Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270106025030/ga3015sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270106025030/ga3015Isup2.hkl |
CCDC reference: 621263
To a solution of bis-3,5-trifluoromethylpyrazole (0.21 g, 1.00 mmol) in CH2Cl2 (20 ml) was added a solution of [Pd(NCMe)2Cl2] (0.13 g, 0.50 mmol) in CH2Cl2 (20 ml). The orange solution was stirred for 3 h. After the reaction period, hexane (20 ml) was added and the solution kept at 269 K to give orange crystals suitable for single-crystal X-ray analysis (yield 0.18 g, 60%). 1H NMR (DMSO-d6): δ 7.45 (2H, s, 4H-pz). Analysis calculated for C10H4Cl2F12N4Pd·H2O: C, 19.90; H, 1.00; N, 9.30. Found: C, 19.90; H, 1.00; N, 9.27
The water molecule was refined with an idealized geometry with the O—H distances restrained to 0.958 Å and H—O—H angle of 104.45° [please ensure that original restraints are given (with s.u. values) rather than obtained values]. All other H atoms were placed in idealized locations and refined as riding, with C—H and N—H distances of 0.95 and 0.88 Å, respectively. For all H atoms, Uiso(H) values were set at 1.2 or 1.5 [just 1.2?] times Ueq(C,N,O).
Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 2003); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
[PdCl2(C5H2F6N2)2]·H2O | F(000) = 1160 |
Mr = 603.49 | Dx = 2.149 Mg m−3 |
MonoclinicP21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 10709 reflections |
a = 12.5046 (5) Å | θ = 2.2–26.4° |
b = 8.1964 (3) Å | µ = 1.41 mm−1 |
c = 18.3119 (7) Å | T = 100 K |
β = 96.480 (1)° | Block, colorless |
V = 1864.85 (12) Å3 | 0.46 × 0.36 × 0.22 mm |
Z = 4 |
Bruker SMART CCD 1000 area-detector diffractometer | 3807 independent reflections |
Radiation source: fine-focus sealed tube | 3582 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.020 |
0.30° ω scans | θmax = 26.4°, θmin = 1.9° |
Absorption correction: multi-scan (SADABS; Bruker, 2003) | h = −15→15 |
Tmin = 0.564, Tmax = 0.747 | k = −10→10 |
15027 measured reflections | l = −22→22 |
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)] = 0.020 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.054 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.02 | w = 1/[σ2(Fo2) + (0.0295P)2 + 1.7857P] where P = (Fo2 + 2Fc2)/3 |
3807 reflections | (Δ/σ)max = 0.002 |
277 parameters | Δρmax = 0.75 e Å−3 |
3 restraints | Δρmin = −0.58 e Å−3 |
[PdCl2(C5H2F6N2)2]·H2O | V = 1864.85 (12) Å3 |
Mr = 603.49 | Z = 4 |
MonoclinicP21/n | Mo Kα radiation |
a = 12.5046 (5) Å | µ = 1.41 mm−1 |
b = 8.1964 (3) Å | T = 100 K |
c = 18.3119 (7) Å | 0.46 × 0.36 × 0.22 mm |
β = 96.480 (1)° |
Bruker SMART CCD 1000 area-detector diffractometer | 3807 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2003) | 3582 reflections with I > 2σ(I) |
Tmin = 0.564, Tmax = 0.747 | Rint = 0.020 |
15027 measured reflections |
R[F2 > 2σ(F2)] = 0.020 | 3 restraints |
wR(F2) = 0.054 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.02 | Δρmax = 0.75 e Å−3 |
3807 reflections | Δρmin = −0.58 e Å−3 |
277 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 | ||
Pd1 | 0.533183 (10) | 0.390565 (16) | 0.382341 (7) | 0.01404 (6) | |
Cl1 | 0.60728 (4) | 0.63323 (5) | 0.42621 (2) | 0.01924 (10) | |
Cl2 | 0.46283 (4) | 0.14874 (6) | 0.33900 (3) | 0.02350 (11) | |
F1 | 0.67055 (11) | 0.4223 (2) | 0.25548 (8) | 0.0478 (4) | |
F2 | 0.80450 (14) | 0.54144 (17) | 0.31612 (8) | 0.0483 (4) | |
F3 | 0.83141 (11) | 0.33989 (18) | 0.24624 (7) | 0.0384 (3) | |
F4 | 0.87782 (11) | −0.16152 (16) | 0.45245 (7) | 0.0332 (3) | |
F5 | 0.90763 (10) | 0.00754 (16) | 0.54225 (7) | 0.0304 (3) | |
F6 | 0.75378 (10) | −0.10978 (14) | 0.52243 (7) | 0.0260 (3) | |
F7 | 0.43305 (18) | 0.4755 (3) | 0.21280 (9) | 0.0782 (7) | |
F8 | 0.46327 (15) | 0.7115 (3) | 0.25428 (9) | 0.0838 (8) | |
F9 | 0.31732 (11) | 0.6636 (2) | 0.18761 (7) | 0.0437 (4) | |
F10 | 0.05135 (12) | 0.64231 (19) | 0.40624 (10) | 0.0474 (4) | |
F11 | 0.06536 (11) | 0.38336 (16) | 0.41318 (8) | 0.0334 (3) | |
F12 | 0.14533 (10) | 0.5300 (2) | 0.49845 (7) | 0.0401 (3) | |
O1 | 0.58972 (14) | 0.1408 (2) | 0.55972 (10) | 0.0371 (4) | |
H1W | 0.5756 (17) | 0.0397 (15) | 0.5831 (13) | 0.045* | |
H2W | 0.5253 (11) | 0.203 (2) | 0.5615 (14) | 0.045* | |
N1 | 0.67832 (12) | 0.28221 (19) | 0.39597 (8) | 0.0165 (3) | |
N2 | 0.69887 (12) | 0.16527 (19) | 0.44689 (8) | 0.0172 (3) | |
H2 | 0.6571 | 0.1408 | 0.4809 | 0.021* | |
N3 | 0.38439 (12) | 0.48950 (19) | 0.36529 (8) | 0.0170 (3) | |
N4 | 0.31187 (12) | 0.47109 (19) | 0.41335 (8) | 0.0171 (3) | |
H4 | 0.3252 | 0.4256 | 0.4570 | 0.021* | |
C1 | 0.76684 (18) | 0.3972 (3) | 0.29282 (12) | 0.0264 (5) | |
C2 | 0.76068 (15) | 0.2798 (2) | 0.35528 (10) | 0.0191 (4) | |
C3 | 0.83507 (15) | 0.1609 (2) | 0.38008 (11) | 0.0208 (4) | |
H3 | 0.9004 | 0.1342 | 0.3610 | 0.025* | |
C4 | 0.79265 (15) | 0.0908 (2) | 0.43845 (11) | 0.0181 (4) | |
C5 | 0.83343 (15) | −0.0442 (2) | 0.48899 (11) | 0.0215 (4) | |
C6 | 0.38638 (17) | 0.6029 (3) | 0.23998 (12) | 0.0309 (5) | |
C7 | 0.33182 (15) | 0.5616 (3) | 0.30626 (11) | 0.0210 (4) | |
C8 | 0.22506 (16) | 0.5918 (2) | 0.31634 (11) | 0.0221 (4) | |
H8 | 0.1711 | 0.6420 | 0.2831 | 0.027* | |
C9 | 0.21571 (15) | 0.5321 (2) | 0.38541 (10) | 0.0185 (4) | |
C10 | 0.11855 (15) | 0.5223 (2) | 0.42609 (11) | 0.0223 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Pd1 | 0.01214 (8) | 0.01634 (9) | 0.01342 (8) | 0.00069 (5) | 0.00055 (5) | 0.00102 (5) |
Cl1 | 0.0196 (2) | 0.0184 (2) | 0.0191 (2) | −0.00011 (16) | −0.00060 (17) | −0.00109 (16) |
Cl2 | 0.0240 (2) | 0.0202 (2) | 0.0247 (2) | −0.00464 (18) | −0.00414 (18) | 0.00053 (18) |
F1 | 0.0296 (7) | 0.0762 (11) | 0.0387 (8) | 0.0138 (7) | 0.0082 (6) | 0.0352 (8) |
F2 | 0.0742 (11) | 0.0262 (7) | 0.0482 (9) | −0.0082 (7) | 0.0229 (8) | 0.0070 (6) |
F3 | 0.0420 (8) | 0.0451 (8) | 0.0326 (7) | 0.0121 (7) | 0.0235 (6) | 0.0101 (6) |
F4 | 0.0381 (7) | 0.0244 (6) | 0.0379 (7) | 0.0146 (6) | 0.0077 (6) | 0.0007 (5) |
F5 | 0.0255 (6) | 0.0331 (7) | 0.0298 (6) | −0.0030 (5) | −0.0092 (5) | 0.0054 (5) |
F6 | 0.0225 (6) | 0.0237 (6) | 0.0315 (7) | −0.0004 (4) | 0.0019 (5) | 0.0069 (5) |
F7 | 0.1051 (15) | 0.0926 (15) | 0.0464 (10) | 0.0592 (13) | 0.0502 (10) | 0.0368 (10) |
F8 | 0.0569 (11) | 0.157 (2) | 0.0365 (9) | −0.0654 (13) | 0.0007 (8) | 0.0233 (11) |
F9 | 0.0278 (7) | 0.0736 (11) | 0.0295 (7) | 0.0096 (7) | 0.0026 (6) | 0.0287 (7) |
F10 | 0.0303 (7) | 0.0421 (8) | 0.0739 (11) | 0.0198 (6) | 0.0232 (7) | 0.0179 (8) |
F11 | 0.0274 (7) | 0.0344 (7) | 0.0405 (8) | −0.0119 (5) | 0.0131 (6) | −0.0110 (6) |
F12 | 0.0279 (7) | 0.0690 (10) | 0.0245 (6) | −0.0109 (7) | 0.0080 (5) | −0.0134 (7) |
O1 | 0.0429 (10) | 0.0312 (8) | 0.0418 (9) | 0.0149 (7) | 0.0248 (8) | 0.0140 (7) |
N1 | 0.0157 (7) | 0.0174 (8) | 0.0161 (7) | 0.0005 (6) | 0.0006 (6) | 0.0010 (6) |
N2 | 0.0158 (7) | 0.0183 (8) | 0.0175 (7) | 0.0014 (6) | 0.0022 (6) | 0.0018 (6) |
N3 | 0.0141 (7) | 0.0201 (8) | 0.0170 (7) | 0.0004 (6) | 0.0021 (6) | 0.0025 (6) |
N4 | 0.0163 (7) | 0.0193 (8) | 0.0159 (7) | 0.0002 (6) | 0.0023 (6) | 0.0020 (6) |
C1 | 0.0246 (11) | 0.0297 (11) | 0.0268 (11) | 0.0053 (8) | 0.0106 (9) | 0.0059 (8) |
C2 | 0.0182 (9) | 0.0207 (9) | 0.0187 (9) | 0.0008 (7) | 0.0029 (7) | −0.0010 (7) |
C3 | 0.0180 (9) | 0.0220 (9) | 0.0227 (9) | 0.0021 (8) | 0.0041 (7) | −0.0033 (8) |
C4 | 0.0157 (9) | 0.0173 (9) | 0.0207 (9) | 0.0011 (7) | −0.0007 (7) | −0.0035 (7) |
C5 | 0.0187 (9) | 0.0196 (10) | 0.0258 (10) | 0.0014 (7) | 0.0005 (8) | 0.0002 (8) |
C6 | 0.0190 (10) | 0.0501 (15) | 0.0238 (11) | 0.0043 (9) | 0.0024 (8) | 0.0146 (9) |
C7 | 0.0184 (9) | 0.0254 (10) | 0.0186 (9) | 0.0000 (8) | −0.0005 (7) | 0.0040 (8) |
C8 | 0.0178 (9) | 0.0253 (10) | 0.0222 (10) | 0.0013 (7) | −0.0019 (8) | 0.0045 (8) |
C9 | 0.0150 (9) | 0.0180 (9) | 0.0219 (9) | 0.0001 (7) | 0.0002 (7) | −0.0020 (7) |
C10 | 0.0178 (9) | 0.0233 (10) | 0.0258 (10) | 0.0008 (7) | 0.0031 (8) | −0.0036 (8) |
Pd1—N1 | 2.0106 (15) | N1—C2 | 1.338 (2) |
Pd1—N3 | 2.0213 (15) | N1—N2 | 1.342 (2) |
Pd1—Cl2 | 2.2748 (5) | N2—C4 | 1.346 (2) |
Pd1—Cl1 | 2.3004 (5) | N2—H2 | 0.8800 |
F1—C1 | 1.332 (3) | N3—C7 | 1.338 (2) |
F2—C1 | 1.326 (3) | N3—N4 | 1.342 (2) |
F3—C1 | 1.325 (2) | N4—C9 | 1.348 (2) |
F4—C5 | 1.328 (2) | N4—H4 | 0.8800 |
F5—C5 | 1.337 (2) | C1—C2 | 1.503 (3) |
F6—C5 | 1.339 (2) | C2—C3 | 1.388 (3) |
F7—C6 | 1.320 (3) | C3—C4 | 1.372 (3) |
F8—C6 | 1.315 (3) | C3—H3 | 0.9500 |
F9—C6 | 1.314 (2) | C4—C5 | 1.495 (3) |
F10—C10 | 1.318 (2) | C6—C7 | 1.497 (3) |
F11—C10 | 1.326 (2) | C7—C8 | 1.390 (3) |
F12—C10 | 1.331 (2) | C8—C9 | 1.373 (3) |
O1—H1W | 0.958 (16) | C8—H8 | 0.9500 |
O1—H2W | 0.958 (16) | C9—C10 | 1.497 (3) |
N1—Pd1—N3 | 176.99 (6) | N2—C4—C3 | 108.54 (17) |
N1—Pd1—Cl2 | 88.08 (5) | N2—C4—C5 | 120.35 (17) |
N3—Pd1—Cl2 | 89.01 (5) | C3—C4—C5 | 131.11 (18) |
N1—Pd1—Cl1 | 90.93 (5) | F4—C5—F5 | 107.58 (16) |
N3—Pd1—Cl1 | 91.98 (5) | F4—C5—F6 | 108.34 (16) |
Cl2—Pd1—Cl1 | 179.005 (18) | F5—C5—F6 | 106.53 (16) |
H1W—O1—H2W | 104.3 (17) | F4—C5—C4 | 110.91 (16) |
C2—N1—N2 | 106.11 (15) | F5—C5—C4 | 112.13 (16) |
C2—N1—Pd1 | 132.71 (13) | F6—C5—C4 | 111.14 (16) |
N2—N1—Pd1 | 120.08 (12) | F9—C6—F8 | 107.1 (2) |
N1—N2—C4 | 110.19 (15) | F9—C6—F7 | 107.8 (2) |
N1—N2—H2 | 124.9 | F8—C6—F7 | 105.4 (2) |
C4—N2—H2 | 124.9 | F9—C6—C7 | 110.82 (17) |
C7—N3—N4 | 105.83 (15) | F8—C6—C7 | 112.4 (2) |
C7—N3—Pd1 | 131.44 (13) | F7—C6—C7 | 112.85 (19) |
N4—N3—Pd1 | 122.16 (12) | N3—C7—C8 | 111.28 (17) |
N3—N4—C9 | 110.45 (15) | N3—C7—C6 | 121.85 (17) |
N3—N4—H4 | 124.8 | C8—C7—C6 | 126.87 (18) |
C9—N4—H4 | 124.8 | C9—C8—C7 | 103.99 (17) |
F3—C1—F2 | 107.65 (18) | C9—C8—H8 | 128.0 |
F3—C1—F1 | 107.79 (19) | C7—C8—H8 | 128.0 |
F2—C1—F1 | 107.15 (18) | N4—C9—C8 | 108.45 (17) |
F3—C1—C2 | 110.52 (17) | N4—C9—C10 | 122.03 (17) |
F2—C1—C2 | 111.89 (18) | C8—C9—C10 | 129.45 (18) |
F1—C1—C2 | 111.64 (17) | F10—C10—F11 | 107.48 (17) |
N1—C2—C3 | 110.97 (17) | F10—C10—F12 | 108.67 (17) |
N1—C2—C1 | 121.55 (17) | F11—C10—F12 | 106.43 (17) |
C3—C2—C1 | 127.47 (18) | F10—C10—C9 | 110.53 (17) |
C4—C3—C2 | 104.20 (17) | F11—C10—C9 | 112.08 (16) |
C4—C3—H3 | 127.9 | F12—C10—C9 | 111.44 (16) |
C2—C3—H3 | 127.9 | ||
Cl2—Pd1—N1—C2 | 98.40 (17) | N2—C4—C5—F4 | 140.79 (18) |
Cl1—Pd1—N1—C2 | −81.48 (17) | C3—C4—C5—F4 | −39.3 (3) |
Cl2—Pd1—N1—N2 | −67.79 (13) | N2—C4—C5—F5 | −98.9 (2) |
Cl1—Pd1—N1—N2 | 112.33 (13) | C3—C4—C5—F5 | 80.9 (3) |
C2—N1—N2—C4 | 0.1 (2) | N2—C4—C5—F6 | 20.2 (2) |
Pd1—N1—N2—C4 | 169.59 (12) | C3—C4—C5—F6 | −159.94 (19) |
Cl2—Pd1—N3—C7 | −88.40 (18) | N4—N3—C7—C8 | 0.7 (2) |
Cl1—Pd1—N3—C7 | 91.46 (18) | Pd1—N3—C7—C8 | 171.88 (14) |
Cl2—Pd1—N3—N4 | 81.62 (14) | N4—N3—C7—C6 | −179.99 (19) |
Cl1—Pd1—N3—N4 | −98.51 (14) | Pd1—N3—C7—C6 | −8.8 (3) |
C7—N3—N4—C9 | −0.6 (2) | F9—C6—C7—N3 | 176.2 (2) |
Pd1—N3—N4—C9 | −172.89 (12) | F8—C6—C7—N3 | −64.0 (3) |
N2—N1—C2—C3 | −0.1 (2) | F7—C6—C7—N3 | 55.1 (3) |
Pd1—N1—C2—C3 | −167.70 (14) | F9—C6—C7—C8 | −4.6 (3) |
N2—N1—C2—C1 | −178.95 (17) | F8—C6—C7—C8 | 115.3 (3) |
Pd1—N1—C2—C1 | 13.5 (3) | F7—C6—C7—C8 | −125.6 (2) |
F3—C1—C2—N1 | −158.75 (18) | N3—C7—C8—C9 | −0.4 (2) |
F2—C1—C2—N1 | 81.3 (2) | C6—C7—C8—C9 | −179.7 (2) |
F1—C1—C2—N1 | −38.8 (3) | N3—N4—C9—C8 | 0.4 (2) |
F3—C1—C2—C3 | 22.6 (3) | N3—N4—C9—C10 | 177.62 (17) |
F2—C1—C2—C3 | −97.3 (2) | C7—C8—C9—N4 | 0.0 (2) |
F1—C1—C2—C3 | 142.6 (2) | C7—C8—C9—C10 | −176.95 (19) |
N1—C2—C3—C4 | 0.1 (2) | N4—C9—C10—F10 | 153.21 (18) |
C1—C2—C3—C4 | 178.83 (19) | C8—C9—C10—F10 | −30.2 (3) |
N1—N2—C4—C3 | −0.1 (2) | N4—C9—C10—F11 | −86.9 (2) |
N1—N2—C4—C5 | 179.83 (16) | C8—C9—C10—F11 | 89.7 (3) |
C2—C3—C4—N2 | 0.0 (2) | N4—C9—C10—F12 | 32.3 (3) |
C2—C3—C4—C5 | −179.89 (19) | C8—C9—C10—F12 | −151.2 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O1 | 0.88 | 1.75 | 2.609 (2) | 164 |
O1—H1W···Cl2i | 0.96 (2) | 2.19 (2) | 3.1268 (16) | 165 (2) |
O1—H2W···Cl1ii | 0.96 (2) | 2.17 (2) | 3.1160 (16) | 173 (2) |
N4—H4···Cl1ii | 0.88 | 2.26 | 3.1168 (16) | 164 |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | [PdCl2(C5H2F6N2)2]·H2O |
Mr | 603.49 |
Crystal system, space group | MonoclinicP21/n |
Temperature (K) | 100 |
a, b, c (Å) | 12.5046 (5), 8.1964 (3), 18.3119 (7) |
β (°) | 96.480 (1) |
V (Å3) | 1864.85 (12) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.41 |
Crystal size (mm) | 0.46 × 0.36 × 0.22 |
Data collection | |
Diffractometer | Bruker SMART CCD 1000 area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2003) |
Tmin, Tmax | 0.564, 0.747 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 15027, 3807, 3582 |
Rint | 0.020 |
(sin θ/λ)max (Å−1) | 0.625 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.020, 0.054, 1.02 |
No. of reflections | 3807 |
No. of parameters | 277 |
No. of restraints | 3 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.75, −0.58 |
Computer programs: SMART (Bruker, 2003), SAINT (Bruker, 2003), SAINT, SHELXTL (Bruker, 2003), SHELXTL.
Pd1—N1 | 2.0106 (15) | Pd1—Cl2 | 2.2748 (5) |
Pd1—N3 | 2.0213 (15) | Pd1—Cl1 | 2.3004 (5) |
N1—Pd1—N3 | 176.99 (6) | N1—Pd1—Cl1 | 90.93 (5) |
N1—Pd1—Cl2 | 88.08 (5) | N3—Pd1—Cl1 | 91.98 (5) |
N3—Pd1—Cl2 | 89.01 (5) | Cl2—Pd1—Cl1 | 179.005 (18) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O1 | 0.88 | 1.75 | 2.609 (2) | 164 |
O1—H1W···Cl2i | 0.958 (16) | 2.192 (19) | 3.1268 (16) | 165 (2) |
O1—H2W···Cl1ii | 0.958 (16) | 2.165 (15) | 3.1160 (16) | 173 (2) |
N4—H4···Cl1ii | 0.88 | 2.26 | 3.1168 (16) | 164 |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x+1, −y+1, −z+1. |
Since the seminal discovery that late transition metal α-diimine complexes oligomerize or polymerize α-olefins (Brookhart et al., 1995), there has been intensive search for other nitrogen-based late transition metal complexes that can also catalyze olefin oligomerization and polymerization with improved catalyst performance (Mecking, 2000). The key highlights of Brookhart-type catalysts are electrophilicity of the catalyst's metal center, which facilitates olefin coordination, and steric bulk of the ligand backbone, which determines the formation of oligomers or polymers (Ittel et al., 2000, Gibson & Spitzmesser, 2003). Recently we reported that pyrazole nickel, [(3,5-R2pzH)2NiBr2] (Nelana et al., 2004), and pyrazole palladium, [(3,5-R2pzH)2PdCl2], R = H, Me and tBu (Li et al., 2002), complexes form active ethylene polymerization catalysts. In an attempt to enhance the electrophilicity of the metal center to achieve greater catalytic activity, we synthesized the title compound bearing the electron-withdrawing CF3 substituents. It was presumed that the CF3 groups would reduce the donor ability of the pyrazole ligand, resulting in an electron-deficient metal center in the catalyst formed, thereby giving greater catalytic activity. However, our preliminary DFT studies did not confirm this assumption; attempts to activate compound (I) with methylaluminoxane (MAO) to produce active olefin polymerization catalyst resulted in the decomposition of (I). We report here the synthesis and structure of (I).
The Pd complex (I) (Fig. 1) exhibits a distorted square-planar geometry. The pyrazole ligands are trans to each other and the NH groups are on the same side of the Pd coordination plane. Both the pyrazole groups are tilted to the same side relative to the plane but to different degrees, displaying Cl1–Pd–N1–N2 and N4–N3–Pd–Cl1 torsion angles of 112.33 (13) and 98.51 (14)°, respectively; the two planar pyrazole rings have an inter-planar angle of 22.09 (11)°. Of 14 relevant complexes found in the Cambridge Structural Database (hereafter CSD; Version 5.27, updated May 2006; Allen, 2002), only four complexes have torsion angles that correspond to the pyrazole rings being tilted to the same side relative to the coordination plane but to different extents, sometimes differing by up to 8°. The related compound (3,5-tBu2pzH)2PdCl2·CH2Cl2 (Li et al., 2002) has angles of 77.2 and 84.9°. In all of these compounds, the substituent on the non-coordinating N atom of the pyrazole rings was an H atom. The remaining ten complexes have the pyrazole rings residing on opposite sides of the metal coordination plane. All of these compounds, such as trans-anti-dichlorobis{1-[2-(methoxy)ethoxymethyl]-3,5-δimethylpyrazole-N}palladium(II) with torsion angles of 77.6 and -102.4° (Boixassa et al., 2003a), have groups other than hydrogen attached to the non-coordinated pyrazole N atom. The ligand–metal–ligand angles larger than 90° involving Cl1 may be due to steric crowding as two CF3 groups are directed toward that Cl atom.
Both the Pd—Cl bond lengths in (I) (Table 1) compare well in length to the average Pd—Cl separation of 2.30 (2) Å calculated for 471 complexes reported in the CSD. Within compound (I), the Pd—Cl2 bond length is statistically significantly shorter than the Pd—Cl1 bond length. The fact that Cl1 participates in two different types of hydrogen bonding with the solvent water molecule and the pyrazole NH group while Cl2 only participates in hydrogen bonding with the solvent water (see below) may explain this distortion from square-planar geometry. The Pd—N bond lengths [average 2.016 (7) Å] in (I) agree well with the average separation of 2.016 (16) Å calculated for 19 Pd pyrazole complexes in the CSD and fall within the reported range of 2.001–2.071 Å.
An interesting feature of (I) is that one solvent water molecule per Pd complex is also present in the lattice. While no similar compounds have been reported with solvent water in the lattice, compound (3,5-tBu2pzH)2PdCl2 (Li et al., 2002) has been reported as a solvate with either one dichloromethane molecule or one-half of a diethyl ether molecule. trans-[(3,5-Me2pzH)2PtCl2] (Boixassa et al., 2003b), which is similar to (I) except that the central atom is platinum and the substituents on the pyrazole rings are methyl groups instead of CF3 groups, does not include a solvent water molecule and forms a dimer via hydrogen bonds between the NH groups and the Cl atoms. The larger CF3 groups in (I) might prevent dimer formation and leave interstitial cavities in the lattice for the water molecules to occupy.
This water molecule participates in three hydrogen-bonding interactions, with the NH atoms of a pyrazole ring and the Cl atoms (Fig. 2 and Table 2). The hydrogen-bonding interaction between the water solvent molecule and the NH group in (I) is significantly stronger, as indicated by a relatively short N—O distance of 2.609 (2) Å, than the hydrogen-bonding interactions for five relevant compounds in the CSD [averaging 2.99 (3) Å]. The N—H···O angle (entry 1 in Table 2) falls within the range 150–170° for these five compounds. The O···Cl hydrogen-bonding lengths (entries 2 and 3 in Table 2) are shorter than the average of 3.24 (7) Å found for 16 compounds with similar hydrogen bonds in the CSD and the O—H···Cl bond angles are within the range 152–177° found for these compounds. A fourth intermolecular hydrogen, of N—H···Cl type (entry 4 in Table 2), has N···Cl shorter than the range of distances of 3.179–3.347 Å found for 24 complexes with similar hydrogen bonds in the CSD and is significantly stronger than the average 3.210 (4) Å for the N···Cl distance found in the similar compound [PdCl2(C5H8N2)2] (Cheng et al., 1990). Overall, the molecules of (I) participating in hydrogen-bonding interactions are arranged into columns propagating in the b direction with no hydrogen-bond links between the columns (Fig. 2).