metal-organic compounds
Poly[bis(μ2-4,4′-bipyridine)bis(3-nitrobenzoato)nickel(II)]
aDepartment of Chemistry, Chung-Yuan Christian University, Chung-Li 320, Taiwan
*Correspondence e-mail: chiaher@cycu.edu.tw
The 7H4NO4)2(C10H8N2)2]n, exhibits a two-dimensional network, which is built up from slightly distorted NiN4O2 polyhedra (2 symmetry), bipyridine ligands, and carboxylate anions. The NiII atoms are six-coordinated by two O atoms of two monodentate carboxylate anions and four N atoms from bipyridine ligands and are connected into layers by the 4,4′-bipyridine ligands.
of the title complex, [Ni(CRelated literature
For background to the hydrothermal synthesis of coordination polymers with organic ligands, see: Kitagawa et al. (2004); Long & Yaghi (2009). For related structures, see: Chiang et al. (2009).
Experimental
Crystal data
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Data collection: APEX2 (Bruker, 2010); cell SAINT (Bruker, 2010); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2010); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
Supporting information
https://doi.org/10.1107/S1600536810050117/jh2232sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810050117/jh2232Isup2.hkl
Hydrothermal reactions were carried out at 453 K for 3 d in a Teflon-lined acid digestion bomb with an internal volume of 23 ml followed by slow cooling at 6 K/h to room temperature. A single-phase product consisting of blue crystals were obtained from a mixture of 4,4'-bipyridine (C10H8N2, 0.0781 g, 0.5 mmol), 3-nitrobenzoic acid (C7H5NO4, 0.0836 g, 0.5 mmol), Ni(NO3)2?6H2O (0.1454 g, 0.5 mmol), and H2O (12.0 ml), NH4OH (0.1 ml).
The synthesis of metal coordination polymers has been a subject of intense research due to their interesting structural chemistry and potential applications in gas storage, separation, catalysis, magnetism, luminescence, and drug delivery (Kitagawa, et al., 2004). Here we report the synthesis of title complex with a two-dimensional structure which was contained nickel and mixed 4,4'-bipyridine and 3-nitrobenzate ligands.
The π-π interactions between the benzene rings of NB ligands (3.55 Å) and form a mimic three-dimensional framework. In generally, the title complex is an analogous of our precious reported cobalt compound (Chiang, et al., 2009).
analysis reveals that the title complex possesses similar two-dimensional layer structure. The octahedral metal ions are coordinated by four nitrogen atoms and two oxygen atoms which belonged to the four bpy ligands, and two NB ligands (Fig. 1). The average bond lengths of Ni—O are 2.058 (1) Å and the Ni—N are 2.128 (2) Å which are falling in the expected normal range. Each metal center was linked adjacent metal centers by four bpy ligands, resulting in a two-dimensional neutral rectangular grid in the bc plane with a (4,4)-net (Fig. 2). The neighboring layers interact throughFor background to the hydrothermal synthesis of coordination polymers with organic ligands, see: Kitagawa et al. (2004); Long & Yaghi (2009). For related structures, see: Chiang et al. (2009).
Data collection: APEX2 (Bruker, 2010); cell
SAINT (Bruker, 2010); data reduction: SAINT (Bruker, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2010); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).[Ni(C7H4NO4)2(C10H8N2)2] | F(000) = 1448 |
Mr = 703.28 | Dx = 1.517 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 7469 reflections |
a = 18.1237 (10) Å | θ = 2.3–28.4° |
b = 11.3663 (6) Å | µ = 0.70 mm−1 |
c = 15.0119 (8) Å | T = 295 K |
β = 95.439 (2)° | Columnar, blue |
V = 3078.5 (3) Å3 | 0.45 × 0.30 × 0.10 mm |
Z = 4 |
Bruker APEXII CCD diffractometer | 3836 independent reflections |
Radiation source: fine-focus sealed tube | 3470 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.023 |
Detector resolution: 8.3333 pixels mm-1 | θmax = 28.4°, θmin = 2.1° |
φ and ω scans | h = −24→24 |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | k = −10→15 |
Tmin = 0.745, Tmax = 0.934 | l = −20→18 |
13263 measured reflections |
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)] = 0.035 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.101 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.055P)2 + 3.5308P] where P = (Fo2 + 2Fc2)/3 |
3836 reflections | (Δ/σ)max = 0.002 |
224 parameters | Δρmax = 0.71 e Å−3 |
0 restraints | Δρmin = −0.53 e Å−3 |
[Ni(C7H4NO4)2(C10H8N2)2] | V = 3078.5 (3) Å3 |
Mr = 703.28 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 18.1237 (10) Å | µ = 0.70 mm−1 |
b = 11.3663 (6) Å | T = 295 K |
c = 15.0119 (8) Å | 0.45 × 0.30 × 0.10 mm |
β = 95.439 (2)° |
Bruker APEXII CCD diffractometer | 3836 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | 3470 reflections with I > 2σ(I) |
Tmin = 0.745, Tmax = 0.934 | Rint = 0.023 |
13263 measured reflections |
R[F2 > 2σ(F2)] = 0.035 | 0 restraints |
wR(F2) = 0.101 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.71 e Å−3 |
3836 reflections | Δρmin = −0.53 e Å−3 |
224 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Ni1 | 0.5000 | 1.19295 (2) | 1.2500 | 0.02130 (10) | |
O1 | 0.57303 (7) | 1.18647 (10) | 1.15316 (8) | 0.0311 (3) | |
N1 | 0.5000 | 1.37958 (17) | 1.2500 | 0.0274 (4) | |
C1 | 0.58736 (10) | 1.20357 (14) | 1.07335 (12) | 0.0298 (3) | |
O2 | 0.54917 (9) | 1.25698 (16) | 1.01439 (10) | 0.0515 (4) | |
C2 | 0.66083 (10) | 1.15107 (15) | 1.05145 (12) | 0.0318 (3) | |
N2 | 0.5000 | 2.00284 (16) | 1.2500 | 0.0264 (4) | |
O3 | 0.81171 (16) | 1.0200 (3) | 0.83539 (19) | 0.1131 (10) | |
N3 | 0.40568 (8) | 1.19913 (11) | 1.15701 (9) | 0.0261 (3) | |
C3 | 0.67500 (11) | 1.13723 (17) | 0.96282 (13) | 0.0387 (4) | |
H3A | 0.6403 | 1.1601 | 0.9165 | 0.046* | |
O4 | 0.70979 (17) | 1.1035 (3) | 0.79302 (15) | 0.1014 (9) | |
N4 | 0.75517 (16) | 1.0686 (2) | 0.85108 (18) | 0.0693 (7) | |
C4 | 0.74173 (13) | 1.08876 (19) | 0.94515 (15) | 0.0474 (5) | |
C5 | 0.79625 (13) | 1.0578 (2) | 1.01120 (18) | 0.0529 (6) | |
H5A | 0.8413 | 1.0273 | 0.9969 | 0.063* | |
C6 | 0.78225 (12) | 1.0733 (2) | 1.09890 (17) | 0.0500 (5) | |
H6A | 0.8184 | 1.0544 | 1.1448 | 0.060* | |
C7 | 0.71441 (11) | 1.11721 (17) | 1.11888 (14) | 0.0395 (4) | |
H7A | 0.7046 | 1.1241 | 1.1784 | 0.047* | |
C8 | 0.49914 (10) | 1.44061 (15) | 1.17354 (11) | 0.0323 (4) | |
H8A | 0.4989 | 1.3993 | 1.1201 | 0.039* | |
C9 | 0.49863 (11) | 1.56217 (15) | 1.17042 (12) | 0.0343 (4) | |
H9A | 0.4974 | 1.6013 | 1.1159 | 0.041* | |
C10 | 0.5000 | 1.6253 (2) | 1.2500 | 0.0289 (5) | |
C11 | 0.5000 | 1.75560 (19) | 1.2500 | 0.0292 (5) | |
C12 | 0.53631 (16) | 1.94065 (18) | 1.19430 (19) | 0.0637 (8) | |
H12A | 0.5634 | 1.9812 | 1.1546 | 0.076* | |
C13 | 0.53672 (18) | 1.81906 (18) | 1.1911 (2) | 0.0685 (9) | |
H13A | 0.5621 | 1.7805 | 1.1486 | 0.082* | |
C14 | 0.40194 (9) | 1.15368 (17) | 1.07508 (12) | 0.0320 (4) | |
H14A | 0.4413 | 1.1079 | 1.0595 | 0.038* | |
C15 | 0.34223 (9) | 1.17121 (17) | 1.01177 (12) | 0.0333 (4) | |
H15A | 0.3423 | 1.1383 | 0.9551 | 0.040* | |
C16 | 0.28214 (8) | 1.23809 (14) | 1.03306 (10) | 0.0258 (3) | |
C17 | 0.28557 (10) | 1.28207 (17) | 1.11967 (12) | 0.0337 (4) | |
H17A | 0.2461 | 1.3252 | 1.1381 | 0.040* | |
C18 | 0.34745 (10) | 1.26177 (17) | 1.17822 (11) | 0.0331 (4) | |
H18A | 0.3488 | 1.2933 | 1.2355 | 0.040* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ni1 | 0.02510 (15) | 0.01629 (15) | 0.02124 (15) | 0.000 | −0.00447 (10) | 0.000 |
O1 | 0.0359 (6) | 0.0310 (6) | 0.0264 (6) | −0.0015 (5) | 0.0027 (5) | 0.0002 (5) |
N1 | 0.0350 (10) | 0.0183 (8) | 0.0277 (9) | 0.000 | −0.0025 (7) | 0.000 |
C1 | 0.0353 (8) | 0.0257 (8) | 0.0280 (8) | −0.0033 (6) | 0.0005 (6) | 0.0002 (6) |
O2 | 0.0540 (9) | 0.0647 (10) | 0.0352 (7) | 0.0153 (8) | 0.0006 (6) | 0.0132 (7) |
C2 | 0.0397 (9) | 0.0245 (8) | 0.0318 (8) | −0.0039 (7) | 0.0063 (7) | 0.0018 (7) |
N2 | 0.0301 (9) | 0.0181 (8) | 0.0300 (9) | 0.000 | −0.0026 (7) | 0.000 |
O3 | 0.116 (2) | 0.138 (2) | 0.0964 (18) | 0.0219 (18) | 0.0682 (17) | −0.0171 (17) |
N3 | 0.0267 (6) | 0.0246 (7) | 0.0255 (6) | 0.0016 (5) | −0.0053 (5) | −0.0006 (5) |
C3 | 0.0510 (11) | 0.0325 (9) | 0.0339 (9) | −0.0080 (8) | 0.0110 (8) | 0.0009 (7) |
O4 | 0.124 (2) | 0.142 (2) | 0.0431 (11) | 0.0011 (18) | 0.0311 (13) | −0.0084 (13) |
N4 | 0.0897 (17) | 0.0634 (14) | 0.0620 (14) | −0.0163 (13) | 0.0458 (14) | −0.0110 (11) |
C4 | 0.0611 (13) | 0.0358 (10) | 0.0494 (12) | −0.0121 (9) | 0.0271 (10) | −0.0027 (9) |
C5 | 0.0479 (11) | 0.0395 (11) | 0.0751 (16) | 0.0005 (9) | 0.0260 (11) | 0.0024 (11) |
C6 | 0.0432 (11) | 0.0449 (12) | 0.0619 (14) | 0.0054 (9) | 0.0052 (10) | 0.0076 (10) |
C7 | 0.0441 (10) | 0.0355 (9) | 0.0390 (10) | 0.0014 (8) | 0.0054 (8) | 0.0047 (8) |
C8 | 0.0471 (9) | 0.0209 (8) | 0.0282 (8) | 0.0022 (7) | −0.0007 (7) | −0.0016 (6) |
C9 | 0.0517 (10) | 0.0207 (8) | 0.0302 (8) | 0.0017 (7) | 0.0020 (7) | 0.0035 (6) |
C10 | 0.0360 (11) | 0.0164 (10) | 0.0339 (12) | 0.000 | 0.0009 (9) | 0.000 |
C11 | 0.0380 (12) | 0.0169 (10) | 0.0321 (11) | 0.000 | 0.0005 (9) | 0.000 |
C12 | 0.0924 (19) | 0.0214 (9) | 0.0867 (19) | 0.0000 (10) | 0.0572 (17) | 0.0040 (10) |
C13 | 0.104 (2) | 0.0216 (10) | 0.090 (2) | 0.0037 (11) | 0.0647 (19) | −0.0007 (10) |
C14 | 0.0261 (7) | 0.0354 (9) | 0.0330 (8) | 0.0052 (6) | −0.0053 (6) | −0.0092 (7) |
C15 | 0.0285 (8) | 0.0419 (10) | 0.0279 (8) | 0.0051 (7) | −0.0053 (6) | −0.0105 (7) |
C16 | 0.0253 (7) | 0.0260 (8) | 0.0250 (7) | −0.0001 (6) | −0.0027 (6) | 0.0009 (6) |
C17 | 0.0324 (8) | 0.0425 (10) | 0.0252 (8) | 0.0131 (7) | −0.0027 (6) | −0.0022 (7) |
C18 | 0.0359 (8) | 0.0396 (9) | 0.0224 (7) | 0.0104 (7) | −0.0044 (6) | −0.0036 (7) |
Ni1—O1 | 2.0580 (12) | C5—H5A | 0.9300 |
Ni1—O1i | 2.0580 (12) | C6—C7 | 1.386 (3) |
Ni1—N3 | 2.1031 (13) | C6—H6A | 0.9300 |
Ni1—N3i | 2.1031 (13) | C7—H7A | 0.9300 |
Ni1—N1 | 2.1212 (19) | C8—C9 | 1.382 (2) |
Ni1—N2ii | 2.1609 (19) | C8—H8A | 0.9300 |
O1—C1 | 1.265 (2) | C9—C10 | 1.391 (2) |
N1—C8 | 1.340 (2) | C9—H9A | 0.9300 |
N1—C8i | 1.340 (2) | C10—C9i | 1.391 (2) |
C1—O2 | 1.231 (2) | C10—C11 | 1.482 (3) |
C1—C2 | 1.523 (2) | C11—C13 | 1.363 (3) |
C2—C7 | 1.389 (3) | C11—C13i | 1.363 (3) |
C2—C3 | 1.388 (2) | C12—C13 | 1.383 (3) |
N2—C12 | 1.318 (2) | C12—H12A | 0.9300 |
N2—C12i | 1.318 (2) | C13—H13A | 0.9300 |
N2—Ni1iii | 2.1610 (19) | C14—C15 | 1.385 (2) |
O3—N4 | 1.207 (3) | C14—H14A | 0.9300 |
N3—C14 | 1.330 (2) | C15—C16 | 1.390 (2) |
N3—C18 | 1.336 (2) | C15—H15A | 0.9300 |
C3—C4 | 1.377 (3) | C16—C17 | 1.389 (2) |
C3—H3A | 0.9300 | C16—C16iv | 1.482 (3) |
O4—N4 | 1.207 (4) | C17—C18 | 1.377 (2) |
N4—C4 | 1.474 (3) | C17—H17A | 0.9300 |
C4—C5 | 1.377 (4) | C18—H18A | 0.9300 |
C5—C6 | 1.375 (4) | ||
O1—Ni1—O1i | 175.90 (7) | C6—C5—H5A | 120.9 |
O1—Ni1—N3 | 93.96 (5) | C4—C5—H5A | 120.9 |
O1i—Ni1—N3 | 86.18 (5) | C5—C6—C7 | 120.1 (2) |
O1—Ni1—N3i | 86.18 (5) | C5—C6—H6A | 120.0 |
O1i—Ni1—N3i | 93.96 (5) | C7—C6—H6A | 120.0 |
N3—Ni1—N3i | 176.17 (7) | C6—C7—C2 | 121.0 (2) |
O1—Ni1—N1 | 92.05 (3) | C6—C7—H7A | 119.5 |
O1i—Ni1—N1 | 92.05 (3) | C2—C7—H7A | 119.5 |
N3—Ni1—N1 | 88.09 (4) | N1—C8—C9 | 123.09 (16) |
N3i—Ni1—N1 | 88.09 (4) | N1—C8—H8A | 118.5 |
O1—Ni1—N2ii | 87.95 (3) | C9—C8—H8A | 118.5 |
O1i—Ni1—N2ii | 87.95 (3) | C8—C9—C10 | 119.10 (16) |
N3—Ni1—N2ii | 91.91 (4) | C8—C9—H9A | 120.4 |
N3i—Ni1—N2ii | 91.91 (4) | C10—C9—H9A | 120.4 |
N1—Ni1—N2ii | 180.000 (1) | C9—C10—C9i | 118.0 (2) |
C1—O1—Ni1 | 150.13 (12) | C9—C10—C11 | 121.02 (10) |
C8—N1—C8i | 117.6 (2) | C9i—C10—C11 | 121.01 (10) |
C8—N1—Ni1 | 121.18 (10) | C13—C11—C13i | 116.1 (2) |
C8i—N1—Ni1 | 121.18 (10) | C13—C11—C10 | 121.95 (12) |
O2—C1—O1 | 127.24 (18) | C13i—C11—C10 | 121.96 (12) |
O2—C1—C2 | 118.78 (16) | N2—C12—C13 | 124.3 (2) |
O1—C1—C2 | 113.98 (15) | N2—C12—H12A | 117.9 |
C7—C2—C3 | 119.16 (18) | C13—C12—H12A | 117.9 |
C7—C2—C1 | 121.09 (16) | C11—C13—C12 | 120.1 (2) |
C3—C2—C1 | 119.76 (17) | C11—C13—H13A | 119.9 |
C12—N2—C12i | 115.1 (2) | C12—C13—H13A | 119.9 |
C12—N2—Ni1iii | 122.44 (11) | N3—C14—C15 | 123.14 (16) |
C12i—N2—Ni1iii | 122.44 (11) | N3—C14—H14A | 118.4 |
C14—N3—C18 | 117.08 (14) | C15—C14—H14A | 118.4 |
C14—N3—Ni1 | 124.60 (11) | C14—C15—C16 | 119.94 (16) |
C18—N3—Ni1 | 118.05 (11) | C14—C15—H15A | 120.0 |
C4—C3—C2 | 118.4 (2) | C16—C15—H15A | 120.0 |
C4—C3—H3A | 120.8 | C17—C16—C15 | 116.46 (14) |
C2—C3—H3A | 120.8 | C17—C16—C16iv | 121.59 (18) |
O3—N4—O4 | 122.9 (3) | C15—C16—C16iv | 121.95 (18) |
O3—N4—C4 | 118.6 (3) | C18—C17—C16 | 119.91 (16) |
O4—N4—C4 | 118.5 (2) | C18—C17—H17A | 120.0 |
C3—C4—C5 | 123.1 (2) | C16—C17—H17A | 120.0 |
C3—C4—N4 | 118.3 (2) | N3—C18—C17 | 123.43 (16) |
C5—C4—N4 | 118.5 (2) | N3—C18—H18A | 118.3 |
C6—C5—C4 | 118.1 (2) | C17—C18—H18A | 118.3 |
Symmetry codes: (i) −x+1, y, −z+5/2; (ii) x, y−1, z; (iii) x, y+1, z; (iv) −x+1/2, −y+5/2, −z+2. |
Experimental details
Crystal data | |
Chemical formula | [Ni(C7H4NO4)2(C10H8N2)2] |
Mr | 703.28 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 295 |
a, b, c (Å) | 18.1237 (10), 11.3663 (6), 15.0119 (8) |
β (°) | 95.439 (2) |
V (Å3) | 3078.5 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.70 |
Crystal size (mm) | 0.45 × 0.30 × 0.10 |
Data collection | |
Diffractometer | Bruker APEXII CCD |
Absorption correction | Multi-scan (SADABS; Bruker, 2000) |
Tmin, Tmax | 0.745, 0.934 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 13263, 3836, 3470 |
Rint | 0.023 |
(sin θ/λ)max (Å−1) | 0.669 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.101, 1.03 |
No. of reflections | 3836 |
No. of parameters | 224 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.71, −0.53 |
Computer programs: APEX2 (Bruker, 2010), SAINT (Bruker, 2010), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2010), SHELXTL (Sheldrick, 2008).
Acknowledgements
This research was supported by the National Science Council, Taiwan (NSC99–2113-M-033–005-MY2).
References
Brandenburg, K. (2010). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Bruker (2000). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2010). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chiang, P.-H., Hsu, S.-C. & Lin, C.-H. (2009). Acta Cryst. E65, m1302–m1303. Web of Science CSD CrossRef IUCr Journals Google Scholar
Kitagawa, S., Kitaura, R. & Noro, S. (2004). Angew. Chem. Int. Ed. 43, 2334–2375. Web of Science CrossRef CAS Google Scholar
Long, J. L. & Yaghi, O. M. (2009). Chem. Soc. Rev. 38, 1213–1214. Web of Science CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
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The synthesis of metal coordination polymers has been a subject of intense research due to their interesting structural chemistry and potential applications in gas storage, separation, catalysis, magnetism, luminescence, and drug delivery (Kitagawa, et al., 2004). Here we report the synthesis of title complex with a two-dimensional structure which was contained nickel and mixed 4,4'-bipyridine and 3-nitrobenzate ligands.
The crystal structure analysis reveals that the title complex possesses similar two-dimensional layer structure. The octahedral metal ions are coordinated by four nitrogen atoms and two oxygen atoms which belonged to the four bpy ligands, and two NB ligands (Fig. 1). The average bond lengths of Ni—O are 2.058 (1) Å and the Ni—N are 2.128 (2) Å which are falling in the expected normal range. Each metal center was linked adjacent metal centers by four bpy ligands, resulting in a two-dimensional neutral rectangular grid in the bc plane with a (4,4)-net (Fig. 2). The neighboring layers interact through π-π interactions between the benzene rings of NB ligands (3.55 Å) and form a mimic three-dimensional framework. In generally, the title complex is an analogous of our precious reported cobalt compound (Chiang, et al., 2009).