catena-Poly[[bis­(pyridine)­lead(II)]bis­(μ-penta­fluoro­benzene­thiol­ato)]

The title compound, [Pb(C₆F₅S)₂(C₅H₅N)₂]_n, shows the Pb^II atom in a ψ-trigonal bipyramidal S₂N₂ bonding environment. Pyridine N atoms occupy axial sites, while thiol­ate S atoms and a stereochemically active lone pair occupy equatorial sites. Very long inter­molecular Pb⋯S inter­actions [3.618 (4) and 3.614 (4) Å] yield a weakly associated one-dimensional polymeric structure extending parallel to [010].

Related literature

Lead(II) thiol­ates tend to form polymeric structures in the solid state via inter­molecular Pb⋯S inter­actions, see: Davidovich et al. (2010) and references therein; Eichhöfer (2005). However, the bonding environment at lead and the degree of inter­molecular bonding may be altered via the introduction of Lewis base ligands that occupy metal coordination sites, see: Appleton et al. (2004); Briand et al. (2007). It has been shown that [(F₅C₆S)₂Pb]_n exhibits a three-dimensional framework structure containing hexa­coordinated Pb^II atoms (Fleischer et al., 2006). For van der Waals radii, see: Bondi (1964); Brown (1978).

Experimental

Crystal data

• [Pb(C₆F₅S)₂C₅H₅N)₂]

• M_r = 763.63

• Monoclinic, C 2/c

• a = 19.9288 (19) Å

• b = 5.0416 (5) Å

• c = 24.9155 (19) Å

• β = 111.339 (3)°

• V = 2331.7 (4) ų

• Z = 4

• Mo Kα radiation

• μ = 7.51 mm⁻¹

• T = 198 K

• 0.57 × 0.15 × 0.10 mm

Data collection

• Bruker SMART1000/P4 diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2008a) T_min = 0.099, T_max = 0.521

• 6756 measured reflections

• 2575 independent reflections

• 2421 reflections with I > 2σ(I)

• R_int = 0.055

Refinement

• R[F² > 2σ(F²)] = 0.040

• wR(F²) = 0.097

• S = 1.06

• 2575 reflections

• 168 parameters

• H-atom parameters constrained

• Δρ_max = 3.83 e Å⁻³

• Δρ_min = −2.71 e Å⁻³

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008b); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008b); molecular graphics: SHELXTL (Sheldrick, 2008b); software used to prepare material for publication: SHELXTL.

Supporting information

S1. Comment

Lead(II) thiolates tend to form polymeric structures in the solid state via intermolecular Pb ··· S interactions (Davidovich et al., 2010, and references therein; Eichhöfer, 2005). However, the bonding environment at lead and the degree of intermolecular bonding may be altered via the introduction of Lewis base ligands that occupy metal coordination sites (Appleton et al., 2004; Briand et al., 2007). It has been shown that [(F₅C₆S)₂Pb]_n exhibits a three-dimensional layered structure containing hexacoordinated Pb^II atoms (Fleischer et al., 2006). The corresponding bis-pyridine adduct (I) (Fig. 1) shows Pb1 in a ψ -trigonal bipyramidal bonding environment, with two pyridine nitrogen atoms in trans axial sites [N1—Pb—N2 = 177.29 (17)°] and two sulfur atoms in cis equatorial sites [S1—Pb—S2 = 87.13 (6)°]. The remaining "open" equatorial site is presumably occupied by the stereochemically active lone pair of Pb^II. This is a similar bonding motif to that observed for (2,6-Me₂C₆H₃S)₂Pb × 2py (Appleton et al., 2004), but shows some subtle structural differences. The Pb—N bond distances in (I) [Pb—N1 = 2.643 (7), Pb—N2 = 2.637 (7) Å] are significantly shorter than those in (2,6-Me₂C₆H₃S)₂Pb × 2py [2.689 (3) and 2.695 (3) Å], while the Pb—S distances [Pb—S1 = 2.650 (2), Pb—S2 = 2.653 (2) Å] are significantly longer [2.6078 (9) and 2.6079 (9) Å for (2,6-Me₂C₆H₃S)₂Pb × 2py]. This may be rationalized by considering the increased electron withdrawing ability of the C₆F₅ group in (I) versus the 2,6-Me₂C₆H₅ group in (2,6-Me₂C₆H₃S)₂Pb × 2py. The result is an effective increase in the Lewis acidity at the Pb centre, and shorter Pb—N Lewis acid-base bonding interactions. Very weak intermolecular Pb ··· S interactions [Pb—S1ⁱ = 3.618 (4), Pb—S2ⁱ = 3.614 (4) Å; (i) -1 + x, y, z; sum of van der Waals' radii = 3.8 Å] (Bondi, 1964; Brown, 1978) between adjacent molecules in (I) yield a one-dimensional polymeric structure (Fig. 2). These contacts are nearly trans to the short Pb—S bonds [S1—Pb—S2ⁱ = 166.75 (5)°, S2—Pb—S1ⁱ = 166.83 (5)°], yielding a distorted octahedral bonding arrangement at Pb. This weakly associated polymeric structure differs from that of (2,6-Me₂C₆H₃S)₂Pb × 2py, which is monomeric in the solid-state. Further, the structure possesses no intramolecular Pb ··· F contacts such as those observed in [(F₅C₆S)₂Pb]_n (Fleischer et al., 2006).

Related literature

Lead(II) thiolates tend to form polymeric structures in the solid state via intermolecular Pb ··· S interactions, see: Davidovich et al., (2010) and references therein; Eichhöfer (2005). However, the bonding environment at lead and the degree of intermolecular bonding may be altered via the introduction of Lewis base ligands that occupy metal coordination sites, see: Appleton et al. (2004); Briand et al. (2007). It has been shown that [(F₅C₆S)₂Pb]_n exhibits a three-dimensional layered structure containing hexacoordinated Pb^II atoms (Fleischer et al., 2006). For van der Waals radii, see: Bondi (1964); Brown (1978).

S2. Experimental

Synthesis of (C₆F₅S)₂Pb × 2py: A solution of pyridine (0.520 g, 6.57 mmol) in thf (3 ml) was added dropwise to a stirred solution of (C₆F₅S)₂Pb (0.100 g, 0.165 mmol) in thf (5 ml) to give a cloudy pale green solution. The solution was stirred for 15 minutes and filtered. After 1 d at 25°C, colorless rod-like crystals of (I) were collected by suction filtration (0.100 g, 0.131 mmol, 79%). Anal. Calc. for C₂₁H₁₀F₁₀N₂PbS₂: C, 34.60; H, 1.32; N, 3.67. Found: C, 34.47; H, 1.05; N, 3.64. Mp 262°C. See expt further details section for spectroscopic data.

S3. Refinement

Hydrogen atoms were placed in calculated positions with C–H distances fixed at 0.93 Å and U_iso values = 1.2 U_eq of the carrier C atom.

Computing details

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008b); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008b); molecular graphics: SHELXTL (Sheldrick, 2008b); software used to prepare material for publication: SHELXTL (Sheldrick, 2008b).

Figures

Fig. 1. X-ray crystal structure of (I), with displacement ellipsoids drawn at the 50% probability level. H atoms have been omitted for clarity. Selected bond distances (Å) and angles (°): Pb—S(1) 2.650 (2), Pb—S(2) 2.653 (2), Pb—N(1) 2.643 (7), Pb—N(2) 2.637 (7), S(1)—Pb—S(2) 87.13 (6), S(1)—Pb—N(1) 91.44 (16), S(1)—Pb—N(2) 86.47 (15), S(2)—Pb—N(1) 86.69 (16), S(2)—Pb—N(2) 91.48 (16), N(1)—Pb—N(2) 177.29 (17).

Fig. 2. X-ray crystal structure of (I) showing the polymeric structure, with displacement ellipsoids drawn at the 50% probability level. All hydrogen atoms and C6F5 group carbon atoms (except α-carbon) have been omitted for clarity. Symmetry transformations used to generate equivalent atoms: (i) -1 + x, y, z; (ii) +1 + x, y, z.

catena-Poly[[bis(pyridine)lead(II)]bis(µ-pentafluorobenzenethiolato)]

Crystal data

[Pb(C6F5S)2C5H5N)2]	F(000) = 1440
Mr = 763.63	Dx = 2.175 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 5261 reflections
a = 19.9288 (19) Å	θ = 2.2–27.9°
b = 5.0416 (5) Å	µ = 7.51 mm^−1
c = 24.9155 (19) Å	T = 198 K
β = 111.339 (3)°	Parallelepiped, colourless
V = 2331.7 (4) Å^3	0.57 × 0.15 × 0.10 mm
Z = 4

Data collection

Bruker SMART1000/P4 diffractometer	2575 independent reflections
Radiation source: fine-focus sealed tube, K760	2421 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.055
ϕ and ω scans	θmax = 27.5°, θmin = 4.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2008a)	h = −25→25
Tmin = 0.099, Tmax = 0.521	k = −6→6
6756 measured reflections	l = −30→32

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.097	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0608P)^2] where P = (Fo^2 + 2Fc^2)/3
2575 reflections	(Δ/σ)max = 0.001
168 parameters	Δρmax = 3.83 e Å^−3
0 restraints	Δρmin = −2.71 e Å^−3

Special details

Experimental. Crystal decay was monitored by repeating the initial 50 frames at the end of the data collection and analyzing duplicate reflections.

FT—IR (cm^-1): 669 w, 702 m, 750 m, 825 vw, 856 s, 972 s, 1001 m, 1153 w, 1215 w, 1263 vw, 1444 s, 1477 versus, 1510 s, 1595 m, 1608 vw, 2341 m, 2360 s. FT-Raman (cm^-1): 74 s, 101 versus, 175 vw, 201 vw, 268 versus, 317 vw, 372 vw, 387 w, 444 vw, 513 m, 584 w, 859 m, 1003 s, 1032 m, 1277 vw, 1393 m, 1636 versus, 3069 m. NMR data (thf-d₈, p.p.m.): ¹H NMR, δ = 7.36 (m, 4H, NC₅H₅), 7.77 (tt, 2H, ³J (¹H-¹H) = 8 Hz, ⁴J (¹H-¹H) = 2 Hz, NC₅H₅), 8.67 (m, 4H, NC₅H₅); ¹³C{¹H} NMR, δ = 115.8 (tm, ²J (¹³C-¹⁹F) = 22 Hz, SC₆F₅), 124.2 (s, NC₅H₅), 136.7 (s, NC₅H₅), 137.1 (dm, ¹J (¹³C-¹⁹F) = 245 Hz, SC₆F₅), 137.7 (dm, ¹J (¹³C-¹⁹F) = 247 Hz, SC₆F₅), 148.4 (dm, ¹J (¹³C-¹⁹F) = 226 Hz, SC₆F₅), 149.4 (s, NC₅H₅); ¹⁹F NMR, δ = -166.2 (m, SC₆F₅), -164.5 (m, SC₆F₅), -133.9 (m, SC₆F₅).

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 (Ų)

	x	y	z	Uiso*/Ueq
Pb	0.0000	0.57741 (4)	0.2500	0.02457 (12)
S1	−0.00240 (9)	0.9584 (2)	0.17593 (6)	0.0308 (3)
F2	−0.1488 (2)	0.9328 (7)	0.0811 (2)	0.0491 (11)
F3	−0.1937 (2)	0.5959 (8)	−0.0085 (2)	0.0643 (15)
F4	−0.1038 (2)	0.2260 (7)	−0.02233 (17)	0.0513 (10)
F5	0.03376 (19)	0.1979 (7)	0.05311 (15)	0.0416 (8)
F6	0.0806 (2)	0.5350 (7)	0.14221 (17)	0.0404 (8)
N1	0.1419 (3)	0.5895 (8)	0.2954 (3)	0.0333 (11)
C1	−0.0321 (3)	0.7450 (9)	0.1159 (2)	0.0261 (10)
C2	−0.1022 (3)	0.7539 (11)	0.0757 (2)	0.0324 (11)
C3	−0.1263 (4)	0.5816 (11)	0.0295 (3)	0.0369 (14)
C4	−0.0802 (4)	0.3944 (11)	0.0226 (3)	0.0341 (13)
C5	−0.0113 (3)	0.3793 (11)	0.0607 (3)	0.0304 (12)
C6	0.0123 (3)	0.5558 (9)	0.1063 (3)	0.0278 (11)
C7	0.1855 (3)	0.7571 (12)	0.2823 (3)	0.0408 (13)
H7	0.1652	0.8817	0.2534	0.049*
C8	0.2590 (4)	0.7531 (14)	0.3097 (3)	0.0512 (17)
H8	0.2880	0.8719	0.2994	0.061*
C9	0.2891 (4)	0.5700 (12)	0.3528 (4)	0.052 (2)
H9	0.3387	0.5646	0.3726	0.062*
C10	0.2453 (4)	0.3984 (13)	0.3659 (4)	0.053 (2)
H10	0.2645	0.2719	0.3946	0.063*
C11	0.1719 (4)	0.4119 (11)	0.3363 (3)	0.0426 (16)
H11	0.1423	0.2918	0.3455	0.051*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Pb	0.02186 (16)	0.02276 (15)	0.02304 (18)	0.000	0.00096 (12)	0.000
S1	0.0382 (8)	0.0238 (6)	0.0243 (7)	−0.0012 (5)	0.0040 (6)	−0.0011 (5)
F2	0.036 (2)	0.054 (2)	0.045 (3)	0.0214 (16)	0.0000 (19)	−0.0131 (16)
F3	0.031 (2)	0.089 (3)	0.052 (3)	0.0185 (19)	−0.011 (2)	−0.030 (2)
F4	0.046 (2)	0.055 (2)	0.042 (2)	0.0075 (18)	0.0033 (18)	−0.0236 (18)
F5	0.0405 (19)	0.0421 (18)	0.042 (2)	0.0155 (16)	0.0150 (17)	−0.0039 (15)
F6	0.0235 (17)	0.050 (2)	0.038 (2)	0.0079 (15)	−0.0006 (16)	−0.0015 (16)
N1	0.022 (2)	0.034 (2)	0.037 (3)	0.0008 (17)	0.003 (2)	0.0018 (18)
C1	0.029 (2)	0.023 (2)	0.023 (3)	0.001 (2)	0.006 (2)	0.0051 (19)
C2	0.028 (2)	0.037 (3)	0.029 (3)	0.010 (2)	0.006 (2)	−0.004 (2)
C3	0.027 (3)	0.045 (3)	0.029 (3)	0.007 (2)	−0.002 (3)	−0.008 (2)
C4	0.034 (3)	0.038 (3)	0.027 (3)	0.003 (2)	0.008 (3)	−0.008 (2)
C5	0.031 (3)	0.032 (2)	0.029 (3)	0.010 (2)	0.012 (3)	0.001 (2)
C6	0.023 (3)	0.030 (3)	0.026 (3)	0.0005 (19)	0.004 (2)	0.0038 (19)
C7	0.033 (3)	0.040 (3)	0.041 (4)	−0.003 (3)	0.005 (3)	0.006 (3)
C8	0.033 (3)	0.054 (4)	0.061 (5)	−0.013 (3)	0.010 (3)	0.003 (3)
C9	0.027 (3)	0.056 (4)	0.061 (5)	−0.001 (3)	0.003 (3)	−0.001 (3)
C10	0.039 (4)	0.049 (4)	0.051 (5)	0.005 (3)	−0.005 (4)	0.009 (3)
C11	0.032 (3)	0.040 (3)	0.047 (4)	−0.002 (2)	0.005 (3)	0.010 (2)

Geometric parameters (Å, º)

Pb—N1	2.636 (5)	C2—C3	1.382 (8)
Pb—N1^i	2.636 (5)	C3—C4	1.371 (8)
Pb—S1^i	2.6519 (14)	C4—C5	1.359 (9)
Pb—S1	2.6519 (14)	C5—C6	1.384 (8)
S1—C1	1.761 (5)	C7—C8	1.373 (8)
F2—C2	1.336 (6)	C7—H7	0.9300
F3—C3	1.334 (8)	C8—C9	1.378 (11)
F4—C4	1.345 (7)	C8—H8	0.9300
F5—C5	1.342 (6)	C9—C10	1.350 (12)
F6—C6	1.334 (7)	C9—H9	0.9300
N1—C11	1.326 (8)	C10—C11	1.380 (10)
N1—C7	1.335 (8)	C10—H10	0.9300
C1—C6	1.379 (8)	C11—H11	0.9300
C1—C2	1.392 (7)
N1—Pb—N1^i	177.34 (18)	F5—C5—C4	119.8 (5)
N1—Pb—S1^i	86.55 (12)	F5—C5—C6	120.7 (5)
N1^i—Pb—S1^i	91.52 (12)	C4—C5—C6	119.5 (5)
N1—Pb—S1	91.52 (12)	F6—C6—C1	120.1 (5)
N1^i—Pb—S1	86.55 (12)	F6—C6—C5	117.3 (5)
S1^i—Pb—S1	87.18 (6)	C1—C6—C5	122.7 (5)
C1—S1—Pb	93.67 (16)	N1—C7—C8	122.8 (6)
C11—N1—C7	117.6 (6)	N1—C7—H7	118.6
C11—N1—Pb	115.3 (4)	C8—C7—H7	118.6
C7—N1—Pb	127.0 (4)	C7—C8—C9	118.7 (7)
C6—C1—C2	115.9 (5)	C7—C8—H8	120.6
C6—C1—S1	122.1 (4)	C9—C8—H8	120.6
C2—C1—S1	122.0 (4)	C10—C9—C8	118.7 (7)
F2—C2—C3	117.8 (5)	C10—C9—H9	120.6
F2—C2—C1	120.1 (5)	C8—C9—H9	120.6
C3—C2—C1	122.1 (5)	C9—C10—C11	119.6 (7)
F3—C3—C4	119.8 (5)	C9—C10—H10	120.2
F3—C3—C2	120.7 (5)	C11—C10—H10	120.2
C4—C3—C2	119.5 (6)	N1—C11—C10	122.5 (7)
F4—C4—C5	120.3 (5)	N1—C11—H11	118.7
F4—C4—C3	119.4 (6)	C10—C11—H11	118.7
C5—C4—C3	120.3 (5)

Symmetry code: (i) −x, y, −z+1/2.