catena-Poly[silver(I)-μ-[1-(pyridin-2-ylmethyl-κN)-3-(3-sulfonato­prop­yl)imidazolin-2-yl­idene]-κC2]

Rietzler, B.; Laus, G.; Kahlenberg, V.; Schottenberger, H.

doi:10.1107/S2414314616002455

metal-organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 1| Part 2| February 2016| x160245

https://doi.org/10.1107/S2414314616002455

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catena-Poly[silver(I)-μ-[1-(pyridin-2-ylmethyl-κN)-3-(3-sulfonatopropyl)imidazolin-2-ylidene]-κC²]

Barbara Rietzler,^a Gerhard Laus,^a Volker Kahlenberg ^b and Herwig Schottenberger ^a ^*

^aUniversity of Innsbruck, Faculty of Chemistry and Pharmacy, Innrain 80, 6020 Innsbruck, Austria, and ^bUniversity of Innsbruck, Institute of Mineralogy and Petrography, Innrain 52, 6020 Innsbruck, Austria
^*Correspondence e-mail: herwig.schottenberger@uibk.ac.at

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 18 January 2016; accepted 9 February 2016; online 13 February 2016)

The title compound, [Ag(C₁₂H₁₄N₃O₃S)]_n, was obtained by deprotonation and metalation of 1-(pyridin-2-ylmethyl)-3-(3-sulfopropyl)imidazolium, inner salt, using silver(I) oxide in methanol. The title compound is a one-dimensional helical coordination polymer. Several C—H⋯O hydrogen bonds and a short Ag—O contact are observed. The C—Ag—N angle is 168.3 (1)° and the N—C—N `carbene angle' is 103.8 (3)°.

Keywords: crystal structure; one-dimensional helical coordination polymer; silver(I); imidazolinylidene.

CCDC reference: 1452331

Structure description

N-Heterocyclic carbene (NHC)–silver complexes are valuable transmetalation reagents or, in other words, carbene transfer agents for the conversion to other metal NHC systems (Lin et al., 2009 ). Recently, the structural diversity of Ag^I–NHC complexes with pyridyl-substituted imidazolium ligands was discussed in terms of different metal-to-ligand ratios. Increasing degrees of coordination completeness culminated in a polymeric structure (Cui et al., 2012 ).

In the crystal structure of the title compound, the central C1—Ag—N3ⁱ [symmetry code: (i) −x + $[{1\over 2}]$ , y + $[{1\over 2}]$ , −z + $[{3\over 2}]$ ] bonds deviate considerably from linearity with an angle of 168.3 (1)°, and the dihedral angle between the heterocyclic rings is 50.2 (2)°. The molecular structure is shown in Fig. 1. The N—C—N `carbene angle' is 103.8 (3)°, in accordance with the mean value of 104.0° in imidazol-2-ylidene–Ag–pyridine complexes from the CSD (119 values from 20 entries). The carbene–metal C1—Ag and nitrogen–metal N3—Ag bonds are 2.065 (4) and 2.144 (3) Å long, respectively, among the shortest in those complexes. The molecules of the title compound form a one-dimensional, helical coordination polymer (Fig. 2). Several C—H⋯O hydrogen bonds (Table 1) and a short Ag—O contact [2.913 (3) Å] are observed (Fig. 3).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C10—H10⋯O3ⁱⁱⁱ	0.95	2.40	3.349 (4)	173
C6—H6A⋯O2^iv	0.99	2.51	3.458 (5)	160
C7—H7B⋯O3^v	0.99	2.38	3.367 (5)	175
C2—H2⋯O2^vi	0.95	2.53	3.179 (5)	126
C12—H12⋯O1^vii	0.95	2.47	3.143 (4)	128
C7—H7A⋯O3^viii	0.99	2.41	3.257 (4)	143
Symmetry codes: (iii) x+1, y, z+1; (iv) -x, -y, -z; (v) -x, -y, -z+1; (vi) $[-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (vii) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (viii) $[x+{\script{1\over 2}}, -y-{\script{1\over 2}}, z+{\script{1\over 2}}]$ .

Figure 1
The asymmetric unit of the title compound, showing the atom labels and 50% probability displacement ellipsoids for non-H atoms.

Figure 2
The molecules of the title compound forming a one-dimensional, helical coordination polymer. H atoms have been omitted for clarity.

Figure 3
Short contacts in the crystal structure of the title compound. [Symmetry codes: (i) −x + $[{1\over 2}]$ , y + $[{1\over 2}]$ , −z + $[{3\over 2}]$ ; (ii) −x + $[{1\over 2}]$ , y − $[{1\over 2}]$ , −z + $[{3\over 2}]$ . For other symmetry codes, see Table 1

For related structures, see: Catalano & Moore (2005 ), Garrison et al. (2005 ), Liu et al. (2007 ), Ye et al. (2008 ), Catalano et al. (2011 ) and Cui et al. (2012). These authors describe other structural motifs with polydentate ligands forming NHC–silver complexes.

Synthesis and crystallization

A suspension of the imidazolium salt (0.40 g, 1.4 mmol) (Tomás-Mendivil et al., 2013 ) and Ag₂O (0.17 g, 0.7 mmol) in MeOH (15 ml) was stirred at room temperature for 18 h. The product was collected by filtration, washed with MeOH and Et₂O and dried to yield colourless crystals (0.44 g, 80%). The PXRD (Cu Kα radiation) of the bulk material is identical to the one calculated from the single-crystal diffraction data (Fig. 4), indicating phase purity.

Figure 4
The observed and calculated powder X-ray diffraction data.

Melting point: 247–252°C. ¹H NMR (300 MHz, D₂O): δ 2.24 (m, 2H), 2.84 (m, 2H), 4.30 (t, J = 6.7 Hz, 2H), 5.67 (s, 2H), 7.45 (s, 1H), 7.51–7.56 (m, 2H), 7.87 (d, J = 7.6 Hz, 1H), 8.12 (t, J = 7.7 Hz, 1H), 8.23 (m, 1H) p.p.m. ¹³C NMR (75 MHz, D₂O): δ 26.8, 47.8, 50.4, 57.8, 123.8, 125.0, 125.8, 126.5, 141.2, 152.3, 154.1, 174.1 p.p.m. IR (neat, ATR): ν 1597 (w), 1439 (w), 1418 (w), 1205 (s), 1157 (s), 1135 (s), 1035 (m), 750 (m), 716 (s), 577 (m), 518 (s) cm⁻¹.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	[Ag(C₁₂H₁₄N₃O₃S)]
M_r	388.19
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	173
a, b, c (Å)	11.1568 (6), 9.7852 (4), 12.5715 (6)
β (°)	107.055 (10)
V (Å³)	1312.09 (12)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	1.71
Crystal size (mm)	0.15 × 0.04 × 0.03

Data collection
Diffractometer	Agilent Xcalibur Ruby Gemini ultra
Absorption correction	Multi-scan (CrysAlis PRO; Agilent, 2014 )
T_min, T_max	0.936, 1
No. of measured, independent and observed [I > 2σ(I)] reflections	8214, 2398, 1921
R_int	0.045
(sin θ/λ)_max (Å⁻¹)	0.602

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.032, 0.066, 1.02
No. of reflections	2398
No. of parameters	181
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.45, −0.38
Computer programs: CrysAlis PRO (Agilent, 2014), SIR2002 (Burla et al., 2003 ), SHELXL97 (Sheldrick, 2008 ), ORTEP-3 for Windows (Farrugia, 2012 ), Mercury (Macrae et al., 2006 ).

Structural data

CCDC reference: 1452331

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314616002455/hb4016sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314616002455/hb4016Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2414314616002455/hb4016Isup3.mol

Supporting information file. DOI: https://doi.org/10.1107/S2414314616002455/hb4016Isup4.cml

checkCIF report

Computing details top

Data collection: CrysAlis PRO (Agilent, 2014); cell refinement: CrysAlis PRO (Agilent, 2014); data reduction: CrysAlis PRO (Agilent, 2014); program(s) used to solve structure: SIR2002 (Burla et al., 2003); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); software used to prepare material for publication: ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al., 2006).

catena-Poly[silver(I)-µ-[1-(pyridin-2-ylmethyl-κN)-3-(3-sulfonatopropyl)imidazolin-2-ylidene]-κC²] top

Crystal data top

[Ag(C₁₂H₁₄N₃O₃S)]	F(000) = 776
M_r = 388.19	D_x = 1.965 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2698 reflections
a = 11.1568 (6) Å	θ = 3.6–27.2°
b = 9.7852 (4) Å	µ = 1.71 mm⁻¹
c = 12.5715 (6) Å	T = 173 K
β = 107.055 (10)°	Fragment, colourless
V = 1312.09 (12) Å³	0.15 × 0.04 × 0.03 mm
Z = 4

Data collection top

Agilent Xcalibur Ruby Gemini ultra diffractometer	2398 independent reflections
Radiation source: Enhance (Mo) X-ray Source	1921 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.045
Detector resolution: 10.3575 pixels mm^-1	θ_max = 25.4°, θ_min = 2.8°
ω scans	h = −13→13
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2014)	k = −11→10
T_min = 0.936, T_max = 1	l = −11→15
8214 measured reflections

Refinement top

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)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.066	H-atom parameters constrained
S = 1.02	w = 1/[σ²(F_o²) + (0.0243P)² + 0.580P] where P = (F_o² + 2F_c²)/3
2398 reflections	(Δ/σ)_max < 0.001
181 parameters	Δρ_max = 0.45 e Å⁻³
0 restraints	Δρ_min = −0.38 e Å⁻³

Special details top

Experimental. Absorption correction: CrysAlisPro, Agilent Technologies, Version 1.171.37.31 (release 14-01-2014 CrysAlis171 .NET) (compiled Jan 14 2014,18:38:05) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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 (Å²) top

	x	y	z	U_iso*/U_eq
Ag	0.14608 (3)	0.10604 (3)	0.58234 (2)	0.02486 (11)
S	−0.03575 (9)	0.10338 (8)	0.17887 (8)	0.0211 (2)
N3	0.4721 (3)	−0.2244 (3)	0.9083 (2)	0.0166 (7)
C5	0.1801 (4)	−0.0473 (3)	0.2667 (3)	0.0206 (8)
H5A	0.1213	−0.1022	0.2948	0.025*
H5B	0.2375	−0.1113	0.245	0.025*
N2	0.3417 (3)	−0.1303 (3)	0.6187 (2)	0.0180 (7)
O1	0.0012 (3)	0.2093 (3)	0.2626 (2)	0.0376 (8)
O2	−0.1035 (3)	0.1553 (3)	0.0696 (2)	0.0340 (7)
C11	0.6205 (4)	0.0030 (4)	0.9122 (3)	0.0251 (9)
H11	0.6711	0.0815	0.9136	0.03*
C8	0.4460 (3)	−0.1385 (3)	0.8205 (3)	0.0162 (8)
N1	0.3119 (3)	−0.0352 (3)	0.4606 (2)	0.0189 (7)
C1	0.2724 (4)	−0.0316 (3)	0.5520 (3)	0.0181 (8)
O3	−0.0995 (3)	−0.0096 (2)	0.2142 (2)	0.0279 (6)
C3	0.4222 (3)	−0.1927 (3)	0.5684 (3)	0.0210 (9)
H3	0.4797	−0.2642	0.5987	0.025*
C2	0.4038 (4)	−0.1338 (3)	0.4695 (3)	0.0200 (8)
H2	0.4455	−0.1549	0.4156	0.024*
C10	0.6490 (4)	−0.0863 (3)	1.0009 (3)	0.0217 (8)
H10	0.7202	−0.0721	1.0636	0.026*
C6	0.1058 (4)	0.0317 (3)	0.1644 (3)	0.0210 (8)
H6A	0.085	−0.0302	0.0993	0.025*
H6B	0.1589	0.1063	0.1498	0.025*
C7	0.3302 (4)	−0.1690 (3)	0.7271 (3)	0.0195 (8)
H7A	0.3121	−0.2681	0.7269	0.023*
H7B	0.2584	−0.1195	0.7402	0.023*
C9	0.5710 (4)	−0.1964 (3)	0.9958 (3)	0.0219 (9)
H9	0.5883	−0.256	1.0581	0.026*
C12	0.5181 (4)	−0.0224 (3)	0.8210 (3)	0.0217 (9)
H12	0.4973	0.0387	0.7595	0.026*
C4	0.2562 (4)	0.0444 (3)	0.3597 (3)	0.0237 (9)
H4A	0.3235	0.0897	0.3359	0.028*
H4B	0.2013	0.1162	0.3755	0.028*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ag	0.0250 (2)	0.02315 (17)	0.02429 (18)	0.00894 (12)	0.00389 (13)	−0.00441 (11)
S	0.0181 (6)	0.0196 (5)	0.0245 (5)	−0.0014 (4)	0.0046 (4)	−0.0012 (4)
N3	0.0172 (18)	0.0154 (15)	0.0164 (16)	0.0015 (12)	0.0039 (14)	0.0006 (11)
C5	0.019 (2)	0.0209 (18)	0.022 (2)	0.0016 (15)	0.0071 (17)	0.0008 (14)
N2	0.0176 (18)	0.0200 (15)	0.0159 (16)	0.0023 (12)	0.0043 (14)	0.0007 (11)
O1	0.0311 (19)	0.0303 (15)	0.0457 (18)	0.0044 (13)	0.0028 (15)	−0.0195 (12)
O2	0.0238 (18)	0.0409 (16)	0.0336 (17)	0.0025 (13)	0.0028 (14)	0.0114 (12)
C11	0.023 (2)	0.0224 (19)	0.034 (2)	−0.0083 (16)	0.015 (2)	−0.0082 (16)
C8	0.017 (2)	0.0171 (17)	0.0159 (19)	0.0039 (14)	0.0067 (16)	−0.0023 (13)
N1	0.0181 (19)	0.0205 (16)	0.0162 (17)	0.0020 (12)	0.0022 (14)	0.0008 (11)
C1	0.022 (2)	0.0170 (18)	0.0130 (19)	−0.0001 (15)	0.0020 (16)	−0.0014 (13)
O3	0.0248 (17)	0.0280 (14)	0.0334 (16)	−0.0037 (12)	0.0126 (13)	0.0033 (11)
C3	0.015 (2)	0.0190 (18)	0.026 (2)	0.0052 (15)	0.0011 (17)	−0.0022 (15)
C2	0.016 (2)	0.0243 (19)	0.019 (2)	0.0009 (15)	0.0036 (17)	−0.0034 (14)
C10	0.014 (2)	0.027 (2)	0.022 (2)	0.0007 (16)	0.0033 (17)	−0.0062 (15)
C6	0.020 (2)	0.0224 (19)	0.021 (2)	−0.0006 (15)	0.0058 (17)	0.0002 (15)
C7	0.019 (2)	0.0205 (18)	0.019 (2)	−0.0006 (15)	0.0052 (17)	0.0000 (14)
C9	0.024 (2)	0.0205 (19)	0.019 (2)	0.0052 (16)	0.0027 (18)	−0.0005 (14)
C12	0.026 (2)	0.0191 (19)	0.023 (2)	−0.0027 (16)	0.0127 (18)	0.0008 (14)
C4	0.027 (3)	0.0194 (18)	0.021 (2)	0.0036 (16)	0.0016 (18)	0.0039 (14)

Geometric parameters (Å, º) top

Ag—C1	2.065 (4)	C8—C12	1.391 (5)
Ag—N3ⁱ	2.144 (3)	C8—C7	1.499 (5)
S—O1	1.448 (3)	N1—C1	1.345 (5)
S—O2	1.452 (3)	N1—C2	1.389 (5)
S—O3	1.453 (3)	N1—C4	1.463 (4)
S—C6	1.785 (4)	C3—C2	1.331 (5)
N3—C9	1.338 (5)	C3—H3	0.95
N3—C8	1.350 (4)	C2—H2	0.95
N3—Agⁱⁱ	2.144 (3)	C10—C9	1.375 (5)
C5—C4	1.520 (5)	C10—H10	0.95
C5—C6	1.521 (5)	C6—H6A	0.99
C5—H5A	0.99	C6—H6B	0.99
C5—H5B	0.99	C7—H7A	0.99
N2—C1	1.361 (4)	C7—H7B	0.99
N2—C3	1.383 (5)	C9—H9	0.95
N2—C7	1.456 (4)	C12—H12	0.95
C11—C10	1.379 (5)	C4—H4A	0.99
C11—C12	1.383 (5)	C4—H4B	0.99
C11—H11	0.95

C1—Ag—N3ⁱ	168.31 (12)	C2—C3—H3	126.5
O1—S—O2	113.30 (16)	N2—C3—H3	126.5
O1—S—O3	112.50 (17)	C3—C2—N1	106.4 (3)
O2—S—O3	112.94 (17)	C3—C2—H2	126.8
O1—S—C6	106.45 (17)	N1—C2—H2	126.8
O2—S—C6	105.77 (17)	C9—C10—C11	117.8 (3)
O3—S—C6	105.04 (16)	C9—C10—H10	121.1
C9—N3—C8	118.2 (3)	C11—C10—H10	121.1
C9—N3—Agⁱⁱ	119.1 (2)	C5—C6—S	113.1 (3)
C8—N3—Agⁱⁱ	122.5 (2)	C5—C6—H6A	109
C4—C5—C6	113.1 (3)	S—C6—H6A	109
C4—C5—H5A	108.9	C5—C6—H6B	109
C6—C5—H5A	108.9	S—C6—H6B	109
C4—C5—H5B	108.9	H6A—C6—H6B	107.8
C6—C5—H5B	108.9	N2—C7—C8	112.8 (3)
H5A—C5—H5B	107.8	N2—C7—H7A	109
C1—N2—C3	111.0 (3)	C8—C7—H7A	109
C1—N2—C7	124.8 (3)	N2—C7—H7B	109
C3—N2—C7	124.1 (3)	C8—C7—H7B	109
C10—C11—C12	119.7 (3)	H7A—C7—H7B	107.8
C10—C11—H11	120.1	N3—C9—C10	123.9 (3)
C12—C11—H11	120.1	N3—C9—H9	118.1
N3—C8—C12	121.3 (3)	C10—C9—H9	118.1
N3—C8—C7	116.5 (3)	C11—C12—C8	119.1 (3)
C12—C8—C7	122.1 (3)	C11—C12—H12	120.5
C1—N1—C2	111.7 (3)	C8—C12—H12	120.5
C1—N1—C4	124.4 (3)	N1—C4—C5	110.6 (3)
C2—N1—C4	123.7 (3)	N1—C4—H4A	109.5
N1—C1—N2	103.8 (3)	C5—C4—H4A	109.5
N1—C1—Ag	125.9 (2)	N1—C4—H4B	109.5
N2—C1—Ag	130.1 (3)	C5—C4—H4B	109.5
C2—C3—N2	107.1 (3)	H4A—C4—H4B	108.1

C9—N3—C8—C12	−1.1 (5)	C12—C11—C10—C9	−1.7 (5)
Agⁱⁱ—N3—C8—C12	174.2 (3)	C4—C5—C6—S	−79.6 (4)
C9—N3—C8—C7	−176.5 (3)	O1—S—C6—C5	68.0 (3)
Agⁱⁱ—N3—C8—C7	−1.3 (4)	O2—S—C6—C5	−171.2 (2)
C2—N1—C1—N2	0.0 (4)	O3—S—C6—C5	−51.5 (3)
C4—N1—C1—N2	174.1 (3)	C1—N2—C7—C8	−115.2 (4)
C2—N1—C1—Ag	175.6 (2)	C3—N2—C7—C8	67.1 (4)
C4—N1—C1—Ag	−10.3 (5)	N3—C8—C7—N2	−147.7 (3)
C3—N2—C1—N1	0.1 (4)	C12—C8—C7—N2	36.9 (5)
C7—N2—C1—N1	−177.9 (3)	C8—N3—C9—C10	−1.1 (5)
C3—N2—C1—Ag	−175.3 (3)	Agⁱⁱ—N3—C9—C10	−176.6 (3)
C7—N2—C1—Ag	6.8 (5)	C11—C10—C9—N3	2.5 (6)
N3ⁱ—Ag—C1—N1	−26.1 (8)	C10—C11—C12—C8	−0.4 (5)
N3ⁱ—Ag—C1—N2	148.3 (5)	N3—C8—C12—C11	1.8 (5)
C1—N2—C3—C2	−0.1 (4)	C7—C8—C12—C11	177.0 (3)
C7—N2—C3—C2	177.9 (3)	C1—N1—C4—C5	−106.9 (4)
N2—C3—C2—N1	0.1 (4)	C2—N1—C4—C5	66.5 (5)
C1—N1—C2—C3	0.0 (4)	C6—C5—C4—N1	172.4 (3)
C4—N1—C2—C3	−174.2 (3)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C10—H10···O3ⁱⁱⁱ	0.95	2.40	3.349 (4)	173
C6—H6A···O2^iv	0.99	2.51	3.458 (5)	160
C7—H7B···O3^v	0.99	2.38	3.367 (5)	175
C2—H2···O2^vi	0.95	2.53	3.179 (5)	126
C12—H12···O1^vii	0.95	2.47	3.143 (4)	128
C7—H7A···O3^viii	0.99	2.41	3.257 (4)	143

Symmetry codes: (iii) x+1, y, z+1; (iv) −x, −y, −z; (v) −x, −y, −z+1; (vi) −x+1/2, y−1/2, −z+1/2; (vii) x+1/2, −y+1/2, z+1/2; (viii) x+1/2, −y−1/2, z+1/2.

Acknowledgements

We are grateful to Christoph Langes for the PXRD measurement.

References

Agilent (2014). CrysAlis PRO. Agilent Technologies, Santa Clara, California, USA. Google Scholar
Burla, M. C., Camalli, M., Carrozzini, B., Cascarano, G. L., Giacovazzo, C., Polidori, G. & Spagna, R. (2003). J. Appl. Cryst. 36, 1103. CrossRef IUCr Journals Google Scholar
Catalano, V. J. & Moore, A. L. (2005). Inorg. Chem. 44, 6558–6566. Web of Science CSD CrossRef PubMed CAS Google Scholar
Catalano, V. J., Munro, L. B., Strasser, C. E. & Samin, A. F. (2011). Inorg. Chem. 50, 8465–8476. Web of Science CSD CrossRef CAS PubMed Google Scholar
Cui, F., Yang, P., Huang, X., Yang, X.-J. & Wu, B. (2012). Organometallics, 31, 3512–3518. Web of Science CSD CrossRef CAS Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Garrison, J. C., Tessier, C. A. & Youngs, W. J. (2005). J. Organomet. Chem. 690, 6008–6020. Web of Science CSD CrossRef CAS Google Scholar
Lin, J. C. Y., Huang, R. T. W., Lee, C. S., Bhattacharyya, A., Hwang, W. S. & Lin, I. J. B. (2009). Chem. Rev. 109, 3561–3598. Web of Science CrossRef PubMed CAS Google Scholar
Liu, B., Chen, W. & Jin, S. (2007). Organometallics, 26, 3660–3667. Web of Science CSD CrossRef CAS Google Scholar
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Tomás-Mendivil, E., Toullec, P. Y., Borge, J., Conejero, S., Michelet, V. & Cadierno, V. (2013). ACS Catal. 3, 3086–3098. Google Scholar
Ye, J., Chen, W. & Wang, D. (2008). Dalton Trans. pp. 4015–4022. Web of Science CSD CrossRef Google Scholar

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