Crystal structure of catena-poly[[[di­aqua­[1,2-bis(pyridin-4-yl)ethene]{4-[2-(pyridin-4-yl)ethen­yl]pyridinium}gold(I)iron(II)]-di-μ-cyanido] bis­[dicyanido­gold(I)] 1,2-bis­(pyridin-4-yl)ethene dihydrate]

Partsevska, S.V.; Naumova, D.D.; Matushko, I.P.; Shova, S.; Gural'skiy, I.A.

doi:10.1107/S2056989020006738

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ISSN: 2056-9890

Volume 76| Part 6| June 2020| Pages 944-947

https://doi.org/10.1107/S2056989020006738

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Crystal structure of catena-poly[[[diaqua[1,2-bis(pyridin-4-yl)ethene]{4-[2-(pyridin-4-yl)ethenyl]pyridinium}gold(I)iron(II)]-di-μ-cyanido] bis[dicyanidogold(I)] 1,2-bis(pyridin-4-yl)ethene dihydrate]

Sofiia V. Partsevska,^a ^* Dina D. Naumova,^a Igor P. Matushko,^a Sergiu Shova ^b and Il'ya A. Gural'skiy ^a,^c

^aDepartment of Chemistry, Taras Shevchenko National University of Kyiv, Volodymyrska St. 64, Kyiv 01601, Ukraine, ^bDepartment of Inorganic Polymers, "Petru Poni" Institute of Macromolecular Chemistry, Romanian Academy of Science, Aleea Grigore Ghica Voda 41-A, Iasi 700487, Romania, and ^cUkrOrgSyntez Ltd, Chervonotkatska St., 67, Kyiv 02094, Ukraine
^*Correspondence e-mail: sofiia.partsevska@univ.kiev.ua

Edited by B. Therrien, University of Neuchâtel, Switzerland (Received 30 April 2020; accepted 19 May 2020; online 29 May 2020)

In the title compound [Fe(bpe)(Hbpe)Au(CN)₂][Au(CN)₂]₂·bpe·2H₂O}_n [where bpe = 1,2-bis(pyridin-4-yl)ethene, C₁₂H₁₀N₂], the Fe^II ion is coordinated in a distorted octahedral [FeN₄O₂] environment by two dicyanoaurate anions, two water molecules and two partially protonated 1,2-di(4-pyridyl)ethylene molecules. Dicyanoaurate anions bridge the Fe^II cations, forming infinite chains, which propagate along the a-axis direction. The chains are connected via aurophilic interactions with two non-coordinated dicyanoaurate anions for each Fe^II ion. The polymeric chains interact with each other via π–π stacking between the guest bpe molecules and multiple hydrogen bonds.

Keywords: crystal structure; polymeric complex; iron(II) complex; dicyanoaurate; aurophilic interactions.

CCDC reference: 2004716

1. Chemical context

Iron(II) complexes exhibiting spin-crossover (SCO) properties attract considerable attention because of their fascinating ability to change multiple physical properties (magnetic, optical, mechanical, etc.) under the influence of external stimuli (Gütlich & Goodwin, 2004 ). These materials can be integrated into various devices as switches, triggers, chemical sensors, etc. (Suleimanov et al., 2015 ). For these reasons, new SCO materials, which undergo transition with defined temperature, hysteresis and abruptness are strongly desired. There are several classical approaches as how to modulate the SCO characteristics of complexes, among them the introduction of slightly modified ligands and co-ligands to obtain new SCO compounds and inclusion of some guest molecules to already existing complexes (Ni et al., 2017 ).

Fe^II Hofmann clathrate (Hofmann & Höchtlen, 1903 ) analogues represent one of the biggest classes of SCO coordination compounds. They are cyanobimetallic complexes of general formula [Fe(L)_n{M(CN)_x}_y] in which the Fe^II ions are connected by bridging cyanometallic anions into infinite layers (n = 2 for monodentate ligands and n = 1 for bis-monodentate ligands). These layers are supported by N-donor aromatic ligands (L = pyridine, diazines and their substituted analogues). Di-, tetra- and octacyanometallic (x = 2, y = 2: M = Cu, Ag, Au; x = 4, y = 1: M = Ni, Pd, Pt) anions have been introduced to develop coordination compounds of this kind. It has been shown that the inclusion of guest molecules can significantly influence the temperature, completeness and step character of spin transition in complexes belonging to this class (Ohtani & Hayami, 2017 ). In order to develop new SCO Hofmann clathrate analogues with voids big enough to incorporate bulky guest molecules, some bis-monodentate pyridine-based ligands have been introduced, such as 4,4′-bipyridine (Yoshida et al., 2013 ), bis(4-pyridyl)acetylene (Bartual-Murgui et al., 2011 ), bis(4-pyridyl)ethylene (Muñoz-Lara et al., 2012 ), etc.

Here we describe the crystal structure of a new cyanometallic Fe^II complex with bpe of general formula [Fe(bpe)(Hbpe)Au(CN)₂](Au(CN)₂)₂·bpe·2H₂O in which the Fe^II ions are stabilized in the high-spin (HS) state.

2. Structural commentary

The title compound crystallizes in the triclinic P $[\overline{1}]$ space group. The iron(II) ion has a distorted [FeN₄O₂] octahedral environment (Fig. 1) formed by two molecules of 1,2-bis(4-pyridyl)ethylene (bpe) [Fe1—N4 = 2.223 (6) Å], two molecules of water [Fe1–O1 = 2.081 (5) Å] and two cyano bridges [Fe1—N1 = 2.180 (6) Å]. Notably, the N5 atoms of the coordinated bpe molecules are protonated (with 0.5 occupancy of each H atom). These N5 atoms create hydrogen bonds with symmetry-generated N5 atoms of bpe molecules from the neighbouring chain [N5⋯N5ⁱ = 2.677 (14) Å, N5—H5A⋯N5ⁱ = 176°; Table 1].

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1A⋯O2	0.93	1.86	2.744 (13)	156
O1—H1B⋯N6	0.93	1.85	2.736 (9)	158
C7—H7⋯N2B	0.93	2.08	2.78 (3)	132
N5—H5A⋯N5ⁱ	0.86	1.82	2.677 (14)	176
O2—H2A⋯N2Aⁱⁱ	0.96	2.49	3.45 (7)	179
O2—H2B⋯N3Bⁱⁱⁱ	0.94	2.43	3.37 (3)	172
O3—H3B⋯N3A	0.92	2.08	2.99 (3)	167
O3—H3A⋯N2A^iv	0.92	2.11	2.98 (4)	159
O3—H3C⋯O3^v	0.94	1.75	2.69 (4)	179
Symmetry codes: (i) -x+2, -y+2, -z; (ii) -x+3, -y, -z-1; (iii) x+1, y, z; (iv) -x+2, -y+1, -z-1; (v) -x+1, -y+1, -z.

Figure 1
A fragment of the crystal structure of the title compound showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. The guest bpe molecule and disorder of the [Au(CN)₂]⁻ counter-ions are not shown for clarity. Symmetry-generated atoms are not labelled.

The deviation from the ideal octahedral geometry of the Fe^II coordination environment is Σ|90 − θ| = 6.8°, where θ are cis-N—Fe—N or cis-N—Fe—O angles. Two CN⁻ anions bridge the Fe²⁺ and Au⁺ cations [Fe1⋯Au1 = 5.280 (3) Å], creating a one-dimensional polymer, Fe1—N1—C1 = 172.8 (7)°, N1—C1—Au1 = 179.1 (8)° and C1—Au1—C1 = 180.0°, leading to a very slight deviation from linearity of the chains. This chain binds one guest bpe and two guest water molecules per Fe^II centre.

3. Supramolecular features

The structure is characterized by the presence of several different kinds of weak interactions that create a three-dimensional supramolecular framework. Two free [Au(CN)₂]⁻ counter-ions are connected with the polymeric chains by aurophilic interactions and C7⋯N2B hydrogen bonds [C7⋯N2B = 2.78 (3) Å, C7—H7⋯N2B = 132°]. These free counter-ions are disordered over two positions with Au1—Au2A = 3.324 (1) Å and Au1—Au2B = 3.101 (5) Å. The polymeric chains are connected to each other via π–π interactions (Fig. 2) between the coordinated and guest molecules of bpe (Cg1⋯Cg2 = 3.650 (5) Å, α = 10.3°, offset = 1.043 Å, where Cg1 and Cg2 are the centroids of the N4/C4–C8 and N6/C16–C20 rings, respectively, and Cg3⋯Cg4 = 3.794 (6) Å, α = 6.8°, offset = 1.835 Å, where Cg3 and Cg4 are the centroids of N5/C11–C15 and N6ⁱⁱ/ Cⁱⁱ16–C20 rings, respectively]. Guest bpe molecules are additionally linked to the polymeric chains by hydrogen bonds with coordinated water molecules [O1⋯N6 = 2.736 (9) Å, O1—H1B⋯N6 = 158°]. One of the guest water molecules forms hydrogen bonds with the coordinated water [Fig. 3; O2⋯O1 = 2.744 (13) Å, O1—H1A⋯O2 = 156°] and weak hydrogen bonds with free dicyanoaurate counter-ions [O2⋯N2Aⁱⁱ = 3.45 (7) Å, O2—H2A⋯N2Aⁱⁱ = 179°; O2⋯N3Bⁱⁱⁱ = 3.37 (3) Å, O2—H2B⋯N3Bⁱⁱⁱ = 172°. The O3 guest water atom is bound to another symmetry-generated counterpart [O3⋯O3^v = 2.69 (4) Å, O3—H3C⋯O3^v = 179°] and free dicyanoaurate counter-ions [O3⋯N3A = 2.99 (3) Å, O3—H3B⋯N3A = 167°; O3⋯N2A^iv = 2.98 (4) Å, O3—H3A⋯N2A^iv = 159°]. Hydrogen-bonding parameters are summarized in Table 1.

Figure 2
A view along the c axis of the crystal packing of the title compound. π–π contacts and hydrogen bonds are shown as black dashed lines. Aurophilic interactions are shown as orange dashed lines. Guest water molecules are omitted for clarity.

Figure 3
A view along the a axis of the crystal packing showing the network of hydrogen bonds as black dashed lines. H atoms not involved in hydrogen bonding and guest bpe molecules are omitted for clarity.

4. Database survey

A search of the Cambridge Structural Database (CSD version 5.40, last update February 2019; Groom et al., 2016 ) revealed that the current structure has never been published before. 101 cyanometallic structures containing Fe—N≡C—Au fragments were found. These hits include multiple temperature-dependant measurements, which were conducted to study the spin-crossover characteristics of Fe^II complexes. For example, these hits include a three-dimensional framework catena-[tetra(μ-cyano)(μ-pyrazine)irondigold] (IRIKUR01–IRIKUR09; Gural'skiy et al., 2016 ). One particular compound resembles the title MOF: catena-[bis(μ-cyano)bis(2-phenylpyrazine)bis(aqua)iron(II)gold(I) bis(cyano)gold(I)] (MOJFEZ; Kucheriv et al., 2019 ).

5. Synthesis and crystallization

Crystals of the title compound were prepared by the slow diffusion method between three layers in a 3 ml tube. The first layer was a solution of K[Au(CN)₂] (0.03 mmol) in water (0.5 ml), the second was a mixture of water/ethanol (1:2, 1.5 ml) and the third layer was a solution of 1,2-di(4-pyridyl)ethylene (0.05 mmol) and [Fe(OTs)₂]·6H₂O (0.01 mmol; OTs = p-toluenesulfonate) in ethanol (0.5 ml) with 0.2 ml of water. After two weeks, red crystals grew in the second layer; the crystals were collected and kept in the mother solution prior to measurement.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The hydrogen atoms were placed at their expected calculated positions (C—H = 0.93, N—H = 0.86, O—H = 0.92–0.96 Å) and refined as riding for the guest water molecules (O2, O3) and aromatic rings, and as rotating for the coordinated water molecule (O1) with U_i_so(H) = 1.2U_iso(C), U_iso(H) = 1.2U_iso(N), U_iso(H) = 1.5U_iso(O). U_aniso values for all C and N atoms in the guest dicyanoaurate anions and the O2 and O3 water molecules were constrained to be equal using the EADP command. Distances N3A—C3A and N2A—C2A were restrained to a target of 1.15 Å and distances Au2A—C3A and Au2A—C2A were restrained to a target of 1.99 Å using the DFIX command. The following distances were restrained to be equal using the SADI command: C2A—N2A and C2B—N2B; Au1—C2A and Au1—C2B; C3A—N3A and C3B—N3B; Au1—C3A and Au1—C3B; C2A—C3A and C2B—C3B.

Table 2
Experimental details

Crystal data
Chemical formula	[AuFe(C₁₂H₁₁N₂)(CN)₂(C₁₂H₁₀N₂)][Au(CN)₂]₂·C₁₂H₁₀N₂·2H₂O
M_r	1422.60
Crystal system, space group	Triclinic, P $[\overline{1}]$
Temperature (K)	293
a, b, c (Å)	10.5601 (7), 11.0044 (12), 11.8145 (10)
α, β, γ (°)	80.212 (8), 69.124 (7), 78.565 (7)
V (Å³)	1249.9 (2)
Z	1
Radiation type	Mo Kα
μ (mm⁻¹)	9.11
Crystal size (mm)	0.4 × 0.3 × 0.2

Data collection
Diffractometer	Rigaku Oxford Diffraction Xcalibur, Eos
Absorption correction	Multi-scan (CrysAlis PRO; Rigaku OD, 2018)
T_min, T_max	0.350, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	9662, 4402, 3540
R_int	0.042
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.156, 1.04
No. of reflections	4402
No. of parameters	272
No. of restraints	9
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	2.27, −1.04
Computer programs: CrysAlis PRO (Rigaku OD, 2018 $[Rigaku OD (2016). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, England.]$ ), SHELXT2014/5 (Sheldrick, 2015a ), SHELXL (Sheldrick, 2015b ) and OLEX2 (Dolomanov et al., 2009 ).

Supporting information

CCDC reference: 2004716

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989020006738/tx2022sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989020006738/tx2022Isup2.hkl

checkCIF report

Computing details top

Data collection: CrysAlis PRO (Rigaku OD, 2018); cell refinement: CrysAlis PRO (Rigaku OD, 2018); data reduction: CrysAlis PRO (Rigaku OD, 2018); program(s) used to solve structure: SHELXT2014/5 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

catena-Poly[[[diaqua[1,2-bis(pyridin-4-yl)ethene]{4-[2-(pyridin-4-yl)ethenyl]pyridinium}gold(I)iron(II)]-di-µ-cyanido] bis[dicyanidogold(I)] 1,2-bis(pyridin-4-yl)ethene dihydrate] top

Crystal data top

[AuFe(C₁₂H₁₁N₂)(CN)₂(C₁₂H₁₀N₂)][Au(CN)₂]₂·C₁₂H₁₀N₂·2H₂O	Z = 1
M_r = 1422.60	F(000) = 670
Triclinic, P1	D_x = 1.890 Mg m⁻³
a = 10.5601 (7) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.0044 (12) Å	Cell parameters from 3572 reflections
c = 11.8145 (10) Å	θ = 1.9–27.9°
α = 80.212 (8)°	µ = 9.11 mm⁻¹
β = 69.124 (7)°	T = 293 K
γ = 78.565 (7)°	Block, red
V = 1249.9 (2) Å³	0.4 × 0.3 × 0.2 mm

Data collection top

Rigaku Oxford Diffraction Xcalibur, Eos diffractometer	3540 reflections with I > 2σ(I)
Detector resolution: 8.0797 pixels mm^-1	R_int = 0.042
ω scans	θ_max = 25.0°, θ_min = 1.9°
Absorption correction: multi-scan (CrysAlisPro; Rigaku OD, 2018)	h = −11→12
T_min = 0.350, T_max = 1.000	k = −13→12
9662 measured reflections	l = −11→14
4402 independent reflections

Refinement top

Refinement on F²	9 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.050	H-atom parameters constrained
wR(F²) = 0.156	w = 1/[σ²(F_o²) + (0.0855P)² + 0.8591P] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max < 0.001
4402 reflections	Δρ_max = 2.27 e Å⁻³
272 parameters	Δρ_min = −1.04 e Å⁻³

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
Au1	1.000000	0.000000	−0.500000	0.0441 (2)
Fe1	1.500000	0.000000	−0.500000	0.0292 (4)
N6	1.2335 (8)	0.1426 (7)	−0.1913 (6)	0.0501 (18)
O1	1.4274 (5)	−0.0394 (6)	−0.3113 (5)	0.0438 (14)
H1A	1.496163	−0.065149	−0.276444	0.066*
H1B	1.381652	0.030289	−0.270914	0.066*
C8	1.3795 (8)	0.2828 (8)	−0.5220 (7)	0.0423 (19)
H8	1.353283	0.259226	−0.581414	0.051*
C5	1.4616 (8)	0.3566 (8)	−0.3576 (8)	0.043 (2)
H5	1.495858	0.380110	−0.303466	0.052*
C4	1.5067 (7)	0.2397 (8)	−0.3988 (7)	0.0395 (19)
H4	1.570087	0.185167	−0.369306	0.047*
C18	1.0834 (8)	0.3621 (9)	−0.0954 (8)	0.048 (2)
N4	1.4646 (6)	0.2017 (6)	−0.4772 (5)	0.0317 (14)
C21	0.9996 (10)	0.4782 (10)	−0.0484 (8)	0.055 (2)
H21	0.942320	0.523726	−0.089865	0.066*
C9	1.2973 (8)	0.5573 (8)	−0.3485 (8)	0.044 (2)
H9	1.240584	0.609573	−0.386971	0.053*
C17	1.1829 (10)	0.2903 (10)	−0.0506 (8)	0.059 (3)
H17	1.201690	0.315099	0.012449	0.071*
N1	1.2923 (6)	0.0142 (7)	−0.5030 (6)	0.0433 (17)
C19	1.0669 (9)	0.3182 (10)	−0.1910 (8)	0.052 (2)
H19	1.003778	0.363330	−0.226531	0.063*
C20	1.1418 (9)	0.2094 (9)	−0.2342 (9)	0.055 (2)
H20	1.126215	0.181889	−0.297643	0.065*
C6	1.3638 (8)	0.4388 (8)	−0.3989 (7)	0.0412 (19)
C11	1.2282 (9)	0.7084 (8)	−0.1962 (8)	0.048 (2)
C7	1.3274 (8)	0.4002 (8)	−0.4855 (7)	0.0415 (19)
H7	1.267286	0.453324	−0.519895	0.050*
C15	1.1322 (10)	0.7868 (9)	−0.2320 (9)	0.057 (3)
H15	1.116876	0.775000	−0.301887	0.069*
C10	1.3093 (9)	0.5968 (8)	−0.2560 (8)	0.047 (2)
H10	1.375191	0.550547	−0.224182	0.057*
N5	1.0744 (8)	0.9079 (7)	−0.0674 (7)	0.0513 (19)
H5A	1.025191	0.968647	−0.026905	0.062*	0.5
C1	1.1866 (8)	0.0083 (8)	−0.5027 (7)	0.0413 (19)
C13	1.1698 (10)	0.8351 (10)	−0.0344 (9)	0.061 (3)
H13	1.185868	0.851036	0.033766	0.073*
C12	1.2496 (10)	0.7344 (9)	−0.0949 (9)	0.057 (2)
H12	1.317168	0.684662	−0.067302	0.069*
C16	1.2541 (9)	0.1809 (10)	−0.1014 (9)	0.058 (3)
H16	1.319389	0.132921	−0.069841	0.070*
C14	1.0551 (11)	0.8852 (10)	−0.1667 (9)	0.064 (3)
H14	0.987822	0.937040	−0.193066	0.077*
N3A	0.7442 (6)	0.2821 (9)	−0.2440 (3)	0.140 (5)	0.8
C3A	0.8293 (4)	0.2875 (6)	−0.3312 (2)	0.140 (5)	0.8
Au2A	0.96785 (10)	0.30552 (9)	−0.49275 (9)	0.1010 (3)	0.8
C2A	1.1004 (4)	0.3499 (6)	−0.6389 (3)	0.140 (5)	0.8
N2A	1.1797 (6)	0.3786 (9)	−0.7294 (4)	0.140 (5)	0.8
N3B	0.703 (3)	0.119 (3)	−0.1529 (17)	0.140 (5)	0.2
C3B	0.7686 (18)	0.1679 (19)	−0.2399 (12)	0.140 (5)	0.2
Au2B	0.8855 (5)	0.2557 (4)	−0.3973 (6)	0.151 (2)	0.2
C2B	1.010 (2)	0.3636 (18)	−0.4940 (14)	0.140 (5)	0.2
N2B	1.095 (3)	0.424 (3)	−0.552 (2)	0.140 (5)	0.2
O2	1.5706 (15)	−0.1345 (17)	−0.1543 (12)	0.109 (5)	0.6
H2A	1.640962	−0.201711	−0.187906	0.164*	0.6
H2B	1.609492	−0.067311	−0.147186	0.164*	0.6
O3	0.574 (2)	0.503 (3)	−0.1194 (19)	0.109 (5)	0.4
H3B	0.617417	0.427938	−0.148163	0.164*	0.2
H3A	0.637317	0.556568	−0.154373	0.164*	0.4
H3C	0.522617	0.501478	−0.035993	0.164*	0.2

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Au1	0.0232 (2)	0.0500 (3)	0.0655 (4)	−0.00604 (19)	−0.0212 (2)	−0.0086 (2)
Fe1	0.0194 (7)	0.0277 (9)	0.0434 (8)	−0.0019 (6)	−0.0110 (6)	−0.0127 (6)
N6	0.056 (4)	0.038 (5)	0.048 (4)	−0.004 (4)	−0.005 (4)	−0.012 (3)
O1	0.041 (3)	0.045 (4)	0.044 (3)	0.005 (3)	−0.013 (3)	−0.014 (3)
C8	0.041 (4)	0.041 (5)	0.047 (5)	−0.003 (4)	−0.014 (4)	−0.015 (4)
C5	0.042 (4)	0.036 (5)	0.054 (5)	−0.009 (4)	−0.013 (4)	−0.017 (4)
C4	0.034 (4)	0.035 (5)	0.055 (5)	0.000 (3)	−0.019 (4)	−0.020 (4)
C18	0.037 (4)	0.045 (6)	0.051 (5)	−0.013 (4)	0.003 (4)	−0.011 (4)
N4	0.029 (3)	0.024 (4)	0.044 (4)	0.000 (3)	−0.014 (3)	−0.011 (3)
C21	0.052 (5)	0.048 (6)	0.065 (6)	−0.003 (4)	−0.014 (5)	−0.024 (5)
C9	0.035 (4)	0.031 (5)	0.065 (6)	0.000 (3)	−0.016 (4)	−0.008 (4)
C17	0.064 (6)	0.072 (8)	0.046 (5)	−0.012 (5)	−0.016 (5)	−0.021 (5)
N1	0.030 (3)	0.037 (4)	0.066 (5)	−0.004 (3)	−0.018 (3)	−0.011 (3)
C19	0.052 (5)	0.059 (7)	0.042 (5)	−0.006 (5)	−0.011 (4)	−0.009 (4)
C20	0.054 (5)	0.051 (6)	0.057 (6)	−0.010 (5)	−0.010 (5)	−0.019 (5)
C6	0.031 (4)	0.041 (5)	0.050 (5)	−0.004 (3)	−0.008 (3)	−0.014 (4)
C11	0.048 (5)	0.037 (5)	0.055 (5)	−0.009 (4)	−0.006 (4)	−0.019 (4)
C7	0.042 (4)	0.036 (5)	0.051 (5)	−0.005 (4)	−0.021 (4)	−0.008 (4)
C15	0.071 (6)	0.041 (6)	0.065 (6)	0.009 (5)	−0.027 (5)	−0.029 (5)
C10	0.056 (5)	0.034 (5)	0.055 (5)	−0.003 (4)	−0.018 (4)	−0.016 (4)
N5	0.056 (5)	0.039 (5)	0.053 (4)	−0.004 (4)	−0.006 (4)	−0.020 (4)
C1	0.026 (4)	0.043 (5)	0.054 (5)	−0.005 (3)	−0.012 (4)	−0.008 (4)
C13	0.058 (6)	0.064 (7)	0.066 (6)	−0.014 (5)	−0.016 (5)	−0.031 (5)
C12	0.064 (6)	0.047 (6)	0.065 (6)	−0.004 (5)	−0.022 (5)	−0.021 (5)
C16	0.047 (5)	0.057 (7)	0.062 (6)	0.008 (5)	−0.014 (5)	−0.014 (5)
C14	0.075 (7)	0.046 (7)	0.076 (7)	0.010 (5)	−0.033 (6)	−0.024 (5)
N3A	0.181 (11)	0.132 (9)	0.155 (11)	0.018 (9)	−0.130 (10)	−0.026 (9)
C3A	0.181 (11)	0.132 (9)	0.155 (11)	0.018 (9)	−0.130 (10)	−0.026 (9)
Au2A	0.1098 (6)	0.0872 (7)	0.1463 (8)	0.0284 (5)	−0.0985 (6)	−0.0475 (5)
C2A	0.181 (11)	0.132 (9)	0.155 (11)	0.018 (9)	−0.130 (10)	−0.026 (9)
N2A	0.181 (11)	0.132 (9)	0.155 (11)	0.018 (9)	−0.130 (10)	−0.026 (9)
N3B	0.181 (11)	0.132 (9)	0.155 (11)	0.018 (9)	−0.130 (10)	−0.026 (9)
C3B	0.181 (11)	0.132 (9)	0.155 (11)	0.018 (9)	−0.130 (10)	−0.026 (9)
Au2B	0.174 (4)	0.092 (3)	0.276 (6)	0.037 (3)	−0.186 (5)	−0.081 (4)
C2B	0.181 (11)	0.132 (9)	0.155 (11)	0.018 (9)	−0.130 (10)	−0.026 (9)
N2B	0.181 (11)	0.132 (9)	0.155 (11)	0.018 (9)	−0.130 (10)	−0.026 (9)
O2	0.101 (10)	0.146 (14)	0.087 (8)	0.033 (9)	−0.066 (7)	−0.010 (8)
O3	0.101 (10)	0.146 (14)	0.087 (8)	0.033 (9)	−0.066 (7)	−0.010 (8)

Geometric parameters (Å, º) top

Au1—C1ⁱ	1.979 (7)	N1—C1	1.130 (10)
Au1—C1	1.979 (7)	C19—H19	0.9300
Au1—Au2A	3.3243	C19—C20	1.366 (13)
Au1—Au2Aⁱ	3.3243	C20—H20	0.9300
Au1—Au2B	3.101 (4)	C6—C7	1.367 (11)
Au1—Au2Bⁱ	3.101 (4)	C11—C15	1.336 (13)
Fe1—O1ⁱⁱ	2.081 (5)	C11—C10	1.479 (11)
Fe1—O1	2.081 (5)	C11—C12	1.379 (12)
Fe1—N4	2.223 (6)	C7—H7	0.9300
Fe1—N4ⁱⁱ	2.223 (6)	C15—H15	0.9300
Fe1—N1ⁱⁱ	2.180 (6)	C15—C14	1.385 (12)
Fe1—N1	2.181 (6)	C10—H10	0.9300
N6—C20	1.294 (12)	N5—H5A	0.8600
N6—C16	1.307 (12)	N5—C13	1.290 (12)
O1—H1A	0.9319	N5—C14	1.330 (12)
O1—H1B	0.9285	C13—H13	0.9300
C8—H8	0.9300	C13—C12	1.385 (13)
C8—N4	1.320 (10)	C12—H12	0.9300
C8—C7	1.377 (11)	C16—H16	0.9300
C5—H5	0.9300	C14—H14	0.9300
C5—C4	1.387 (11)	N3A—C3A	1.1014
C5—C6	1.401 (12)	C3A—Au2A	1.9543
C4—H4	0.9300	Au2A—C2A	1.8554
C4—N4	1.315 (9)	C2A—N2A	1.1381
C18—C21	1.472 (13)	N3B—C3B	1.1270
C18—C17	1.390 (13)	C3B—Au2B	2.0356
C18—C19	1.377 (12)	Au2B—C2B	1.8767
C21—C21ⁱⁱⁱ	1.317 (17)	C2B—N2B	1.1712
C21—H21	0.9300	O2—H2A	0.9640
C9—H9	0.9300	O2—H2B	0.9427
C9—C6	1.466 (11)	O3—H3B	0.9225
C9—C10	1.298 (11)	O3—H3A	0.9170
C17—H17	0.9300	O3—H3C	0.9389
C17—C16	1.393 (13)

C1ⁱ—Au1—C1	180.0	C16—C17—H17	120.4
C1ⁱ—Au1—Au2A	98.7 (3)	C1—N1—Fe1	172.8 (7)
C1—Au1—Au2A	81.3 (3)	C18—C19—H19	119.5
C1—Au1—Au2Aⁱ	98.7 (14)	C20—C19—C18	121.0 (9)
C1ⁱ—Au1—Au2Aⁱ	81.3 (14)	C20—C19—H19	119.5
C1ⁱ—Au1—Au2B	88.0 (3)	N6—C20—C19	123.2 (9)
C1—Au1—Au2B	92.0 (3)	N6—C20—H20	118.4
C1ⁱ—Au1—Au2Bⁱ	92 (3)	C19—C20—H20	118.4
C1—Au1—Au2Bⁱ	88 (3)	C5—C6—C9	122.6 (7)
Au2Aⁱ—Au1—Au2A	180.0 (18)	C7—C6—C5	116.4 (8)
Au2B—Au1—Au2Bⁱ	180 (5)	C7—C6—C9	120.9 (8)
O1ⁱⁱ—Fe1—O1	180.0	C15—C11—C10	124.7 (8)
O1ⁱⁱ—Fe1—N4ⁱⁱ	89.1 (2)	C15—C11—C12	116.4 (9)
O1—Fe1—N4	89.1 (2)	C12—C11—C10	118.9 (9)
O1ⁱⁱ—Fe1—N4	90.9 (2)	C8—C7—H7	119.9
O1—Fe1—N4ⁱⁱ	90.9 (2)	C6—C7—C8	120.1 (8)
O1—Fe1—N1ⁱⁱ	90.4 (2)	C6—C7—H7	119.9
O1—Fe1—N1	89.6 (2)	C11—C15—H15	119.5
O1ⁱⁱ—Fe1—N1ⁱⁱ	89.6 (2)	C11—C15—C14	121.1 (9)
O1ⁱⁱ—Fe1—N1	90.4 (2)	C14—C15—H15	119.5
N4—Fe1—N4ⁱⁱ	180.0	C9—C10—C11	126.2 (9)
N1ⁱⁱ—Fe1—N4	89.6 (2)	C9—C10—H10	116.9
N1ⁱⁱ—Fe1—N4ⁱⁱ	90.4 (2)	C11—C10—H10	116.9
N1—Fe1—N4ⁱⁱ	89.6 (2)	C13—N5—H5A	121.4
N1—Fe1—N4	90.4 (2)	C13—N5—C14	117.3 (8)
N1ⁱⁱ—Fe1—N1	180.0	C14—N5—H5A	121.4
C20—N6—C16	118.2 (8)	N1—C1—Au1	179.0 (8)
Fe1—O1—H1A	114.1	N5—C13—H13	118.2
Fe1—O1—H1B	113.4	N5—C13—C12	123.5 (9)
H1A—O1—H1B	100.1	C12—C13—H13	118.2
N4—C8—H8	118.2	C11—C12—C13	119.6 (9)
N4—C8—C7	123.6 (7)	C11—C12—H12	120.2
C7—C8—H8	118.2	C13—C12—H12	120.2
C4—C5—H5	120.5	N6—C16—C17	123.0 (9)
C4—C5—C6	119.0 (7)	N6—C16—H16	118.5
C6—C5—H5	120.5	C17—C16—H16	118.5
C5—C4—H4	118.2	C15—C14—H14	119.0
N4—C4—C5	123.5 (8)	N5—C14—C15	122.1 (9)
N4—C4—H4	118.2	N5—C14—H14	119.0
C17—C18—C21	124.5 (8)	N3A—C3A—Au2A	174.7
C19—C18—C21	120.2 (9)	C3A—Au2A—Au1	88.63 (19)
C19—C18—C17	115.4 (9)	C2A—Au2A—Au1	101.1 (2)
C8—N4—Fe1	121.6 (5)	C2A—Au2A—C3A	169.8
C4—N4—Fe1	120.0 (5)	N2A—C2A—Au2A	178.6
C4—N4—C8	117.1 (7)	N3B—C3B—Au2B	179.57 (10)
C18—C21—H21	117.8	C3B—Au2B—Au1	89.4 (6)
C21ⁱⁱⁱ—C21—C18	124.4 (12)	C2B—Au2B—Au1	105.7 (7)
C21ⁱⁱⁱ—C21—H21	117.8	C2B—Au2B—C3B	156.3
C6—C9—H9	116.6	N2B—C2B—Au2B	174.6
C10—C9—H9	116.6	H2A—O2—H2B	110.8
C10—C9—C6	126.9 (8)	H3B—O3—H3A	104.8
C18—C17—H17	120.4	H3A—O3—H3C	120.1
C18—C17—C16	119.2 (9)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···O2	0.93	1.86	2.744 (13)	156
O1—H1B···N6	0.93	1.85	2.736 (9)	158
C7—H7···N2B	0.93	2.08	2.78 (3)	132
N5—H5A···N5^iv	0.86	1.82	2.677 (14)	176
O2—H2A···N2Aⁱⁱ	0.96	2.49	3.45 (7)	179
O2—H2B···N3B^v	0.94	2.43	3.37 (3)	172
O3—H3B···N3A	0.92	2.08	2.99 (3)	167
O3—H3A···N2A^vi	0.92	2.11	2.98 (4)	159
O3—H3C···O3^vii	0.94	1.75	2.69 (4)	179

Symmetry codes: (ii) −x+3, −y, −z−1; (iv) −x+2, −y+2, −z; (v) x+1, y, z; (vi) −x+2, −y+1, −z−1; (vii) −x+1, −y+1, −z.

Funding information

Funding for this research was provided by: Ministry of Education and Science of Ukraine (grant No. 19BF037-01M; grant No. 19BF037-04); H2020-MSCA-RISE-2016 (grant No. 734322).

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