catena-Poly[[bis[quinazolin-4(3H)-one-κN¹]cadmium(II)]-di-μ-chlorido]

The asymmetric unit of the title compound, [CdCl₂(C₈H₆N₂O)₂]_n, consists of one mol­ecule of the 3H-quinazolin-4-one ligand, one Cd²⁺ cation, which is located on a twofold axis, and one chlorido ligand in a general position. The latter bridges metal cations, forming a one-dimensional polymer along the b axis. The Cd...Cd distance along the chain is 3.7309 (7) Å. The octa­hedral coordination around the metal is completed by two ligands in a trans axial geometry which coordinate through the N atom in 1 position. Moderately strong classical N—H...O hydrogen bonds around crystallographic inversion centers cross-link adjacent polymeric chains.

Key indicators

• Single-crystal X-ray study
• T = 130 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.043
• wR factor = 0.102
• Data-to-parameter ratio = 16.8

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT232_ALERT_2_B Hirshfeld Test Diff (M-X)  Cd1    --  Cl1     ..      10.73 su
PLAT972_ALERT_2_B Large Calcd. Non-Metal Negative Residual Density      -2.77 eA-3

Alert level C
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600          4

Alert level G
PLAT063_ALERT_4_G Crystal Size Likely too Large for Beam Size ....       0.80 mm

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

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 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
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The title compound represents the first crystal structure of a complex in which 3H-quinazolin-4-one acts as a ligand; the uncoordinated organic molecule has not been reported neither. The title compound is a chain polymer in which each Cd(II) cation is coordinated by four bridging chloro ligands in the equatorial plane and two monodentate 3H-quinazolin-4-one ligands in the axial positions of a pseudo-octahedron. The chain direction corresponds to the shortest lattice parameter; a section of the polymer is shown in Fig. 1. The metal···nitrogen vector and the metal–halide plane subtend an angle of 84.5 (1)°. The angle N—Cd—Nⁱⁱ (ii:-x, y, 1/2 - z) amounts to 175.3 (2)°, and the dihedral angle between the least squares plane through the ligand and the metal–halide plane to 67.00 (6)°. Tilting of the ligand molecules in this structure is stabilized by intermolecular N—H···O hydrogen bonds around crystallographic inversion centers (Table 1, Fig.2).

Related literature

The crystal structure of 3H-pyrimidin-4-one was reported by Vaillancourt et al. (1998). For related Cd(II) coordination polymers, see: Hu & Englert (2002); Hu et al. (2003); Englert & Schiffers (2006a,b); Cao et al. (2008). For a general review of halide-bridged chain polymers, see: Englert (2010).

S2. Experimental

A solution of 73.33 mg (0.4 mmol) of cadmium (II) chloride in 20 ml of water was added to a solution of 116.92 mg (0.8 mmol) of 3H-quinazolin-4-one in 30 ml of acetone. A precipitate formed immediately which was recovered by filtration. Single crystals suitable for the diffraction experiment were obtained by dissolving this precipitate in a 1:3 water:acetone mixture and slow evaporation at room temperature. The crystals grew as colourless needles.

S3. Refinement

Carbon-bound H atoms were positioned geometrically and treated as riding on their C atoms, with C—H distances of 0.93 Å (aromatic) and were refined with U_iso(H)=1.2Ueq(C). Nitrogen-bound H atom involved in the intermolecular hydrogen bonding was located by difference Fourier synthesis and refined freely [N—H =0.87 (5) Å].

Computing details

Data collection: SMART (Bruker,2000); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. Section of the chain polymer, viewed along the c axis.
	Fig. 2. Projection of the structure along the b direction.

catena-Poly[[bis[quinazolin-4(3H)-one-κN¹]cadmium(II)]- di-µ-chlorido]

Crystal data

[CdCl2(C8H6N2O)2]	F(000) = 936
Mr = 475.60	Dx = 1.967 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 8356 reflections
a = 28.839 (6) Å	θ = 2.3–28.4°
b = 3.7309 (7) Å	µ = 1.71 mm^−1
c = 17.846 (4) Å	T = 130 K
β = 123.26 (3)°	Needle, colourless
V = 1605.6 (8) Å^3	0.80 × 0.03 × 0.02 mm
Z = 4

Data collection

Bruker SMART APEX diffractometer	1983 independent reflections
Radiation source: fine-focus sealed tube	1831 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.081
ω scans	θmax = 28.4°, θmin = 2.3°
Absorption correction: multi-scan (MULABS; Blessing, 1995)	h = −38→38
Tmin = 0.936, Tmax = 0.958	k = −4→4
10107 measured reflections	l = −23→23

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.102	H atoms treated by a mixture of independent and constrained refinement
S = 1.16	w = 1/[σ^2(Fo^2) + (0.045P)^2] where P = (Fo^2 + 2Fc^2)/3
1983 reflections	(Δ/σ)max < 0.001
118 parameters	Δρmax = 0.91 e Å^−3
0 restraints	Δρmin = −2.47 e Å^−3

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
Cd1	0.0000	0.41717 (11)	0.2500	0.02822 (14)
Cl1	0.03110 (4)	0.9258 (3)	0.36946 (6)	0.0345 (2)
O1	0.25065 (13)	0.8403 (9)	0.4033 (2)	0.0456 (8)
N1	0.09451 (14)	0.4438 (9)	0.2882 (2)	0.0345 (7)
C2	0.12966 (17)	0.4725 (11)	0.3729 (3)	0.0348 (9)
H2	0.1180	0.4045	0.4102	0.042*
N3	0.18220 (15)	0.5931 (11)	0.4126 (3)	0.0389 (8)
C4	0.20342 (17)	0.7146 (12)	0.3647 (3)	0.0371 (9)
C4A	0.16615 (17)	0.6802 (11)	0.2686 (3)	0.0341 (9)
C5	0.18303 (17)	0.7898 (12)	0.2120 (3)	0.0373 (9)
H5	0.2179	0.8906	0.2359	0.045*
C6	0.14774 (18)	0.7473 (13)	0.1212 (3)	0.0410 (9)
H6	0.1587	0.8181	0.0831	0.049*
C7	0.09534 (19)	0.5976 (13)	0.0859 (3)	0.0406 (9)
H7	0.0718	0.5669	0.0243	0.049*
C8	0.07797 (18)	0.4957 (10)	0.1400 (3)	0.0343 (9)
H8	0.0428	0.3983	0.1151	0.041*
C8A	0.11298 (17)	0.5373 (11)	0.2328 (3)	0.0333 (8)
H3	0.206 (2)	0.609 (13)	0.470 (3)	0.040 (13)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.0258 (2)	0.0272 (2)	0.0302 (2)	0.000	0.01445 (17)	0.000
Cl1	0.0353 (5)	0.0325 (5)	0.0343 (5)	0.0002 (4)	0.0182 (4)	0.0008 (4)
O1	0.0363 (16)	0.055 (2)	0.0443 (17)	−0.0100 (14)	0.0211 (14)	−0.0023 (15)
N1	0.0304 (16)	0.0340 (18)	0.0388 (18)	−0.0007 (14)	0.0188 (15)	−0.0008 (15)
C2	0.0326 (19)	0.033 (2)	0.040 (2)	−0.0001 (16)	0.0205 (18)	0.0015 (17)
N3	0.0307 (17)	0.047 (2)	0.0354 (19)	−0.0019 (16)	0.0158 (16)	0.0004 (17)
C4	0.033 (2)	0.035 (2)	0.041 (2)	−0.0013 (17)	0.0192 (18)	−0.0019 (18)
C4A	0.0321 (19)	0.030 (2)	0.040 (2)	−0.0001 (16)	0.0194 (18)	0.0002 (16)
C5	0.033 (2)	0.033 (2)	0.049 (2)	0.0009 (17)	0.0244 (19)	0.0025 (18)
C6	0.044 (2)	0.040 (2)	0.047 (2)	0.003 (2)	0.030 (2)	0.001 (2)
C7	0.042 (2)	0.042 (2)	0.039 (2)	0.004 (2)	0.0231 (19)	−0.0009 (19)
C8	0.034 (2)	0.0256 (19)	0.042 (2)	0.0015 (15)	0.0196 (18)	−0.0011 (15)
C8A	0.0332 (19)	0.0272 (19)	0.041 (2)	0.0031 (16)	0.0217 (18)	0.0010 (16)

Geometric parameters (Å, º)

Cd1—N1	2.422 (3)	N3—H3	0.87 (5)
Cd1—N1^i	2.422 (3)	C4—C4A	1.445 (6)
Cd1—Cl1^ii	2.5714 (11)	C4A—C5	1.402 (6)
Cd1—Cl1^iii	2.5714 (11)	C4A—C8A	1.403 (6)
Cd1—Cl1	2.6180 (11)	C5—C6	1.370 (6)
Cd1—Cl1^i	2.6180 (11)	C5—H5	0.9300
Cl1—Cd1^iv	2.5714 (11)	C6—C7	1.396 (6)
O1—C4	1.233 (5)	C6—H6	0.9300
N1—C2	1.283 (6)	C7—C8	1.363 (6)
N1—C8A	1.400 (5)	C7—H7	0.9300
C2—N3	1.350 (5)	C8—C8A	1.397 (6)
C2—H2	0.9300	C8—H8	0.9300
N3—C4	1.373 (6)
N1—Cd1—N1^i	175.31 (17)	C2—N3—H3	124 (3)
N1—Cd1—Cl1^ii	95.13 (9)	C4—N3—H3	113 (3)
N1^i—Cd1—Cl1^ii	88.22 (9)	O1—C4—N3	120.7 (4)
N1—Cd1—Cl1^iii	88.22 (9)	O1—C4—C4A	124.8 (4)
N1^i—Cd1—Cl1^iii	95.13 (9)	N3—C4—C4A	114.4 (4)
Cl1^ii—Cd1—Cl1^iii	89.06 (5)	C5—C4A—C8A	120.5 (4)
N1—Cd1—Cl1	84.90 (9)	C5—C4A—C4	120.2 (4)
N1^i—Cd1—Cl1	91.69 (9)	C8A—C4A—C4	119.4 (4)
Cl1^ii—Cd1—Cl1	179.01 (3)	C6—C5—C4A	119.5 (4)
Cl1^iii—Cd1—Cl1	91.93 (4)	C6—C5—H5	120.2
N1—Cd1—Cl1^i	91.69 (9)	C4A—C5—H5	120.2
N1^i—Cd1—Cl1^i	84.90 (9)	C5—C6—C7	119.8 (4)
Cl1^ii—Cd1—Cl1^i	91.93 (4)	C5—C6—H6	120.1
Cl1^iii—Cd1—Cl1^i	179.01 (3)	C7—C6—H6	120.1
Cl1—Cd1—Cl1^i	87.08 (5)	C8—C7—C6	121.3 (4)
Cd1^iv—Cl1—Cd1	91.93 (4)	C8—C7—H7	119.3
C2—N1—C8A	116.8 (4)	C6—C7—H7	119.3
C2—N1—Cd1	112.0 (3)	C7—C8—C8A	120.1 (4)
C8A—N1—Cd1	128.1 (3)	C7—C8—H8	120.0
N1—C2—N3	125.5 (4)	C8A—C8—H8	120.0
N1—C2—H2	117.3	C8—C8A—N1	120.1 (4)
N3—C2—H2	117.3	C8—C8A—C4A	118.8 (4)
C2—N3—C4	122.6 (4)	N1—C8A—C4A	121.1 (4)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3···O1^v	0.87 (5)	1.90 (4)	2.762 (5)	172 (6)

Symmetry code: (v) −x+1/2, −y+3/2, −z+1.