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• 1. INTRODUCTION

  Assembly and characterization of coordination compounds constructed from metal ions have attracted intensive attention because of their finetuning structure diversity and potential applications in many areas such as magnetism, fluorescence, molecular recognition, ion exchange, gas sorption and storage, nonlinear optics, catalysis and biochemistry^[1-5]. As we all know, copper (II) exists in the form of complexes^[6], such as oxidase, superoxide dismutase (SOD), rusticyanin and so on, which are involved in the enzyme catalysis and material storage in life process. Copper (II) is the active center of multiple enzymes that can play unique roles in the redox system of organism, and has been widely used in biological detection, such as intercalation mode of DNA^[7], antibacterial properties and proteins. Fluorescent compounds are currently of great interest because of their various applications in chemosensors^[8], photochemistry^{[9, 10]}, and electroluminescent (EL)^{[11, 12]}. In order to obtain new functional coordinated compounds, the oxygen-containing ligands, such as phenolate, hydroxide, oxide and carboxylate, have been usually chosen to construct functional frameworks. Meanwhile, the addition of N-containing ligands is also beneficial to the improvement of coordination environment of the center metal ions. In this work, N-containing ligands including IDB (N, N-di (2-benzimidazolylmethyl) imine) and EDTB (N, N, N′, N′-tetrakis-[(2-benzimidazolyl) methyl]-1, 2-ethanediamine]) were adopted to construct functional complexes with the copper (II) cations. As expected, two new copper complexes were synthesized and characterized by elemental analysis, single-crystal X-ray diffraction, infrared spectrum (IR) and thermogravimetric analysis (TGA). Furthermore, we have demonstrated that the two compounds have excellent fluorescent properties and potential applications in fluorescent- emitting materials.

  2. EXPERIMENTAL

  2.1. Reagents and instruments

  The ligands IDB and EDTB were synthesized according to the references^{[13, 14]}. All reagents were of AR grade except that o-phenylenediamine (CP grade) was commercially available and used without purification. The crystal data of the compounds were collected on a Bruker SMARTAPEX CCD diffractometer. Their Fourier transform infrared (FT-IR) spectra were measured on a Nicolet iS50 FT-IR spectrometer by dispersing samples in KBr disks in the 4000～200 cm^-1 region. The fluorescence spectra were performed on a PerkinElmer LS 55 fluorescence spectrophotometer. Thermogravimetric analyses (TGA) were conducted by powder samples using TG-DTA instruments (THC-2) from room temperature up to 700 ℃ at a heating rate of 5.0 ℃/min.

  2.2. Synthesis

  2.3. Structure determination

  Crystals of 1 (0.15mm × 0.15mm × 0.12mm) and 2 (0.18mm × 0.12mm × 0.10mm) were chosen and mounted on Bruker SMART APEX CCD diffractometers equipped with a graphite-monochromatic Mo-Kα radiation (λ = 0.071073 nm) by using an ω scan mode at 150(2) K, respectively. The structures were solved by direct methods and refined with full-matrix least-squares procedures on F² with the SHELXL-97. For 1, a total of 7598 reflections were collected and 4326 were independent (R_int = 0.0341) in the range of 2.01≤θ≤27.00º, of which 3556 with I > 2σ(I) were observed. For 2, in the range of 1.96 ≤ θ ≤ 25.01º, a total of 16988 reflections were collected and 8371 were independent (R_int = 0.1083), of which 4039 with I > 2σ(I) were observed. All diffraction data were corrected via Lp factors and empirical absorption. The non-hydrogen atoms were refined anisotropically and the hydrogen atoms were calculated according to theoretical models. All crystallographic data of compounds 1 and 2 are summarized in Table 1, the selected bond lengths and bond angles in Table 2, and the hydrogen bond lengths and bond angles in Table 3.

  Table 1

  

  Table 1.  Crystals Data for Compounds 1 and 2

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  Compound12Empirical formulaC₃₆H₄₆C_l2CuN₁₀O₄C₄₈H₅₄CuN ₁₀O₁₂Largest diff. peak and hole / e·nm^-31092 and-921702 and -594

  Formula weight	817.27	1025.54
  Crystal system	Triclinic	Triclinic
  Crystal size	0.15mm x 0.15mm x 0.12mm	0.18mm x 0.12mmx 0.10mm
  Space group	P1	P1
  a/ Å	9.565(2)	11.487(3)
  b / Å	9.863(2)	13.396(4)
  c / Å	10.252(3)	17.977(5)
  Å/°	81.915	73.899(5)
  β / °	88.33	86.629(5)
  y / °	87.347	65.018(4)
  V / Å3	956.28(40)	2403.8(12)
  Z	1	2
  Dc/g-cm-3	1.419	1.417
  μ / mm-1	0.764	0.528
  F(000)	427	1072
  θ range / °	2.01 to 27.00	1.96 to 25.01
  Reflections collected	7598	16988
  Independent reflections	4326 (Rint = 0.0341)	8371 (Rint = 0.1083)
  Observed reflections (I > 2σ(I))	3556	4039
  Max. and min. transmission	0.9139 and 0.8940	0.9491 and 0.9109
  Data / restraints / parameters	4083 / 23 / 277	8371 / 23 / 718
  GOOF(F2)	1.095	0.962
  Final R indices (I > 2σ(I))	R = 0.0505, wR = 0.1417	R = 0.0769, wR = 0.1632
  R indices (all data)	R = 0.0591, wR = 0.1525	R = 0.1721, wR = 0.2109
  w = 1/[σ2(Fo 2) + (0.0901P)2 + 0.7811P], where P = (Fo2 + 2Fc 2)/3

  Table 2

  

  Table 2.  Selected Bond Lengths (Å) and Bond Angles (°) for Compounds 1 and 2

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  Compound1BondDist.BondDist.BondDist.Cu(1)–N(1)2.626(2)Cu(1)–N(4)2.020(2)Cu(1)–N(2)2.006(2)Angle(°)Angle(°)Angle(°)N(1)–Cu(1)–N(1a)180.00(11)N(2)–Cu(1)–N(2a)180.00(11)N(4)–Cu(1)–N(4a)180.00(11)Compound2BondDist.BondDist.BondDist.Cu(1)–N(1)2.482(6)Cu(1)–N(3)1.985(7)Cu(1)–N(7)2.080(5)Angle(°)Angle(°)Angle(°)N(1)–Cu(1)–N(2)71.7(2)N(2)–Cu(1)–N(3)92.5(2)N(3)–Cu(1)–N(7)94.4(2)N(1)–Cu(1)–N(9)93.9(2)N(3)–Cu(1)–N(5)91.4(2)N(7)–Cu(1)–N(9)89.0(2)

  Cu(1)–N(1a)	2.626(2)	Cu(1)–N(4a)	2.020(2)	Cu(1)–N(2a)	2.006(2)
  N(1)–Cu(1)–N(2)	74.70(8)	N(1a)–Cu(1)–N(2)	105.30(9)	N(2)–Cu(1)–N(4)	88.18(8)
  N(1)–Cu(1)–N(2a)	105.30(9)	N(1a)–Cu(1)–N(2a)	74.70(8)	N(2)–Cu(1)–N(4a)	91.82(8)
  N(1)–Cu(1)–N(4)	74.18(8)	N(1a)–Cu(1)–N(4)	105.82(9)	N(2a)–Cu(1)–N(4a)	88.18(8)
  N(1)–Cu(1)–N(4a)	105.82(9)	N(1a)–Cu(1)–N(4a)	74.18(8)	N(2a)–Cu(1)–N(4)	91.82(8)
  Cu(1)–N(2)	2.450(4)	Cu(1)–N(5)	2.047(5)	Cu(1)–N(9)	1.978(7)
  N(1)–Cu(1)–N(3)	76.9(2)	N(2)–Cu(1)–N(5)	143.0(2)	N(3)–Cu(1)–N(9)	168.3(2)
  N(1)–Cu(1)–N(5)	73.4(2)	N(2)–Cu(1)–N(7)	74.9(2)	N(5)–Cu(1)–N(7)	141.4(2)
  N(1)–Cu(1)–N(7)	144.9(2)	N(2)–Cu(1)–N(9)	77.6(2)	N(5)–Cu(1)–N(9)	92.9(2)
  Symmetry transformation used to generate the equivalent atoms. a: 1-x, 1-y, -z

  Table 3

  

  Table 3.  Hydrogen Bond Lengths (Å) and Bond Angles (°) for Compounds 1 and 2

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  1O(1S′)–H(1)···O(1S′)a0.822.212.793128O(6W)–H(6W)···O(1S)0.982.232.8549120Symmetry codes: (a) 2-x, 1-y, 1-z; (b)1-x, 1-y, 1-z; (c) 1-x, -y, 1-z; (d) -1+x, y, z; (e) 1-x, 1-y, -z; (f) -x, 1-y, 1-z

  Compound	D–H⋅⋅⋅A	d(D–H)	d(H⋅⋅⋅A)	d(D⋅⋅⋅A)	∠DHA
  O(1S)–H(1S)···Cl(1)b	0.83	2.38	3.195	167
  O(1)–H(1D)···Cl(1)c	0.809	2.44	3.241	171
  O(1)–H(1C)···Cl(1)	0.817	2.38	3.191	170
  N(5)–H(5)···O(1S′)	0.88	1.89	2.748	165.7
  N(5)–H(5)···O(1S)	0.88	2.11	2.905	149.5
  N(3)–H(3)···O(1)b	0.88	1.97	2.807	158.4
  N(1)–H(1)···Cl(1)	0.91	2.43	3.279	155.4
  N(10)–H(10)···O(6W)	1.01	1.79	2.7976	173
  N(8)–H(8)···O(3S)d	1.01	1.78	2.7707	165
  2	O(3W)–H(3W)···O(2W)	0.98	1.97	2.7948	140
  	O(2W)–H(2W)···O(3W)	0.98	1.82	2.7948	169
  	O(4W)–H(4W)···O(5W)e	0.98	2.16	3.1254	167
  	O(5W)–H(5W)···O(3W)e	0.98	2.12	2.7443	120
  	O(6W)–H(6W)···O(1W)f	0.98	1.97	2.8835	153

  2.4. Fluorescence spectra measurement

  The fluorescence spectra of compounds 1 and 2 were measured with PerkinElmer LS 55 fluorescence spectrophotometer at a scan speed of 500 nm/min at room temperature. The fluorescent spectra of compound 1 were recorded with excitation at 383 nm, with the slit width for excitation to be 10 nm and that for emission of 15 nm. The fluorescence spectra of compound 2 were recorded under 355 nm excitation, with the slit width for excitation of 10 nm and slit width for emission to be 20 nm.

  2.2.1. Synthesis of compound 1

  0.55g IDB (2.0 mmol) and 0.17 g CuCl₂·2H₂O (1.0 mmol) were dissolved in 20 mL hot ethanol and 5 mL water, respectively, followed by mixing together and refluxing for 10 h. Afterwards, the mixture was cooled to room temperature, filtered to get blue filtrate and naturally volatilized at room temperature. Several days later, purple crystals were separated out from the filtrate. After recrystallization with ethanol, the purple crystal 1 suitable for X-ray single-crystal structure analysis was obtained. IR (KBr) ν/cm^-1: 3690～2911(br.s): 2943(s), 1270(s), 1625(m), 1415(m), 745(s), 285(w). Anal. Calcd. (%) for C₃₆H₄₆Cl₂CuN₁₀O₄: C, 52.86; H, 5.62; N, 17.13. Found (%): C, 52.93; H, 5.46; N, 17.05.

  2.2.2. Synthesis of compound 2

  0.58 g EDTB (1.0 mmol) and 0.17 g CuCl₂·2H₂O (1.0 mmol) dissolved in 20 mL hot ethanol and 5 mL water, respectively were mixed together, followed by adding 0.32 g sodium salicylate (2.0 mmol) dissolved in 10 mL hot ethanol and reflux for 8 hours. After slowly cooling to room temperature and filtration, green filtrate was afforded. With natural volatilization for several days, green crystals were separated out from the filtrate. After recrystallization with ethanol, the green crystal 2 suitable for X-ray single-crystal structure analysis was obtained. IR (KBr) ν/cm^-1: 3460 ～ 2952(br.s), 2940(s), 1272(s), 1630(m), 1425(m), 750(s), 295(w). Anal. Calcd. (%) for C₄₈H₅₄CuN₁₀O₁₂: C, 56.17; H, 5.27; N, 13.65. Found (%): C, 56.25; H, 5.21; N, 13.51.

  3. RESULTS AND DISCUSSION

  3.1. X-ray single-crystal structure analysis

  The molecular structure and crystal packing diagram of compound 1 are depicted in Figs. 1 and 2, respectively. The asymmetric unit of 1 consists of one Cu (II) cation, two IDBs (ligand), two chlorine anions, two ethanol molecules and two water molecules. As shown in Fig. 1, the central Cu (II) locates in a six-coordinated octahedral environment, which is surrounded by two amine nitrogen atoms (N (1), N (1a)) and four nitrogen atoms (N (2), N (2a), N (4), N (4a)) from four benzimidazole rings of two IDBs. In the octahedron, N (1), N (1a) occupy the axial positions, while N (2), N (2a), N (4) and N (4a) locate at the equatorial plane and the parallelogram four corners. Table 2 shows all bond lengths of Cu (1)-N in a normal range, and the bond lengths of Cu (1)- N (2) and Cu (1)-N (2a) are 2.006(2) Å; Cu (1)-N (4) and Cu (1)-N (4a) are 2.020(2) Å; Cu (1)-N (1) and Cu (1)-N (1a) are 2.626(2) Å. But the Cu (1)-N (1) and Cu (1)-N (1a) bonds are longer than Cu (1)-N (2), Cu (1)-N (2a), Cu (1)-N (4) and Cu (1)-N (4a) attributed to the stronger electron-donating ability of benzimidazole nitrogen atoms. The bond angles of N (1)-Cu (1)-N (1a), N (2)-Cu (1)-N (2a) and N (4)- Cu (1)-N (4a) are 180(11)°, identical, and generally linear, but N (1)-Cu (1)-N (2), N (1)-Cu (1)-N (2a), N (1a)-Cu (1)-N (2), N (1a)-Cu (1)-N (2a), N (2)- Cu (1)-N (4a) and N (2)-Cu (1)-N (4) are 74.70(8)°, 105.30(9)°, 105.30(9)°, 74.70(8)°, 91.82(8)° and 88.18(8)°, respectively, reflecting the distorted octahedral coordination geometry of the copper center. All above data demonstrate that the cation [Cu (IDB)₂]²⁺ of compound 1 owns a distorted octahedral coordination geometry. The crystal packing diagram as shown in Fig. 2 presents that 1 contains one structural unit[Cu (IDB)₂]Cl₂·2CH₃CH₂OH· 2H₂O. Compound 1 is further stabilized by versatile hydrogen bonds (Table 3) observed among the nitrogen atoms of benzimidazole from ligand IDB (N (3), N (5), N (3a), N (5a)), oxygen atoms of ethanol molecules (O (1S)), oxygen atoms of water molecules (O (1)) and chlorine atoms (Cl (1)). The chlorine anions provide charges for the coordinate cation in the external environment, instead of coordinating with the Cu (1) cation. A variety of forces in the whole compound 1 molecules, such as van der Waals forces and hydrogen bonding, give full scope to their respective roles. Meanwhile, intramolecular as well as intermolecular hydrogen bonds appear in compound 1, which lead to a more complicated and more stable supramolecular compound molecule.

  Figure 1

  

  Figure 1.  Molecular structure of compound 1

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  Figure 2

  

  Figure 2.  Packing diagram of compound 1

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  The molecular structure and crystal packing diagram of compound 2 are depicted in Figs. 3 and 4, respectively. The asymmetric unit of compound 2 consists of one Cu (II) cation, one EDTB (ligand), two salicylate anions and six water molecules. Similar to 1, the Cu (II) center of 2 displays a distorted octahedral coordination geometry constructed by two amine nitrogen atoms (N (1), N (2)) and four nitrogen atoms (N (3), N (5), N (7), N (9)) from four benzimidazole rings of one and the same EDTB. However, the distorted degree is different. The bond lengths of Cu (1)-N (3), Cu (1)-N (5), Cu (1)-N (7) and Cu (1)-N (9) are 1.985(7), 2.047(5), 2.080(5) and 1.978(7) Å, respectively, all shorter than those of Cu (1)-N (1) and Cu (1)-N (2) in 2.482(6) and 2.450(4) Å, respectively, which is consistent with that the benzimidazole nitrogen atoms have stronger donating electron ability than the amine nitrogen atoms. Therefore, the Cu (II) center of compound 2 is in a distorted octahedron environment, in which the two nitrogen atoms (N (1), N (7)) occupy the axial positions and the four nitrogen atoms (N (3), N (5), N (2) and N (9)) locate at the equatorial plane. The bond angle N (1)-Cu (1)-N (7) along the axis is 144.9(2)°. The bond angles formed between N (1) in the axial position and N (3), N (5), N (2), N (9) in the equatorial positions are as follows: N (1)-Cu (1)-N (2) 71.7(2)°, N (1)-Cu (1)-N (3) 76.9(2)°, N (1)-Cu (1)- N (5) 73.4(2)° and N (1)-Cu (1)-N (9) 93.9(2)°. The bond angles are formed between N (7) in the axial position and N (3), N (5), N (2), N (9) in the equatorial positions: N (5)-Cu (1)-N (7), 141.4(2)°; N (2)- Cu (1)-N (7), 74.9(2)°; N (3)-Cu (1)-N (7), 94.4(2)°; N (9)-Cu (1)-N (7), 89.0(2)°. The bond angles formed between N (3), N (5), N (2) and N (9) in the equatorial positions are as below: N (3)-Cu (1)-N (9) 168.3(2)°, N (2)-Cu (1)-N (5) 143.0(2)°, N (2)-Cu (1)-N (9) 77.6(2)°, N (3)-Cu (1)-N (5) 91.4(2)°; N (2)-Cu (1)- N (3) 92.5(2)°, N (5)-Cu (1)-N (9), 92.9(2)°. All the above data demonstrate that the cation [Cu (EDTB)]²⁺ of 2 owns a distorted octahedral coordination geometry. Table 3 lists the hydrogen bonds in compound 2. The crystal packing diagram of 2 (Fig. 4) presents that it contains two structural units [Cu (EDTB)]·2[C₆H₄(OH) COO]·6H₂O. There are persistent intramolecular and intermolecular hydrogen bonds among the nitrogen atoms of benzimidazole from ligand EDTB (N (4), N (6), N (8) and N (10)), oxygen atoms of water molecules (O (1W), O (2W) , O (3W), O (4W), O (5W), O (6W)) and oxygen atoms of salicylate anions (O (1T), O (2T) , O (3T), O (1S), O (2S), O (3S)). The salicylate anions (C₆H₄(OH) COO-) provide charges for the coordinate cation in the external environment, instead of coordinating with the Cu (1) cation. Therefore, there exists not only Van der Waals force but also hydrogen bonds in and also among the structure units, thus making the whole framework structure system stable. In a word, compounds 1 and 2 exhibit similar structures due to the similar intramolecular and intermolecular hydrogen bonding interactions, which contribute to the formation of stable structures.

  Figure 3

  

  Figure 3.  Molecular structure of compound 2

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  Figure 4

  

  Figure 4.  Packing diagram of compound 2

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  3.2. IR-spectrum

  IR transmission spectrum was recorded in the region of 4000~200 cm^-1. These spectra show broad and strong IR transmittance bands of compound 1 in the 2911~3690 cm^-1 region, attributable to O-H stretching vibration in water and ethanol, N-H and C-H stretching vibration of benzimidazole ring of the ligand IDB; sharp bands at 2943 and 1270 cm- 1 are respectively attributed to the C-H stretching vibration of -CH^2- in IDB and C-N stretching vibration of imine in IDB; sharp bands around 1625, 1415 and 745 cm^-1 that are skeletal vibration and puckering vibration of benzene ring of the ligand IDB; weak absorption at 285 cm^-1 in the far infrared range is attributed to the characteristic peak of benzimidazole and amino nitrogen of the ligand IDB to coordinate with metal ions Cu (Ⅱ). The crystal structure of compound 1 reveals the same environment.

  These spectra show broad and strong IR transmittance bands of compound 2 in the 2952～3460 cm^-1 region, attributable to O-H stretching vibration in the water of complexes, N-H and C-H stretching vibration of benzimidazole ring of EDTB. The band observed at 2940 cm^-1 is reported as C-H stretching vibration of -CH^2- in the ligand EDTB. The strong band in the region at 1272 cm^-1 is attributable to C-N stretching vibration of tertiary amine in EDTB. The bands observed around at 1630, 1425 and 750 cm^-1 are assigned to the skeletal vibration and puckering vibration of benzene ring of the ligand EDTB; weak absorption peak at 295 cm^-1 in the far infrared range is due to the characteristic peak of benzimidazole nitrogen and amino nitrogen of the ligand EDTB to coordinate with metal ions Cu (Ⅱ). The crystal structure of compound 2 reveals the same environment.

  3.3. Thermal analysis

  Thermal stability of compounds 1 and 2 was investigated by TGA (Fig. 5). Four distinct weight loss regions were observed at the TGA image of compound 1. The first stage in the temperature range of 150～175 ℃ could be attributed to the release of two water molecules of crystallization (actual 4.5wt%, calcd. 4.40wt%). The second stage in the temperature range of 175 to 315 ℃ is owing to the release of two ethanol molecules, with the weight loss decreased from 4.5wt% to 11.2wt% (calcd. 11.26%). A third weight loss of 8.7wt% is observed at 315 ℃ due to the removal of two chlorine anions (calcd. 8.69%). A final weight loss of 68.0% from 450 to 600 ℃ is due to the decomposition of ligand IDB (calcd. 67.78%). 0 100 200 300 400 500 600 0%

  Figure 5

  

  Figure 5.  DTA curves of compounds 1 and 2

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  As shown in Fig. 5, the TGA image of compound 2 reveals three distinct weight loss stages. In the first weight loss of 10.5wt%, the thermal degradation from 135 to 175 ℃ could be attributed mainly to the departure of six crystal water molecules (calcd. 10.53wt%), the second weight loss of 26.7% is assigned to the release of two salicylate anions (calcd. 26.70wt%) from 175 to 355 ℃, and the third weight loss of 56.5% from 430 to 600 ℃ results from the decomposition of ligand EDTB (calcd.56.60%).

  3.4. Fluorescence spectrum

  The fluorescence spectra of compounds 1 and 2 have been studied at room temperature in ethanol. Fig. 6 shows the emission spectra recorded in the ranges of 350～550 and 300～600 nm, respectively. The characteristic emission peak of compound 1 exhibits at 445 nm (excitation at 383 nm), and the characteristic emission peak of compound 2 exhibits at 572 nm (excitation at 355 nm), which can be assigned to the ligand-centered electronic transitions, that is π-π^* or n-π^* electronic transition. Comparably, the emission peak of compound 2 (572 nm) shows a red shift relatively with the emission peak of compound 1 (445 nm) because compound 2 owns the ligand EDTB (every last EDTB contains four benzimidazole rings), however compound 1 owns the ligand IDB (every last IDB contains two benzimidazole rings). Particularly, the fluorescence emission spectra study reveals that compounds 1 and 2 exhibit purple and green emission, respectively. They have been shown in keeping with the crystal colours.

  Figure 6

  

  Figure 6.  Fluorescence spectra of compounds 1 and 2 (1×10^-4 mol/L) in ethanol

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  4. CONCLUSION

  In the present work, two novel copper (II) coordination compounds based on the N-containing groups (benzimidazole and amine) ligand were synthesized. Structures of the compound were characterized by X-ray, FTIR and TGA. Further, the compound exhibits purple and green emissions in the fluorescence spectra, respectively. Inspired by this work, we will further pursue our researches on specific properties of these compounds. They should be applied in biological detection as a fluorescent probe.

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  Figure 1  Molecular structure of compound 1

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  Figure 2  Packing diagram of compound 1

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  Figure 3  Molecular structure of compound 2

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  Figure 4  Packing diagram of compound 2

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  Figure 5  DTA curves of compounds 1 and 2

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  Figure 6  Fluorescence spectra of compounds 1 and 2 (1×10^-4 mol/L) in ethanol

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  Table 1.  Crystals Data for Compounds 1 and 2

  Compound12Empirical formulaC₃₆H₄₆C_l2CuN₁₀O₄C₄₈H₅₄CuN ₁₀O₁₂Largest diff. peak and hole / e·nm^-31092 and-921702 and -594

  Formula weight	817.27	1025.54
  Crystal system	Triclinic	Triclinic
  Crystal size	0.15mm x 0.15mm x 0.12mm	0.18mm x 0.12mmx 0.10mm
  Space group	P1	P1
  a/ Å	9.565(2)	11.487(3)
  b / Å	9.863(2)	13.396(4)
  c / Å	10.252(3)	17.977(5)
  Å/°	81.915	73.899(5)
  β / °	88.33	86.629(5)
  y / °	87.347	65.018(4)
  V / Å3	956.28(40)	2403.8(12)
  Z	1	2
  Dc/g-cm-3	1.419	1.417
  μ / mm-1	0.764	0.528
  F(000)	427	1072
  θ range / °	2.01 to 27.00	1.96 to 25.01
  Reflections collected	7598	16988
  Independent reflections	4326 (Rint = 0.0341)	8371 (Rint = 0.1083)
  Observed reflections (I > 2σ(I))	3556	4039
  Max. and min. transmission	0.9139 and 0.8940	0.9491 and 0.9109
  Data / restraints / parameters	4083 / 23 / 277	8371 / 23 / 718
  GOOF(F2)	1.095	0.962
  Final R indices (I > 2σ(I))	R = 0.0505, wR = 0.1417	R = 0.0769, wR = 0.1632
  R indices (all data)	R = 0.0591, wR = 0.1525	R = 0.1721, wR = 0.2109
  w = 1/[σ2(Fo 2) + (0.0901P)2 + 0.7811P], where P = (Fo2 + 2Fc 2)/3

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  Table 2.  Selected Bond Lengths (Å) and Bond Angles (°) for Compounds 1 and 2

  Compound1BondDist.BondDist.BondDist.Cu(1)–N(1)2.626(2)Cu(1)–N(4)2.020(2)Cu(1)–N(2)2.006(2)Angle(°)Angle(°)Angle(°)N(1)–Cu(1)–N(1a)180.00(11)N(2)–Cu(1)–N(2a)180.00(11)N(4)–Cu(1)–N(4a)180.00(11)Compound2BondDist.BondDist.BondDist.Cu(1)–N(1)2.482(6)Cu(1)–N(3)1.985(7)Cu(1)–N(7)2.080(5)Angle(°)Angle(°)Angle(°)N(1)–Cu(1)–N(2)71.7(2)N(2)–Cu(1)–N(3)92.5(2)N(3)–Cu(1)–N(7)94.4(2)N(1)–Cu(1)–N(9)93.9(2)N(3)–Cu(1)–N(5)91.4(2)N(7)–Cu(1)–N(9)89.0(2)

  Cu(1)–N(1a)	2.626(2)	Cu(1)–N(4a)	2.020(2)	Cu(1)–N(2a)	2.006(2)
  N(1)–Cu(1)–N(2)	74.70(8)	N(1a)–Cu(1)–N(2)	105.30(9)	N(2)–Cu(1)–N(4)	88.18(8)
  N(1)–Cu(1)–N(2a)	105.30(9)	N(1a)–Cu(1)–N(2a)	74.70(8)	N(2)–Cu(1)–N(4a)	91.82(8)
  N(1)–Cu(1)–N(4)	74.18(8)	N(1a)–Cu(1)–N(4)	105.82(9)	N(2a)–Cu(1)–N(4a)	88.18(8)
  N(1)–Cu(1)–N(4a)	105.82(9)	N(1a)–Cu(1)–N(4a)	74.18(8)	N(2a)–Cu(1)–N(4)	91.82(8)
  Cu(1)–N(2)	2.450(4)	Cu(1)–N(5)	2.047(5)	Cu(1)–N(9)	1.978(7)
  N(1)–Cu(1)–N(3)	76.9(2)	N(2)–Cu(1)–N(5)	143.0(2)	N(3)–Cu(1)–N(9)	168.3(2)
  N(1)–Cu(1)–N(5)	73.4(2)	N(2)–Cu(1)–N(7)	74.9(2)	N(5)–Cu(1)–N(7)	141.4(2)
  N(1)–Cu(1)–N(7)	144.9(2)	N(2)–Cu(1)–N(9)	77.6(2)	N(5)–Cu(1)–N(9)	92.9(2)
  Symmetry transformation used to generate the equivalent atoms. a: 1-x, 1-y, -z

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  Table 3.  Hydrogen Bond Lengths (Å) and Bond Angles (°) for Compounds 1 and 2

  1O(1S′)–H(1)···O(1S′)a0.822.212.793128O(6W)–H(6W)···O(1S)0.982.232.8549120Symmetry codes: (a) 2-x, 1-y, 1-z; (b)1-x, 1-y, 1-z; (c) 1-x, -y, 1-z; (d) -1+x, y, z; (e) 1-x, 1-y, -z; (f) -x, 1-y, 1-z

  Compound	D–H⋅⋅⋅A	d(D–H)	d(H⋅⋅⋅A)	d(D⋅⋅⋅A)	∠DHA
  O(1S)–H(1S)···Cl(1)b	0.83	2.38	3.195	167
  O(1)–H(1D)···Cl(1)c	0.809	2.44	3.241	171
  O(1)–H(1C)···Cl(1)	0.817	2.38	3.191	170
  N(5)–H(5)···O(1S′)	0.88	1.89	2.748	165.7
  N(5)–H(5)···O(1S)	0.88	2.11	2.905	149.5
  N(3)–H(3)···O(1)b	0.88	1.97	2.807	158.4
  N(1)–H(1)···Cl(1)	0.91	2.43	3.279	155.4
  N(10)–H(10)···O(6W)	1.01	1.79	2.7976	173
  N(8)–H(8)···O(3S)d	1.01	1.78	2.7707	165
  2	O(3W)–H(3W)···O(2W)	0.98	1.97	2.7948	140
  	O(2W)–H(2W)···O(3W)	0.98	1.82	2.7948	169
  	O(4W)–H(4W)···O(5W)e	0.98	2.16	3.1254	167
  	O(5W)–H(5W)···O(3W)e	0.98	2.12	2.7443	120
  	O(6W)–H(6W)···O(1W)f	0.98	1.97	2.8835	153

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