metal-organic compounds
Dibromido(2,3-di-2-pyridylpyrazine-κ2N2,N3)platinum(II)
aSchool of Applied Chemical Engineering, The Research Institute of Catalysis, Chonnam National University, Gwangju 500-757, Republic of Korea
*Correspondence e-mail: hakwang@chonnam.ac.kr
The PtII ion in the title complex, [PtBr2(C14H10N4)], has a slightly distorted square-planar environment defined by the two pyridyl N atoms of the chelating 2,3-di-2-pyridylpyrazine ligand and two bromide anions. In the crystal, the pyridyl rings are considerably inclined to the least-squares plane of the PtBr2N2 unit [maximum deviation = 0.064 (2) Å] with dihedral angles of 65.2 (2) and 66.0 (2)°. The nearly planar pyrazine ring [maximum deviation = 0.020 (5) Å] is almost perpendicular to the unit plane with a dihedral angle of 89.2 (2)°. Two independent weak intermolecular C—H⋯Br hydrogen bonds, both involving the same Br atom as a hydrogen-bond acceptor, give rise to chains running along the a and b axes, forming a layer structure extending parallel to (001). The complexes are stacked in columns along the a axis. When viewed down the b axis, the successive complexes stack in the opposite direction.
Related literature
For an isomer of the title complex, see: Ha (2011). For crystal structures of the related PtII complexes, see: Granifo et al. (2000); Cai et al. (2009).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 2000); cell SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97.
Supporting information
10.1107/S160053681103412X/xu5295sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S160053681103412X/xu5295Isup2.hkl
The title complex was obtained as a byproduct from the reaction of K2PtBr4 (0.2967 g, 0.500 mmol) with 2,3-di-2-pyridylpyrazine (0.1173 g, 0.501 mmol) in H2O (20 ml). After stirring of the reaction mixture for 3 h at room temperature, the formed precipitate was separated by filtration, washed with H2O and acetone, to give the main product as a red-brown powder (0.1326 g) (Ha, 2011). The yellow byproduct (0.0299 g) was obtained from the mixture of filtrate and washing solution. Crystals suitable for X-ray analysis were obtained by slow evaporation from a CH3NO2 solution of the byproduct.
H atoms were positioned geometrically and allowed to ride on their respective parent atoms [C—H = 0.95 Å and Uiso(H) = 1.2Ueq(C)]. The highest peak (1.66 e Å-3) and the deepest hole (-0.84 e Å-3) in the difference Fourier map are located 1.95 Å and 0.89 Å from the atoms H12 and Pt1, respectively.
Data collection: SMART (Bruker, 2000); cell
SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).[PtBr2(C14H10N4)] | F(000) = 1080 |
Mr = 589.17 | Dx = 2.544 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 4242 reflections |
a = 8.4989 (12) Å | θ = 2.7–27.0° |
b = 15.348 (2) Å | µ = 14.32 mm−1 |
c = 12.0277 (16) Å | T = 200 K |
β = 101.403 (3)° | Block, yellow |
V = 1538.0 (4) Å3 | 0.18 × 0.18 × 0.13 mm |
Z = 4 |
Bruker SMART 1000 CCD diffractometer | 3323 independent reflections |
Radiation source: fine-focus sealed tube | 2484 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.046 |
ϕ and ω scans | θmax = 27.0°, θmin = 2.2° |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | h = −9→10 |
Tmin = 0.105, Tmax = 0.156 | k = −11→19 |
10118 measured reflections | l = −13→15 |
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)] = 0.032 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.067 | H-atom parameters constrained |
S = 0.99 | w = 1/[σ2(Fo2) + (0.0237P)2] where P = (Fo2 + 2Fc2)/3 |
3323 reflections | (Δ/σ)max < 0.001 |
190 parameters | Δρmax = 1.66 e Å−3 |
0 restraints | Δρmin = −0.84 e Å−3 |
[PtBr2(C14H10N4)] | V = 1538.0 (4) Å3 |
Mr = 589.17 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 8.4989 (12) Å | µ = 14.32 mm−1 |
b = 15.348 (2) Å | T = 200 K |
c = 12.0277 (16) Å | 0.18 × 0.18 × 0.13 mm |
β = 101.403 (3)° |
Bruker SMART 1000 CCD diffractometer | 3323 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | 2484 reflections with I > 2σ(I) |
Tmin = 0.105, Tmax = 0.156 | Rint = 0.046 |
10118 measured reflections |
R[F2 > 2σ(F2)] = 0.032 | 0 restraints |
wR(F2) = 0.067 | H-atom parameters constrained |
S = 0.99 | Δρmax = 1.66 e Å−3 |
3323 reflections | Δρmin = −0.84 e Å−3 |
190 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 | ||
Pt1 | 0.52128 (3) | 0.060963 (16) | 0.31708 (2) | 0.02517 (9) | |
Br1 | 0.38241 (9) | −0.07734 (4) | 0.30704 (6) | 0.03471 (18) | |
Br2 | 0.27287 (9) | 0.14353 (5) | 0.26735 (6) | 0.0413 (2) | |
N1 | 0.8219 (7) | 0.0077 (3) | 0.0833 (5) | 0.0314 (14) | |
N2 | 0.7631 (7) | 0.1861 (4) | 0.0810 (5) | 0.0368 (15) | |
N3 | 0.7311 (6) | −0.0055 (3) | 0.3550 (4) | 0.0238 (12) | |
N4 | 0.6520 (7) | 0.1724 (3) | 0.3406 (4) | 0.0284 (13) | |
C1 | 0.8029 (8) | 0.0499 (4) | 0.1780 (5) | 0.0265 (15) | |
C2 | 0.7701 (8) | 0.1400 (4) | 0.1755 (6) | 0.0304 (16) | |
C3 | 0.7799 (10) | 0.1437 (5) | −0.0117 (6) | 0.042 (2) | |
H3 | 0.7738 | 0.1755 | −0.0802 | 0.051* | |
C4 | 0.8060 (9) | 0.0552 (5) | −0.0126 (6) | 0.0394 (19) | |
H4 | 0.8128 | 0.0272 | −0.0819 | 0.047* | |
C5 | 0.8339 (8) | −0.0057 (4) | 0.2819 (5) | 0.0231 (14) | |
C6 | 0.9675 (8) | −0.0587 (4) | 0.3011 (6) | 0.0305 (16) | |
H6 | 1.0386 | −0.0590 | 0.2492 | 0.037* | |
C7 | 0.9973 (9) | −0.1111 (5) | 0.3954 (6) | 0.0392 (18) | |
H7 | 1.0881 | −0.1485 | 0.4087 | 0.047* | |
C8 | 0.8944 (8) | −0.1088 (4) | 0.4708 (6) | 0.0333 (17) | |
H8 | 0.9149 | −0.1436 | 0.5375 | 0.040* | |
C9 | 0.7622 (8) | −0.0557 (4) | 0.4483 (5) | 0.0266 (15) | |
H9 | 0.6909 | −0.0544 | 0.4999 | 0.032* | |
C10 | 0.7583 (9) | 0.1933 (4) | 0.2760 (5) | 0.0307 (16) | |
C11 | 0.8525 (9) | 0.2669 (4) | 0.3000 (6) | 0.0397 (19) | |
H11 | 0.9274 | 0.2815 | 0.2540 | 0.048* | |
C12 | 0.8379 (10) | 0.3187 (5) | 0.3903 (6) | 0.043 (2) | |
H12 | 0.9026 | 0.3693 | 0.4073 | 0.052* | |
C13 | 0.7293 (10) | 0.2969 (5) | 0.4557 (6) | 0.044 (2) | |
H13 | 0.7186 | 0.3322 | 0.5187 | 0.053* | |
C14 | 0.6361 (9) | 0.2243 (4) | 0.4303 (5) | 0.0352 (18) | |
H14 | 0.5598 | 0.2096 | 0.4753 | 0.042* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Pt1 | 0.02370 (16) | 0.02954 (16) | 0.02362 (14) | 0.00465 (12) | 0.00797 (11) | 0.00200 (11) |
Br1 | 0.0235 (4) | 0.0404 (4) | 0.0414 (4) | −0.0026 (3) | 0.0092 (3) | −0.0002 (3) |
Br2 | 0.0357 (5) | 0.0529 (5) | 0.0367 (4) | 0.0204 (4) | 0.0108 (3) | 0.0100 (3) |
N1 | 0.035 (4) | 0.029 (3) | 0.033 (3) | 0.004 (3) | 0.014 (3) | −0.002 (3) |
N2 | 0.043 (4) | 0.035 (4) | 0.033 (3) | 0.001 (3) | 0.009 (3) | 0.012 (3) |
N3 | 0.026 (3) | 0.024 (3) | 0.021 (3) | −0.004 (2) | 0.003 (2) | 0.000 (2) |
N4 | 0.032 (4) | 0.025 (3) | 0.028 (3) | 0.004 (3) | 0.005 (3) | 0.003 (2) |
C1 | 0.019 (4) | 0.036 (4) | 0.025 (4) | −0.003 (3) | 0.005 (3) | 0.001 (3) |
C2 | 0.023 (4) | 0.028 (4) | 0.042 (4) | −0.001 (3) | 0.009 (3) | 0.004 (3) |
C3 | 0.058 (6) | 0.041 (5) | 0.033 (4) | −0.002 (4) | 0.021 (4) | 0.013 (3) |
C4 | 0.042 (5) | 0.051 (5) | 0.029 (4) | 0.006 (4) | 0.014 (3) | 0.014 (3) |
C5 | 0.023 (4) | 0.027 (4) | 0.018 (3) | −0.002 (3) | 0.001 (3) | 0.000 (3) |
C6 | 0.017 (4) | 0.035 (4) | 0.042 (4) | 0.003 (3) | 0.012 (3) | 0.006 (3) |
C7 | 0.024 (4) | 0.044 (5) | 0.050 (5) | 0.008 (3) | 0.010 (4) | 0.013 (4) |
C8 | 0.030 (4) | 0.031 (4) | 0.038 (4) | 0.004 (3) | 0.005 (3) | 0.006 (3) |
C9 | 0.025 (4) | 0.031 (4) | 0.024 (3) | −0.006 (3) | 0.004 (3) | 0.004 (3) |
C10 | 0.035 (4) | 0.022 (4) | 0.032 (4) | −0.001 (3) | 0.001 (3) | 0.008 (3) |
C11 | 0.042 (5) | 0.032 (4) | 0.046 (5) | 0.001 (4) | 0.012 (4) | 0.003 (4) |
C12 | 0.045 (5) | 0.029 (4) | 0.048 (5) | 0.000 (4) | −0.009 (4) | −0.004 (4) |
C13 | 0.067 (6) | 0.030 (5) | 0.031 (4) | 0.009 (4) | 0.002 (4) | −0.005 (3) |
C14 | 0.055 (5) | 0.030 (4) | 0.019 (4) | 0.009 (4) | 0.007 (3) | 0.002 (3) |
Pt1—N3 | 2.026 (5) | C4—H4 | 0.9500 |
Pt1—N4 | 2.029 (5) | C5—C6 | 1.380 (8) |
Pt1—Br1 | 2.4202 (8) | C6—C7 | 1.373 (9) |
Pt1—Br2 | 2.4335 (8) | C6—H6 | 0.9500 |
N1—C1 | 1.347 (8) | C7—C8 | 1.379 (9) |
N1—C4 | 1.349 (8) | C7—H7 | 0.9500 |
N2—C3 | 1.323 (8) | C8—C9 | 1.371 (9) |
N2—C2 | 1.329 (8) | C8—H8 | 0.9500 |
N3—C9 | 1.344 (7) | C9—H9 | 0.9500 |
N3—C5 | 1.357 (7) | C10—C11 | 1.381 (9) |
N4—C10 | 1.341 (8) | C11—C12 | 1.372 (9) |
N4—C14 | 1.368 (8) | C11—H11 | 0.9500 |
C1—C2 | 1.410 (9) | C12—C13 | 1.367 (10) |
C1—C5 | 1.493 (8) | C12—H12 | 0.9500 |
C2—C10 | 1.479 (9) | C13—C14 | 1.366 (10) |
C3—C4 | 1.376 (9) | C13—H13 | 0.9500 |
C3—H3 | 0.9500 | C14—H14 | 0.9500 |
N3—Pt1—N4 | 87.7 (2) | C6—C5—C1 | 118.7 (6) |
N3—Pt1—Br1 | 88.20 (14) | C7—C6—C5 | 119.7 (6) |
N4—Pt1—Br1 | 174.08 (15) | C7—C6—H6 | 120.2 |
N3—Pt1—Br2 | 178.19 (14) | C5—C6—H6 | 120.2 |
N4—Pt1—Br2 | 91.13 (15) | C6—C7—C8 | 119.5 (7) |
Br1—Pt1—Br2 | 93.08 (3) | C6—C7—H7 | 120.3 |
C1—N1—C4 | 117.0 (6) | C8—C7—H7 | 120.3 |
C3—N2—C2 | 117.7 (6) | C9—C8—C7 | 119.1 (6) |
C9—N3—C5 | 119.6 (5) | C9—C8—H8 | 120.5 |
C9—N3—Pt1 | 119.7 (4) | C7—C8—H8 | 120.5 |
C5—N3—Pt1 | 120.4 (4) | N3—C9—C8 | 121.7 (6) |
C10—N4—C14 | 120.0 (6) | N3—C9—H9 | 119.2 |
C10—N4—Pt1 | 122.2 (4) | C8—C9—H9 | 119.2 |
C14—N4—Pt1 | 117.6 (5) | N4—C10—C11 | 120.2 (6) |
N1—C1—C2 | 120.7 (6) | N4—C10—C2 | 120.3 (6) |
N1—C1—C5 | 113.7 (6) | C11—C10—C2 | 119.5 (6) |
C2—C1—C5 | 125.4 (6) | C12—C11—C10 | 120.0 (7) |
N2—C2—C1 | 121.0 (6) | C12—C11—H11 | 120.0 |
N2—C2—C10 | 113.9 (6) | C10—C11—H11 | 120.0 |
C1—C2—C10 | 124.7 (6) | C13—C12—C11 | 119.3 (7) |
N2—C3—C4 | 122.4 (6) | C13—C12—H12 | 120.3 |
N2—C3—H3 | 118.8 | C11—C12—H12 | 120.3 |
C4—C3—H3 | 118.8 | C14—C13—C12 | 119.9 (7) |
N1—C4—C3 | 121.1 (7) | C14—C13—H13 | 120.0 |
N1—C4—H4 | 119.4 | C12—C13—H13 | 120.0 |
C3—C4—H4 | 119.4 | C13—C14—N4 | 120.5 (7) |
N3—C5—C6 | 120.5 (6) | C13—C14—H14 | 119.8 |
N3—C5—C1 | 120.8 (6) | N4—C14—H14 | 119.8 |
N4—Pt1—N3—C9 | 115.6 (5) | N1—C1—C5—C6 | 45.0 (8) |
Br1—Pt1—N3—C9 | −60.1 (4) | C2—C1—C5—C6 | −129.7 (7) |
N4—Pt1—N3—C5 | −70.2 (5) | N3—C5—C6—C7 | −0.6 (10) |
Br1—Pt1—N3—C5 | 114.1 (4) | C1—C5—C6—C7 | −179.3 (6) |
N3—Pt1—N4—C10 | 62.4 (5) | C5—C6—C7—C8 | −1.1 (11) |
Br2—Pt1—N4—C10 | −116.2 (5) | C6—C7—C8—C9 | 1.6 (11) |
N3—Pt1—N4—C14 | −113.5 (5) | C5—N3—C9—C8 | −1.2 (9) |
Br2—Pt1—N4—C14 | 67.8 (5) | Pt1—N3—C9—C8 | 173.0 (5) |
C4—N1—C1—C2 | −0.9 (9) | C7—C8—C9—N3 | −0.4 (10) |
C4—N1—C1—C5 | −175.9 (6) | C14—N4—C10—C11 | 0.3 (10) |
C3—N2—C2—C1 | 3.3 (10) | Pt1—N4—C10—C11 | −175.6 (5) |
C3—N2—C2—C10 | 177.1 (6) | C14—N4—C10—C2 | −176.9 (6) |
N1—C1—C2—N2 | −2.5 (10) | Pt1—N4—C10—C2 | 7.3 (9) |
C5—C1—C2—N2 | 171.9 (6) | N2—C2—C10—N4 | 128.9 (7) |
N1—C1—C2—C10 | −175.6 (6) | C1—C2—C10—N4 | −57.6 (10) |
C5—C1—C2—C10 | −1.2 (11) | N2—C2—C10—C11 | −48.3 (9) |
C2—N2—C3—C4 | −0.8 (11) | C1—C2—C10—C11 | 125.3 (7) |
C1—N1—C4—C3 | 3.3 (10) | N4—C10—C11—C12 | 0.2 (11) |
N2—C3—C4—N1 | −2.6 (12) | C2—C10—C11—C12 | 177.4 (6) |
C9—N3—C5—C6 | 1.7 (9) | C10—C11—C12—C13 | −0.1 (11) |
Pt1—N3—C5—C6 | −172.5 (5) | C11—C12—C13—C14 | −0.3 (11) |
C9—N3—C5—C1 | −179.6 (6) | C12—C13—C14—N4 | 0.8 (11) |
Pt1—N3—C5—C1 | 6.2 (8) | C10—N4—C14—C13 | −0.8 (10) |
N1—C1—C5—N3 | −133.7 (6) | Pt1—N4—C14—C13 | 175.3 (5) |
C2—C1—C5—N3 | 51.5 (9) |
D—H···A | D—H | H···A | D···A | D—H···A |
C6—H6···Br1i | 0.95 | 2.88 | 3.524 (6) | 126 |
C11—H11···Br1ii | 0.95 | 2.88 | 3.688 (7) | 143 |
Symmetry codes: (i) x+1, y, z; (ii) −x+3/2, y+1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | [PtBr2(C14H10N4)] |
Mr | 589.17 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 200 |
a, b, c (Å) | 8.4989 (12), 15.348 (2), 12.0277 (16) |
β (°) | 101.403 (3) |
V (Å3) | 1538.0 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 14.32 |
Crystal size (mm) | 0.18 × 0.18 × 0.13 |
Data collection | |
Diffractometer | Bruker SMART 1000 CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2000) |
Tmin, Tmax | 0.105, 0.156 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10118, 3323, 2484 |
Rint | 0.046 |
(sin θ/λ)max (Å−1) | 0.639 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.032, 0.067, 0.99 |
No. of reflections | 3323 |
No. of parameters | 190 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.66, −0.84 |
Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
C6—H6···Br1i | 0.95 | 2.88 | 3.524 (6) | 126.0 |
C11—H11···Br1ii | 0.95 | 2.88 | 3.688 (7) | 143.2 |
Symmetry codes: (i) x+1, y, z; (ii) −x+3/2, y+1/2, −z+1/2. |
Acknowledgements
This work was supported by the Priority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (grant No. 2010–0029626).
References
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
The title complex, [PtBr2(dpp)] (dpp is 2,3-di-2-pyridylpyrazine, C14H10N4), is a structural isomer of the previously reported Pt(II) complex (Ha, 2011). The PtII ion has a slightly distorted square-planar environment defined by the two pyridyl N atoms of the chelating dpp ligand and two bromide anions (Fig. 1). The coordination mode of the dpp ligand is similar to that found in the mononuclear Pt(II) complexes [PtCl2(dpq)] (dpq = 2,3-di-2-pyridylquinoxaline) (Granifo et al., 2000) and [PtCl2(dcdpp)] (dcdpp = 2,3-dicyano-5,6-di-2-pyridylpyrazine) (Cai et al., 2009).
The N3—Pt1—N4 chelate angle of 87.7 (2)° and Br—Br repelling contribute the distortion of square, and therefore the trans axes are slightly bent [<Br1—Pt1—N4 = 174.08 (15)° and <Br2—Pt1—N3 = 178.19 (14)°]. The Pt—N and Pt—Br bond lengths are nearly equivalent, respectively (Table 1). In the crystal, the two pyridyl rings are considerably inclined to the least-squares plane of the PtBr2N2 unit [maximum deviation = 0.064 (2) Å] with dihedral angles of 65.2 (2)° and 66.0 (2)°, respectively. The nearly planar pyrazine ring [maximum deviation = 0.020 (5) Å] is almost perpendicular to the unit plane with a dihedral angle of 89.2 (2)°. The dihedral angle between the two pyridyl rings is 80.5 (2)°. Two independent intermolecular C—H···Br hydrogen bonds, both involving the same Br atom as an H-bond acceptor, give rise to chains running along the a and b axes, forming a layer structure extending parallel to the ab plane (Fig. 2 and Table 2). The complexes are stacked in columns along the a axis. When viewed down the b axis, the successive complexes stack in the opposite direction. In the columns, numerous inter- and intramolecular π-π interactions between the six-membered rings are present, the shortest ring centroid-centroid distance being 3.833 (4) Å.