Poly[[{μ(3)-2-[4-(2-hy-droxy-eth-yl)piperazin-1-yl]ethane-sulfonato}-silver(I)] trihydrate].

Ethane-sulfonic acid-based buffers like 2-[4-(2-hy-droxy-eth-yl)-piperazin-1-yl]ethane-sulfonic acid (HEPES) are commonly used in biological experiments because of their ability to act as non-coordinating ligands towards metal ions. However, recent work has shown that some of these buffers may in fact coordinate metal ions. The title complex, {[Ag(C(8)H(17)N(2)O(4)S)]·3H(2)O}(n), is a metal-organic framework formed from HEPES and a silver(I) ion. In this polymeric complex, each Ag atom is primarily coordinated by two N atoms in a distorted linear geometry. Weaker secondary bonding inter-actions from the hy-droxy and sulfate O atoms of HEPES complete a distorted seesaw geometry. The crystal structure is stabilized by O-H⋯O hydrogen-bonding interactions.

Related literature

For other compounds with silver bound to ethane­sulfonic acid derivatives that are used as buffers, see: Jiang, Liu et al. (2008 ▶), where HEPES is used, and Jiang, Ma et al. (2008 ▶), where MES is used. For background on metal coordination to buffer compounds like HEPES, see: Soares & Conde (2000 ▶); Sokolowska & Bal (2005 ▶). For copper complexes of HEPES inter­fering with protein assays, see: Gregory & Sajdera (1970 ▶); Lleu & Rebel (1991 ▶); Kaushal & Barnes (1986 ▶). For general information on HEPES and related buffers, see: Good et al. (1966 ▶).

Experimental

Crystal data

[Ag(C8H17N2O4S)]·3H2O

M = 399.21

Monoclinic,

a = 11.2811 (19) Å

b = 10.0973 (17) Å

c = 12.875 (2) Å

β = 90.910 (3)°

V = 1466.4 (4) Å3

Z = 4

Mo Kα radiation

μ = 1.55 mm−1

T = 100 K

0.25 × 0.10 × 0.07 mm

Data collection

Bruker APEXI CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T min = 0.699, T max = 0.900

11308 measured reflections

2946 independent reflections

2446 reflections with I > 2σ(I)

R int = 0.050

Refinement

R[F 2 > 2σ(F 2)] = 0.036

wR(F 2) = 0.090

S = 1.09

2946 reflections

190 parameters

9 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 1.58 e Å−3

Δρmin = −0.73 e Å−3

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S160053681103008X/mw2014sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681103008X/mw2014Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

[Ag(C8H17N2O4S)]·3H2O	F(000) = 816
Mr = 399.21	Dx = 1.808 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1601 reflections
a = 11.2811 (19) Å	θ = 2.7–21.3°
b = 10.0973 (17) Å	µ = 1.55 mm−1
c = 12.875 (2) Å	T = 100 K
β = 90.910 (3)°	Column, colorless
V = 1466.4 (4) Å3	0.25 × 0.10 × 0.07 mm
Z = 4

Bruker APEXI CCD diffractometer	2946 independent reflections
Radiation source: fine-focus sealed tube	2446 reflections with I > 2σ(I)
graphite	Rint = 0.050
φ and ω scans	θmax = 26.3°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker 2001)	h = −14→14
Tmin = 0.699, Tmax = 0.900	k = −12→11
11308 measured reflections	l = −16→16

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.090	H atoms treated by a mixture of independent and constrained refinement
S = 1.09	w = 1/[σ2(Fo2) + (0.0356P)2] where P = (Fo2 + 2Fc2)/3
2946 reflections	(Δ/σ)max = 0.001
190 parameters	Δρmax = 1.58 e Å−3
9 restraints	Δρmin = −0.73 e Å−3

Experimental. Two A level alerts are generated by cif check: Angle Calc 87.45 (5), Rep 94.22 (9), Dev..135.40 Sigma N2-AG1-O2 Angle Calc 89.17 (5), Rep 87.18 (7), Dev..135.40 Sigma O2-AG1-O4 Both of the reported angles were verified during refinement with SHELXL-97 and can be confirmed by analyzing the resulting cif with Mercury.

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. Distance and angle restraints were applied to the hydrogen atoms associated with the three solvent water molecules found from the difference Fourier map.

	x	y	z	Uiso*/Ueq
Ag1	0.38547 (2)	0.14705 (2)	0.29401 (2)	0.01471 (11)
S1	0.68653 (8)	−0.16901 (8)	0.41427 (7)	0.0135 (2)
O1	0.6794 (2)	−0.3109 (2)	0.39089 (19)	0.0177 (6)
O2	0.7190 (2)	−0.1418 (2)	0.52171 (19)	0.0189 (6)
O3	0.7607 (2)	−0.1011 (3)	0.3391 (2)	0.0196 (6)
O4	0.5744 (2)	0.2274 (2)	0.39058 (19)	0.0175 (6)
H4	0.6437	0.2101	0.3717	0.026*
O5	0.8863 (3)	0.3405 (3)	0.4864 (2)	0.0317 (7)
H5C	0.883 (5)	0.412 (3)	0.452 (3)	0.048*
H5D	0.862 (4)	0.281 (3)	0.444 (3)	0.048*
O6	0.7024 (3)	0.6635 (2)	0.1703 (2)	0.0211 (6)
H6A	0.707 (4)	0.582 (2)	0.158 (3)	0.032*
H6C	0.704 (4)	0.666 (4)	0.2369 (15)	0.032*
O7	0.0771 (3)	0.4128 (3)	0.6131 (2)	0.0321 (7)
H7C	0.027 (3)	0.374 (4)	0.574 (3)	0.048*
H7D	0.143 (2)	0.375 (4)	0.617 (4)	0.048*
N1	0.3695 (2)	−0.0753 (3)	0.2742 (2)	0.0123 (6)
N2	0.3799 (3)	0.3721 (3)	0.2809 (2)	0.0142 (7)
C1	0.2842 (3)	−0.1321 (3)	0.3490 (3)	0.0139 (7)
H1B	0.3071	−0.1046	0.4203	0.017*
H1A	0.2879	−0.2300	0.3458	0.017*
C2	0.3296 (3)	−0.1120 (4)	0.1675 (3)	0.0148 (8)
H2B	0.3345	−0.2093	0.1593	0.018*
H2A	0.3832	−0.0711	0.1166	0.018*
C3	0.2954 (3)	0.4323 (3)	0.3552 (3)	0.0153 (8)
H3B	0.2998	0.5300	0.3503	0.018*
H3A	0.3182	0.4064	0.4269	0.018*
C4	0.3408 (3)	0.4125 (3)	0.1743 (3)	0.0140 (7)
H4A	0.3948	0.3735	0.1228	0.017*
H4B	0.3454	0.5101	0.1681	0.017*
C5	0.4886 (3)	−0.1349 (3)	0.2912 (3)	0.0124 (7)
H5B	0.5429	−0.1006	0.2379	0.015*
H5A	0.4826	−0.2321	0.2820	0.015*
C6	0.5408 (3)	−0.1060 (4)	0.3980 (3)	0.0144 (8)
H6D	0.4893	−0.1455	0.4512	0.017*
H6B	0.5421	−0.0090	0.4091	0.017*
C7	0.5006 (3)	0.4236 (3)	0.3009 (3)	0.0164 (8)
H7B	0.4966	0.5212	0.3076	0.020*
H7A	0.5504	0.4031	0.2404	0.020*
C8	0.5599 (3)	0.3672 (3)	0.3982 (3)	0.0187 (8)
H8B	0.6384	0.4094	0.4086	0.022*
H8A	0.5111	0.3881	0.4593	0.022*

	U11	U22	U33	U12	U13	U23
Ag1	0.01836 (18)	0.00864 (16)	0.01706 (17)	−0.00008 (10)	−0.00190 (12)	−0.00012 (11)
S1	0.0165 (5)	0.0111 (4)	0.0130 (4)	0.0014 (3)	−0.0011 (4)	0.0000 (3)
O1	0.0216 (14)	0.0125 (12)	0.0190 (14)	0.0033 (10)	−0.0010 (12)	−0.0018 (11)
O2	0.0219 (15)	0.0213 (14)	0.0133 (13)	0.0004 (11)	−0.0053 (11)	−0.0043 (11)
O3	0.0214 (15)	0.0181 (13)	0.0194 (14)	−0.0005 (11)	0.0043 (12)	0.0007 (11)
O4	0.0177 (13)	0.0118 (13)	0.0228 (14)	0.0004 (10)	−0.0014 (11)	0.0000 (11)
O5	0.0340 (18)	0.0341 (18)	0.0270 (17)	−0.0089 (14)	−0.0016 (15)	−0.0027 (13)
O6	0.0262 (16)	0.0168 (14)	0.0203 (14)	0.0012 (11)	0.0016 (13)	−0.0001 (12)
O7	0.0300 (18)	0.0325 (18)	0.0334 (18)	0.0154 (14)	−0.0098 (14)	−0.0091 (14)
N1	0.0110 (16)	0.0115 (15)	0.0142 (16)	−0.0011 (11)	0.0006 (12)	0.0015 (12)
N2	0.0151 (17)	0.0123 (15)	0.0151 (16)	−0.0013 (11)	0.0008 (13)	0.0031 (12)
C1	0.0163 (19)	0.0119 (18)	0.0134 (18)	−0.0016 (14)	0.0006 (15)	−0.0001 (14)
C2	0.019 (2)	0.0154 (18)	0.0097 (17)	−0.0001 (14)	0.0015 (15)	−0.0012 (14)
C3	0.0180 (19)	0.0124 (18)	0.0154 (19)	0.0057 (14)	0.0003 (15)	−0.0006 (15)
C4	0.0175 (19)	0.0110 (18)	0.0135 (18)	0.0013 (14)	0.0036 (15)	0.0020 (14)
C5	0.0164 (19)	0.0091 (17)	0.0117 (17)	0.0020 (13)	0.0000 (15)	0.0015 (14)
C6	0.0147 (19)	0.0160 (18)	0.0125 (18)	0.0021 (14)	−0.0026 (15)	−0.0012 (15)
C7	0.0143 (19)	0.0111 (18)	0.024 (2)	−0.0033 (14)	0.0002 (16)	0.0017 (16)
C8	0.019 (2)	0.0133 (19)	0.024 (2)	−0.0012 (14)	−0.0048 (17)	−0.0046 (16)

Ag1—N1	2.266 (3)	C1—C4ii	1.506 (5)
Ag1—N2	2.280 (3)	C1—H1B	0.9900
Ag1—O2i	2.666 (2)	C1—H1A	0.9900
Ag1—O4	2.581 (2)	C2—C3ii	1.503 (5)
S1—O2	1.452 (3)	C2—H2B	0.9900
S1—O3	1.461 (3)	C2—H2A	0.9900
S1—O1	1.466 (3)	C3—C2iii	1.503 (5)
S1—C6	1.772 (4)	C3—H3B	0.9900
O4—C8	1.425 (4)	C3—H3A	0.9900
O4—H4	0.8400	C4—C1iii	1.506 (5)
O5—H5C	0.851 (19)	C4—H4A	0.9900
O5—H5D	0.855 (18)	C4—H4B	0.9900
O6—H6A	0.839 (18)	C5—C6	1.515 (5)
O6—H6C	0.858 (18)	C5—H5B	0.9900
O7—H7C	0.848 (19)	C5—H5A	0.9900
O7—H7D	0.838 (19)	C6—H6D	0.9900
N1—C5	1.485 (4)	C6—H6B	0.9900
N1—C2	1.486 (4)	C7—C8	1.521 (5)
N1—C1	1.486 (4)	C7—H7B	0.9900
N2—C7	1.477 (4)	C7—H7A	0.9900
N2—C3	1.490 (4)	C8—H8B	0.9900
N2—C4	1.492 (4)	C8—H8A	0.9900
N1—Ag1—N2	167.73 (11)	C3ii—C2—H2A	109.2
N1—Ag1—O2i	92.58 (8)	H2B—C2—H2A	107.9
N1—Ag1—O4	115.41 (8)	N2—C3—C2iii	111.2 (3)
N2iii—Ag1—O2i	94.22 (9)	N2—C3—H3B	109.4
N2—Ag1—O4	75.16 (9)	C2iii—C3—H3B	109.4
O2i—Ag1—O4iii	87.18 (7)	N2—C3—H3A	109.4
O2—S1—O3	113.85 (16)	C2iii—C3—H3A	109.4
O2—S1—O1	113.13 (14)	H3B—C3—H3A	108.0
O3—S1—O1	110.65 (15)	N2—C4—C1iii	111.3 (3)
O2—S1—C6	105.35 (16)	N2—C4—H4A	109.4
O3—S1—C6	107.02 (16)	C1iii—C4—H4A	109.4
O1—S1—C6	106.21 (16)	N2—C4—H4B	109.4
C8—O4—H4	109.5	C1iii—C4—H4B	109.4
H5C—O5—H5D	105 (4)	H4A—C4—H4B	108.0
H6A—O6—H6C	103 (3)	N1—C5—C6	113.1 (3)
H7C—O7—H7D	113 (4)	N1—C5—H5B	109.0
C5—N1—C2	107.1 (3)	C6—C5—H5B	109.0
C5—N1—C1	109.9 (3)	N1—C5—H5A	109.0
C2—N1—C1	108.2 (3)	C6—C5—H5A	109.0
C5—N1—Ag1	108.4 (2)	H5B—C5—H5A	107.8
C2—N1—Ag1	111.9 (2)	C5—C6—S1	112.6 (2)
C1—N1—Ag1	111.2 (2)	C5—C6—H6D	109.1
C7—N2—C3	110.0 (3)	S1—C6—H6D	109.1
C7—N2—C4	108.8 (3)	C5—C6—H6B	109.1
C3—N2—C4	107.2 (3)	S1—C6—H6B	109.1
C7—N2—Ag1	108.3 (2)	H6D—C6—H6B	107.8
C3—N2—Ag1	112.1 (2)	N2—C7—C8	113.8 (3)
C4—N2—Ag1	110.4 (2)	N2—C7—H7B	108.8
N1—C1—C4ii	111.7 (3)	C8—C7—H7B	108.8
N1—C1—H1B	109.3	N2—C7—H7A	108.8
C4ii—C1—H1B	109.3	C8—C7—H7A	108.8
N1—C1—H1A	109.3	H7B—C7—H7A	107.7
C4ii—C1—H1A	109.3	O4—C8—C7	111.4 (3)
H1B—C1—H1A	108.0	O4—C8—H8B	109.4
N1—C2—C3ii	112.0 (3)	C7—C8—H8B	109.4
N1—C2—H2B	109.2	O4—C8—H8A	109.4
C3ii—C2—H2B	109.2	C7—C8—H8A	109.4
N1—C2—H2A	109.2	H8B—C8—H8A	108.0
N2—Ag1—N1—C5	130.6 (5)	C7—N2—C4—C1iii	−177.5 (3)
N2—Ag1—N1—C2	12.7 (6)	C3—N2—C4—C1iii	−58.5 (4)
N2—Ag1—N1—C1	−108.5 (5)	Ag1—N2—C4—C1iii	63.8 (3)
N1—Ag1—N2—C7	−131.4 (5)	C2—N1—C5—C6	−179.8 (3)
N1—Ag1—N2—C3	107.1 (5)	C1—N1—C5—C6	−62.4 (4)
N1—Ag1—N2—C4	−12.4 (6)	Ag1—N1—C5—C6	59.3 (3)
C5—N1—C1—C4ii	−172.7 (3)	N1—C5—C6—S1	−176.3 (2)
C2—N1—C1—C4ii	−56.0 (4)	O2—S1—C6—C5	−175.8 (2)
Ag1—N1—C1—C4ii	67.3 (3)	O3—S1—C6—C5	62.7 (3)
C5—N1—C2—C3ii	174.6 (3)	O1—S1—C6—C5	−55.5 (3)
C1—N1—C2—C3ii	56.1 (4)	C3—N2—C7—C8	74.0 (4)
Ag1—N1—C2—C3ii	−66.7 (3)	C4—N2—C7—C8	−168.8 (3)
C7—N2—C3—C2iii	176.5 (3)	Ag1—N2—C7—C8	−48.8 (3)
C4—N2—C3—C2iii	58.4 (4)	N2—C7—C8—O4	61.9 (4)
Ag1—N2—C3—C2iii	−62.9 (3)

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7C···O5iv	0.85 (2)	1.96 (2)	2.777 (4)	161 (4)
O6—H6A···O3v	0.84 (2)	1.88 (2)	2.706 (4)	166 (4)
O6—H6C···O1vi	0.86 (2)	2.02 (2)	2.868 (4)	169 (4)
O5—H5C···O7vii	0.85 (2)	2.01 (2)	2.834 (4)	163 (5)
O5—H5D···O6viii	0.86 (2)	2.02 (2)	2.864 (4)	171 (4)
O4—H4···O6viii	0.84	1.89	2.726 (4)	178

Ag1—N1	2.266 (3)
Ag1—N2	2.280 (3)
Ag1—O2i	2.666 (2)
Ag1—O4	2.581 (2)

N1—Ag1—N2	167.73 (11)
N1—Ag1—O2i	92.58 (8)
N1—Ag1—O4	115.41 (8)
N2ii—Ag1—O2i	94.22 (9)
N2—Ag1—O4	75.16 (9)
O2i—Ag1—O4ii	87.18 (7)

Symmetry codes: (i) ; (ii) .

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O7—H7C⋯O5iii	0.85 (2)	1.96 (2)	2.777 (4)	161 (4)
O6—H6A⋯O3iv	0.84 (2)	1.88 (2)	2.706 (4)	166 (4)
O6—H6C⋯O1v	0.86 (2)	2.02 (2)	2.868 (4)	169 (4)
O5—H5C⋯O7vi	0.85 (2)	2.01 (2)	2.834 (4)	163 (5)
O5—H5D⋯O6vii	0.86 (2)	2.02 (2)	2.864 (4)	171 (4)
O4—H4⋯O6vii	0.84	1.89	2.726 (4)	178

Symmetry codes: (iii) ; (iv) ; (v) ; (vi) ; (vii) .