Crystal structure and fluorescence properties of catena-poly[[(2,2′-bi-1H-imidazole-κ²N,N′)cadmium]-di-μ-chlorido]

The title complex shows selective sensitivity to detecting nitro­benzene in DMF media due to the fluorescent quenching.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.043
• wR factor = 0.113
• Data-to-parameter ratio = 18.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full value Low .      0.965 Note
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1 Note
              C6 H6 Cd Cl2 N4
PLAT906_ALERT_3_C Large K value in the Analysis of Variance ......      2.215 Check
PLAT972_ALERT_2_C Check Calcd Residual Density  0.82A From     Cd1      -1.64 eA-3

Alert level G
PLAT004_ALERT_5_G Polymeric Structure Found with Maximum Dimension          1 Info
PLAT005_ALERT_5_G No Embedded Refinement Details found  in the CIF     Please Do !
PLAT007_ALERT_5_G Number of Unrefined Donor-H Atoms ..............          2 Report
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Cd1    --  Cl2_a   ..        5.5 s.u.
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Cd1    --  Cl1_b   ..       12.0 s.u.
PLAT899_ALERT_4_G SHELXL97   is Deprecated and Succeeded by SHELXL       2014 Note
PLAT910_ALERT_3_G Missing # of FCF Reflection(s) Below Theta(Min)           1 Note
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600         79 Note
PLAT978_ALERT_2_G Number C-C Bonds with Positive Residual Density           1 Note

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

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

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Computing details

Data collection: APEX2 (Bruker, 2012); cell refinement: SAINT (Bruker, 2012); data reduction: SAINT (Bruker, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

catena-Poly[[(2,2'-bi-1H-imidazole-κ²N,N')cadmium]-di-µ-chlorido]

Crystal data

[CdCl2(C6H6N4)]	F(000) = 608
Mr = 317.45	Dx = 2.262 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3238 reflections
a = 14.977 (5) Å	θ = 2.7–28.3°
b = 8.777 (3) Å	µ = 2.87 mm^−1
c = 7.160 (3) Å	T = 296 K
β = 97.900 (5)°	Block, colorless
V = 932.3 (6) Å^3	0.26 × 0.21 × 0.17 mm
Z = 4

Data collection

Bruker APEXII CCD area-detector diffractometer	2229 independent reflections
Radiation source: fine-focus sealed tube	1997 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.042
phi and ω scans	θmax = 28.3°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Bruker, 2012)	h = −12→19
Tmin = 0.523, Tmax = 0.641	k = −11→11
5643 measured reflections	l = −9→7

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)] = 0.043	H-atom parameters constrained
wR(F^2) = 0.113	w = 1/[σ^2(Fo^2) + (0.0676P)^2 + 0.4551P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max < 0.001
2229 reflections	Δρmax = 1.50 e Å^−3
119 parameters	Δρmin = −1.62 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: 0.044 (3)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
Cd1	0.23613 (2)	−0.15121 (3)	0.09150 (4)	0.02900 (17)
Cl1	0.13506 (7)	−0.32441 (12)	−0.12634 (15)	0.0334 (2)
Cl2	0.33418 (8)	−0.35735 (11)	0.28324 (18)	0.0385 (3)
N1	0.3334 (2)	0.0418 (4)	0.2122 (5)	0.0313 (7)
N2	0.3617 (3)	0.2854 (4)	0.2529 (6)	0.0381 (8)
H7	0.3545	0.3826	0.2492	0.046*
N3	0.1636 (2)	0.0810 (4)	0.0127 (5)	0.0317 (7)
N4	0.1669 (3)	0.3302 (4)	0.0271 (6)	0.0403 (9)
H8	0.1863	0.4213	0.0515	0.048*
C1	0.3014 (3)	0.1809 (4)	0.1799 (6)	0.0271 (8)
C2	0.4183 (3)	0.0601 (6)	0.3068 (7)	0.0415 (10)
H2	0.4577	−0.0189	0.3468	0.050*
C3	0.4364 (3)	0.2096 (6)	0.3338 (7)	0.0455 (11)
H3	0.4893	0.2522	0.3952	0.055*
C4	0.2120 (3)	0.2008 (5)	0.0758 (6)	0.0297 (8)
C5	0.0842 (3)	0.1383 (6)	−0.0763 (7)	0.0410 (11)
H5	0.0365	0.0801	−0.1346	0.049*
C6	0.0854 (3)	0.2916 (7)	−0.0671 (7)	0.0489 (13)
H6	0.0395	0.3577	−0.1157	0.059*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.0339 (2)	0.0185 (2)	0.0330 (2)	−0.00127 (9)	−0.00124 (13)	−0.00016 (9)
Cl1	0.0291 (5)	0.0343 (5)	0.0368 (5)	−0.0095 (4)	0.0048 (4)	−0.0071 (4)
Cl2	0.0386 (6)	0.0319 (5)	0.0468 (6)	0.0149 (4)	0.0129 (5)	0.0112 (4)
N1	0.0334 (17)	0.0234 (15)	0.0358 (18)	−0.0003 (13)	0.0009 (13)	−0.0044 (13)
N2	0.044 (2)	0.0264 (18)	0.047 (2)	−0.0092 (15)	0.0150 (16)	−0.0079 (16)
N3	0.0334 (17)	0.0297 (17)	0.0320 (17)	0.0002 (14)	0.0049 (13)	0.0043 (14)
N4	0.048 (2)	0.0257 (17)	0.052 (2)	0.0143 (15)	0.0236 (19)	0.0099 (16)
C1	0.0300 (18)	0.0227 (16)	0.031 (2)	−0.0048 (15)	0.0129 (15)	−0.0025 (15)
C2	0.031 (2)	0.047 (3)	0.044 (2)	0.0051 (19)	−0.0024 (17)	−0.008 (2)
C3	0.037 (2)	0.053 (3)	0.046 (3)	−0.015 (2)	0.0044 (18)	−0.010 (2)
C4	0.0311 (19)	0.0236 (19)	0.037 (2)	0.0067 (16)	0.0151 (15)	0.0047 (16)
C5	0.030 (2)	0.054 (3)	0.038 (2)	0.0056 (18)	0.0020 (17)	0.0118 (19)
C6	0.043 (3)	0.057 (3)	0.048 (3)	0.023 (2)	0.013 (2)	0.019 (2)

Geometric parameters (Å, º)

Cd1—N1	2.323 (3)	N3—C5	1.365 (5)
Cd1—N3	2.342 (4)	N4—C4	1.343 (5)
Cd1—Cl1	2.5271 (11)	N4—C6	1.354 (7)
Cd1—Cl2	2.6001 (12)	N4—H8	0.8600
Cd1—Cl1^i	2.6944 (13)	C1—C4	1.450 (6)
Cd1—Cl2^ii	2.8150 (14)	C2—C3	1.348 (8)
N1—C1	1.320 (5)	C2—H2	0.9300
N1—C2	1.365 (5)	C3—H3	0.9300
N2—C1	1.342 (5)	C5—C6	1.348 (7)
N2—C3	1.360 (7)	C5—H5	0.9300
N2—H7	0.8600	C6—H6	0.9300
N3—C4	1.321 (6)
N1—Cd1—N3	72.61 (11)	C4—N3—Cd1	113.3 (3)
N1—Cd1—Cl1	163.82 (9)	C5—N3—Cd1	141.1 (3)
N3—Cd1—Cl1	98.98 (9)	C4—N4—C6	107.8 (4)
N1—Cd1—Cl2	91.80 (9)	C4—N4—H8	126.1
N3—Cd1—Cl2	160.47 (9)	C6—N4—H8	126.1
Cl1—Cd1—Cl2	98.87 (5)	N1—C1—N2	110.7 (4)
N1—Cd1—Cl1^i	99.64 (9)	N1—C1—C4	119.3 (3)
N3—Cd1—Cl1^i	87.70 (8)	N2—C1—C4	130.0 (4)
Cl1—Cd1—Cl1^i	93.69 (4)	C3—C2—N1	109.9 (4)
Cl2—Cd1—Cl1^i	83.31 (4)	C3—C2—H2	125.0
N1—Cd1—Cl2^ii	84.49 (9)	N1—C2—H2	125.0
N3—Cd1—Cl2^ii	93.59 (8)	C2—C3—N2	106.1 (4)
Cl1—Cd1—Cl2^ii	82.24 (4)	C2—C3—H3	127.0
Cl2—Cd1—Cl2^ii	96.60 (4)	N2—C3—H3	127.0
Cl1^i—Cd1—Cl2^ii	175.87 (3)	N3—C4—N4	110.5 (4)
Cd1—Cl1—Cd1^ii	99.20 (4)	N3—C4—C1	120.3 (3)
Cd1—Cl2—Cd1^i	94.46 (4)	N4—C4—C1	129.1 (4)
C1—N1—C2	105.6 (4)	C6—C5—N3	109.9 (5)
C1—N1—Cd1	114.5 (3)	C6—C5—H5	125.1
C2—N1—Cd1	139.8 (3)	N3—C5—H5	125.1
C1—N2—C3	107.6 (4)	C5—C6—N4	106.2 (4)
C1—N2—H7	126.2	C5—C6—H6	126.9
C3—N2—H7	126.2	N4—C6—H6	126.9
C4—N3—C5	105.6 (4)
N1—Cd1—Cl1—Cd1^ii	41.8 (3)	Cl2—Cd1—N3—C5	−140.3 (4)
N3—Cd1—Cl1—Cd1^ii	99.06 (9)	Cl1^i—Cd1—N3—C5	−77.8 (4)
Cl2—Cd1—Cl1—Cd1^ii	−88.90 (4)	Cl2^ii—Cd1—N3—C5	98.2 (4)
Cl1^i—Cd1—Cl1—Cd1^ii	−172.70 (4)	C2—N1—C1—N2	−1.1 (5)
Cl2^ii—Cd1—Cl1—Cd1^ii	6.62 (3)	Cd1—N1—C1—N2	−179.6 (2)
N1—Cd1—Cl2—Cd1^i	93.14 (9)	C2—N1—C1—C4	178.4 (4)
N3—Cd1—Cl2—Cd1^i	56.8 (3)	Cd1—N1—C1—C4	−0.2 (4)
Cl1—Cd1—Cl2—Cd1^i	−99.06 (4)	C3—N2—C1—N1	0.8 (5)
Cl1^i—Cd1—Cl2—Cd1^i	−6.35 (3)	C3—N2—C1—C4	−178.6 (4)
Cl2^ii—Cd1—Cl2—Cd1^i	177.80 (3)	C1—N1—C2—C3	1.0 (5)
N3—Cd1—N1—C1	0.5 (3)	Cd1—N1—C2—C3	178.9 (3)
Cl1—Cd1—N1—C1	61.0 (5)	N1—C2—C3—N2	−0.5 (5)
Cl2—Cd1—N1—C1	−167.6 (3)	C1—N2—C3—C2	−0.1 (5)
Cl1^i—Cd1—N1—C1	−84.0 (3)	C5—N3—C4—N4	−1.1 (4)
Cl2^ii—Cd1—N1—C1	96.0 (3)	Cd1—N3—C4—N4	−179.7 (3)
N3—Cd1—N1—C2	−177.4 (5)	C5—N3—C4—C1	179.6 (4)
Cl1—Cd1—N1—C2	−116.8 (4)	Cd1—N3—C4—C1	0.9 (4)
Cl2—Cd1—N1—C2	14.6 (4)	C6—N4—C4—N3	1.5 (5)
Cl1^i—Cd1—N1—C2	98.1 (4)	C6—N4—C4—C1	−179.2 (4)
Cl2^ii—Cd1—N1—C2	−81.9 (4)	N1—C1—C4—N3	−0.5 (6)
N1—Cd1—N3—C4	−0.7 (2)	N2—C1—C4—N3	178.8 (4)
Cl1—Cd1—N3—C4	−166.5 (2)	N1—C1—C4—N4	−179.8 (4)
Cl2—Cd1—N3—C4	37.6 (4)	N2—C1—C4—N4	−0.5 (7)
Cl1^i—Cd1—N3—C4	100.1 (3)	C4—N3—C5—C6	0.3 (5)
Cl2^ii—Cd1—N3—C4	−83.8 (3)	Cd1—N3—C5—C6	178.3 (3)
N1—Cd1—N3—C5	−178.7 (5)	N3—C5—C6—N4	0.6 (6)
Cl1—Cd1—N3—C5	15.5 (5)	C4—N4—C6—C5	−1.2 (5)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H7···Cl2^iii	0.86	2.32	3.174 (4)	172
N4—H8···Cl1^iii	0.86	2.63	3.237 (4)	129

Symmetry code: (iii) x, y+1, z.