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A new polymeric copper complex, [Cu2(C6H12N4O2)(C2N3)2]n or [Cu2(oxen)[N(CN)2]2]n [oxenH2 is N,N′-bis(2-aminoethyl)oxamide], has been synthesized and its structure determined by X-ray diffraction methods. In the polymer chain, oxen and dicyanamide (dca) groups both act as bridges to link CuII cations, illustrating the potential of oxen and dca in coordination chemistry and supramolecular polymer chemistry.
Supporting information
CCDC reference: 196623
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.005 Å
- R factor = 0.040
- wR factor = 0.073
- Data-to-parameter ratio = 19.9
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
To a stirred solution of Cu(oxen)·2H2O (0.136 g, 0.5 mmol) in H2O (20 ml) was added an equimolar amount of Cu(ClO4)2·6H2O (0.185 g, 0.5 mmol); the solution changed from purple to blue immediately. A solution of Na(dca) (0.045 g, 0.5 mmol) in ethanol was then added. The solution was stirred for 30 min at room temperature. The filtered solution was allowed to evaporate at room temperature. After 7 d, green crystals of the title complex were obtained.
H atoms were positioned geometrically and refined with riding model constraints.
Data collection: SMART (Bruker, 1997); cell refinement: SMART; data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXTL (Bruker, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
catena-Poly[[[µ-
N,
N'-bis(2-aminoethyl)oxamido]dicopper(II)]-di-µ- dicyanoamido]
top
Crystal data top
[Cu2(C6H12N4O2)(C2N3)2] | F(000) = 432 |
Mr = 431.39 | Dx = 1.910 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 7.0622 (6) Å | Cell parameters from 2360 reflections |
b = 9.6969 (8) Å | θ = 2.8–30.5° |
c = 11.3531 (9) Å | µ = 2.87 mm−1 |
β = 105.308 (2)° | T = 293 K |
V = 749.89 (11) Å3 | Prism, green |
Z = 2 | 0.2 × 0.1 × 0.07 mm |
Data collection top
Bruker SMART APEX CCD diffractometer | 2166 independent reflections |
Radiation source: fine-focus sealed tube | 1667 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.030 |
Detector resolution: 15µm x 15µm pixels mm-1 | θmax = 30.0°, θmin = 2.8° |
ω scans | h = −9→9 |
Absorption correction: multi-scan (SADABS; Bruker, 1997) | k = −13→9 |
Tmin = 0.650, Tmax = 0.818 | l = −14→15 |
5902 measured reflections | |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.073 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.001P)2 + P] where P = (Fo2 + 2Fc2)/3 |
2166 reflections | (Δ/σ)max < 0.001 |
109 parameters | Δρmax = 0.48 e Å−3 |
0 restraints | Δρmin = −0.39 e Å−3 |
Crystal data top
[Cu2(C6H12N4O2)(C2N3)2] | V = 749.89 (11) Å3 |
Mr = 431.39 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.0622 (6) Å | µ = 2.87 mm−1 |
b = 9.6969 (8) Å | T = 293 K |
c = 11.3531 (9) Å | 0.2 × 0.1 × 0.07 mm |
β = 105.308 (2)° | |
Data collection top
Bruker SMART APEX CCD diffractometer | 2166 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1997) | 1667 reflections with I > 2σ(I) |
Tmin = 0.650, Tmax = 0.818 | Rint = 0.030 |
5902 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.073 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.48 e Å−3 |
2166 reflections | Δρmin = −0.39 e Å−3 |
109 parameters | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Cu1 | 0.14825 (5) | 0.88096 (4) | 0.71360 (3) | 0.03289 (11) | |
O1 | −0.2398 (3) | 0.9914 (2) | 0.40149 (17) | 0.0359 (5) | |
N1 | 0.5875 (4) | 1.1589 (3) | 1.1846 (2) | 0.0415 (6) | |
N2 | 0.2613 (4) | 1.1825 (3) | 1.0445 (3) | 0.0509 (8) | |
N3 | 0.1283 (4) | 1.0448 (3) | 0.8616 (3) | 0.0588 (8) | |
N4 | −0.0970 (3) | 0.8945 (3) | 0.5904 (2) | 0.0364 (6) | |
N5 | 0.0027 (3) | 0.7333 (2) | 0.7793 (2) | 0.0358 (6) | |
H5A | 0.0828 | 0.6612 | 0.8061 | 0.043* | |
H5B | −0.0377 | 0.7667 | 0.8426 | 0.043* | |
C1 | 0.4373 (4) | 1.1652 (3) | 1.1155 (3) | 0.0345 (6) | |
C2 | 0.1995 (4) | 1.1050 (3) | 0.9483 (3) | 0.0364 (6) | |
C3 | −0.0996 (4) | 0.9676 (3) | 0.4961 (2) | 0.0308 (6) | |
C4 | −0.2605 (4) | 0.8136 (4) | 0.6093 (3) | 0.0458 (8) | |
H4A | −0.3481 | 0.7864 | 0.5317 | 0.055* | |
H4B | −0.3344 | 0.8664 | 0.6547 | 0.055* | |
C5 | −0.1680 (4) | 0.6882 (3) | 0.6814 (3) | 0.0441 (8) | |
H5C | −0.2628 | 0.6426 | 0.7164 | 0.053* | |
H5D | −0.1266 | 0.6233 | 0.6281 | 0.053* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cu1 | 0.02499 (16) | 0.0385 (2) | 0.02917 (17) | −0.00403 (15) | −0.00349 (12) | 0.00268 (15) |
O1 | 0.0262 (9) | 0.0443 (12) | 0.0306 (10) | −0.0090 (8) | −0.0043 (8) | 0.0052 (8) |
N1 | 0.0314 (12) | 0.0467 (16) | 0.0407 (14) | 0.0015 (11) | −0.0002 (11) | 0.0005 (11) |
N2 | 0.0302 (13) | 0.0605 (18) | 0.0516 (17) | 0.0119 (12) | −0.0076 (12) | −0.0150 (14) |
N3 | 0.0503 (17) | 0.066 (2) | 0.0500 (18) | 0.0162 (15) | −0.0052 (14) | −0.0169 (15) |
N4 | 0.0261 (11) | 0.0475 (15) | 0.0306 (12) | −0.0093 (10) | −0.0012 (9) | 0.0050 (11) |
N5 | 0.0291 (12) | 0.0394 (14) | 0.0349 (13) | 0.0047 (10) | 0.0013 (10) | 0.0055 (10) |
C1 | 0.0313 (14) | 0.0345 (15) | 0.0371 (15) | 0.0029 (12) | 0.0077 (12) | 0.0000 (12) |
C2 | 0.0251 (13) | 0.0410 (16) | 0.0394 (16) | 0.0093 (12) | 0.0022 (11) | 0.0008 (13) |
C3 | 0.0252 (12) | 0.0341 (15) | 0.0291 (13) | −0.0048 (11) | 0.0001 (10) | −0.0020 (11) |
C4 | 0.0284 (14) | 0.065 (2) | 0.0381 (17) | −0.0152 (14) | −0.0019 (12) | 0.0141 (15) |
C5 | 0.0372 (16) | 0.0468 (19) | 0.0452 (18) | −0.0145 (14) | 0.0054 (14) | 0.0012 (14) |
Geometric parameters (Å, º) top
Cu1—N4 | 1.922 (2) | N2—C1 | 1.301 (3) |
Cu1—N1i | 1.957 (2) | N2—C2 | 1.302 (4) |
Cu1—N5 | 2.017 (2) | N3—C2 | 1.141 (4) |
Cu1—O1ii | 2.025 (2) | N4—C3 | 1.280 (3) |
Cu1—N3 | 2.343 (3) | N4—C4 | 1.458 (4) |
O1—C3 | 1.275 (3) | N5—C5 | 1.474 (3) |
O1—Cu1ii | 2.025 (2) | C3—C3ii | 1.522 (5) |
N1—C1 | 1.142 (3) | C4—C5 | 1.514 (4) |
N1—Cu1i | 1.957 (2) | | |
| | | |
N4—Cu1—N1i | 168.23 (11) | C2—N3—Cu1 | 150.4 (2) |
N4—Cu1—N5 | 82.43 (9) | C3—N4—C4 | 125.8 (2) |
N1i—Cu1—N5 | 98.11 (10) | C3—N4—Cu1 | 117.22 (18) |
N4—Cu1—O1ii | 82.45 (9) | C4—N4—Cu1 | 116.90 (18) |
N1i—Cu1—O1ii | 94.85 (9) | C5—N5—Cu1 | 109.08 (18) |
N5—Cu1—O1ii | 162.35 (8) | N1—C1—N2 | 173.8 (3) |
N4—Cu1—N3 | 105.22 (10) | N3—C2—N2 | 173.1 (3) |
N1i—Cu1—N3 | 86.49 (10) | O1—C3—N4 | 129.9 (2) |
N5—Cu1—N3 | 94.76 (12) | O1—C3—C3ii | 118.3 (3) |
O1ii—Cu1—N3 | 97.94 (11) | N4—C3—C3ii | 111.8 (3) |
C3—O1—Cu1ii | 110.21 (17) | N4—C4—C5 | 105.5 (2) |
C1—N1—Cu1i | 169.8 (3) | N5—C5—C4 | 108.6 (2) |
C1—N2—C2 | 119.9 (3) | | |
Symmetry codes: (i) −x+1, −y+2, −z+2; (ii) −x, −y+2, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N5—H5A···O1iii | 0.90 | 2.05 | 2.941 (3) | 168 |
N5—H5B···N2iv | 0.90 | 2.33 | 3.180 (4) | 157 |
Symmetry codes: (iii) x+1/2, −y+3/2, z+1/2; (iv) −x, −y+2, −z+2. |
Experimental details
Crystal data |
Chemical formula | [Cu2(C6H12N4O2)(C2N3)2] |
Mr | 431.39 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 293 |
a, b, c (Å) | 7.0622 (6), 9.6969 (8), 11.3531 (9) |
β (°) | 105.308 (2) |
V (Å3) | 749.89 (11) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 2.87 |
Crystal size (mm) | 0.2 × 0.1 × 0.07 |
|
Data collection |
Diffractometer | Bruker SMART APEX CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 1997) |
Tmin, Tmax | 0.650, 0.818 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5902, 2166, 1667 |
Rint | 0.030 |
(sin θ/λ)max (Å−1) | 0.703 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.073, 1.06 |
No. of reflections | 2166 |
No. of parameters | 109 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.48, −0.39 |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N5—H5A···O1i | 0.90 | 2.05 | 2.941 (3) | 168 |
N5—H5B···N2ii | 0.90 | 2.33 | 3.180 (4) | 157 |
Symmetry codes: (i) x+1/2, −y+3/2, z+1/2; (ii) −x, −y+2, −z+2. |
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Supramolecular polymer chemistry, an important branch of modern chemical science, is developing as the combination of supramolecular chemistry and polymer chemistry (Lehn, 1995, 1999; Kholbystov et al., 2001). Inorganic crystal engineering is an important branch of supramolecular polymer chemistry research, because it offers the prospect of deliberately designing new materials with useful properties (Zhang et al., 2001; Braga et al., 1999).
Dca (dicyanamide, [N(CN)2]−) and trans-oxen [N,N'-bis(2-aminoethyl)oxamido2−] have been shown to be useful species for the construction of one- and two-dimensional coordination architectures (Groeneman et al., 1998; Choi & Suh, 1999; Batten et al., 2000; Manson et al., 1998). Dca itself can act as a monodentate, bidentate (two types of binding) or tridentate ligand. In the last few years, coordination polymers containing dca as ligand have attracted much attention and led to many homometallic or heterometallic networks of varied topologies and magnetic properties (van Albada et al., 2000; Hvastijova et al., 1998). When other ligands are introduced, different kinds of structures can be obtained, such as one-dimensional chains (Sun et al., 2001; Escuer et al., 2000), ladders (Wang et al., 2000), two-dimensional sheets (Marshall et al., 2002; Jensen et al., 2001), and three-dimensional interpenetrating diamondoid nets (Wang et al., 2000). Therefore, we chose dca and oxen groups as ligands to construct a new coordination polymer. Here we report the synthesis and structure of the title polymeric complex, (I).
The structure of (I), with the atomic numbering, is shown in Fig. 1. The repeat unit of the polymer is a dinuclear one, containing two centrosymmetrically related Cu2+ cations, with oxen and dca groups connecting the cations together. The CuII cations exhibit square-based pyramidal coordination geometry; the basal plane is formed by two N atoms and one O atom from an oxen group and one N atom from a dca group. The apical site is occupied by one N atom from another dca group, with a bond length of 2.343 (3) Å. The chain polymeric structure is depicted in Fig. 2. In the chain, oxen and dca groups both act as bridging ligands, alternately connecting copper cations. Fig. 3 shows the packing, viewed along the a axis. An intermolecular hydrogen-bond network is present (Table 2), through which the polymer chains are connected into a two-dimensional structure and copper ions are arranged in a net.
The IR spectrum shows the characteristic CN stretching vibration at 2250 and 2350 cm−1, C═O at 1105 cm−1, and N—H at 3145 and 3380 cm−1.