A new silver–silver-bonded dimer complex: solid-state structure of bis­[μ-2H-1,3-benzoxazine-2,4(3H)-dionato]disilver(I)

The first structure of a silver complex of an aromatic cyclic amide has been determined. The complex is a centrosymmetric dimer, [Ag(C₈H₄NO₃)₂], with the same eight-membered ring construction as silver carboxyl­ates, including a significantly short Ag—Ag bond [2.8042 (12) Å].

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.010 Å
• R factor = 0.039
• wR factor = 0.102
• Data-to-parameter ratio = 8.7

checkCIF/PLATON results

No syntax errors found





Alert level A
PLAT027_ALERT_3_A _diffrn_reflns_theta_full (too) Low ............      23.28 Deg.

Alert level B
THETM01_ALERT_3_B  The value of sine(theta_max)/wavelength is less than 0.575
            Calculated sin(theta_max)/wavelength =    0.5561
PLAT023_ALERT_3_B Resolution (too) Low [sin(th)/Lambda < 0.6].....      23.28 Deg.

Alert level C
REFNR01_ALERT_3_C  Ratio of reflections to parameters is < 10 for a
            centrosymmetric structure
            sine(theta)/lambda                0.5561
            Proportion of unique data used    1.0000
            Ratio reflections to parameters   8.6610
PLAT088_ALERT_3_C Poor Data / Parameter Ratio ....................       8.66
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K
PLAT342_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...         10
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.12 Ratio

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

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

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Computing details

Data collection: COLLECT (Nonius, 2000); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO (Otwinowski & Minor, 1997) and SCALEPACK; program(s) used to solve structure: SHELXTL (Bruker, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL and Materials Studio (Accelrys, 2002); software used to prepare material for publication: SHELXTL.

bis[µ-2H-1,3-benzoxazine-2,4(3H)-dionato]disilver(I)

Crystal data

[Ag(C8H4NO3)2]	F(000) = 520
Mr = 539.98	Dx = 2.494 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 4643 reflections
a = 7.3677 (9) Å	θ = 1.0–23.3°
b = 13.0995 (19) Å	µ = 2.77 mm^−1
c = 7.4839 (10) Å	T = 293 K
β = 95.430 (7)°	Cube, colorless
V = 719.05 (17) Å^3	0.07 × 0.07 × 0.05 mm
Z = 2

Data collection

Nonius KappaCCD area-detector diffractometer	1022 independent reflections
Radiation source: fine-focus sealed tube	749 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.080
Detector resolution: 9 pixels mm^-1	θmax = 23.3°, θmin = 4.0°
ω scans	h = −7→8
Absorption correction: integration (Coppens, 1970)	k = −14→14
Tmin = 0.068, Tmax = 0.200	l = −8→8
4643 measured reflections

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.102	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0461P)^2 + 0.288P] where P = (Fo^2 + 2Fc^2)/3
1022 reflections	(Δ/σ)max = 0.001
118 parameters	Δρmax = 0.62 e Å^−3
0 restraints	Δρmin = −0.63 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
Ag1	1.03764 (8)	0.89574 (4)	−0.01729 (9)	0.0629 (3)
O1	0.7220 (6)	1.0475 (4)	0.1317 (6)	0.0497 (12)
O2	0.9063 (7)	0.7179 (4)	0.1963 (7)	0.0593 (14)
O3	0.6491 (6)	0.7608 (3)	0.3016 (7)	0.0521 (13)
N1	0.8174 (8)	0.8829 (4)	0.1499 (8)	0.0439 (14)
C1	0.6933 (10)	0.9575 (5)	0.1779 (9)	0.0436 (16)
C2	0.5317 (9)	0.9310 (5)	0.2626 (9)	0.0386 (16)
C3	0.3921 (10)	0.9997 (5)	0.2874 (9)	0.0455 (18)
H3	0.4002	1.0665	0.2468	0.055*
C4	0.2428 (10)	0.9701 (6)	0.3711 (10)	0.0518 (19)
H4	0.1504	1.0166	0.3873	0.062*
C5	0.2305 (10)	0.8698 (6)	0.4317 (10)	0.055 (2)
H5	0.1302	0.8498	0.4897	0.066*
C6	0.3663 (10)	0.8000 (6)	0.4062 (10)	0.0538 (19)
H6	0.3575	0.7330	0.4453	0.065*
C7	0.5131 (9)	0.8311 (5)	0.3230 (9)	0.0454 (17)
C8	0.7966 (10)	0.7856 (5)	0.2141 (10)	0.0495 (18)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ag1	0.0674 (5)	0.0401 (4)	0.0872 (5)	0.0010 (3)	0.0387 (4)	0.0067 (3)
O1	0.063 (3)	0.028 (3)	0.062 (3)	−0.004 (2)	0.021 (3)	0.003 (2)
O2	0.065 (3)	0.034 (3)	0.083 (4)	0.011 (3)	0.027 (3)	0.006 (3)
O3	0.055 (3)	0.030 (3)	0.074 (3)	−0.002 (2)	0.023 (3)	0.005 (2)
N1	0.047 (3)	0.029 (3)	0.055 (3)	0.002 (3)	0.006 (3)	0.002 (3)
C1	0.054 (4)	0.035 (4)	0.042 (4)	−0.002 (3)	0.003 (3)	−0.002 (3)
C2	0.041 (4)	0.034 (4)	0.041 (4)	−0.004 (3)	0.003 (3)	−0.001 (3)
C3	0.055 (5)	0.034 (4)	0.048 (4)	0.003 (3)	0.003 (4)	0.003 (3)
C4	0.042 (4)	0.055 (5)	0.059 (5)	0.003 (4)	0.007 (4)	−0.007 (4)
C5	0.049 (5)	0.054 (5)	0.064 (5)	−0.015 (4)	0.019 (4)	−0.004 (4)
C6	0.054 (5)	0.033 (4)	0.077 (5)	−0.011 (3)	0.018 (4)	0.000 (4)
C7	0.048 (4)	0.033 (4)	0.055 (4)	0.001 (3)	0.007 (4)	0.000 (3)
C8	0.058 (5)	0.039 (4)	0.053 (4)	−0.005 (4)	0.014 (4)	0.001 (3)

Geometric parameters (Å, º)

Ag1—N1	2.147 (6)	C1—C2	1.443 (10)
Ag1—O1^i	2.170 (5)	C2—C3	1.392 (9)
Ag1—Ag1^i	2.8042 (12)	C2—C7	1.395 (9)
Ag1—O2^ii	2.712 (5)	C3—C4	1.372 (10)
O1—C1	1.252 (8)	C3—H3	0.93
O1—Ag1^i	2.170 (5)	C4—C5	1.396 (10)
O2—C8	1.216 (8)	C4—H4	0.93
O3—C8	1.360 (9)	C5—C6	1.381 (10)
O3—C7	1.381 (8)	C5—H5	0.93
N1—C1	1.368 (9)	C6—C7	1.361 (10)
N1—C8	1.376 (8)	C6—H6	0.93
N1—Ag1—O1^i	161.17 (19)	C2—C3—H3	119.6
N1—Ag1—Ag1^i	81.68 (13)	C3—C4—C5	119.6 (7)
O1^i—Ag1—Ag1^i	83.01 (13)	C3—C4—H4	120.2
C1—O1—Ag1^i	126.7 (5)	C5—C4—H4	120.2
C8—O3—C7	121.2 (5)	C6—C5—C4	120.5 (7)
C1—N1—C8	120.6 (6)	C6—C5—H5	119.7
C1—N1—Ag1	125.9 (5)	C4—C5—H5	119.7
C8—N1—Ag1	113.0 (5)	C7—C6—C5	118.8 (7)
O1—C1—N1	119.8 (7)	C7—C6—H6	120.6
O1—C1—C2	121.1 (6)	C5—C6—H6	120.6
N1—C1—C2	119.2 (6)	C6—C7—O3	118.1 (6)
C3—C2—C7	117.8 (6)	C6—C7—C2	122.4 (6)
C3—C2—C1	123.6 (6)	O3—C7—C2	119.5 (6)
C7—C2—C1	118.6 (6)	O2—C8—O3	116.6 (6)
C4—C3—C2	120.8 (7)	O2—C8—N1	122.7 (7)
C4—C3—H3	119.6	O3—C8—N1	120.7 (6)
O1^i—Ag1—N1—C1	53.0 (9)	C3—C4—C5—C6	−0.7 (11)
Ag1^i—Ag1—N1—C1	17.1 (5)	C4—C5—C6—C7	0.8 (11)
O1^i—Ag1—N1—C8	−134.2 (6)	C5—C6—C7—O3	178.8 (6)
Ag1^i—Ag1—N1—C8	−170.2 (5)	C5—C6—C7—C2	0.1 (11)
Ag1^i—O1—C1—N1	−3.0 (8)	C8—O3—C7—C6	177.7 (6)
Ag1^i—O1—C1—C2	176.2 (4)	C8—O3—C7—C2	−3.5 (9)
C8—N1—C1—O1	174.1 (6)	C3—C2—C7—C6	−0.9 (10)
Ag1—N1—C1—O1	−13.7 (8)	C1—C2—C7—C6	179.2 (7)
C8—N1—C1—C2	−5.1 (9)	C3—C2—C7—O3	−179.7 (6)
Ag1—N1—C1—C2	167.1 (4)	C1—C2—C7—O3	0.4 (9)
O1—C1—C2—C3	4.7 (10)	C7—O3—C8—O2	−177.6 (6)
N1—C1—C2—C3	−176.0 (6)	C7—O3—C8—N1	2.3 (10)
O1—C1—C2—C7	−175.4 (6)	C1—N1—C8—O2	−178.0 (7)
N1—C1—C2—C7	3.8 (9)	Ag1—N1—C8—O2	8.8 (9)
C7—C2—C3—C4	1.0 (9)	C1—N1—C8—O3	2.2 (10)
C1—C2—C3—C4	−179.2 (6)	Ag1—N1—C8—O3	−171.0 (5)
C2—C3—C4—C5	−0.2 (10)

Symmetry codes: (i) −x+2, −y+2, −z; (ii) x, −y+3/2, z−1/2.