Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103023631/sk1667sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270103023631/sk1667Isup2.hkl |
CCDC reference: 229073
The title complex was obtained by mixing an acetonitrile solution of [Cu(CH3CN)4][BF4] with Ppy3 in a 2:3 molar ratio for 24 h. After filtration, CH2Cl2 was added to the precipitate. Deep-blue crystals were obtained after simple evaporation of the CH2Cl2 solution. Elemental analysis of the crystalline powder gave satisfactory results: Calculated: C 42.98, H 3.09, N 9.55%; found: C 43.02, H 3.81, N 9.36%. During the synthesis of Ppy3, incomplete substitution of PCl3 by 2-pyridyl anions would lead to the formation of hydroxybis(2-pyridyl)phosphine, which would give rise to the production of bis(2-pyridyl)phosphinic acid in the subsequent air oxidation. This is believed to be the route for the generation of the pyridylphosphinate observed in the title complex.
H atoms on the pyridyl rings were placed in calculated positions, with C—H distances of 0.93 Å. Fixed positions, isotropic ADPs (0.05) and occcupancy factors (40/60%)of the H atoms of the disordered CH2Cl2 molecule were included in the final cycle of least-squares refinement. All other H atoms were included as riding, with Uiso(H) values equal to 1.2Ueq of the carrier atoms.
Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1992); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 1992–1997); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
[Cu(C10H8N2O2P)2]·2CH2Cl2 | F(000) = 678 |
Mr = 671.70 | Dx = 1.665 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 20 reflections |
a = 8.404 (3) Å | θ = 4.3–7.1° |
b = 14.392 (2) Å | µ = 1.37 mm−1 |
c = 11.167 (2) Å | T = 293 K |
β = 97.42 (2)° | Prism, blue |
V = 1339.5 (6) Å3 | 0.64 × 0.60 × 0.30 mm |
Z = 2 |
Rigaku AFC6S diffractometer | 1664 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.024 |
Graphite monochromator | θmax = 25.0°, θmin = 2.3° |
ω–2θ scans | h = 0→9 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→17 |
Tmin = 0.425, Tmax = 0.663 | l = −13→13 |
2647 measured reflections | 3 standard reflections every 150 reflections |
2358 independent reflections | intensity decay: 0.6% |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.033 | H-atom parameters constrained |
wR(F2) = 0.102 | w = 1/[σ2(Fo2) + 0.3429P] where P = (Fo2 + 2Fc2)/3 |
S = 1.04 | (Δ/σ)max < 0.001 |
2358 reflections | Δρmax = 0.47 e Å−3 |
197 parameters | Δρmin = −0.37 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0184 (15) |
[Cu(C10H8N2O2P)2]·2CH2Cl2 | V = 1339.5 (6) Å3 |
Mr = 671.70 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 8.404 (3) Å | µ = 1.37 mm−1 |
b = 14.392 (2) Å | T = 293 K |
c = 11.167 (2) Å | 0.64 × 0.60 × 0.30 mm |
β = 97.42 (2)° |
Rigaku AFC6S diffractometer | 1664 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.024 |
Tmin = 0.425, Tmax = 0.663 | 3 standard reflections every 150 reflections |
2647 measured reflections | intensity decay: 0.6% |
2358 independent reflections |
R[F2 > 2σ(F2)] = 0.033 | 0 restraints |
wR(F2) = 0.102 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.47 e Å−3 |
2358 reflections | Δρmin = −0.37 e Å−3 |
197 parameters |
Experimental. The scan width was (1.47 + 0.30tanθ)° with an ω scan speed of 16° per minute (up to 5 scans to achieve I/σ(I) > 10). Stationary background counts were recorded at each end of the scan, and the scan time:background time ratio was 2:1. |
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 | Occ. (<1) | |
Cu | 0.5000 | 0.5000 | 0.5000 | 0.02675 (19) | |
Cl1A | 0.1810 (18) | 0.7474 (12) | 0.6954 (14) | 0.107 (5) | 0.40 |
Cl1B | 0.2187 (11) | 0.7437 (6) | 0.6921 (10) | 0.0714 (11) | 0.60 |
Cl2A | −0.0366 (8) | 0.7395 (8) | 0.4851 (9) | 0.110 (3) | 0.40 |
Cl2B | −0.0049 (7) | 0.7128 (5) | 0.4719 (5) | 0.115 (2) | 0.60 |
P1 | 0.64648 (10) | 0.54520 (7) | 0.74932 (7) | 0.0342 (2) | |
O1 | 0.7050 (3) | 0.47171 (17) | 0.6702 (2) | 0.0385 (6) | |
O2 | 0.7252 (3) | 0.5641 (2) | 0.8732 (2) | 0.0529 (7) | |
N1 | 0.3584 (3) | 0.50057 (19) | 0.6346 (2) | 0.0289 (5) | |
N2 | 0.5574 (3) | 0.63285 (18) | 0.5418 (2) | 0.0307 (6) | |
C1 | 0.4317 (4) | 0.5199 (2) | 0.7473 (3) | 0.0298 (7) | |
C2 | 0.3467 (4) | 0.5202 (2) | 0.8452 (3) | 0.0407 (9) | |
H2 | 0.3978 | 0.5345 | 0.9219 | 0.049* | |
C3 | 0.1847 (4) | 0.4989 (3) | 0.8280 (3) | 0.0435 (8) | |
H3 | 0.1270 | 0.4961 | 0.8936 | 0.052* | |
C4 | 0.1100 (4) | 0.4820 (2) | 0.7136 (3) | 0.0436 (9) | |
H4 | 0.0005 | 0.4699 | 0.7000 | 0.052* | |
C5 | 0.2011 (4) | 0.4833 (2) | 0.6186 (3) | 0.0383 (8) | |
H5 | 0.1508 | 0.4718 | 0.5409 | 0.046* | |
C6 | 0.6252 (4) | 0.6504 (2) | 0.6564 (3) | 0.0334 (7) | |
C7 | 0.6645 (4) | 0.7402 (3) | 0.6937 (4) | 0.0477 (9) | |
H7 | 0.7139 | 0.7517 | 0.7718 | 0.057* | |
C8 | 0.6291 (5) | 0.8132 (3) | 0.6129 (4) | 0.0576 (11) | |
H8 | 0.6539 | 0.8740 | 0.6365 | 0.069* | |
C9 | 0.5579 (5) | 0.7948 (3) | 0.4987 (4) | 0.0571 (11) | |
H9 | 0.5318 | 0.8429 | 0.4441 | 0.068* | |
C10 | 0.5248 (5) | 0.7036 (3) | 0.4650 (3) | 0.0440 (9) | |
H10 | 0.4785 | 0.6912 | 0.3865 | 0.053* | |
C11A | 0.1624 (13) | 0.7459 (10) | 0.5332 (11) | 0.068 (4) | 0.40 |
C11B | 0.0889 (11) | 0.7944 (6) | 0.5705 (7) | 0.065 (2) | 0.60 |
H11A | 0.1953 | 0.8097 | 0.5037 | 0.050* | 0.40 |
H12A | 0.2275 | 0.7031 | 0.4960 | 0.050* | 0.40 |
H11B | 0.0153 | 0.8357 | 0.5981 | 0.050* | 0.60 |
H12B | 0.1571 | 0.8294 | 0.5204 | 0.050* | 0.60 |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu | 0.0320 (3) | 0.0245 (3) | 0.0238 (3) | −0.0022 (2) | 0.00378 (19) | −0.0019 (2) |
Cl1A | 0.145 (11) | 0.115 (6) | 0.054 (4) | −0.002 (6) | −0.014 (5) | 0.017 (4) |
Cl1B | 0.078 (2) | 0.065 (2) | 0.068 (2) | 0.0036 (15) | 0.0004 (15) | 0.0105 (17) |
Cl2A | 0.044 (2) | 0.137 (8) | 0.145 (7) | −0.026 (3) | −0.006 (3) | 0.025 (5) |
Cl2B | 0.168 (6) | 0.112 (4) | 0.064 (2) | −0.072 (4) | 0.011 (3) | −0.032 (2) |
P1 | 0.0310 (4) | 0.0438 (6) | 0.0262 (4) | 0.0005 (4) | −0.0029 (3) | −0.0015 (4) |
O1 | 0.0335 (12) | 0.0440 (15) | 0.0369 (13) | 0.0073 (10) | 0.0007 (10) | 0.0013 (11) |
O2 | 0.0503 (15) | 0.073 (2) | 0.0312 (13) | −0.0036 (13) | −0.0109 (11) | −0.0041 (13) |
N1 | 0.0301 (12) | 0.0292 (13) | 0.0273 (13) | −0.0007 (11) | 0.0040 (10) | −0.0019 (12) |
N2 | 0.0379 (14) | 0.0259 (14) | 0.0283 (13) | −0.0014 (12) | 0.0047 (11) | 0.0000 (11) |
C1 | 0.0358 (16) | 0.0247 (19) | 0.0288 (16) | 0.0032 (13) | 0.0041 (13) | 0.0022 (13) |
C2 | 0.053 (2) | 0.040 (2) | 0.0307 (18) | −0.0010 (16) | 0.0093 (15) | −0.0025 (15) |
C3 | 0.0467 (19) | 0.0391 (19) | 0.050 (2) | 0.0000 (18) | 0.0250 (16) | −0.0014 (19) |
C4 | 0.0307 (17) | 0.043 (2) | 0.059 (2) | −0.0030 (15) | 0.0154 (16) | −0.0028 (18) |
C5 | 0.0346 (17) | 0.038 (2) | 0.0412 (19) | −0.0026 (14) | −0.0001 (14) | −0.0011 (15) |
C6 | 0.0302 (16) | 0.037 (2) | 0.0331 (17) | −0.0062 (14) | 0.0043 (13) | −0.0052 (15) |
C7 | 0.049 (2) | 0.043 (2) | 0.051 (2) | −0.0126 (18) | 0.0081 (17) | −0.0160 (19) |
C8 | 0.063 (3) | 0.033 (2) | 0.080 (3) | −0.0152 (19) | 0.021 (2) | −0.017 (2) |
C9 | 0.078 (3) | 0.030 (2) | 0.065 (3) | −0.0039 (19) | 0.013 (2) | 0.005 (2) |
C10 | 0.062 (2) | 0.033 (2) | 0.0373 (19) | −0.0024 (17) | 0.0040 (16) | 0.0031 (16) |
C11A | 0.045 (6) | 0.094 (11) | 0.067 (7) | 0.003 (6) | 0.017 (5) | 0.033 (7) |
C11B | 0.086 (6) | 0.059 (5) | 0.049 (4) | −0.009 (4) | 0.010 (4) | −0.002 (4) |
Cu—N2 | 2.012 (3) | C3—C4 | 1.371 (5) |
Cu—N1 | 2.034 (2) | C3—H3 | 0.9300 |
Cu—O1 | 2.429 (2) | C4—C5 | 1.386 (5) |
Cl1A—C11A | 1.80 (2) | C4—H4 | 0.9300 |
Cl1B—C11B | 1.785 (13) | C5—H5 | 0.9300 |
Cl2A—C11A | 1.692 (12) | C6—C7 | 1.386 (5) |
Cl2B—C11B | 1.728 (9) | C7—C8 | 1.392 (6) |
P1—O2 | 1.480 (2) | C7—H7 | 0.9300 |
P1—O1 | 1.502 (3) | C8—C9 | 1.363 (6) |
P1—C6 | 1.831 (3) | C8—H8 | 0.9300 |
P1—C1 | 1.838 (3) | C9—C10 | 1.383 (5) |
N1—C5 | 1.334 (4) | C9—H9 | 0.9300 |
N1—C1 | 1.356 (4) | C10—H10 | 0.9300 |
N2—C10 | 1.337 (4) | C11A—H11A | 1.026 |
N2—C6 | 1.356 (4) | C11A—H12A | 0.954 |
C1—C2 | 1.382 (4) | C11B—H11B | 0.939 |
C2—C3 | 1.384 (5) | C11B—H12B | 0.989 |
C2—H2 | 0.9300 | ||
N2—Cu—N1 | 88.30 (10) | N1—C5—H5 | 118.8 |
N2—Cu—O1 | 81.56 (9) | C4—C5—H5 | 118.8 |
N1—Cu—O1 | 81.14 (9) | N2—C6—C7 | 120.8 (3) |
O2—P1—O1 | 122.61 (14) | N2—C6—P1 | 112.3 (2) |
O2—P1—C6 | 112.16 (16) | C7—C6—P1 | 126.8 (3) |
O1—P1—C6 | 105.31 (14) | C6—C7—C8 | 119.1 (4) |
O2—P1—C1 | 111.58 (15) | C6—C7—H7 | 120.5 |
O1—P1—C1 | 104.44 (14) | C8—C7—H7 | 120.5 |
C6—P1—C1 | 97.62 (14) | C9—C8—C7 | 119.5 (4) |
P1—O1—Cu | 95.11 (10) | C9—C8—H8 | 120.3 |
C5—N1—C1 | 119.1 (3) | C7—C8—H8 | 120.3 |
C5—N1—Cu | 124.4 (2) | C8—C9—C10 | 119.1 (4) |
C1—N1—Cu | 116.57 (19) | C8—C9—H9 | 120.4 |
C10—N2—C6 | 119.3 (3) | C10—C9—H9 | 120.4 |
C10—N2—Cu | 123.5 (2) | N2—C10—C9 | 122.1 (3) |
C6—N2—Cu | 117.0 (2) | N2—C10—H10 | 118.9 |
N1—C1—C2 | 121.0 (3) | C9—C10—H10 | 118.9 |
N1—C1—P1 | 112.3 (2) | Cl2A—C11A—Cl1A | 105.9 (8) |
C2—C1—P1 | 126.6 (2) | Cl2A—C11A—H11A | 104.1 (9) |
C1—C2—C3 | 119.3 (3) | Cl1A—C11A—H11A | 108.7 (12) |
C1—C2—H2 | 120.4 | Cl2A—C11A—H12A | 115.2 (12) |
C3—C2—H2 | 120.4 | Cl1A—C11A—H12A | 117.8 (11) |
C4—C3—C2 | 119.5 (3) | H11A—C11A—H12A | 104.1 (9) |
C4—C3—H3 | 120.2 | Cl2B—C11B—Cl1B | 113.0 (6) |
C2—C3—H3 | 120.2 | Cl2B—C11B—H11B | 111.9 (7) |
C3—C4—C5 | 118.6 (3) | Cl1B—C11B—H11B | 111.9 (7) |
C3—C4—H4 | 120.7 | Cl2B—C11B—H12B | 103.7 (6) |
C5—C4—H4 | 120.7 | Cl1B—C11B—H12B | 107.3 (7) |
N1—C5—C4 | 122.4 (3) | H11B—C11B—H12B | 108.5 (8) |
Experimental details
Crystal data | |
Chemical formula | [Cu(C10H8N2O2P)2]·2CH2Cl2 |
Mr | 671.70 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 293 |
a, b, c (Å) | 8.404 (3), 14.392 (2), 11.167 (2) |
β (°) | 97.42 (2) |
V (Å3) | 1339.5 (6) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 1.37 |
Crystal size (mm) | 0.64 × 0.60 × 0.30 |
Data collection | |
Diffractometer | Rigaku AFC6S diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.425, 0.663 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2647, 2358, 1664 |
Rint | 0.024 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.033, 0.102, 1.04 |
No. of reflections | 2358 |
No. of parameters | 197 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.47, −0.37 |
Computer programs: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1992), MSC/AFC Diffractometer Control Software, TEXSAN (Molecular Structure Corporation, 1992–1997), SIR92 (Altomare et al., 1993), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
Cu—N2 | 2.012 (3) | P1—O2 | 1.480 (2) |
Cu—N1 | 2.034 (2) | P1—O1 | 1.502 (3) |
Cu—O1 | 2.429 (2) | ||
N2—Cu—N1 | 88.30 (10) | C2—C1—P1 | 126.6 (2) |
N2—Cu—O1 | 81.56 (9) | N2—C6—P1 | 112.3 (2) |
N1—Cu—O1 | 81.14 (9) | C7—C6—P1 | 126.8 (3) |
N1—C1—P1 | 112.3 (2) |
Published examples of metal complexes of phosphinates (R2P(O)O−) are limited (Annan et al., 1991; Betz & Bino, 1988; Chakraborty et al., 2000; Kongprakaiwoot et al., 2002). Their binding atoms are almost exclusively confined to O atoms. Derivation of the R groups (e.g. pyridyl) enables the development of multidentate phosphinates and opens a new field in coordination chemistry. However, there are even fewer examples of such compounds in the literature than there are of underivatized phosphinates. The N,O-bidentate mode only occurrs in {bis(4,5-di-isopropylimidazol-2-yl)phosphinic acid}- dichlorozinc monohydrate (Ball et al., 1984) and the tridentate mode in the [Ru{py2P(O)O}{py3PO}]+ cation (Keene & Stephenson, 1991). The latter is the only structurally identified example of a metal complex bearing pyridylphosphinate. During the course of a study of metal complexes with pyridylphosphines, we accidentally isolated the title compound, (I), and found it to be the first homoleptic pyridylphosphinate metal complex. The isolation of this compound may encourage further studies of possible applications for the new tridentate ligand, py2P(O)OH, as well as other multidentate phosphinate derivatives.
X-ray structural analysis was carried out in order to elucidate the coordination mode of the bis(2-pyridyl)phosphonate (L) ligand. The molecular structure of (I) is illustrated in Fig. 1. The asymmetric unit contains half the CuL2 complex and a dichloromethane solvent molecule. The CuII center sits at the inversion center and is coordinated with both pyridyl rings from both ligands. Each phosphinate ligand further provides an O atom to occupy the axial positions above and below the CuN4 plane (Fig. 1). The Cu···O distance is extremely long [2.430 (3) Å] but falls between the sum of the covalent radii (2.11 Å) and the sum of the van der Waals radii (2.95 Å). One other notable feature is that the O1—Cu—O1i [symmetric code: (i) 1 − x, 1 − y, 1 − z] vector is tilted away from the normal of the CuN4 plane. These facts may cast some doubt on the existence of the Cu···O interaction in the title complex. However, the existence of the interaction is evidenced by the bending (folding?) of the P1—O1 segment towards the Cu center, which is manifested by the reduction of the P—C—N angles as well as the enlargement of the P—C—C angles from their ideal (120°) angle (Table 1). The off-normal O1—Cu1—O1i vector and the extremely long Cu···O distances may very well be the result of the balance between the tendency to bond the axial O atoms (electronic attraction) and the resistance to distortion of the phosphinate ligand (steric rigidity). The elongatation of the Cu···O bond may also arise for the same reason as the often-observed Jahn–Teller distortion in CuII complexes. Although the ligand field in (I) hardly produces electronically degenerate state, as required by the Jahn–Teller theorem, the argument of lowering energy due to the tetragonal distortion still holds true in the case of (I).
The only other example of a metal bispyridylphosphinate in the literature, as mentioned above, is [Ru{py3P=O}{py2P(O)O}] [BF4] (Keene & Stephenson,1991). The N,N,O-tridentate mode of the bispyridylphosphinate in this Ru complex is similar to that observed in the title complex but differs in its strong M—O interaction [Ru—O=2.11 (2) Å]. The strength of this interaction may be due to the electronic configuration (d6) for RuII. Because the need for electronic input from the ligand is greater for RuII (d6) than for CuII (d9), RuII ions are usually six coordinated, while CuII ions usually prefer four- (square planar) or five-coordination (square pyramid) modes. This argument may explain why the RuII ion forms normal Ru—O bonds in [Ru{py3P=O}{py2P(O)O}][BF4] and add addtional support to the existence of elongated Cu—O bonds in (I). The distortion of the py/Ru/py moieties (mean Ru—N···X=173.5°, X is the centroid of the py ring) is more obvious than that observed in the title complex (mean Cu—N···X=176.1 (2)°), and this result is consistent with the stronger M—O interaction in the Ru complex.
Although the py/Cu/py moieties are coplanar, as required by the existence of an inversion center, all of the pyridine rings around the CuII center are not coplanar with the CuN4 plane. Therefore, there are no significant pπ···dπ interactions strengthening the Cu—N bonds. The Cu—N bond lengths (Table 1) are, however, still comparable to the literature values (2.00–2.07 Å; International Tables of Crystallography, 1992, Vol. C, pp. 738–739).
Because H atoms are not always located in X-ray analysis, the possibility exists for one of the ligands to be neutral in charge. However, the distinct blue color (a common color for CuII complexes) of the crystal and the equality of the P—O distances in the moiety support the anionic assignment of py2P(O)O−. The normal atomic displacement parameters of the two O atoms (Fig. 1) also indicate that disorder of the py2P(O)OH group is unlikely.
The dichlomethane solvent molecule is disordered. The non-H atoms of the two major orientations (A, with an occupancy of 40%, and B, with an occupancy of 60%) were located and refined anisotropically.