0.0443 | 0.0320 |
| S | 0.980 | 1.030 |
| R1/wR2 (I > 2σ(I)) R1/wR2 (all data) | 0.0574/0.1333 0.0840/0.1489 | 0.0555/0.1474 0.0813/0.1769 |
| ∆ρmax/∆ρmin/e Å−3 | 0.323/−0.202 | 0.437/−0.250 |
Table 2.
Selected bond distances (A°) and angles (deg) of A1 and B1.
| A1 | B1 | ||
|---|---|---|---|
| Bond | Dist. | Bond | Dist. |
| C(8)–C(10) | 1.373(2) | C(8)–C(10) | 1.380(2) |
| C(10)–C(11) | 1.396(2) | C(8)–C(9) | 1.443(2) |
| O(8)–C(13) | 1.355(2) | C(8)–C(7) | 1.443(3) |
| O(1)–C(1) | 1.432(2) | N(1)–C(10) | 1.314(2) |
| O(1)–C(7) | 1.359(2) | N(1)–C(11) | 1.418(2) |
| C(1)–O(2) | 1.440(2) | O(1)–C(7) | 1.211(2) |
| O(2)–C(9) | 1.365(2) | O(2)–C(9) | 1.216(2) |
| Angle | (°) | Angle | (°) |
| C(8)–C(10)–C(11) | 131.80(16) | N(1)–C(10)–C(8) | 125.12(16) |
| C(10)–C(8)–C(7) | 124.20(17) | C(10)–N(1)–C(11) | 126.83(14) |
| C(10)–C(11)–C(12) | 123.86(15) | C(10)–C(8)–C(9) | 121.40(15) |
| C(10)–C(11)–C(13) | 117.04(15) | C(10)–C(8)–C(7) | 117.80(15) |
| C(13)–C(11)–C(12) | 117.18(15) | C(9)–C(8)–C(7) | 120.24(14) |
| C(7)–C(8)–C(9) | 117.93(16) | C(12)–C(11)–C(16) | 120.87(15) |
| C(10)–C(8)–C(7) | 124.20(17) | C(12)–C(11)–N(1) | 120.38(14) |
| C(10)–C(8)–C(9) | 117.50(16) | C(16)–C(11)–N(1) | 118.75(14) |
Table 3.
Intra- and intermolecular distances and π···π interactions of A1 and B1.
| D–H···A | Symmetry | D–H (Å) | H···A (Å) | D···A (Å) | ∠D–H···A (°) |
|---|---|---|---|---|---|
| N(1)–H(1A)···O(5) A1 | Intra | 0.89 | 1.95 | 2.750 (2) | 149.4 |
| N(1)–H(1B)···O(6) A1 | x−1,y,z | 0.89 | 1.89 | 2.776 (2) | 170.5 |
| N(1)–H(1A)···O(2) B1 | Intra | 0.8600 | 2.0696 | 2.7267 (2) | 132.65 |
| C(12)–H(12A)···O(1) B1 | x−1, 2−y, x−z | 0.9300 | 2.3182 | 3.2265 (2) | 165.33 |
| ring | Symmetry | Dihedral angels (°) | dπ···π(Å) | dc–c (Å) | |
| Cg(3)···Cg(3) a B1 | –x, 1−y, x−z | 0 | 4.354 | 3.370 | |
| Cg(3)···Cg(3) a B1 | x−1, 1−y, x−z | 0 | 4.685 | 3.543 | |
a Cg(3) ring denotes phenyl ring of B1: C(11)–C(16).
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MDPI and ACS Style
Zeng, W.; Jiang, J.; Jiang, G.; Li, Y. Synthesis, Characterization, and Fluorescence Properties of Two New Heterocyclic Compounds Containing 1,5-Dioxaspiro Group. Crystals 2018, 8, 269. https://doi.org/10.3390/cryst8070269
AMA Style
Zeng W, Jiang J, Jiang G, Li Y. Synthesis, Characterization, and Fluorescence Properties of Two New Heterocyclic Compounds Containing 1,5-Dioxaspiro Group. Crystals. 2018; 8(7):269. https://doi.org/10.3390/cryst8070269
Chicago/Turabian StyleZeng, Wulan, Jinhe Jiang, Guanyu Jiang, and Yuehui Li. 2018. "Synthesis, Characterization, and Fluorescence Properties of Two New Heterocyclic Compounds Containing 1,5-Dioxaspiro Group" Crystals 8, no. 7: 269. https://doi.org/10.3390/cryst8070269
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