Bis(cyanido-κC)(ethane-1,2-diamine-κ²N,N′)silver(II)

The title compound, [Ag(CN)₂(C₂H₈N₂)], was obtained from the reaction of ethane-1,2-diamine (en) with K[Ag(CN)₂]. The compound crystallizes as an inversion twin, the ratio of the twin components being 0.72 (4):0.28 (4). The Ag^II atom is in a slightly disorted square-planar environment. The chelate ring has an envelope conformation. The Ag^II—N(en) bond lengths are 2.071 (2) and 2.078 (2) Å. In the crystal structure, symmetry-related mol­ecules are linked by N—H...N hydrogen bonds to form a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.016
• wR factor = 0.042
• Data-to-parameter ratio = 22.8

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT115_ALERT_5_B ADDSYM Detects Noncrystallographic Inversion ...         88 PerFi

Alert level C
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Ag1    -   C3      ..       5.26 su
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          4

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           29.14
           From the CIF: _reflns_number_total               1913
           Count of symmetry unique reflns         1127
           Completeness (_total/calc)            169.74%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       786
           Fraction of Friedel pairs measured     0.697
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   1 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
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

The molecular stucture of the title compound is shown in Fig. 1. The compound crystallized in the chiral space group P2₁2₁2₁ as an inversion twin; the refined BASF value is 0.28 (4).

The Ag^II atom has an almost perfect square planar environement (Table 1). The five-membered chelate ring has an envelope conformation with atom C1 at the flap.

The Ag^II—N(en) bond distances of 2.071 (2) and 2.078 (2) Å are significantly shorter than the same distances observed in some silver(II) 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane macrocyclic complexes; 2.185 (5) to 2.195 (6) Å (Wang et al., 2002) and 2.194 (3) to 2.196 (3) Å (Po et al., 1991). In the corresponding silver(I) complex, [Ag(CN)en)], prepared solvothermally, the Ag^I—N(en) distances are 2.283 (6) and 2.355 (6) Å (Pretsch & Hartl, 2005).

In the crystal structure symmetry related molecules are linked by N—H···N(CN) hydrogen bonds to form a three-dimensional network (Fig. 2).

Related literature

For related literature, see: Pretsch & Hartl (2005); Wang et al. (2002); Po et al. (1991).

S2. Experimental

The title compound was prepared by the addition of ethane-1,2-diamine in methanol to an equimolar amount of K[Ag(CN)₂] in water. The solution was stirred for 15 min then filtered and allowed to evaporate slowly in air. Colourless crystals appeared along with some black deposits on the walls of the vessel, which suggested disproportionation of silver(I) to give silver(II) and silver(0).

S3. Refinement

The H-atoms were included in calculated positions and treated as riding atoms: N—H = 0.92 Å and C—H = 0.99 Å, with U_iso(H) = 1.2U_eq(N or C).

Computing details

Data collection: X-AREA (Stoe & Cie, 2005); cell refinement: X-AREA (Stoe & Cie, 2005); data reduction: X-RED32 (Stoe & Cie, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Figures

	Fig. 1. The molecular sturcture showing the atomic numbering scheme and displacement parameters drawn at the 50% probabilty level.
	Fig. 2. The crystal packing viewed along the c axis. Intermolecular N—H···N hydrogen bonds are shown as dotted lines.

Bis(cyanido-κC)(ethane-1,2-diamine-κ²N,N')silver(II)

Crystal data

[Ag(CN)2(C2H8N2)]	F(000) = 428
Mr = 220.01	Dx = 2.050 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 6960 reflections
a = 6.9140 (8) Å	θ = 1.8–28.7°
b = 9.3481 (11) Å	µ = 2.74 mm^−1
c = 11.0289 (11) Å	T = 173 K
V = 712.83 (14) Å^3	Needle, colourless
Z = 4	0.50 × 0.20 × 0.10 mm

Data collection

Stoe IPDS II diffractometer	1913 independent reflections
Radiation source: fine-focus sealed tube	1889 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
φ and ω scans	θmax = 29.1°, θmin = 2.9°
Absorption correction: multi-scan (MULABS in PLATON; Spek, 2003)	h = −9→9
Tmin = 0.539, Tmax = 0.760	k = −12→12
6842 measured reflections	l = −14→15

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.016	w = 1/[σ^2(Fo^2) + (0.0247P)^2 + 0.4752P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.042	(Δ/σ)max = 0.001
S = 1.08	Δρmax = 0.46 e Å^−3
1913 reflections	Δρmin = −0.51 e Å^−3
84 parameters	Extinction correction: SHELXL 97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0269 (10)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), with 784 Friedel pairs (99.7%)
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.28 (4)

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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	0.31636 (2)	0.86283 (2)	0.26335 (1)	0.0170 (1)
N1	0.1329 (3)	0.7590 (2)	0.3838 (2)	0.0200 (6)
N2	0.1723 (3)	0.7398 (2)	0.13599 (18)	0.0198 (5)
N3	0.5059 (3)	1.0508 (2)	0.4625 (2)	0.0265 (6)
N4	0.5486 (4)	1.0323 (3)	0.0698 (2)	0.0269 (6)
C1	−0.0334 (4)	0.7046 (3)	0.3122 (2)	0.0247 (6)
C2	0.0448 (4)	0.6364 (3)	0.1993 (2)	0.0268 (6)
C3	0.4387 (4)	0.9800 (2)	0.3892 (2)	0.0196 (6)
C4	0.4706 (4)	0.9651 (3)	0.1414 (2)	0.0204 (6)
H1NA	0.19650	0.68450	0.42100	0.0240*
H1A	−0.12130	0.78440	0.29080	0.0300*
H1B	−0.10710	0.63360	0.36010	0.0300*
H1NB	0.09080	0.82150	0.44250	0.0240*
H2A	0.11910	0.54940	0.22070	0.0320*
H2B	−0.06310	0.60800	0.14550	0.0320*
H2NA	0.09970	0.79770	0.08630	0.0240*
H2NB	0.26030	0.69130	0.08880	0.0240*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ag1	0.0170 (1)	0.0154 (1)	0.0187 (1)	−0.0005 (1)	0.0004 (1)	0.0002 (1)
N1	0.0218 (10)	0.0187 (9)	0.0195 (10)	−0.0020 (7)	0.0021 (7)	0.0031 (8)
N2	0.0204 (9)	0.0184 (9)	0.0207 (9)	−0.0039 (9)	−0.0009 (9)	−0.0017 (7)
N3	0.0250 (11)	0.0283 (11)	0.0261 (11)	−0.0039 (8)	−0.0002 (8)	−0.0037 (9)
N4	0.0252 (10)	0.0304 (11)	0.0252 (11)	−0.0051 (10)	0.0005 (9)	0.0003 (9)
C1	0.0223 (10)	0.0255 (11)	0.0264 (12)	−0.0071 (9)	0.0016 (9)	0.0010 (10)
C2	0.0318 (11)	0.0209 (9)	0.0278 (11)	−0.0119 (11)	0.0012 (10)	−0.0019 (11)
C3	0.0182 (10)	0.0195 (10)	0.0210 (11)	−0.0009 (9)	0.0016 (9)	0.0028 (9)
C4	0.0173 (10)	0.0228 (10)	0.0212 (11)	−0.0023 (9)	−0.0005 (9)	−0.0006 (9)

Geometric parameters (Å, º)

Ag1—N1	2.078 (2)	N1—H1NB	0.9200
Ag1—N2	2.071 (2)	N2—H2NA	0.9200
Ag1—C3	1.960 (2)	N2—H2NB	0.9200
Ag1—C4	1.965 (3)	C1—C2	1.500 (3)
N1—C1	1.485 (3)	C1—H1A	0.9900
N2—C2	1.483 (3)	C1—H1B	0.9900
N3—C3	1.143 (3)	C2—H2A	0.9900
N4—C4	1.144 (4)	C2—H2B	0.9900
N1—H1NA	0.9200
N1—Ag1—N2	83.14 (8)	C2—N2—H2NA	110.00
N1—Ag1—C3	94.12 (9)	C2—N2—H2NB	110.00
N1—Ag1—C4	175.20 (10)	N1—C1—C2	107.9 (2)
N2—Ag1—C3	176.69 (10)	N2—C2—C1	109.2 (2)
N2—Ag1—C4	93.84 (9)	Ag1—C3—N3	178.2 (2)
C3—Ag1—C4	88.78 (10)	Ag1—C4—N4	174.6 (3)
Ag1—N1—C1	107.03 (15)	N1—C1—H1A	110.00
Ag1—N2—C2	109.18 (14)	N1—C1—H1B	110.00
C1—N1—H1NB	110.00	C2—C1—H1A	110.00
H1NA—N1—H1NB	109.00	C2—C1—H1B	110.00
Ag1—N1—H1NB	110.00	H1A—C1—H1B	108.00
C1—N1—H1NA	110.00	N2—C2—H2A	110.00
Ag1—N1—H1NA	110.00	N2—C2—H2B	110.00
Ag1—N2—H2NA	110.00	C1—C2—H2A	110.00
Ag1—N2—H2NB	110.00	C1—C2—H2B	110.00
H2NA—N2—H2NB	108.00	H2A—C2—H2B	108.00
N2—Ag1—N1—C1	−20.61 (15)	Ag1—N1—C1—C2	45.1 (2)
C3—Ag1—N1—C1	157.53 (16)	Ag1—N2—C2—C1	34.7 (2)
N1—Ag1—N2—C2	−7.65 (16)	N1—C1—C2—N2	−53.5 (3)
C4—Ag1—N2—C2	176.10 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1NA···N4^i	0.92	2.27	3.099 (3)	150
N1—H1NB···N4^ii	0.92	2.18	3.097 (3)	172
N2—H2NA···N3^iii	0.92	2.10	3.002 (3)	167
N2—H2NB···N3^i	0.92	2.16	3.042 (3)	161

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