Hydrothermal Synthesis, Crystal structure, DFT and Application of a Dinuclear Cadmium(II) Complex Based on NPHSNPAB

Jin-Long DONG Zhen SONG Rui-Tao ZHU Ting-Ting ZHAO Hao-Yang LI Jian-Guo REN

Citation:  DONG Jin-Long, SONG Zhen, ZHU Rui-Tao, ZHAO Ting-Ting, LI Hao-Yang, REN Jian-Guo. Hydrothermal Synthesis, Crystal structure, DFT and Application of a Dinuclear Cadmium(II) Complex Based on NPHSNPAB[J]. Chinese Journal of Structural Chemistry, 2016, 35(12): 1876-1884. doi: 10.14102/j.cnki.0254-5861.2011-1164 shu

Hydrothermal Synthesis, Crystal structure, DFT and Application of a Dinuclear Cadmium(II) Complex Based on NPHSNPAB

English

  • The complexation of transition metal ions with polydentate ligands is a well studied area of research in coordination chemistry[1, 2]. In particular, azo ligands possess remarkable capacity for coordination with transition metal atoms. Azo-metal complexes as an important kind of dyes and pigments were widely used to color products of textile, leather, paper and plastics[3-5]. In textile industry, metallization has been applied in the textile industry for many years[6]. It is well-known that metallic textiles are able to provide shiny appearance, lustrousness, light reflectivity and thermo-insulation[7]. However, metallic fabric produced in such traditional manners exhibits many defects, such as stiffness, air proof, high price and heavy in weight. In light of the above problems, the metallic yarns that were usually from vacuum plating aluminum or cladding dyeing on PET film, substituted for metallic fabric, were widely used. The product obtained the original effects of metallic fabric, and made the price dropped substantially, which promoted the development of textile industry. The dye of protective coating plays a key role in making metallic yarns. It determines the appearance and performance of metallic yarns and affects the scope of application and market prospect[6].

    Investigations discover that the acid yellow-99 (AY-99) dyes are very important in the field of dyes of coating. AY-99 is short for N-phenyl-2-[2-hydroxyl- 3-sulfo-5-nitrophenylazo] butadione-1, 3 (NPHSNPAB), belonging to the anionic azo dye class, which is widely used in dyeing protein fibers, silk, nylon, metallic yarns, etc[8]. As a part of long term program for the survey of structure for the dye molecules, our group has reported the crystal structures of some dyes such as monoazo[9] and azo-Cu[10]. X-ray single-crystal structure of complex dyes is very important, because it not only provides details of molecular conformations but also can help explore the technical performance of new products[11].

    In this paper, we synthesized a new dinuclear cadmium (II) complex by hydrothermal synthesis technique. Meanwhile, the crystals of complex 1 were obtained successfully. The hydrothermal synthesis, crystal structure, TG-DTA, DFT studies and applications of complex 1 were reported. The obtained results suggest that the dinuclear cadmium (II) complex may be a desired yellow-emission dye and favored in textile industry.

    NPHSNPAB was prepared according to literature[9]. Other chemical materials and solvents used were analytical grade available commercially.

    Melting points were determined on a BEIJING TECH MPD X-5 melting point apparatus. All melting points were uncorrected. Microanalytical data (C, H and N) were obtained with a Perkin- Elmer model 240 C elemental analyzer. The FT-IR spectra were determined on a Nicolet infrared spectrometer by dispersing samples in KBr disks in the 4000~400 cm-1 region. The crystal data of the title complex were collected on a Bruker Smart 2000 diffractometer. The thermo gravimetric analysis was carried out under nitrogen condition on a Rigaku Thermo plus Evo TG 8120 instrument at a heating rate of 10 ◦C/min from 35 to 700 ◦C. The UV-visible absorption spectra were recorded on the Cary 50 Bio spectrometer and the fluorescence spectroscopy was performed on a Varian Cray Eclipse fluorescence spectrometer.

    A mixture of NPHSNPAB (0.822 g, 2 mmol), Cd (NO3)2·4H2O (6.7 mg, 2 mmol), ethyl alcohol (10 mL) and H2O (20 mL) was refluxed for 30 min, adjusted Ph = ~6.5, sealed in a 50 mL Teflon-lined stainless autoclave and heated to 140 ℃ for 72 h under autogenous pressure, and finally cooled at a rate of 4.5 ℃/h to room temperature. The resulting red block crystals were filtered off and collected for X-ray analysis. Yield: 65.3%. m.p. > 300 ℃. Anal. Calcd. for C36H44Cd2N8O22S2 (%): C, 35.18; H, 3.42; N, 9.12. Found: C, 35.23; H, 3.50; N, 9.08. The selected IR bands are (cm-1): 3463 (s), 1665 (m), 1597 (m), 1516 (vs), 1490 (s), 1448 (m), 1288 (s), 1241 (m), 1198 (m), 1076 (m), 1047 (s), 954 (w), 763 (m), 634 (m), 586 (m) and 505 (m).

    The crystal was selected and mounted on a Bruker Smart 2000 diffractometer equipped with graphitemonochromated MoKα radiation (λ = 0.71073 Å). The data were collected at 293 K and a total of 4781 reflections were collected in the range 1.58≤θ≤ 25.01° including 3949 independent reflections (Rint = 0.0169). The structure was solved by direct methods using the SHELXS-97[12]. The H atoms were assigned with common isotropic displacement factors and included in the final refinement by use of geometrical restraints. All non-hydrogen atoms were refined anisotropically. Full-matrix least-squares refinement on F2 was carried out using SHEHXL- 97[13].

    Density functional theoretical (DFT) computations have been performed at the B3LYP/Cd /LANL2DZ/O, N, C, H, S/6-31G (d) level to derive the optimized geometry of normal modes of [Cd (NPHSNPAB) 2(H2O)(CH3CH2OH)] using Gaussian 09 package[14]. Molecular geometry was fully optimized by Berny’s optimization algorithm using redundant internal coordinates. The optimized structure was confirmed to be minimum at its potential energy surface.

    The obtained dye is incorporated into the conventional protective coatings, then coated on the vacuum aluminum metalized PET (VMPET) through the coating roll and rapidly drying at 160 ℃.

    The title complex was synthesized by the hydrothermal method. The hydrothermal synthesis technique is an effective method to obtain new organicinorganic hybrid compounds. However, the understanding of hydrothermal reaction mechanism is still far behind. Generally, many factors can affect the formation and crystal growth of products, such as stoichiometry of raw materials, temperature, reaction time and pH values. For the title complex, although it was obtained from the mixture with the pH ranging from 5.5 to 8.0, the quality of the crystal is the best in pH = ~6.5. The reactants were refluxed for 30 min before being sealed in a Teflon-lined auto- clave, which was one of the important factors influencing the self-assembly of the structure[15].

    IR spectrum was recorded in the region of 4000~ 400 cm-1. The presence of broad band in the wave number range of 3100~3500 cm-1 is assigned as the -OH stretching frequency of the coordination water and ethanol molecules[16, 17]. The weak band at 2921 cm-1 is assigned to asymmetric C-H stretching vibrations of -CH2 groups[18]. The strong band at 1665 cm-1 is assigned to the C=O vibration. The complex shows characteristic strong bands of asymmetric and symmetric C-C bond stretching vibrations at ~1241 and ~954 cm-1, respectively. The strong absorptions at about 1047 and 634 cm-1 could be attributed to the S-O stretching vibrations of SO3 - fragment. In the far IR region, additional medium bands at 586 and 505 cm-1 may be due to the Cd-O vibration[19].

    Perspective view of the molecular structure with atom numbering scheme of the complex is shown in Fig. 1a. The complex crystallizes in space group P1 and its unit cell comprises of two molecules. There are two Cd2+ atoms, two NPHSNPAB ligands, four crystal water molecules and two coordinated ethanol molecules in the asymmetric unit. The local coordination environment around Cd2+ shows that the Cd2+ center is coordinated by six oxygen atoms, of which one is from the sulfonic oxygen, one from the ethanol molecule, one from the phenolic hydroxyl group and three from water molecules. The Cd-O distances range from 2.143(3) to 2.460(3) Å (Table 1), which are typical and comparable to those observed in the literatures[20-22].

    Figure 1

    Figure 1.  (a) Molecular structure of complex 1 with primary atom labeling scheme and (b) Bridged O-O edge sharing polyhedral representation in adjacent units of the complex (Hydrogen atoms and main structural unit are omitted for intelligibility)

    Table 1

    Table 1.  Selected Bond Lengths (Å) and Bond Angles (°) for Complex 1
    DownLoad: CSV
    BondDist.BondDist.BondDist.Cd(1)–O(8)2.143(3)Cd(1)–O(9)2.211(4)Cd(1)–O(7)2.257(3)Angle(°)Angle(°)Angle(°)O(8)–Cd(1)–O(9)105.95(14)O(8)–Cd(1)–O(2W)95.29(12)O(8)–Cd(1)–O(7)85.50(11)O(2W)–Cd(1)–O(1W)90.40(11)O(9)–Cd(1)–O(1W)#177.32(13)O(1W)–Cd(1)–O(1W)#178.78(11)
    Cd(1)–O(1W)2.315(3)Cd(1)–O(2W)2.238(3)Cd(1)–O(1W)#12.460(3)
    N(1)–C(7)1.352(6)N(2)–C(8)1.315(5)N(2)–N(3)1.297(5)
    O(1)–C(7)1.237(5)O(8)–C(16)1.292(5)
    O(9)–Cd(1)–O(7)153.95(14)O(8)–Cd(1)–O(1W)165.87(11)O(9)–Cd(1)–O(1W)86.66(13)
    O(7)–Cd(1)–O(1W)80.39(10)O(8)–Cd(1)–O(1W)#197.48(11)O(2W)–Cd(1)–O(1W)#1165.44(11)
    O(7)–Cd(1)–O(1W)#178.04(11)O(9)–Cd(1)–O(2W)92.48(14)O(2W)–Cd(1)–O(7)110.00(12)
    Symmetry code: (#1) 2–x, –y, 2–z

    The title complex can be regarded as two distorted octahedra fused at a common edge that contains the bridging μ2-H2O ligands, each of which resides at a center of inversion (Fig. 1b). The two Cd2+ atoms are linked by two bridging water molecules to form the rhomboidal [Cd2(μ2-OH2)2] core with the Cd-O distances of 2.315(3) and 2.458(3) Å, and O (1W)- Cd (1)-O (1AW) bond angle of 78.78(11)º. The distance between the two cadmium ions Cd…Cd is 3.691 Å for 1 and is typical for dinuclear cadmium complexes[23]. The Cd (1)-O (2W)-(O (1W))2-O (8)- O (7)-O (9) fragment of the molecule forms a distorted octahedron, in which equatorial vertices are occupied by three water oxygen atoms and one phenolic hydroxyl oxygen atom, whereas ethanol molecule and sulfonic oxygen atoms are at the axial positions[24].

    Furthermore, DFT calculations of the molecule were performed using the GAUSSIAN09 quantum mechanical software package. The molecule was optimized (Fig. 2). Small discrepancies can still be noticed owing to the small basis sets used for the present complex (for Cd one can use only the 6-31G basis sets). The core CdO6 also shows a distorted octahedral arrangement, as observed in the crystal structure. This could be due to the Jahn-Teller effect.

    From the perspective view, there are interesting and strong N-H…O, O-H…O, O-H…N and O-H…S hydrogen bonds (Table 2) and π-π stacking interactions, which linked the molecule to form a 3D net structure[20-24]. Viewed along a axis, intermolecular hydrogen bonds among sulfonic, amide, ethanol and water molecules S, N, O atoms named O (9)-H (9A)…O (7), N (1)-H (1A)…O (2), O (2W)- H (4W)…S (1), O (1W)-H (2W)…O (5), O (9)-H (9A) …S (1), etc. form a parallelogram net structure, as shown in Fig. 3a. Then, viewed along the b axis, Cd…Cd and π-π stacking interactions form 2D layer step structures (Fig. 3b). Interatomic distances ranging from 2.675(5) to 3.693(4) Å and angles within 134.5 ~ 177.3º indicate strong hydrogen bonds. A strong π-π stacking is observed in between the two ligand parts with a centroid-to-centroid distance of 3.575 Å. This indicates that noncovalent interactions can also play a crucial role in constructing the whole packing. However, it could be suggested that these interactions reinforce the overall stability of the 3D supramolecular network[25].

    Table 2

    Table 2.  Hydrogen Bond Lengths (Å) and Bond Angles (°) for Complex 1
    DownLoad: CSV
    D–H⋅⋅⋅Ad(D–H)d(H⋅⋅⋅A)d(D⋅⋅⋅A)(Å)∠DHA(°)N(1)–H(1A)⋅⋅⋅O(2)i0.8611.962.675(5)140.3O(2W)–H(4W)⋅⋅⋅S(1)iv0.83(2)2.93(3)3.693(4)154(5)
    O(9)–H(9A)⋅⋅⋅O(7)ii0.931.882.759(5)156.4
    O(9)–H(9A) ⋅⋅⋅S(1)ii0.933.023.951(4)177.3
    O(1W)–H(1W)⋅⋅⋅O(3)iii0.84(2)2.07(2)2.886(5)166(5)
    O(1W)–H(1W)⋅⋅⋅O(4)iii0.84(2)2.38(4)3.028(5)134(5)
    O(1W)–H(1W)⋅⋅⋅N(4)iii0.84(2)2.55(3)3.353(5)162(5)
    O(1W)–H(2W)⋅⋅⋅O(5)iv0.83(2)1.92(3)2.721(5)162(5)
    O(1W)–H(2W)⋅⋅⋅S(1)iv0.83(2)2.94(4)3.607(3)138(5)
    O(2W)–H(3W)⋅⋅⋅O(2)v0.83(2)1.96(2)2.776(5)167(6)
    O(2W)–H(4W)⋅⋅⋅O(6)iv0.83(2)1.97(2)2.781(5)166(6)
    Symmetry codes: (i) x, y, z; (ii) 2–x, –y, 2–z; (iii) x, –1+y, z; (iv) 3–x, –y, 2–z; (v) 2–x, 1–y, 1–z

    Figure 2

    Figure 2.  Optimized structure of complex 1 on the basis of DFT calculations

    Figure 3

    Figure 3.  Molecular packing diagram for complex 1. (a) A parallelogram net structure viewed along the a axis, connected by hydrogen bonds; (b) 2D layer steps viewed from the b axis, connected by Cd…Cd and π-π stacking interactions

    The UV-vis absorption spectra of NPHSNPAB and [Cd (NPHSNPAB)(H2O)2(CH3CH2OH)]2 in ethanol are shown in Fig. 4a. The absorption spectra of NPHSNPAB displayed three absorption peaks at 252, 301 and 388 nm, respectively. The peak around 252 nm may be attributed to a transition of the 2-amino-4-nitro-6-sulfo-phenol moiety of the mole -cule with n-π* characteristic. The shoulder-like peak located around 301 nm can be assigned to the n-π* electronic transition of -N=N- group. At last, the maximum peak located around 388 nm must be related to a π-π* transition contributing to the whole π-electronic system in conjugation with the chromophore. The absorption spectra of the complex display two similar absorption peaks at 321 and 393 nm. In comparison with the ligand, the absorption bands in the visible region of the complex were red-shifted. These strong absorptions of the complex in the near ultraviolet region can be assigned as ligand-to-metal charge transition (LMCT) and intraligand transitions[26].

    Figure 4

    Figure 4.  (a) Absorption spectra of a. ligand and b. complex 1. Concentration of 1.0×10-5 M and (b) Fluorescence spectra of a. the ligand and b. complex 1 (λex = 400 nm) with the concentration of 1.0×10-6 M

    In the meantime, the fluorescence property of the ligand and complex 1 in ethanol were investigated at room temperature. As shown in Fig. 4b, upon excitation at 400 nm, the complex shows the main emission peak at 594 nm and a minor emission at 455 nm. Obviously, large red shifted emission occurs in the complex with respect to the free NPHSNPAB ligand. The emission band at 594 nm for the complex might be attributed to LMCT[26]. At the same time, the fluorescence emission spectral studies reveal that the complex exhibits yellowemission.

    The TG-DTA curves of complex 1 showed that the decomposition occurred in the temperature range of 33~276 ℃ with a net weight loss of 15.70%, which is consistent with the elimination of fourcoordinated water and two-coordinated ethanol molecules (calcd. 13.37%) and residual water solvent. Subsequently, it continues with a weight loss of 26.68% around 323 ℃. The decomposition process suggested the departure of acetoacetanilide and azo groups appearing almost simultaneously. The final product above 699 ℃ should mainly be CdO. Therefore, the complex can be applied above 200 ℃ (Fig. 5).

    Figure 5

    Figure 5.  TG-DTA curves of complex 1

    Frontier molecular orbitals (HOMO and LUMO) and their properties such as energy, polarizability, redox and chemical reactivity are very important parameters for physicists and chemists. The frontier molecular orbitals are also used for predicting the most reactive position in p-electron systems and also explained various types of reactions in conjugated system[27]. Based on density functional theory (DFT) and taking one repeat unit as a model, the geometries and electron density distributions of the HOMO and LUMO energy levels of complex 1 were obtained in Fig. 6. The LUMO is located over the acetoacetyl, whereas HOMO is located mainly on 2-amino-4-nitropheno-6-sulfoacid ring. The HOMO→LUMO transition implies an electron density transfer from acetoacetyl group to 2-amino- 4-nitropheno-6-sulfoacid ring. Besides that, lower energy gap in HOMO and LUMO explains the eventual charge transfer interactions taking place within the molecule and high polarisability of the complex. The energy band gap, ΔE, between HOMO and LUMO of the molecule was found about 3.05 eV. Therefore, the stability of complex 1 is better due to the high energy band gap.

    Figure 6

    Figure 6.  Selected computed (Gaussian 09) orbital plot for complex 1

    The metallic yarns are important accessory textile materials made from PET film. In general, the PET film is coated with aluminum under vacuum condition (Fig. 7a), and then coated with protective coatings with rapidly drying at 160 ℃. Finally, the coated film is processed into filaments step by step. The filaments are called metallic yarns which could show metallic luster woven in textiles and make the textiles popular with people of all ages. Fig. 7b depicts the color of complex 1 on VMPET, and it shows that good golden yellow on VMPET is observed.

    Figure 7

    Figure 7.  Color of complex 1 on VMPET (a) Blank and (b) Colored

    In summary, we have described a simple and efficient synthetic method for new dinuclear cadmium ( II) complex, and the crystals are obtained, which are structurally characterized by the singlecrystal X-ray method and found to be a distorted octahedral coordination sphere. The hydrogen bonds and π-π stacking interactions extend the complex into a final 3D supramolecular framework. The TG-DTA studies confirmed the complex can be utilized for applications about 200 ℃, and DFT studies indicate its very good stability. Owing to the good stability, it will not cause environmental pollution and toxicity.

    1. [1]

      Zhang J. P, Zhang Y. B, Lin J. B, Chen X. M. Metal azolate frameworks: from crystal engineering to functional materials[J]. Chem. Rev, 2011, 112:  1001-1033.

    2. [2]

      Pan M, Su C. Y. Coordination assembly of Borromean structures[J]. CrystEngComm, 2014, 16:  7847-7859. doi: 10.1039/C4CE00616J

    3. [3]

      Karapinar E, Aksu I. An investigation of fastness properties of textile materials colored with azo dyes[J]. J. Tex. Eng, 2013, 20:  17-24. doi: 10.7216/130075992013209002

    4. [4]

      Bahatti H. S, Seshadri S. Synthesis and fastness properties of styryl and azo disperse dyes derived from 6-nitro substituted 3-aryl-2-methyl-4(3H)-quinazolinone[J]. Color. Technol, 2004, 120:  151-155. doi: 10.1111/cte.2004.120.issue-4

    5. [5]

      Raghavendra K. R, Kumar A. K. Synthesis of some novel azo dyes and their dyeing, redox and antifungal properties[J]. Int. J. Pharmaceut Chem. Biol. Sci, 2013, 5:  1756-1760.

    6. [6]

      Yip J, Jiang S. Q, Wong C. Characterization of metallic textiles deposited by magnetron sputtering and traditional metallic treatments[J]. Surf. Coat. Tech, 2009, 204:  380-385. doi: 10.1016/j.surfcoat.2009.07.040

    7. [7]

      van der Velden N. M, Kuusk K, K?hler A. R. Life cycle assessment and eco-design of smart textiles: the importance of material selection demonstrated through e-textile product redesign[J]. Materials and Design, 2015, 84:  313-324. doi: 10.1016/j.matdes.2015.06.129

    8. [8]

      Khan M. M. R, Ray M, Guha A. K. Mechanistic studies on the binding of acid yellow 99 on coir pith[J]. Bioresource Technol, 2011, 102:  2394-2399. doi: 10.1016/j.biortech.2010.10.107

    9. [9]

      Dong, J. L.; Zhang, G. L.; Guo, M. Y.; Wu, C.; Ren, J. G. 2-[2-(2-Carboxyphenyl) hydrazinylidene]-3-oxo-N-phenylbutyramide. Acta Cryst. E, 2011, 67: o3408.

    10. [10]

      Ren Y. H, Dong J. L, Wang Z. W, Ren J. G. Synthesis and crystal structure of the azo copper(II)-complex[J]. Chin. J. Struct. Chem, 2011, 30:  376-379.

    11. [11]

      Kamaljit S, Aman M, Robinson W. T. Single-crystal X-ray structure analysis of some heterocyclic monoazo disperse dyes[J]. Dyes Pigments, 2007, 74:  95-102. doi: 10.1016/j.dyepig.2006.01.018

    12. [12]

      Sheldrick G. M. Correction Software[J]. University of Gottingen, Germany, 1997, :  .

    13. [13]

      Sheldrick G. M. Program for the Solution of Crystal Structures[J]. University of Gottingen, Germany, 1997, :  .

    14. [14]

      Frisch M. J, Trucks G. W, Schlegel H. B.Gaussian 09, Revision D.01, Gaussian Inc., Wallingford CT, 2013.

    15. [15]

      Wang J. P, Guo G. L, Niu J. Y. Hydrothermal syntheses, crystal structures of three new organic-inorganic hybrids constructed from Keggin-type [BW12O40]5 - clusters and transition metal complexes[J]. J. Mol. Struct, 2008, 885:  161-167. doi: 10.1016/j.molstruc.2007.10.025

    16. [16]

      Want B, Ahmed E, Kotru P. N. Single crystal growth and characterization of holmium tartrate trihydrate[J]. J. Cryst. Growth, 2007, 299:  336-343. doi: 10.1016/j.jcrysgro.2006.11.225

    17. [17]

      Renugadevi R, Kesavasamy R. Synthesis, crystal growth and spectroscopic investigation of novel metal organic crystal: β-alanine cadmium bromide monohydrate (β-ACBM)[J]. Spectro. Acta A, 2014, 128:  622-628. doi: 10.1016/j.saa.2014.03.005

    18. [18]

      hanya V. S, Sudarsanakumar M. R, Suma S, Kurup M. R. P, Sithambaresan M, Roy S. M. Spectral, thermal, structural, dielectric and microhardness studies of gel grown diaquasuccinatocadmium(II) hemihydrate[J]. Spectro. Acta A, 2012, 93:  295-299. doi: 10.1016/j.saa.2012.03.012

    19. [19]

      Nakamoto, K. Infrared Spectra of Inorganic and Coordination Compounds, Fifth Ed., John Willey & Sons, New York, 1997.

    20. [20]

      Zhang T, Tian A. Q, Feng X, Seik W. N, Tian P. H, Wang Y. Synthesis, crystal structure and luminescence properties of a cadmium(II) complex based on 2-hydroxy-6-methylisonicotinic acid[J]. Chin. J. Struct. Chem, 2016, 35:  279-285.

    21. [21]

      Cui P. P, Cui L. F, Zhang L. L. Solvothermal synthesis of a 3D luminescent cadmium-organic framework with msw topological net[J]. Chin. J. Struct. Chem, 2013, 32:  1890-1896.

    22. [22]

      Chen S. C, Zhang Z. H, Huang K. L, Luo H. K, He M. Y, Du M, Chen Q. Alkali-metal-regulated construction of superhydrophilic ZnII and CdII coordination polymers with perhalogenated terephthalate ligands[J]. Cryst. Eng. Comm, 2013, 15:  9613-9622. doi: 10.1039/c3ce41108g

    23. [23]

      Ristovica M. S, Zianna A, Psomas G, Hatzidimitriou A. G, Coutouli-Argyropoulou E, Lalia-Kantouri M. Interaction of dinuclear cadmium(II) 5-Cl-salicylaldehyde complexes with calf-thymus DNA[J]. Mater. Sci. Eng. C, 2016, 61:  579-590. doi: 10.1016/j.msec.2015.12.054

    24. [24]

      Kumai R, Horiuchi S, Sagayama H, Arima T. H, Watanabe M, Noda Y, Tokura Y. Structural assignment of polarization in hydrogen-bonded supramolecular ferroelectrics[J]. J. Am. Chem. Soc, 2007, 43:  12920-12921.

    25. [25]

      Bai Y, Shang W. L, Dang D. B, Sun J. D, Gao H. Synthesis, crystal structure and luminescent properties of one coordination polymer of cadmium(II) with mixed thiocyanate and hexamethylenetetramine[J]. Spectro. Acta A, 2009, 72:  407-411. doi: 10.1016/j.saa.2008.10.033

    26. [26]

      Huang X. Y, Li J. From single to multiple atomic layers: a unique approach to the systematic tuning of structures and properties of inorganic-organic hybrid nanostructured semiconductors[J]. J. Am. Chem. Soc, 2007, 129:  3157-3162. doi: 10.1021/ja065799e

    27. [27]

      Fukui K, Yonezawa T, Shingu H. A molecular orbital theory of reactivity in aromatic hydrocarbons[J]. J. Chem. Phys, 1952, 20:  722-725. doi: 10.1063/1.1700523

  • Figure 1  (a) Molecular structure of complex 1 with primary atom labeling scheme and (b) Bridged O-O edge sharing polyhedral representation in adjacent units of the complex (Hydrogen atoms and main structural unit are omitted for intelligibility)

    Figure 2  Optimized structure of complex 1 on the basis of DFT calculations

    Figure 3  Molecular packing diagram for complex 1. (a) A parallelogram net structure viewed along the a axis, connected by hydrogen bonds; (b) 2D layer steps viewed from the b axis, connected by Cd…Cd and π-π stacking interactions

    Figure 4  (a) Absorption spectra of a. ligand and b. complex 1. Concentration of 1.0×10-5 M and (b) Fluorescence spectra of a. the ligand and b. complex 1 (λex = 400 nm) with the concentration of 1.0×10-6 M

    Figure 5  TG-DTA curves of complex 1

    Figure 6  Selected computed (Gaussian 09) orbital plot for complex 1

    Figure 7  Color of complex 1 on VMPET (a) Blank and (b) Colored

    Table 1.  Selected Bond Lengths (Å) and Bond Angles (°) for Complex 1

    BondDist.BondDist.BondDist.Cd(1)–O(8)2.143(3)Cd(1)–O(9)2.211(4)Cd(1)–O(7)2.257(3)Angle(°)Angle(°)Angle(°)O(8)–Cd(1)–O(9)105.95(14)O(8)–Cd(1)–O(2W)95.29(12)O(8)–Cd(1)–O(7)85.50(11)O(2W)–Cd(1)–O(1W)90.40(11)O(9)–Cd(1)–O(1W)#177.32(13)O(1W)–Cd(1)–O(1W)#178.78(11)
    Cd(1)–O(1W)2.315(3)Cd(1)–O(2W)2.238(3)Cd(1)–O(1W)#12.460(3)
    N(1)–C(7)1.352(6)N(2)–C(8)1.315(5)N(2)–N(3)1.297(5)
    O(1)–C(7)1.237(5)O(8)–C(16)1.292(5)
    O(9)–Cd(1)–O(7)153.95(14)O(8)–Cd(1)–O(1W)165.87(11)O(9)–Cd(1)–O(1W)86.66(13)
    O(7)–Cd(1)–O(1W)80.39(10)O(8)–Cd(1)–O(1W)#197.48(11)O(2W)–Cd(1)–O(1W)#1165.44(11)
    O(7)–Cd(1)–O(1W)#178.04(11)O(9)–Cd(1)–O(2W)92.48(14)O(2W)–Cd(1)–O(7)110.00(12)
    Symmetry code: (#1) 2–x, –y, 2–z
    下载: 导出CSV

    Table 2.  Hydrogen Bond Lengths (Å) and Bond Angles (°) for Complex 1

    D–H⋅⋅⋅Ad(D–H)d(H⋅⋅⋅A)d(D⋅⋅⋅A)(Å)∠DHA(°)N(1)–H(1A)⋅⋅⋅O(2)i0.8611.962.675(5)140.3O(2W)–H(4W)⋅⋅⋅S(1)iv0.83(2)2.93(3)3.693(4)154(5)
    O(9)–H(9A)⋅⋅⋅O(7)ii0.931.882.759(5)156.4
    O(9)–H(9A) ⋅⋅⋅S(1)ii0.933.023.951(4)177.3
    O(1W)–H(1W)⋅⋅⋅O(3)iii0.84(2)2.07(2)2.886(5)166(5)
    O(1W)–H(1W)⋅⋅⋅O(4)iii0.84(2)2.38(4)3.028(5)134(5)
    O(1W)–H(1W)⋅⋅⋅N(4)iii0.84(2)2.55(3)3.353(5)162(5)
    O(1W)–H(2W)⋅⋅⋅O(5)iv0.83(2)1.92(3)2.721(5)162(5)
    O(1W)–H(2W)⋅⋅⋅S(1)iv0.83(2)2.94(4)3.607(3)138(5)
    O(2W)–H(3W)⋅⋅⋅O(2)v0.83(2)1.96(2)2.776(5)167(6)
    O(2W)–H(4W)⋅⋅⋅O(6)iv0.83(2)1.97(2)2.781(5)166(6)
    Symmetry codes: (i) x, y, z; (ii) 2–x, –y, 2–z; (iii) x, –1+y, z; (iv) 3–x, –y, 2–z; (v) 2–x, 1–y, 1–z
    下载: 导出CSV
  • 加载中
计量
  • PDF下载量:  0
  • 文章访问数:  5098
  • HTML全文浏览量:  121
文章相关
  • 收稿日期:  2016-02-02
  • 接受日期:  2016-04-19
通讯作者: 陈斌, bchen63@163.com
  • 1. 

    沈阳化工大学材料科学与工程学院 沈阳 110142

  1. 本站搜索
  2. 百度学术搜索
  3. 万方数据库搜索
  4. CNKI搜索

/

返回文章