catena-Poly[[(trifluoro­methane­sulfon­ato-κO)silver(I)]-μ-di-2-pyridyl­amine-κ²N²:N^2′], a chain polymer with short Ag...C contacts

The title compound, [Ag(CF₃O₃S)(C₁₀H₉N₃)]_n, is a chain polymer in which neighbouring monomeric units are related by a glide plane. The silver centre is four-coordinate; the donor atoms are one trifluoro­methane­sulfonate O atom and one pyridine N atom from each of two symmetry-related dipyridylamines, and an additional and unexpected Ag...C contact [2.6464 (16) Å] is observed to a pyridine C atom. The chains are reinforced by one classical N—H...O and two `weak' C—H...O hydrogen bonds.

S1. Comment

We are interested in complexes of the ligand 2,2'-dipyridylamine (DPA), and have reported some of its complexes with silver, gold and palladium, together with the structure of [(DPA)(PPh₃)Ag](OTf) (OTf is trifluoromethanesulfonate; Burgos et al., 2003). This displays, to a first approximation, three-coordinate silver, the donor atoms being the P atom (of PPh₃) and both pyridine N atoms of the same DPA ligand. An additional Ag···O interaction of 2.725 (3) Å, supported by an N—H···O hydrogen bond, links the molecules to form chains. The synthesis of the title compound [(DPA)Ag(Otf)], (I), was reported at the time, but not the structure, which we present here.

The asymmetric unit is presented in Fig. 1. It is striking that the compound does not display the structure of a simple molecule [(DPA)Ag(OTf)], with coordination through the pyridine N atoms and a trifluoromethanesulfonate O atom, as might perhaps have been expected. Instead, coordination occurs via one pyridine N atom (N11), the trifluoromethanesulfonate atom O3 and the second pyridine N atom (N21) of a different asymmetric unit (the latter not shown in Fig. 1; the extended structure is discussed below). The Ag—N distances (Table 1) are broadly similar to those of [(DPA)(PPh₃)Ag](OTf) [Ag—N = 2.264 (2) and 2.283 (2) Å], but the Ag—O distance is appreciably shorter and may be assumed to correspond to a stronger bonding interaction.

Within the asymmetric unit there is also an unexpected contact from silver to a ring C atom, namely Ag···C23, approximately perpendicular to the ring (the angle between the vector Ag···C23 and the mean ring plane is 70.7°). In contrast to the more familiar situation, for example, in the complex of silver perchlorate and benzene [Ag—C = 2.565 (1) Å in a low-temperature neutron study (McMullan et al., 1997)], the silver is coordinated to just this one C atom, rather than at equal distances to two neighbouring ring C atoms; the distances to atoms C22 and C24 are much greater at 3.049 (2) and 3.260 (2) Å respectively. There are difficulties involved in searching the Cambridge Structural Database (Version 5.27; Allen, 2002) for such contacts (are they coded as bonds or not?), but we were unable to find a further example of such a short contact involving a pyridine ligand.

The dimensions of the DPA ligand may be regarded as normal, although the N11—C12 bond is somewhat short at 1.337 (2) Å. The interplanar angle between the rings is 34.60 (5)°. More informative are the torsion angles N11—C12—N1—C22 and N21—C22—N1—C12 (Table 1), which are very approximately syn- and antiperiplanar, respectively. The additional contact to the Ag atom results in no significant changes to the dimensions of the ring N21/C22–C26.

The extended structure most importantly involves an Ag—N21 bond to a neighbouring molecule generated by the n-glide plane. This leads to four-coordination at the Ag atom and to the formation of a chain polymer parallel to the y axis (Fig. 2). Within this polymer, one classical N—H···O hydrogen bond and two `weak' C—H···O interactions (Desiraju & Steiner, 1999) (the first three hydrogen bonds of Table 2), including a bifurcated system involving the common acceptor O2, presumably act as stabilizing features; a long Ag···O1 contact within the chain [3.2079 (14) Å] is probably less relevant and is not included in the figure. There are short C—H···X (X = O and F) contacts (Table 2) between neighbouring chains.

S2. Experimental

The complex was synthesized as described by Burgos et al. (2003) and recrystallized from dichloromethane/pentane.

S3. Refinement

The amine H atom was refined freely but with an N—H bond length restraint [N—H = ? (?) Å]. Other H atoms were included using a riding model with fixed C—H bond lengths of 0.95 Å; U_iso(H) values were fixed at 1.2U_eq of the parent atom.

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The asymmetric unit of the title compound in the crystal. Dispalcement ellipsoids represent 50% probability levels.
	Fig. 2. Packing diagram of one the title compound, viewed perpendicular to the xy plane. Secondary interactions are indicated by dashed lines (thick, N—H···O bonds; thin, C—H···O bonds). The origin is at the lower right-hand corner, with the x and y axes drawn vertically and horizontally respectively.

catena-Poly[[(trifluoromethanesulfonato-κO)silver(I)]-µ-di-2- pyridylamine-κ²N²:N^2']

Crystal data

[Ag(CF3O3S)(C10H9N3)]	F(000) = 840
Mr = 428.14	Dx = 2.060 Mg m^−3
MonoclinicP21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 8192 reflections
a = 10.9077 (8) Å	θ = 2–28°
b = 9.9610 (6) Å	µ = 1.66 mm^−1
c = 13.2994 (8) Å	T = 143 K
β = 107.223 (3)°	Tablet, colourless
V = 1380.21 (16) Å^3	0.21 × 0.10 × 0.04 mm
Z = 4

Data collection

Bruker SMART 1000 CCD diffractometer	4029 independent reflections
Radiation source: fine-focus sealed tube	3394 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.050
Detector resolution: 8.192 pixels mm^-1	θmax = 30.0°, θmin = 2.1°
ω and φ scans	h = −15→15
Absorption correction: multi-scan (SADABS; Bruker, 1998)	k = −13→13
Tmin = 0.803, Tmax = 0.936	l = −18→18
22658 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)] = 0.024	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.058	H atoms treated by a mixture of independent and constrained refinement
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0348P)^2] where P = (Fo^2 + 2Fc^2)/3
4029 reflections	(Δ/σ)max = 0.001
203 parameters	Δρmax = 0.71 e Å^−3
1 restraint	Δρmin = −0.47 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.

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)

- 3.9775 (0.0069) x + 2.4802 (0.0069) y + 12.8336 (0.0027) z = 1.6896 (0.0032)

* -0.0184 (0.0011) N11 * 0.0241 (0.0011) C12 * -0.0089 (0.0012) C13 * -0.0110 (0.0012) C14 * 0.0165 (0.0012) C15 * -0.0023 (0.0012) C16

Rms deviation of fitted atoms = 0.0152

- 3.8667 (0.0073) x - 3.4362 (0.0063) y + 12.4361 (0.0033) z = 1.0645 (0.0065)

Angle to previous plane (with approximate e.s.d.) = 34.60 (0.05)

* -0.0041 (0.0011) N21 * -0.0147 (0.0011) C22 * 0.0198 (0.0011) C23 * -0.0073 (0.0012) C24 * -0.0113 (0.0013) C25 * 0.0176 (0.0012) C26

Rms deviation of fitted atoms = 0.0136

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
Ag	0.654332 (12)	0.417932 (13)	0.205239 (11)	0.02513 (5)
N1	0.60359 (12)	0.11452 (14)	0.30346 (11)	0.0169 (3)
H1	0.6066 (18)	0.0353 (16)	0.3053 (15)	0.017 (5)*
N11	0.48176 (12)	0.30023 (14)	0.22151 (11)	0.0183 (3)
C12	0.48602 (14)	0.17155 (17)	0.25101 (12)	0.0166 (3)
C13	0.37563 (15)	0.09087 (17)	0.22982 (13)	0.0205 (3)
H13	0.3818	−0.0016	0.2480	0.025*
C14	0.25813 (15)	0.1491 (2)	0.18198 (14)	0.0246 (4)
H14	0.1819	0.0970	0.1669	0.029*
C15	0.25188 (15)	0.2852 (2)	0.15588 (14)	0.0246 (4)
H15	0.1717	0.3280	0.1252	0.029*
C16	0.36476 (15)	0.35545 (18)	0.17583 (13)	0.0219 (3)
H16	0.3608	0.4476	0.1567	0.026*
N21	0.82469 (13)	0.10918 (14)	0.37185 (11)	0.0174 (3)
C22	0.71549 (14)	0.18078 (16)	0.35683 (12)	0.0160 (3)
C23	0.71650 (15)	0.31159 (17)	0.39606 (13)	0.0189 (3)
H23	0.6384	0.3586	0.3881	0.023*
C24	0.83336 (16)	0.37096 (19)	0.44662 (13)	0.0228 (3)
H24	0.8363	0.4608	0.4711	0.027*
C25	0.94608 (16)	0.29875 (19)	0.46140 (14)	0.0254 (4)
H25	1.0272	0.3378	0.4956	0.030*
C26	0.93652 (15)	0.16893 (19)	0.42487 (14)	0.0227 (3)
H26	1.0132	0.1180	0.4377	0.027*
S	0.86705 (4)	0.21888 (4)	0.12677 (3)	0.01708 (8)
C1	0.84934 (17)	0.2596 (2)	−0.01049 (14)	0.0302 (4)
O1	0.93431 (13)	0.09288 (12)	0.14354 (11)	0.0272 (3)
O2	0.93863 (12)	0.33110 (13)	0.18348 (10)	0.0272 (3)
O3	0.73477 (11)	0.21333 (14)	0.12852 (10)	0.0257 (3)
F1	0.78059 (14)	0.16751 (18)	−0.07471 (10)	0.0544 (4)
F2	0.79006 (14)	0.37703 (16)	−0.03641 (11)	0.0506 (4)
F3	0.96306 (12)	0.26783 (17)	−0.02798 (10)	0.0502 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ag	0.02244 (7)	0.01877 (8)	0.03667 (9)	−0.00211 (5)	0.01257 (5)	0.00529 (5)
N1	0.0142 (6)	0.0116 (7)	0.0235 (7)	−0.0002 (5)	0.0035 (5)	0.0002 (5)
N11	0.0137 (6)	0.0180 (7)	0.0232 (7)	0.0017 (5)	0.0055 (5)	0.0013 (5)
C12	0.0143 (7)	0.0179 (8)	0.0179 (7)	0.0001 (5)	0.0054 (5)	−0.0010 (6)
C13	0.0178 (7)	0.0189 (8)	0.0244 (8)	−0.0038 (6)	0.0056 (6)	−0.0005 (6)
C14	0.0147 (7)	0.0308 (10)	0.0276 (9)	−0.0045 (6)	0.0053 (6)	−0.0024 (7)
C15	0.0154 (7)	0.0298 (10)	0.0268 (9)	0.0048 (6)	0.0035 (6)	−0.0008 (7)
C16	0.0185 (7)	0.0205 (9)	0.0258 (8)	0.0044 (6)	0.0052 (6)	0.0026 (6)
N21	0.0152 (6)	0.0175 (7)	0.0189 (6)	0.0016 (5)	0.0042 (5)	−0.0001 (5)
C22	0.0161 (7)	0.0162 (8)	0.0155 (7)	−0.0006 (5)	0.0044 (5)	0.0014 (5)
C23	0.0189 (7)	0.0172 (8)	0.0200 (7)	0.0013 (6)	0.0050 (6)	−0.0003 (6)
C24	0.0256 (8)	0.0175 (8)	0.0236 (8)	−0.0038 (6)	0.0047 (6)	−0.0024 (6)
C25	0.0190 (8)	0.0245 (10)	0.0283 (9)	−0.0047 (6)	0.0003 (6)	−0.0017 (7)
C26	0.0157 (7)	0.0250 (9)	0.0255 (8)	0.0012 (6)	0.0032 (6)	0.0005 (7)
S	0.01620 (17)	0.01458 (19)	0.02056 (18)	−0.00013 (13)	0.00561 (13)	−0.00044 (14)
C1	0.0240 (8)	0.0421 (12)	0.0250 (9)	0.0016 (8)	0.0083 (7)	0.0025 (8)
O1	0.0268 (6)	0.0158 (7)	0.0396 (7)	0.0027 (5)	0.0109 (5)	0.0012 (5)
O2	0.0258 (6)	0.0178 (6)	0.0333 (7)	−0.0018 (5)	0.0016 (5)	−0.0051 (5)
O3	0.0187 (6)	0.0305 (7)	0.0301 (6)	−0.0007 (5)	0.0104 (5)	−0.0014 (5)
F1	0.0530 (8)	0.0786 (12)	0.0276 (6)	−0.0120 (8)	0.0058 (6)	−0.0184 (7)
F2	0.0524 (8)	0.0562 (9)	0.0427 (7)	0.0201 (7)	0.0136 (6)	0.0279 (7)
F3	0.0319 (6)	0.0884 (12)	0.0369 (7)	0.0030 (7)	0.0202 (5)	0.0142 (7)

Geometric parameters (Å, º)

Ag—N21^i	2.2072 (14)	N21—C22	1.351 (2)
Ag—N11	2.2817 (13)	N21—C26	1.353 (2)
Ag—O3	2.5484 (13)	C22—C23	1.402 (2)
Ag—C23	2.6464 (16)	C23—C24	1.385 (2)
N1—C22	1.384 (2)	C23—H23	0.9500
N1—C12	1.387 (2)	C24—C25	1.387 (2)
N1—H1	0.790 (15)	C24—H24	0.9500
N11—C12	1.337 (2)	C25—C26	1.374 (3)
N11—C16	1.357 (2)	C25—H25	0.9500
C12—C13	1.405 (2)	C26—H26	0.9500
C13—C14	1.379 (2)	S—O1	1.4375 (13)
C13—H13	0.9500	S—O2	1.4420 (13)
C14—C15	1.396 (3)	S—O3	1.4510 (12)
C14—H14	0.9500	S—C1	1.8234 (19)
C15—C16	1.372 (2)	C1—F1	1.324 (2)
C15—H15	0.9500	C1—F3	1.330 (2)
C16—H16	0.9500	C1—F2	1.332 (3)
N21^i—Ag—N11	133.59 (5)	N21—C22—C23	121.73 (14)
N21^i—Ag—O3	114.14 (5)	N1—C22—C23	122.84 (14)
N11—Ag—O3	91.06 (4)	C24—C23—C22	118.81 (15)
N21^i—Ag—C23	139.34 (5)	C24—C23—Ag	103.43 (11)
N11—Ag—C23	71.80 (5)	C22—C23—Ag	92.50 (10)
O3—Ag—C23	92.46 (5)	C24—C23—H23	120.6
C22—N1—C12	127.31 (14)	C22—C23—H23	120.6
C22—N1—H1	116.0 (14)	Ag—C23—H23	74.3
C12—N1—H1	116.7 (14)	C23—C24—C25	119.80 (17)
C12—N11—C16	117.80 (14)	C23—C24—H24	120.1
C12—N11—Ag	124.22 (10)	C25—C24—H24	120.1
C16—N11—Ag	116.24 (11)	C26—C25—C24	117.80 (15)
N11—C12—N1	119.13 (14)	C26—C25—H25	121.1
N11—C12—C13	122.42 (14)	C24—C25—H25	121.1
N1—C12—C13	118.45 (15)	N21—C26—C25	124.09 (16)
C14—C13—C12	118.43 (16)	N21—C26—H26	118.0
C14—C13—H13	120.8	C25—C26—H26	118.0
C12—C13—H13	120.8	O1—S—O2	115.04 (8)
C13—C14—C15	119.59 (16)	O1—S—O3	115.37 (8)
C13—C14—H14	120.2	O2—S—O3	114.08 (8)
C15—C14—H14	120.2	O1—S—C1	104.32 (9)
C16—C15—C14	118.17 (15)	O2—S—C1	103.40 (9)
C16—C15—H15	120.9	O3—S—C1	102.33 (8)
C14—C15—H15	120.9	F1—C1—F3	108.02 (16)
N11—C16—C15	123.44 (16)	F1—C1—F2	107.61 (16)
N11—C16—H16	118.3	F3—C1—F2	107.86 (17)
C15—C16—H16	118.3	F1—C1—S	111.33 (15)
C22—N21—C26	117.65 (15)	F3—C1—S	111.15 (13)
C22—N21—Ag^ii	126.51 (11)	F2—C1—S	110.72 (13)
C26—N21—Ag^ii	114.86 (11)	S—O3—Ag	115.97 (7)
N21—C22—N1	115.40 (14)
N21^i—Ag—N11—C12	164.26 (11)	N1—C22—C23—Ag	−71.87 (15)
O3—Ag—N11—C12	38.65 (13)	N21^i—Ag—C23—C24	−33.87 (15)
C23—Ag—N11—C12	−53.60 (13)	N11—Ag—C23—C24	−170.85 (13)
N21^i—Ag—N11—C16	−0.33 (15)	O3—Ag—C23—C24	98.84 (12)
O3—Ag—N11—C16	−125.94 (12)	N21^i—Ag—C23—C22	−154.29 (9)
C23—Ag—N11—C16	141.81 (13)	N11—Ag—C23—C22	68.73 (9)
C16—N11—C12—N1	−176.26 (14)	O3—Ag—C23—C22	−21.58 (10)
Ag—N11—C12—N1	19.4 (2)	C22—C23—C24—C25	−2.7 (2)
C16—N11—C12—C13	4.5 (2)	Ag—C23—C24—C25	−103.19 (16)
Ag—N11—C12—C13	−159.89 (12)	C23—C24—C25—C26	−0.3 (3)
C22—N1—C12—N11	20.0 (2)	C22—N21—C26—C25	−2.1 (3)
C22—N1—C12—C13	−160.69 (15)	Ag^ii—N21—C26—C25	167.34 (15)
N11—C12—C13—C14	−3.6 (2)	C24—C25—C26—N21	2.7 (3)
N1—C12—C13—C14	177.09 (15)	O1—S—C1—F1	61.63 (15)
C12—C13—C14—C15	0.1 (3)	O2—S—C1—F1	−177.72 (13)
C13—C14—C15—C16	2.2 (3)	O3—S—C1—F1	−58.94 (16)
C12—N11—C16—C15	−1.9 (2)	O1—S—C1—F3	−58.85 (17)
Ag—N11—C16—C15	163.69 (14)	O2—S—C1—F3	61.81 (17)
C14—C15—C16—N11	−1.4 (3)	O3—S—C1—F3	−179.41 (15)
C26—N21—C22—N1	−179.14 (14)	O1—S—C1—F2	−178.71 (14)
Ag^ii—N21—C22—N1	12.9 (2)	O2—S—C1—F2	−58.06 (15)
C26—N21—C22—C23	−1.1 (2)	O3—S—C1—F2	60.73 (15)
Ag^ii—N21—C22—C23	−169.14 (11)	O1—S—O3—Ag	145.43 (8)
C12—N1—C22—N21	−159.64 (15)	O2—S—O3—Ag	8.96 (10)
C12—N1—C22—C23	22.4 (2)	C1—S—O3—Ag	−102.00 (9)
N21—C22—C23—C24	3.4 (2)	N21^i—Ag—O3—S	55.92 (9)
N1—C22—C23—C24	−178.69 (15)	N11—Ag—O3—S	−164.27 (8)
N21—C22—C23—Ag	110.27 (14)	C23—Ag—O3—S	−92.44 (8)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C23—H23···O1^i	0.95	2.46	3.213 (2)	136
N1—H1···O2^ii	0.79 (2)	2.11 (2)	2.8739 (19)	163 (2)
C13—H13···O2^ii	0.95	2.53	3.278 (2)	136
C25—H25···O3^iii	0.95	2.48	3.275 (2)	142
C14—H14···O1^iv	0.95	2.63	3.462 (2)	147
C15—H15···F3^iv	0.95	2.63	3.372 (2)	135
C16—H16···F2^v	0.95	2.60	3.397 (2)	142

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