(N,N′-Diethyl­dithio­carbamato-κ²S,S′)bis­[2-(2-pyrid­yl)phenyl-κ²C¹,N]iridium(III)

In the title compound, [Ir(C₁₁H₈N)₂(C₅H₁₀NS₂)], the Ir center has a distorted octa­hedral environment. The N donors of the two chelating 2-(2-pyrid­yl)phenyl ligands are in trans positions with respect to each other and the two C atoms are in a cis configuration. The packing is partially facilitated by C—H...π inter­actions between aromatic rings in neighboring mol­ecules, connecting the mol­ecules into infinite chains along the c axis of the unit cell. These chains are in turn connected by C—H...π inter­actions between neighboring chains. A crystallographic twofold rotation axis passes through Ir and C,N of the dithiocarbamate ligand.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.008 Å
• R factor = 0.023
• wR factor = 0.071
• Data-to-parameter ratio = 18.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Ir1    -   S1      ..       6.25 su

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Organic light-emitting diodes (OLEDs) have been actively investigated due to their potential applications in flat panel displays and light-emitting devices. Most recently, heavy metal complexes in OLEDs have attracted much attention as efficient phosphors because they can harvest both singlet and triplet excited states, and thus the OLEDs internal efficiency can theoretically reach 100% (Lamansky et al., 2001). Especially iridium (III) complexes with cyclometalated ligands show intense phosphorescence at room temperature and this behavior makes them very promising phosphor dyes in OLEDs (Baldo et al., 1998 & Lamansky et al., 2001). Also, metal complexes containing dithiolate ligands have been extensively studied. However, only relatively few iridium (III) dithiolate complexes have been described. The title compound, which emits green luminescence in both solid state and organic solution upon irradiation by UV-light at ambient temperature, may plays a very important role as a potential electrophosphorescent material.

In the crystal structure of the title molecule, the Ir center resides in a distorted octahedral environment. The nitrogen donors of the the two chelating 2-phenylpyridinato ligands are in trans posistion to each other, the two carbon atoms are in a cis configuration (Scheme 1). As expected, the Ir—C bonds (2.015 (4) Å) are shorter than the Ir—N bond distances (2.045 (4) Å). These values are very similar to those in similar complexes such as (ppy)₂Ir(acac) (ppy: 2-phenylpyridine; acac: actylacetone)(Ir—C: 2.020 (2) Å; Ir—N: 2.090 (10) Å) (Garces et al., 1993). The similarity of the S—C bond lengths in the N,N'-diethyldithiocarbamate (Et₂dtc) ligand indicates that the charge is delocalized over both sulfur atoms. The Et₂dtc chelate angle (S1—Ir1—S1a) is 71.12 (5)°, and the phenyl and metalated pyridine rings in the same ppy ligand are coplanar (the dihedral angle between the two planes is 0.3 (1)°). Selected important bond distances and angles are given in the selected geomtetric parameters table.

The packing of compound (I) is partially facilitated by C—H···π interactions between aromatic rings in neighboring molecules, the two most prominent such interactions are given in the hydrogen bonding table (Cg1 represents the centroid of ring C6/C7/C8/C9/C10/C11, Cg2 that of N1/C1/C2/C3/C4/C5). The first of these interactions, which acts in centrosymmetric pairs between each two molecules, connects the molecules to infinite chains along the c axis of the unit cell. The second slightly weaker type of C—H···π interaction connects these chains with each other (Figures 2 and 3).

Related literature

For related literature, see: Baldo et al. (1998); Garces et al. (1993); Lamansky et al. (2001); Watts et al. (1984).

S2. Experimental

Iridium trichloride hydrate and 2-phenylpyridine were purchased and used without further purification. The synthesis of the target product involves two steps. First, iridium trichloride hydrate (0.352 g, 1.0 mmol) was combined with 2.5 equiv of the cyclometalating ligand, 2-phenylpyridine (0.385 g, 2.5 mmol), was dissolved in a mixture of 2-ethoxyethanol (30 ml) and water (10 ml), and then refluxed for 24 h. The solution was cooled to room temperature, and the yellow precipitate was collected on a glass filter frit. After drying, the crude product was directly used for the next step without further purification (Watts et al., 1984). In the second step, the product (0.075 mmol), sodium N,N'-diethyldithio-carbamate (NaEt₂dtc) (0.25 mmol) and anhydrous sodium carbonate (Na₂CO₃, 1.0 mmol) were dissolved in 2-ethoxyethanol (10 ml). The mixture was refluxed under argon for 18 h. After cooling to room temperature, a small quantity of water was added. The resulting red precipitate was collected by filtration, washed with water, ethanol and hexane, and dried in vacuum. The crude product was purified by column chromatography on silica gel with CH₂Cl₂/petroleum ether (1:3) as the eluent. The residue was dried under vacuum and recrystallized from dichloromethane/hexane (1:1, v/v). Yield: 0.215 g (65.2%), ¹H NMR (CDCl₃, 300 MHz, p.p.m.) 1.20–1.25 (t, J = 7.5 Hz, 6H), 3.46–3.53 (m, 2H), 3.73–3.80 (m, 2H), 6.28 (d, J = 7.8 Hz, 2H), 6.60 (dd, J = 7.2 Hz, 2H), 6.76 (dd, J = 8.1 Hz, 2H), 7.14–7.21 (m, 2H), 7.50 (d, J = 8.4 Hz, 2H) 7.66 (dd, J = 6.9 Hz, 2H) 7.81 (d, J = 7.2 Hz, 2H) 9.57 (d, J = 8.7 Hz, 2H). Calcd for C₂₇H₂₆N₃S₂Ir: C, 49.98; H, 4.04; N, 6.48%, Found: C, 50.23; H, 4.10; N, 6.21%. MS (FAB): m/e, 649 (M⁺).

S3. Refinement

All H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with C—H distances in the range 0.93–0.98 Å, and with U_iso(H) = 1.2U _eq for aryl H atoms and 1.5U_eq for the methyl H atoms. Methyl H atoms were allowed to rotate to best fit the experimental electron density.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SMART; data reduction: SAINT (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The structure of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level (-x, y, 0.5 - z).
	Fig. 2. Packing Diagram of (I), view down the b axis showing the infinite chains created by the C—H···π interactions between C4—H4 and the ring C6/C7/C8/C9/C10/C11.
	Fig. 3. Packing Diagram of (I), view down the c axis along the infinite chains shown in Figure 2. Red dashed lines: C—H···π interactions of C4—H4 to ring C6/C7/C8/C9/C10/C11 forming the infinite chains. Blue: C8—H8 to ring N1/C1/C2/C3/C4/C5 connecting these chains.

(N,N'-Diethyldithiocarbamato-κ²S,S')bis[2-(2-pyridyl)phenyl- κ²C¹,N]iridium(III)

Crystal data

[Ir(C11H8N)2(C5H10NS2)]	F(000) = 1272
Mr = 648.83	Dx = 1.718 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2854 reflections
a = 16.401 (3) Å	θ = 4–27.5°
b = 11.436 (2) Å	µ = 5.51 mm^−1
c = 13.540 (3) Å	T = 293 K
β = 99.00 (3)°	Block, red
V = 2508.2 (9) Å^3	0.10 × 0.10 × 0.10 mm
Z = 4

Data collection

Siemens SMART CCD area-detector diffractometer	2852 independent reflections
Radiation source: fine-focus sealed tube	2597 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.000
φ and ω scans	θmax = 27.4°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = 0→21
Tmin = 0.576, Tmax = 0.582	k = 0→14
2852 measured reflections	l = −17→17

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.023	H-atom parameters constrained
wR(F^2) = 0.071	w = 1/[σ^2(Fo^2) + (0.0376P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.15	(Δ/σ)max = 0.001
2852 reflections	Δρmax = 0.87 e Å^−3
153 parameters	Δρmin = −1.12 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997a), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0046 (2)

Special details

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	−0.1615 (2)	−0.1270 (4)	0.1595 (3)	0.0431 (9)
C2	−0.2324 (3)	−0.1397 (4)	0.0889 (4)	0.0536 (11)
H2	−0.2740	−0.1899	0.1020	0.064*
C3	−0.2418 (3)	−0.0792 (5)	0.0005 (4)	0.0594 (12)
H3	−0.2889	−0.0891	−0.0469	0.071*
C4	−0.1801 (3)	−0.0031 (5)	−0.0171 (4)	0.0566 (11)
H4	−0.1851	0.0395	−0.0763	0.068*
C5	−0.1117 (3)	0.0082 (5)	0.0544 (3)	0.0476 (10)
H5	−0.0704	0.0597	0.0425	0.057*
C6	0.1429 (3)	−0.1884 (4)	0.2456 (3)	0.0459 (9)
C7	0.1972 (3)	−0.2661 (4)	0.2101 (4)	0.0649 (14)
H7	0.2485	−0.2814	0.2479	0.078*
C8	0.1746 (4)	−0.3200 (5)	0.1191 (5)	0.0761 (16)
H8	0.2115	−0.3693	0.0940	0.091*
C9	0.0977 (4)	−0.3010 (5)	0.0653 (4)	0.0711 (15)
H9	0.0821	−0.3398	0.0050	0.085*
C10	0.0428 (3)	−0.2244 (4)	0.1000 (3)	0.0557 (11)
H10	−0.0091	−0.2126	0.0627	0.067*
C11	0.0647 (3)	−0.1648 (3)	0.1901 (3)	0.0405 (8)
C12	0.0000	0.2174 (5)	0.2500	0.0392 (12)
C13	0.0614 (3)	0.4009 (4)	0.2065 (4)	0.0583 (12)
H13A	0.0350	0.4686	0.1720	0.070*
H13B	0.0837	0.3532	0.1578	0.070*
C14	0.1303 (5)	0.4405 (6)	0.2859 (7)	0.095 (2)
H14A	0.1091	0.4938	0.3304	0.143*
H14B	0.1719	0.4790	0.2551	0.143*
H14C	0.1541	0.3739	0.3230	0.143*
Ir1	0.0000	−0.040880 (17)	0.2500	0.03458 (10)
N1	−0.1011 (2)	−0.0514 (3)	0.1408 (3)	0.0382 (7)
N2	0.0000	0.3332 (4)	0.2500	0.0454 (11)
S1	0.06343 (6)	0.13548 (9)	0.18733 (8)	0.0423 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.045 (2)	0.0360 (19)	0.050 (2)	−0.0042 (17)	0.0123 (16)	−0.0108 (19)
C2	0.050 (2)	0.047 (2)	0.063 (3)	−0.0046 (19)	0.007 (2)	−0.015 (2)
C3	0.057 (3)	0.059 (3)	0.058 (3)	0.009 (2)	−0.005 (2)	−0.014 (3)
C4	0.062 (3)	0.059 (3)	0.048 (3)	0.014 (2)	0.004 (2)	0.000 (2)
C5	0.050 (2)	0.051 (2)	0.042 (2)	0.005 (2)	0.0099 (18)	0.005 (2)
C6	0.056 (2)	0.036 (2)	0.048 (2)	0.0074 (18)	0.0196 (18)	0.0059 (19)
C7	0.069 (3)	0.053 (3)	0.077 (4)	0.024 (2)	0.022 (3)	0.005 (3)
C8	0.096 (4)	0.057 (3)	0.082 (4)	0.029 (3)	0.036 (3)	−0.008 (3)
C9	0.109 (4)	0.054 (3)	0.055 (3)	0.013 (3)	0.027 (3)	−0.014 (3)
C10	0.074 (3)	0.046 (2)	0.050 (3)	0.005 (2)	0.018 (2)	−0.002 (2)
C11	0.050 (2)	0.0335 (19)	0.040 (2)	0.0012 (16)	0.0147 (16)	0.0005 (17)
C12	0.032 (2)	0.045 (3)	0.040 (3)	0.000	0.005 (2)	0.000
C13	0.068 (3)	0.040 (2)	0.068 (3)	−0.009 (2)	0.015 (2)	0.006 (2)
C14	0.080 (4)	0.102 (5)	0.104 (6)	−0.041 (4)	0.014 (4)	−0.004 (4)
Ir1	0.03838 (14)	0.03183 (13)	0.03526 (14)	0.000	0.01116 (8)	0.000
N1	0.0421 (17)	0.0381 (17)	0.0355 (17)	0.0013 (13)	0.0092 (13)	−0.0024 (13)
N2	0.045 (3)	0.034 (2)	0.057 (3)	0.000	0.011 (2)	0.000
S1	0.0413 (5)	0.0386 (5)	0.0504 (6)	−0.0006 (4)	0.0180 (4)	0.0012 (5)

Geometric parameters (Å, º)

C1—N1	1.367 (5)	C10—C11	1.394 (6)
C1—C2	1.393 (6)	C10—H10	0.9300
C1—C6^i	1.454 (6)	C11—Ir1	2.015 (4)
C2—C3	1.370 (7)	C12—N2	1.324 (8)
C2—H2	0.9300	C12—S1^i	1.719 (3)
C3—C4	1.384 (9)	C12—S1	1.719 (3)
C3—H3	0.9300	C13—N2	1.465 (5)
C4—C5	1.369 (7)	C13—C14	1.504 (9)
C4—H4	0.9300	C13—H13A	0.9700
C5—N1	1.342 (6)	C13—H13B	0.9700
C5—H5	0.9300	C14—H14A	0.9600
C6—C7	1.395 (6)	C14—H14B	0.9600
C6—C11	1.408 (6)	C14—H14C	0.9600
C6—C1^i	1.454 (6)	Ir1—C11^i	2.015 (4)
C7—C8	1.376 (8)	Ir1—N1	2.045 (4)
C7—H7	0.9300	Ir1—N1^i	2.045 (4)
C8—C9	1.371 (8)	Ir1—S1	2.4792 (11)
C8—H8	0.9300	Ir1—S1^i	2.4792 (11)
C9—C10	1.389 (7)	N2—C13^i	1.465 (5)
C9—H9	0.9300
N1—C1—C2	119.3 (4)	S1^i—C12—S1	114.0 (3)
N1—C1—C6^i	114.3 (4)	N2—C13—C14	111.0 (5)
C2—C1—C6^i	126.4 (4)	N2—C13—H13A	109.4
C3—C2—C1	121.0 (4)	C14—C13—H13A	109.4
C3—C2—H2	119.5	N2—C13—H13B	109.4
C1—C2—H2	119.5	C14—C13—H13B	109.4
C2—C3—C4	118.9 (4)	H13A—C13—H13B	108.0
C2—C3—H3	120.6	C13—C14—H14A	109.5
C4—C3—H3	120.6	C13—C14—H14B	109.5
C5—C4—C3	118.6 (5)	H14A—C14—H14B	109.5
C5—C4—H4	120.7	C13—C14—H14C	109.5
C3—C4—H4	120.7	H14A—C14—H14C	109.5
N1—C5—C4	123.3 (5)	H14B—C14—H14C	109.5
N1—C5—H5	118.4	C11^i—Ir1—C11	90.6 (2)
C4—C5—H5	118.4	C11^i—Ir1—N1	80.27 (16)
C7—C6—C11	121.0 (4)	C11—Ir1—N1	94.94 (15)
C7—C6—C1^i	123.7 (4)	C11^i—Ir1—N1^i	94.94 (15)
C11—C6—C1^i	115.3 (3)	C11—Ir1—N1^i	80.27 (16)
C8—C7—C6	119.8 (5)	N1—Ir1—N1^i	173.25 (17)
C8—C7—H7	120.1	C11^i—Ir1—S1	170.21 (11)
C6—C7—H7	120.1	C11—Ir1—S1	99.15 (12)
C9—C8—C7	120.1 (5)	N1—Ir1—S1	97.86 (10)
C9—C8—H8	120.0	N1^i—Ir1—S1	87.65 (9)
C7—C8—H8	120.0	C11^i—Ir1—S1^i	99.15 (12)
C8—C9—C10	120.7 (5)	C11—Ir1—S1^i	170.21 (11)
C8—C9—H9	119.7	N1—Ir1—S1^i	87.65 (9)
C10—C9—H9	119.6	N1^i—Ir1—S1^i	97.86 (10)
C9—C10—C11	120.9 (5)	S1—Ir1—S1^i	71.12 (5)
C9—C10—H10	119.6	C5—N1—C1	119.0 (4)
C11—C10—H10	119.6	C5—N1—Ir1	125.4 (3)
C10—C11—C6	117.5 (4)	C1—N1—Ir1	115.6 (3)
C10—C11—Ir1	128.1 (3)	C12—N2—C13	121.9 (3)
C6—C11—Ir1	114.4 (3)	C12—N2—C13^i	121.9 (3)
N2—C12—S1^i	123.02 (17)	C13—N2—C13^i	116.2 (5)
N2—C12—S1	123.02 (17)	C12—S1—Ir1	87.46 (17)
N1—C1—C2—C3	1.2 (7)	C4—C5—N1—Ir1	179.1 (4)
C6^i—C1—C2—C3	−178.0 (4)	C2—C1—N1—C5	−0.4 (6)
C1—C2—C3—C4	−1.2 (7)	C6^i—C1—N1—C5	178.9 (4)
C2—C3—C4—C5	0.5 (8)	C2—C1—N1—Ir1	−179.9 (3)
C3—C4—C5—N1	0.3 (8)	C6^i—C1—N1—Ir1	−0.5 (4)
C11—C6—C7—C8	0.6 (7)	C11^i—Ir1—N1—C5	−177.0 (4)
C1^i—C6—C7—C8	−179.7 (5)	C11—Ir1—N1—C5	−87.2 (4)
C6—C7—C8—C9	−2.6 (9)	S1—Ir1—N1—C5	12.7 (4)
C7—C8—C9—C10	2.2 (9)	S1^i—Ir1—N1—C5	83.3 (3)
C8—C9—C10—C11	0.2 (8)	C11^i—Ir1—N1—C1	2.4 (3)
C9—C10—C11—C6	−2.1 (6)	C11—Ir1—N1—C1	92.2 (3)
C9—C10—C11—Ir1	174.7 (4)	S1—Ir1—N1—C1	−167.8 (3)
C7—C6—C11—C10	1.7 (6)	S1^i—Ir1—N1—C1	−97.3 (3)
C1^i—C6—C11—C10	−178.0 (4)	S1^i—C12—N2—C13	172.4 (3)
C7—C6—C11—Ir1	−175.5 (3)	S1—C12—N2—C13	−7.6 (3)
C1^i—C6—C11—Ir1	4.8 (5)	S1^i—C12—N2—C13^i	−7.6 (3)
C10—C11—Ir1—C11^i	84.4 (4)	S1—C12—N2—C13^i	172.4 (3)
C6—C11—Ir1—C11^i	−98.8 (3)	C14—C13—N2—C12	−98.1 (5)
C10—C11—Ir1—N1	4.1 (4)	C14—C13—N2—C13^i	81.9 (5)
C6—C11—Ir1—N1	−179.1 (3)	N2—C12—S1—Ir1	180.0
C10—C11—Ir1—N1^i	179.3 (4)	S1^i—C12—S1—Ir1	0.0
C6—C11—Ir1—N1^i	−3.9 (3)	C11—Ir1—S1—C12	−178.88 (12)
C10—C11—Ir1—S1	−94.7 (4)	N1—Ir1—S1—C12	84.78 (10)
C6—C11—Ir1—S1	82.1 (3)	N1^i—Ir1—S1—C12	−99.14 (10)
C4—C5—N1—C1	−0.3 (7)	S1^i—Ir1—S1—C12	0.0

Symmetry code: (i) −x, y, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···Cg1^ii	0.93	2.85	3.610 (6)	140
C8—H8···Cg2^iii	0.93	3.00	3.897 (7)	163

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