catena-Poly[[diiodidocadmium]-μ-[4,4′-(2,3,5,6-tetra­methyl-1,4-phenyl­ene)bis­(methyl­ene)]bis­(3,5-dimethyl-1H-pyrazole)-κ²N²:N^2′]

The heterocylic ligand of the polymeric title compound, [CdI₂(C₂₂H₃₀N₄)], links two adjacent CdI₂ units, forming a chain running parallel to [01]. The Cd^II atom is located on a twofold rotation axis and shows a distorted tetra­hedral CdI₂N₂ coordination. The mid-point of the benzene ring of the ligand lies on a center of inversion. There are no classical hydrogen-bonding inter­actions present.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.008 Å
• R factor = 0.054
• wR factor = 0.134
• Data-to-parameter ratio = 21.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for         C6
PLAT420_ALERT_2_C D-H Without Acceptor       N2     -   H2     ...          ?
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1

Alert level G
PLAT004_ALERT_5_G Info: Polymeric Structure Found with Dimension .          1
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT083_ALERT_2_G SHELXL Second Parameter in WGHT Unusually Large.       7.42
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K
PLAT764_ALERT_4_G Overcomplete CIF Bond List Detected (Rep/Expd) .       1.12 Ratio
PLAT961_ALERT_5_G Dataset Contains no Negative Intensities .......          !

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   3 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   7 ALERT level G = General information/check it is not something unexpected

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

---

S1. Comment

The heterocyclic ligand is a new member of the class of geminal bis-(1-pyrazol-1-yl)alkanes developed fourty years ago by Trofimenko, who also investigated its coordination abilities (Trofimenko, 1970). However, no crystal structures of adducts of the parent 4,4'-(1,4-phenylene)bis(methylene)bis(3,5-dimethyl-1H-pyrazole) ligand have been reported to date.

The heterocylic ligand of the polymeric title compound CdI₂(C₂₂H₃₀N₄) (Fig. 1) links two adjacent CdI₂ units to form a chain running parallel to [101]. The Cd^II atom shows a distorted tetrahedral CdI₂N₂ coordination. The 1H-pyrazole H atom is not involved in hydrogen bonding interactions, presumably due to the presence of the bulky methyl group and the CdI₂ unit in its vicinity.

Related literature

For the synthesis of the ligand, see: Trofimenko (1970).

S2. Experimental

A solution of cadmium diiodide (7.3 mg, 0.02 mmol) in methanol (2 ml) was added to a solution of 4,4'-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene)bis(3,5-dimethyl-1H-pyrazole) (3.5 mg, 0.01 mmol) in ethanol (2 ml). The solution was allowed to evaporate for several days to afford colorless crystals in 80% yield. Calc. for C₂₂H₃₀N₄CdI₂: C 36.87, H 4.22, N 7.82%. Found: C 36.71, H 4.25, N 7.69%.

S3. Refinement

H atoms were placed in calculated positions [C—H 0.93–0.98 Å, N–H 0.88 Å; U(H) = 1.2–1.5U_eq(C,N)]. The highest peak in the final difference Fourier map is in the vicinity (1.35 Å) of H10B.

Computing details

Data collection: CrystalClear (Rigaku, 2006); cell refinement: CrystalClear (Rigaku, 2006); data reduction: CrystalClear (Rigaku, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

Fig. 1. Figure 1. Thermal ellipsoid plot of a portion of the polymeric chain structure of CdI2(C22H30N4). Ellipsoids are drawn at the 50% probability level. [Symmetry code: i) -x+1/2, -y+5/2, -z.]

catena-Poly[[diiodidocadmium]-µ-[4,4'-(2,3,5,6-tetramethyl- 1,4-phenylene)bis(methylene)]bis(3,5-dimethyl-1H-pyrazole)- κ²N²:N^2']

Crystal data

[CdI2(C22H30N4)]	F(000) = 1376
Mr = 716.70	Dx = 1.848 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 3092 reflections
a = 22.118 (8) Å	θ = 2.1–30.6°
b = 6.840 (2) Å	µ = 3.26 mm^−1
c = 17.057 (6) Å	T = 293 K
β = 93.407 (5)°	Cuboid, colorless
V = 2575.8 (16) Å^3	0.20 × 0.20 × 0.20 mm
Z = 4

Data collection

Rigaku Saturn 724 CCD diffractometer	2951 independent reflections
Radiation source: fine-focus sealed tube	2589 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.041
ϕ and ω scans	θmax = 27.5°, θmin = 2.4°
Absorption correction: multi-scan (CrystalClear; Rigaku, 2006)	h = −28→28
Tmin = 0.763, Tmax = 1.000	k = −8→8
14901 measured reflections	l = −22→21

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)] = 0.054	H-atom parameters constrained
wR(F^2) = 0.134	w = 1/[σ^2(Fo^2) + (0.0555P)^2 + 7.4182P] where P = (Fo^2 + 2Fc^2)/3
S = 1.18	(Δ/σ)max = 0.001
2951 reflections	Δρmax = 1.12 e Å^−3
137 parameters	Δρmin = −0.74 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.00092 (15)

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
I1	0.53637 (2)	0.41499 (7)	0.12116 (3)	0.0692 (2)
Cd1	0.5000	0.60117 (8)	0.2500	0.0424 (2)
N1	0.43399 (19)	0.8146 (7)	0.1908 (2)	0.0438 (10)
N2	0.44190 (19)	0.8589 (6)	0.1144 (2)	0.0421 (10)
H2	0.4695	0.8045	0.0863	0.051*
C1	0.3667 (4)	0.9231 (11)	0.2924 (4)	0.071 (2)
H1A	0.3239	0.8970	0.2889	0.106*
H1B	0.3741	1.0464	0.3181	0.106*
H1C	0.3873	0.8213	0.3220	0.106*
C2	0.3894 (2)	0.9304 (8)	0.2115 (3)	0.0433 (12)
C3	0.3678 (2)	1.0496 (8)	0.1477 (3)	0.0409 (11)
C4	0.4023 (2)	0.9968 (8)	0.0868 (3)	0.0421 (11)
C5	0.4040 (3)	1.0599 (9)	0.0030 (3)	0.0554 (15)
H5A	0.3636	1.0599	−0.0210	0.083*
H5B	0.4287	0.9710	−0.0246	0.083*
H5C	0.4206	1.1892	0.0009	0.083*
C6	0.3180 (3)	1.1960 (10)	0.1503 (3)	0.0590 (16)
H6A	0.3353	1.3203	0.1674	0.071*
H6B	0.2905	1.1547	0.1893	0.071*
C7	0.2817 (2)	1.2271 (8)	0.0728 (3)	0.0438 (12)
C8	0.2379 (2)	1.0890 (7)	0.0473 (4)	0.0469 (13)
C9	0.2061 (2)	1.1132 (8)	−0.0256 (3)	0.0460 (12)
C10	0.1571 (3)	0.9684 (10)	−0.0503 (5)	0.0701 (19)
H10A	0.1639	0.9195	−0.1018	0.105*
H10B	0.1183	1.0318	−0.0512	0.105*
H10C	0.1578	0.8617	−0.0137	0.105*
C11	0.2249 (3)	0.9125 (9)	0.0990 (5)	0.0687 (19)
H11A	0.2565	0.8998	0.1397	0.103*
H11B	0.2232	0.7962	0.0675	0.103*
H11C	0.1868	0.9310	0.1223	0.103*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1	0.0695 (3)	0.0714 (4)	0.0668 (3)	0.0130 (2)	0.0040 (2)	−0.0205 (2)
Cd1	0.0394 (3)	0.0439 (3)	0.0428 (3)	0.000	−0.0077 (2)	0.000
N1	0.039 (2)	0.053 (3)	0.038 (2)	0.007 (2)	−0.0068 (18)	−0.001 (2)
N2	0.037 (2)	0.048 (2)	0.041 (2)	0.0054 (19)	−0.0001 (18)	−0.0006 (19)
C1	0.084 (5)	0.087 (5)	0.040 (3)	0.029 (4)	0.004 (3)	−0.001 (3)
C2	0.043 (3)	0.048 (3)	0.037 (3)	0.003 (2)	−0.010 (2)	−0.005 (2)
C3	0.037 (3)	0.046 (3)	0.038 (2)	0.007 (2)	−0.008 (2)	−0.005 (2)
C4	0.044 (3)	0.039 (3)	0.042 (3)	0.003 (2)	−0.006 (2)	−0.001 (2)
C5	0.067 (4)	0.058 (3)	0.042 (3)	0.018 (3)	0.010 (3)	0.001 (3)
C6	0.060 (4)	0.072 (4)	0.043 (3)	0.025 (3)	−0.008 (3)	−0.011 (3)
C7	0.039 (3)	0.045 (3)	0.047 (3)	0.017 (2)	−0.007 (2)	−0.005 (2)
C8	0.040 (3)	0.039 (3)	0.062 (3)	0.007 (2)	−0.001 (2)	0.006 (2)
C9	0.036 (3)	0.042 (3)	0.060 (3)	0.006 (2)	−0.004 (2)	−0.009 (2)
C10	0.052 (4)	0.055 (4)	0.101 (5)	−0.002 (3)	−0.011 (4)	−0.016 (4)
C11	0.050 (4)	0.063 (4)	0.093 (5)	0.004 (3)	0.009 (3)	0.024 (4)

Geometric parameters (Å, º)

I1—Cd1	2.7034 (8)	C5—H5B	0.9600
Cd1—N1^i	2.260 (4)	C5—H5C	0.9600
Cd1—N1	2.260 (4)	C6—C7	1.520 (7)
Cd1—I1^i	2.7034 (8)	C6—H6A	0.9700
N1—C2	1.329 (7)	C6—H6B	0.9700
N1—N2	1.358 (6)	C7—C9^ii	1.392 (8)
N2—C4	1.353 (6)	C7—C8	1.403 (8)
N2—H2	0.8800	C8—C9	1.403 (8)
C1—C2	1.497 (8)	C8—C11	1.532 (8)
C1—H1A	0.9600	C9—C7^ii	1.392 (8)
C1—H1B	0.9600	C9—C10	1.509 (8)
C1—H1C	0.9600	C10—H10A	0.9600
C2—C3	1.420 (7)	C10—H10B	0.9600
C3—C4	1.375 (7)	C10—H10C	0.9600
C3—C6	1.491 (7)	C11—H11A	0.9600
C4—C5	1.494 (7)	C11—H11B	0.9600
C5—H5A	0.9600	C11—H11C	0.9600
N1^i—Cd1—N1	99.6 (2)	C4—C5—H5C	109.5
N1^i—Cd1—I1	116.88 (12)	H5A—C5—H5C	109.5
N1—Cd1—I1	98.99 (11)	H5B—C5—H5C	109.5
N1^i—Cd1—I1^i	98.99 (11)	C3—C6—C7	114.9 (4)
N1—Cd1—I1^i	116.88 (12)	C3—C6—H6A	108.5
I1—Cd1—I1^i	123.80 (4)	C7—C6—H6A	108.5
C2—N1—N2	105.2 (4)	C3—C6—H6B	108.5
C2—N1—Cd1	137.3 (4)	C7—C6—H6B	108.5
N2—N1—Cd1	117.2 (3)	H6A—C6—H6B	107.5
C4—N2—N1	111.9 (4)	C9^ii—C7—C8	120.3 (5)
C4—N2—H2	124.1	C9^ii—C7—C6	120.1 (5)
N1—N2—H2	124.1	C8—C7—C6	119.6 (5)
C2—C1—H1A	109.5	C7—C8—C9	119.7 (5)
C2—C1—H1B	109.5	C7—C8—C11	120.2 (5)
H1A—C1—H1B	109.5	C9—C8—C11	120.1 (5)
C2—C1—H1C	109.5	C7^ii—C9—C8	120.0 (5)
H1A—C1—H1C	109.5	C7^ii—C9—C10	121.0 (5)
H1B—C1—H1C	109.5	C8—C9—C10	119.0 (5)
N1—C2—C3	111.1 (5)	C9—C10—H10A	109.5
N1—C2—C1	121.4 (5)	C9—C10—H10B	109.5
C3—C2—C1	127.5 (5)	H10A—C10—H10B	109.5
C4—C3—C2	104.6 (4)	C9—C10—H10C	109.5
C4—C3—C6	130.0 (5)	H10A—C10—H10C	109.5
C2—C3—C6	125.4 (5)	H10B—C10—H10C	109.5
N2—C4—C3	107.2 (4)	C8—C11—H11A	109.5
N2—C4—C5	118.8 (5)	C8—C11—H11B	109.5
C3—C4—C5	133.9 (5)	H11A—C11—H11B	109.5
C4—C5—H5A	109.5	C8—C11—H11C	109.5
C4—C5—H5B	109.5	H11A—C11—H11C	109.5
H5A—C5—H5B	109.5	H11B—C11—H11C	109.5
N1^i—Cd1—N1—C2	−76.4 (5)	N1—N2—C4—C5	−178.8 (5)
I1—Cd1—N1—C2	164.2 (5)	C2—C3—C4—N2	−1.1 (6)
I1^i—Cd1—N1—C2	28.8 (6)	C6—C3—C4—N2	179.4 (6)
N1^i—Cd1—N1—N2	96.0 (4)	C2—C3—C4—C5	179.3 (6)
I1—Cd1—N1—N2	−23.4 (4)	C6—C3—C4—C5	−0.2 (11)
I1^i—Cd1—N1—N2	−158.7 (3)	C4—C3—C6—C7	29.6 (9)
C2—N1—N2—C4	−1.4 (6)	C2—C3—C6—C7	−149.9 (5)
Cd1—N1—N2—C4	−176.1 (3)	C3—C6—C7—C9^ii	−99.5 (7)
N2—N1—C2—C3	0.7 (6)	C3—C6—C7—C8	77.4 (7)
Cd1—N1—C2—C3	173.7 (4)	C9^ii—C7—C8—C9	−0.5 (9)
N2—N1—C2—C1	179.2 (5)	C6—C7—C8—C9	−177.5 (5)
Cd1—N1—C2—C1	−7.7 (9)	C9^ii—C7—C8—C11	179.5 (5)
N1—C2—C3—C4	0.3 (6)	C6—C7—C8—C11	2.6 (8)
C1—C2—C3—C4	−178.2 (6)	C7—C8—C9—C7^ii	0.5 (9)
N1—C2—C3—C6	179.9 (5)	C11—C8—C9—C7^ii	−179.5 (5)
C1—C2—C3—C6	1.4 (9)	C7—C8—C9—C10	−177.1 (5)
N1—N2—C4—C3	1.6 (6)	C11—C8—C9—C10	2.9 (8)

Symmetry codes: (i) −x+1, y, −z+1/2; (ii) −x+1/2, −y+5/2, −z.