[2,6-Bis(3,4-di­hydro-2H-pyrrol-5-yl)­pyridine]­tri­chloro­rhodium(III) di­benzene solvate

The structure of the mononuclear octahedral rhodium(III) complex, [RhCl₃(L)]·2C₆H₆, with L = 2,6-bis(3,4-di­hydro-2H-pyrrol-5-yl)­pyridine (C₁₃H₁₅N₃), possesses a twofold axis passing through Rh, the equatorial Cl atom and the N atom pyridine ring.

Key indicators

• Single-crystal X-ray study
• T = 153 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.026
• wR factor = 0.059
• Data-to-parameter ratio = 15.9

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_710  Alert C Delete 1-2-3 or 2-3-4 (CIF) Linear Torsion Angle #     34
                   C5  -N2  -RH1 -CL2  -142.00 50.00   1.555   1.555   1.555   1.555

PLAT_710  Alert C Delete 1-2-3 or 2-3-4 (CIF) Linear Torsion Angle #     35
                   C5  -N2  -RH1 -CL2    38.00 45.00   2.555   1.555   1.555   1.555

PLAT_732  Alert C Angle   Calc    88.68(3), Rep    88.68(1) ....       2.14 s.u-Ratio
                     N2   -RH1  -CL1     1.555   1.555   1.555

PLAT_732  Alert C Angle   Calc    91.32(3), Rep    91.32(1) ....       2.14 s.u-Ratio
                     CL1  -RH1  -CL2     1.555   1.555   1.555

PLAT_733  Alert C Torsion Calc      0.3(3), Rep    0.33(14) ....       2.14 s.u-Ratio
                     C5  -C6  -C7  -C6     1.555   1.555   1.555   2.555

PLAT_733  Alert C Torsion Calc      0.3(3), Rep    0.34(14) ....       2.14 s.u-Ratio
                     C6  -C5  -N2  -C5     1.555   1.555   1.555   2.555

PLAT_733  Alert C Torsion Calc      1.9(3), Rep    1.90(13) ....       2.31 s.u-Ratio
                     C4  -N1  -RH1 -N1     1.555   1.555   1.555   2.555

General Notes



FORMU_01  There is a discrepancy between the atom counts in the
          _chemical_formula_sum and _chemical_formula_moiety. This is
          usually due to the moiety formula being in the wrong format.
          Atom count from _chemical_formula_sum:   C25 H27 Cl3 N3 Rh1
          Atom count from _chemical_formula_moiety:C37 H39 Cl3 N3 Rh1

ABSTM_02  When printed, the submitted absorption T values will be replaced
          by the scaled T values. Since the ratio of scaled T's is
          identical to the ratio of reported T values, the scaling does
          not imply a change to the absorption corrections used in the
          study.
          Ratio of Tmax expected/reported      1.096
          Tmax scaled      0.903 Tmin scaled      0.543


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 7 Alert Level C = Please check

---

S1. Comment

In the context of our study on hydrogenation reactions catalysed by transition metals, we have synthesized a rhodium complex containing the tridentate ligand 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine (Bernauer & Gretillat, 1989). RhCl₃.nH₂O reacts with 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine (L) in refluxing dichloromethane to afford in good yield [RhCl₃(L)]·2C₆H₆, (I). The coordination of L to the Rh atom can be monitored by ¹H NMR; a position inversion and a downfield shift of the pyridinyl H atoms are observed. Thus, free ligand H_para = 7.80 p.p.m. and H_meta = 8.15 p.p.m. may be compared with coordinated ligand H_para = 8.47 p.p.m. and H_meta = 8.34 p.p.m.

The three N atoms of the tridentate ligand along with three Cl atoms form a distorted octahedral geometry around the metal atom in (I) (Fig. 1 and Table 1). Complex (I) crystallizes with two molecules of C₆H₆ per asymmetric unit. The bond distances and angles are similar to other [RhCl₃(η³-L)] complexes; L = bis(oxazolinyl)pyridine (Nishiyama et al., 1991), L = bis(pyrazolyl)pyridine (Christenson et al., 1995), L = 2,6-bis(ethylidyneimino)pyridine (Haarman et al., 1997), L = 2,3,6-tris(2-pyridyl)-1,3,5-triazine (Paul et al., 1998), L = 2,2':6',2''-terpyridine (Ziegler et al., 1999; Kwong et al., 2001).

The formation of five-membered chelate rings imposes an important distortion around the Rh atom. The N1—Rh1—N(2) [79.54 (5)°] and N1—Rh1—N1ⁱ [159.07 (10)°; symmetry code: (i) −x, y, −z + 1/2] angles are significantly smaller than the values of 90 and 180° expected for an ideal octahedral geometry). The equatorial plane formed by atoms L, Rh1 and Cl2 is planar, with an average deviation of 0.042 Å; only atoms C1 and C2 of the pyrrole fragment are out of plane, by −0.100 (2) and 0.088 (2) Å, respectively. The distance between Rh and the central N2 atom of 1.941 (2) Å is shorter than the other Rh—N1 bond of 2.031 (2) Å.

In the crystal structure, there is no meaningful interaction between the complex and the two benzene molecules, one molecule being parallel to the equatorial plane of (I) [4.0 (5)°] and the other being almost perpendicular [67.9 (2)°].

S2. Experimental

To a dichloromethane solution (15 ml) of RhCl₃.nH₂O (70 mg) was added dropwise a 5 ml solution of 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine (58 mg, 0.27 mmol). The mixture was stirred and refluxed for 2 h. After cooling to room temperature, a brown–orange precipitate was observed. The solid was filtered off and washed twice with cold CH₂Cl₂ and once with diethyl ether to give [RhCl₃{2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine}] in 65% yield [based on 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine]. To a small amount of [RhCl₃{2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine}] dissolved in hot benzene was added diethyl ether. Crystals of (I) formed after a few days. ¹H NMR (CDCl₃, p.p.m.): 8.47 (t, 1H), 8.34 (d, 2H), 4.16 (m, 4H), 3.50 (m, 4H), 2.50 (m, 4H). MS (ESI, m/z): 444; [RhCl₃(L)] + Na. Analysis calculated for C₁₉H₂₁Cl₃N₃Rh: C 45.58, H 4.23, N 8.39%; found: C 45.24, H 8.26, N 4.14%.

S3. Refinement

H atoms were included in calculated positions and treated in the riding-model approximation.

Computing details

Data collection: EXPOSE in IPDS Software (Stoe & Cie, 2000); cell refinement: CELL in IPDS Software; data reduction: INTEGRATE in IPDS Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures

Fig. 1. The molecular structure of (I) (Farrugia, 1997). The C6H6 molecules and H atoms have been omitted for clarity. Displacement ellipsoids are drawn at the 50% probability level.

[RhCl₃{2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine}] benzene solvate

Crystal data

[RhCl3(C13H15N3)]·2C6H6	F(000) = 1176
Mr = 578.76	Dx = 1.534 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 11.434 (2) Å	Cell parameters from 8000 reflections
b = 10.630 (2) Å	θ = 2.6–25.9°
c = 20.948 (4) Å	µ = 1.02 mm^−1
β = 100.12 (3)°	T = 153 K
V = 2506.5 (8) Å^3	Block, yellow
Z = 4	0.5 × 0.4 × 0.1 mm

Data collection

Stoe IPDS diffractometer	2341 independent reflections
Radiation source: fine-focus sealed tube	1964 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.049
Detector resolution: 0.81Å pixels mm^-1	θmax = 25.9°, θmin = 2.6°
ϕ oscillation scans	h = −12→14
Absorption correction: multi-scan (Blessing, 1995)	k = −12→13
Tmin = 0.495, Tmax = 0.824	l = −24→25
8616 measured reflections

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)] = 0.026	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.059	H-atom parameters constrained
S = 0.98	w = 1/[σ^2(Fo^2) + (0.0361P)^2] where P = (Fo^2 + 2Fc^2)/3
2341 reflections	(Δ/σ)max < 0.001
147 parameters	Δρmax = 0.89 e Å^−3
0 restraints	Δρmin = −0.89 e Å^−3

Special details

Experimental. A crystal was mounted at 153 K on a Stoe Image Plate Diffraction System (Stoe & Cie, 2000) using Mo Kα graphite monochromated radiation. Image plate distance 70 mm, ϕ oscillation scans 0 − 180°, step Δϕ = 1.2°, 3 minutes per frame.

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
C1	0.1801 (2)	0.2301 (2)	0.14892 (11)	0.0233 (5)
H1A	0.1259	0.1887	0.1145	0.028*
H1B	0.2262	0.1667	0.1756	0.028*
C2	0.2621 (2)	0.3215 (2)	0.12068 (12)	0.0261 (5)
H2A	0.2549	0.3096	0.0742	0.031*
H2B	0.3443	0.3086	0.1408	0.031*
C3	0.2202 (2)	0.4544 (2)	0.13595 (11)	0.0217 (5)
H3A	0.2859	0.5055	0.1572	0.026*
H3B	0.1814	0.4968	0.0969	0.026*
C4	0.1353 (2)	0.4272 (2)	0.18001 (11)	0.0175 (5)
C5	0.07004 (19)	0.51704 (19)	0.21466 (10)	0.0172 (5)
C6	0.0721 (2)	0.6479 (2)	0.21414 (12)	0.0227 (5)
H6	0.1206	0.6912	0.1903	0.027*
C7	0.0000	0.7126 (3)	0.2500	0.0239 (7)
H7	0.0000	0.8001	0.2500	0.029*
C8	0.4757 (2)	0.1200 (2)	0.01968 (13)	0.0313 (6)
H8	0.4592	0.2006	0.0328	0.038*
C9	0.4237 (2)	0.0169 (2)	0.04405 (12)	0.0309 (6)
H9	0.3727	0.0281	0.0736	0.037*
C10	0.4483 (2)	−0.1035 (2)	0.02399 (12)	0.0316 (6)
H10	0.4135	−0.1730	0.0401	0.038*
C11	−0.0869 (3)	0.0523 (3)	−0.04569 (16)	0.0441 (8)
H11	−0.1459	0.0877	−0.0767	0.053*
C12	−0.0982 (3)	0.0525 (3)	0.01880 (16)	0.0423 (7)
H12	−0.1648	0.0884	0.0314	0.051*
C13	−0.0119 (3)	0.0002 (3)	0.06396 (13)	0.0429 (8)
H13	−0.0198	0.0000	0.1074	0.051*
N1	0.11468 (16)	0.30933 (16)	0.18824 (9)	0.0168 (4)
N2	0.0000	0.4572 (2)	0.2500	0.0153 (5)
Cl1	−0.16151 (5)	0.27971 (5)	0.16405 (2)	0.02139 (14)
Cl2	0.0000	0.05244 (6)	0.2500	0.02382 (19)
Rh1	0.0000	0.27462 (2)	0.2500	0.01405 (9)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0240 (13)	0.0214 (11)	0.0273 (12)	0.0019 (9)	0.0120 (10)	−0.0059 (9)
C2	0.0240 (13)	0.0290 (12)	0.0283 (13)	0.0020 (10)	0.0124 (11)	0.0006 (10)
C3	0.0175 (12)	0.0230 (11)	0.0267 (12)	−0.0056 (9)	0.0093 (10)	0.0000 (9)
C4	0.0137 (11)	0.0177 (11)	0.0212 (11)	−0.0024 (8)	0.0034 (9)	−0.0002 (8)
C5	0.0151 (11)	0.0144 (11)	0.0223 (11)	−0.0015 (8)	0.0040 (9)	−0.0001 (8)
C6	0.0226 (13)	0.0142 (11)	0.0317 (12)	−0.0052 (9)	0.0059 (11)	0.0036 (9)
C7	0.0251 (18)	0.0121 (15)	0.0339 (18)	0.000	0.0032 (15)	0.000
C8	0.0311 (15)	0.0276 (13)	0.0350 (14)	−0.0006 (10)	0.0052 (12)	−0.0005 (10)
C9	0.0248 (14)	0.0411 (15)	0.0283 (13)	−0.0034 (11)	0.0090 (11)	0.0003 (11)
C10	0.0314 (15)	0.0319 (14)	0.0315 (14)	−0.0084 (11)	0.0053 (12)	0.0077 (11)
C11	0.0340 (18)	0.0380 (16)	0.056 (2)	−0.0151 (12)	−0.0044 (16)	0.0129 (13)
C12	0.0339 (17)	0.0310 (15)	0.068 (2)	−0.0080 (11)	0.0260 (16)	−0.0124 (13)
C13	0.052 (2)	0.0500 (17)	0.0302 (14)	−0.0350 (15)	0.0166 (14)	−0.0141 (13)
N1	0.0152 (10)	0.0147 (9)	0.0211 (9)	0.0003 (7)	0.0050 (8)	−0.0019 (7)
N2	0.0112 (13)	0.0185 (13)	0.0168 (12)	0.000	0.0038 (11)	0.000
Cl1	0.0185 (3)	0.0229 (3)	0.0227 (3)	−0.0040 (2)	0.0033 (2)	0.0039 (2)
Cl2	0.0350 (5)	0.0096 (3)	0.0270 (4)	0.000	0.0060 (4)	0.000
Rh1	0.01525 (14)	0.00957 (13)	0.01882 (13)	0.000	0.00710 (9)	0.000

Geometric parameters (Å, º)

C1—N1	1.471 (3)	C8—H8	0.9300
C1—C2	1.539 (3)	C9—C10	1.391 (4)
C1—H1A	0.9700	C9—H9	0.9300
C1—H1B	0.9700	C10—C8^ii	1.379 (4)
C2—C3	1.543 (3)	C10—H10	0.9300
C2—H2A	0.9700	C11—C13^iii	1.373 (5)
C2—H2B	0.9700	C11—C12	1.380 (4)
C3—C4	1.480 (3)	C11—H11	0.9300
C3—H3A	0.9700	C12—C13	1.360 (5)
C3—H3B	0.9700	C12—H12	0.9300
C4—N1	1.293 (3)	C13—C11^iii	1.373 (5)
C4—C5	1.478 (3)	C13—H13	0.9300
C5—N2	1.343 (3)	N1—Rh1	2.031 (2)
C5—C6	1.392 (3)	N2—C5^i	1.343 (3)
C6—C7	1.391 (3)	N2—Rh1	1.941 (2)
C6—H6	0.9300	Cl1—Rh1	2.3424 (9)
C7—C6^i	1.391 (3)	Cl2—Rh1	2.3618 (8)
C7—H7	0.9300	Rh1—N1^i	2.031 (2)
C8—C10^ii	1.379 (4)	Rh1—Cl1^i	2.3424 (9)
C8—C9	1.386 (4)
N1—C1—C2	104.98 (18)	C10—C9—H9	120.2
N1—C1—H1A	110.8	C8^ii—C10—C9	120.1 (2)
C2—C1—H1A	110.8	C8^ii—C10—H10	120.0
N1—C1—H1B	110.8	C9—C10—H10	120.0
C2—C1—H1B	110.8	C13^iii—C11—C12	119.8 (3)
H1A—C1—H1B	108.8	C13^iii—C11—H11	120.1
C1—C2—C3	105.4 (2)	C12—C11—H11	120.1
C1—C2—H2A	110.7	C13—C12—C11	119.9 (3)
C3—C2—H2A	110.7	C13—C12—H12	120.0
C1—C2—H2B	110.7	C11—C12—H12	120.0
C3—C2—H2B	110.7	C12—C13—C11^iii	120.3 (3)
H2A—C2—H2B	108.8	C12—C13—H13	119.9
C4—C3—C2	102.30 (18)	C11^iii—C13—H13	119.9
C4—C3—H3A	111.3	C4—N1—C1	110.94 (19)
C2—C3—H3A	111.3	C4—N1—Rh1	114.49 (15)
C4—C3—H3B	111.3	C1—N1—Rh1	134.56 (14)
C2—C3—H3B	111.3	C5—N2—C5^i	123.4 (3)
H3A—C3—H3B	109.2	C5—N2—Rh1	118.29 (13)
N1—C4—C3	115.3 (2)	C5^i—N2—Rh1	118.29 (13)
N1—C4—C5	116.2 (2)	N2—Rh1—N1	79.54 (5)
C3—C4—C5	128.55 (19)	N2—Rh1—N1^i	79.54 (5)
N2—C5—C6	119.4 (2)	N1—Rh1—N1^i	159.07 (10)
N2—C5—C4	111.49 (19)	N2—Rh1—Cl1^i	88.678 (14)
C6—C5—C4	129.1 (2)	N1—Rh1—Cl1^i	88.59 (5)
C7—C6—C5	118.5 (2)	N1^i—Rh1—Cl1^i	90.93 (5)
C7—C6—H6	120.7	N2—Rh1—Cl1	88.678 (14)
C5—C6—H6	120.7	N1—Rh1—Cl1	90.93 (5)
C6—C7—C6^i	120.8 (3)	N1^i—Rh1—Cl1	88.59 (5)
C6—C7—H7	119.6	Cl1^i—Rh1—Cl1	177.36 (3)
C6^i—C7—H7	119.6	N2—Rh1—Cl2	180.0
C10^ii—C8—C9	120.3 (2)	N1—Rh1—Cl2	100.46 (5)
C10^ii—C8—H8	119.8	N1^i—Rh1—Cl2	100.46 (5)
C9—C8—H8	119.8	Cl1^i—Rh1—Cl2	91.322 (14)
C8—C9—C10	119.6 (3)	Cl1—Rh1—Cl2	91.322 (14)
C8—C9—H9	120.2
N1—C1—C2—C3	−10.5 (2)	C6—C5—N2—Rh1	−179.66 (14)
C1—C2—C3—C4	9.3 (2)	C4—C5—N2—Rh1	1.00 (19)
C2—C3—C4—N1	−5.1 (2)	C5—N2—Rh1—N1	−1.56 (11)
C2—C3—C4—C5	176.1 (2)	C5^i—N2—Rh1—N1	178.44 (11)
N1—C4—C5—N2	0.7 (2)	C5—N2—Rh1—N1^i	178.44 (11)
C3—C4—C5—N2	179.50 (19)	C5^i—N2—Rh1—N1^i	−1.56 (11)
N1—C4—C5—C6	−178.6 (2)	C5—N2—Rh1—Cl1^i	87.25 (10)
C3—C4—C5—C6	0.2 (4)	C5^i—N2—Rh1—Cl1^i	−92.75 (10)
N2—C5—C6—C7	−0.7 (3)	C5—N2—Rh1—Cl1	−92.75 (10)
C4—C5—C6—C7	178.54 (18)	C5^i—N2—Rh1—Cl1	87.25 (10)
C5—C6—C7—C6^i	0.33 (14)	C5—N2—Rh1—Cl2	−142 (50)
C10^ii—C8—C9—C10	−0.2 (4)	C5^i—N2—Rh1—Cl2	38 (45)
C8—C9—C10—C8^ii	0.2 (4)	C4—N1—Rh1—N2	1.90 (14)
C13^iii—C11—C12—C13	−0.3 (4)	C1—N1—Rh1—N2	−177.0 (2)
C11—C12—C13—C11^iii	0.3 (4)	C4—N1—Rh1—N1^i	1.90 (13)
C3—C4—N1—C1	−1.8 (3)	C1—N1—Rh1—N1^i	−177.0 (2)
C5—C4—N1—C1	177.22 (18)	C4—N1—Rh1—Cl1^i	−87.01 (14)
C3—C4—N1—Rh1	179.09 (15)	C1—N1—Rh1—Cl1^i	94.1 (2)
C5—C4—N1—Rh1	−1.9 (2)	C4—N1—Rh1—Cl1	90.39 (14)
C2—C1—N1—C4	7.9 (2)	C1—N1—Rh1—Cl1	−88.5 (2)
C2—C1—N1—Rh1	−173.20 (15)	C4—N1—Rh1—Cl2	−178.10 (14)
C6—C5—N2—C5^i	0.34 (14)	C1—N1—Rh1—Cl2	3.0 (2)
C4—C5—N2—C5^i	−179.00 (19)

Symmetry codes: (i) −x, y, −z+1/2; (ii) −x+1, −y, −z; (iii) −x, −y, −z.