Diaqua­dichloridobis[quinazolin-4(1H)-one-κN³]copper(II)

In the title complex, [CuCl₂(C₈H₆N₂O)₂(H₂O)₂], the Cu^II ion is located on an inversion center and is octahedrally coordinated by two N atoms of the 1H-quinazolin-4-one ligand, two chloride ligands and two aqua ligands. The axial Cu—O distances are significantly longer [2.512 (2) Å], than the Cu—N [2.022 (2) Å] and Cu—Cl [2.3232 (4) Å] distances as a result of Jahn–Teller distortion. Aqua ligands are involved in intra- and inter­molecular hydrogen bonding, and N—H...O inter­molecular hydrogen bonds are formed between the organic ligands. In addition, weak π–π inter­actions are observed between the benzene rings of the ligand [centroid–centroid distance = 3.678 (1) Å].

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.032
• wR factor = 0.089
• Data-to-parameter ratio = 12.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.96
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Cu1    --  O1W     ..       7.36 su
PLAT314_ALERT_2_C Check Small Angle for H2O: Metal-O1W    -H1W          88.83 Deg.
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600         72

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          3
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K
PLAT794_ALERT_5_G Note: Tentative Bond Valency for Cu1     .......       2.01

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

   2 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
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

In solutions, 4-quinazolinone could have in principle three isomers—1H, 3H, and 4-OH, as shown in Figure 1, with preference of 3H-tautomer. Recently, the crystal structure of a Cd^II coordination complex has been reported, in which 3H-quinazolin-4-one (3H-tautomer) acted as a ligand (Turgunov & Englert, 2010). We now report the structure of a Cu^II complex in which 1H-quinazolin-4-one (1H-tautomer) acts as a ligand.

In the title compound, Cu^II ion is located on the inversion center and has an octahedral coordination environment: two ligands coordinated via N atoms in position 3, two chloride ligands and two aqua ligands (Figure 2). The distances between Cu and coordination atoms are the following: d(Cu—N3) = 2.022 (2) Å, d(Cu—Cl) = 2.3232 (4) Å and d(Cu—Ow) = 2.512 (2) Å. Long distances of metal-aqua bonds than other four coordination bonds indicate existence of the Jahn-Teller elongation effect.

Aqua ligands are involved in intramolecular and intermolecular hydrogen bonding. Intramoleculer H-bonding is occurring with carbonyl group of the ligand. An intermolecular H-bonding of aqua and chloride ligands gives raise to chains along [001] (Figure 3). In addition, between ligand and water molecules are formed weak C–H···O hydrogen bonds. Intermolecular N—H···O and N—H···Cl hydrogen bonds formed between the organic and chloride ligands link molecular complexes into hydrogen-bonded chains along [100] (Figure 4; Table 1). Weak π···π ring interactions connect the molecular complexes along [010] and [001] directions. [Cg1···Cg1^vi=3.678 (1) Å, where Cg1=C4A–C5–C6–C7–C8–C8A; ^vi = x, 3/2 - y, 1/2 + z].

Related literature

The crystal structure of pyrimidin-4(3H)-one was reported by Vaillancourt et al. (1998). For a Cd(II) coordination polymer with quinazolin-4(3H)-one, see: Turgunov & Englert (2010). For computational studies of quinazolin-4-one derivatives, see: Bakalova et al. (2004).

S2. Experimental

A solution of 17.05 mg (0.1 mmol) of copper(II) chloride dihydrate in 2 ml of water was added to a solution of 29.23 mg (0.2 mmol) of 3H-quinazolin-4-one in 5 ml of ethanol. The solution allowed to stand at room temperature for one week, after which light-blue crystals were obtained.

S3. Refinement

C-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). N-bound H atoms and water H atoms involved in the intermolecular hydrogen bonding were found by difference Fourier synthesis and refined isotropically with a distance restrains of 0.87 (2) and 0.85 (2) Å, respectively [N—H =0.84 (2) Å, O1w—H1w=0.84 (2) Å, O1w—H2w=0.85 (2) Å].

Computing details

Data collection: CrysAlis PRO (Oxford Diffraction, 2007); cell refinement: CrysAlis PRO (Oxford Diffraction, 2007); data reduction: CrysAlis PRO (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Bruker, 1998); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

	Fig. 1. The 3H, 1H and 4-OH tautomers of 4-quinazolinone.
	Fig. 2. The molecular structure of the title complex with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 3. Crystal packing of the title compound viewed along the a axis, showing the formation of a hydrogen-bonded chain along [001]. Molecular complexes are furhter linked by π–π stacking interactions, formed between ligands, along [010] and [001] directions [Cg1···Cg1^vi=3.678 (1) Å].
	Fig. 4. Part of the crystal structure of the title compound showing the formation of a hydrogen-bonded chain along [100].

Diaquadichloridobis[quinazolin-4(1H)-one-κN³]copper(II)

Crystal data

[CuCl2(C8H6N2O)2(H2O)2]	F(000) = 470
Mr = 462.77	Dx = 1.813 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54180 Å
Hall symbol: -P 2ybc	Cell parameters from 4533 reflections
a = 6.7438 (3) Å	θ = 4.8–75.3°
b = 18.5328 (8) Å	µ = 5.03 mm^−1
c = 6.7831 (3) Å	T = 293 K
β = 90.735 (3)°	Prism, light-blue
V = 847.69 (6) Å^3	0.55 × 0.35 × 0.20 mm
Z = 2

Data collection

Oxford Diffraction Xcalibur Ruby diffractometer	1725 independent reflections
Radiation source: Enhance (Cu) X-ray Source	1639 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.040
Detector resolution: 10.2576 pixels mm^-1	θmax = 77.1°, θmin = 4.8°
ω scans	h = −5→8
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2007)	k = −23→22
Tmin = 0.366, Tmax = 1.000	l = −8→8
5548 measured reflections

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)] = 0.032	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.089	w = 1/[σ^2(Fo^2) + (0.0535P)^2 + 0.3464P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max < 0.001
1725 reflections	Δρmax = 0.37 e Å^−3
137 parameters	Δρmin = −0.46 e Å^−3
3 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: 0.0067 (7)

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
Cu1	0.0000	0.5000	0.5000	0.02135 (17)
Cl1	0.20934 (7)	0.45671 (2)	0.74764 (6)	0.02750 (17)
O1	−0.12427 (19)	0.66628 (7)	0.5870 (2)	0.0280 (3)
N1	0.4508 (2)	0.65113 (9)	0.4461 (2)	0.0227 (3)
C2	0.3358 (3)	0.59405 (10)	0.4636 (3)	0.0229 (4)
H2A	0.3936	0.5490	0.4458	0.028*
N3	0.1427 (2)	0.59595 (8)	0.5049 (2)	0.0209 (3)
C4	0.0522 (3)	0.66252 (9)	0.5382 (3)	0.0198 (4)
C4A	0.1738 (3)	0.72721 (10)	0.5123 (2)	0.0196 (4)
C5	0.0922 (3)	0.79617 (10)	0.5345 (3)	0.0239 (4)
H5A	−0.0399	0.8014	0.5693	0.029*
C6	0.2088 (3)	0.85635 (11)	0.5046 (3)	0.0288 (4)
H6A	0.1540	0.9022	0.5167	0.035*
C7	0.4101 (3)	0.84875 (11)	0.4560 (3)	0.0311 (4)
H7A	0.4871	0.8897	0.4363	0.037*
C8	0.4945 (3)	0.78128 (11)	0.4373 (3)	0.0276 (4)
H8A	0.6278	0.7764	0.4064	0.033*
C8A	0.3762 (3)	0.72057 (10)	0.4656 (2)	0.0205 (4)
O1W	0.2398 (3)	0.46004 (9)	0.2416 (2)	0.0356 (4)
H1W	0.218 (5)	0.4172 (11)	0.274 (5)	0.057 (10)*
H1	0.570 (3)	0.6432 (17)	0.417 (5)	0.054 (9)*
H2W	0.219 (6)	0.462 (2)	0.118 (3)	0.065 (10)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0191 (2)	0.0140 (2)	0.0308 (3)	−0.00062 (12)	−0.00334 (16)	0.00158 (13)
Cl1	0.0262 (3)	0.0276 (3)	0.0286 (3)	0.00254 (16)	−0.00262 (18)	0.00244 (16)
O1	0.0175 (6)	0.0225 (7)	0.0441 (8)	0.0005 (5)	0.0050 (5)	−0.0008 (6)
N1	0.0149 (7)	0.0243 (8)	0.0290 (8)	0.0010 (6)	0.0006 (6)	0.0016 (6)
C2	0.0209 (8)	0.0190 (8)	0.0289 (9)	0.0025 (7)	−0.0013 (7)	0.0001 (7)
N3	0.0189 (7)	0.0161 (7)	0.0278 (7)	0.0015 (5)	−0.0009 (6)	0.0013 (6)
C4	0.0198 (8)	0.0170 (8)	0.0224 (8)	−0.0001 (6)	−0.0017 (6)	−0.0003 (6)
C4A	0.0196 (8)	0.0200 (8)	0.0191 (7)	−0.0005 (6)	−0.0020 (6)	−0.0002 (6)
C5	0.0256 (9)	0.0208 (9)	0.0253 (9)	0.0006 (7)	−0.0017 (7)	−0.0013 (7)
C6	0.0395 (11)	0.0180 (9)	0.0287 (9)	−0.0010 (8)	−0.0041 (8)	−0.0005 (7)
C7	0.0387 (11)	0.0230 (10)	0.0315 (10)	−0.0141 (8)	−0.0021 (8)	0.0013 (7)
C8	0.0242 (9)	0.0306 (10)	0.0280 (9)	−0.0088 (8)	−0.0003 (7)	0.0016 (8)
C8A	0.0205 (8)	0.0218 (9)	0.0192 (7)	−0.0024 (7)	−0.0027 (6)	0.0006 (6)
O1W	0.0416 (9)	0.0273 (8)	0.0380 (9)	0.0003 (6)	0.0032 (7)	−0.0016 (6)

Geometric parameters (Å, º)

Cu1—N3	2.0221 (15)	C4A—C5	1.400 (3)
Cu1—N3^i	2.0221 (15)	C4A—C8A	1.410 (3)
Cu1—Cl1	2.3232 (4)	C5—C6	1.381 (3)
Cu1—Cl1^i	2.3232 (4)	C5—H5A	0.9300
O1—C4	1.241 (2)	C6—C7	1.409 (3)
N1—C2	1.318 (2)	C6—H6A	0.9300
N1—C8A	1.389 (2)	C7—C8	1.380 (3)
N1—H1	0.841 (18)	C7—H7A	0.9300
C2—N3	1.336 (2)	C8—C8A	1.394 (3)
C2—H2A	0.9300	C8—H8A	0.9300
N3—C4	1.396 (2)	O1W—H1W	0.837 (18)
C4—C4A	1.464 (2)	O1W—H2W	0.848 (19)
N3—Cu1—N3^i	180.0	C5—C4A—C4	120.84 (16)
N3—Cu1—Cl1	90.40 (4)	C8A—C4A—C4	120.04 (16)
N3^i—Cu1—Cl1	89.60 (4)	C6—C5—C4A	119.75 (18)
N3—Cu1—Cl1^i	89.60 (4)	C6—C5—H5A	120.1
N3^i—Cu1—Cl1^i	90.40 (4)	C4A—C5—H5A	120.1
Cl1—Cu1—Cl1^i	180.0	C5—C6—C7	120.38 (19)
C2—N1—C8A	121.43 (15)	C5—C6—H6A	119.8
C2—N1—H1	116 (2)	C7—C6—H6A	119.8
C8A—N1—H1	122 (2)	C8—C7—C6	120.79 (17)
N1—C2—N3	125.02 (16)	C8—C7—H7A	119.6
N1—C2—H2A	117.5	C6—C7—H7A	119.6
N3—C2—H2A	117.5	C7—C8—C8A	118.77 (18)
C2—N3—C4	119.11 (15)	C7—C8—H8A	120.6
C2—N3—Cu1	116.00 (12)	C8A—C8—H8A	120.6
C4—N3—Cu1	124.80 (12)	N1—C8A—C8	121.77 (17)
O1—C4—N3	121.02 (16)	N1—C8A—C4A	117.05 (15)
O1—C4—C4A	121.77 (16)	C8—C8A—C4A	121.17 (17)
N3—C4—C4A	117.21 (15)	H1W—O1W—H2W	106 (3)
C5—C4A—C8A	119.11 (16)

Symmetry code: (i) −x, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1W···O1^i	0.84 (2)	1.92 (3)	2.732 (2)	162 (3)
O1W—H2W···Cl1^ii	0.85 (2)	2.51 (2)	3.355 (2)	171 (4)
N1—H1···O1^iii	0.84 (2)	2.39 (3)	3.022 (2)	133 (3)
N1—H1···Cl1^iv	0.84 (2)	2.63 (3)	3.324 (2)	140 (3)
C2—H2A···O1W	0.93	2.38	2.972 (3)	121
C7—H7A···O1W^v	0.93	2.57	3.421 (3)	152

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