Synthesis and crystal structure of 1,1′-bis­{[4-(pyridin-2-yl)-1,2,3-triazol-1-yl]meth­yl}ferrocene, and its complexation with Cu^I

The ferrocene-bridged compound 1,1′-bis­(pyridyl­triazoylmeth­yl)ferrocene acquires an anti conformation in its solid state but forms a discrete tetra­nuclear [2 + 2] complex with [Cu(CH₃CN)₄](PF₆) in solution.

Abstract

The title compound, [Fe(C₁₃H₁₁N₄)₂], was synthesized starting from 1,1′-ferro­cene­di­carb­oxy­lic acid in a three-step reaction sequence. The di­carb­oxy­lic acid was reduced to 1,1′-ferrocenedi­methanol using LiAlH₄ and subsequently converted to 1,1′-bis­(azido­meth­yl)ferrocene in the presence of NaN₃. The diazide was treated with 2-ethynyl­pyridine under ‘click’ conditions to give the title compound in 75% yield. The Fe^II center lies on an inversion center in the crystal. The two pyridyl­triazole wings are oriented in an anti conformation and positioned exo from the Fe^II center. In the solid state, the mol­ecules inter­act by C—H⋯N, C—H⋯π, and π–π inter­actions. The complexation of the ligand with [Cu(CH₃CN)₄](PF₆) gives a tetra­nuclear dimeric complex.

Chemical context  

Metal–organic supra­molecular chemistry is an emerging area in inorganic chemistry: the structurally challenging functional supra­molecules can be constructed from the self-assembly of multidentate organic ligands and transition-metal ions in relatively few synthetic steps (Cook & Stang, 2015 ▸). Such supra­molecules are designed by careful selection of the conformational flexibility of the linker groups in multidentate ligands, and the coordination preference of transition-metal ions. We have recently studied the self-assemblies of m-xylylene- or 2,7-naphthalene­bis­(methyl­ene)-bridged tetra­dentate bis­(pyridyl­triazole) ligands with Cu^II ions to give discrete [2 + 2] metallocycles (Pokharel et al., 2013 ▸, 2014 ▸). In a continuation of our work, we became inter­ested in the design of metalloligands, i.e., metal-containing organic linkers, to produce mixed-metal complexes with different topologies.

Ferrocene, a well-known metallocene, exhibits high thermal stability, reversible electrochemistry, and conformational flexibility, making it an ideal precursor for the development of polymetallic metallo­supra­molecular complexes (Astruc, 2017 ▸). Introduction of the iron(II) center as the structural component of the ligand allows the study of electronic coupling between metal centers in heterometallic metallo­supra­molecular assemblies. Although 1,1′-disubstituted ferrocenes featuring the pyridyl moiety as a donor group have been exploited in metallo­supra­molecular assemblies (Quinodoz et al., 2004 ▸; Buda et al., 1998 ▸; Ion et al., 2002 ▸; Lindner et al., 2003 ▸; Sachsinger & Hall, 1997 ▸), the ferrocene-bridged bis­(pyridyl­triazole)-based tetra­dentate ligands are relatively new in coordination chemistry (Findlay et al., 2018 ▸; Manck et al., 2017 ▸; Romero et al., 2011 ▸). Herein, we report the synthesis of the 1,1′-bis­(methyl­ene­pyridyl­triazole) ferrocene ligand starting from 1,1′-ferrocenedi­carb­oxy­lic acid in a three-step sequence and its complexation with Cu^I ions (Fig. 1 ▸).

Figure 1.

The synthetic scheme showing the formation of the title compound and its complexation with Cu^I.

1,1′-Ferrocenedi­methanol, 2, was synthesized by reduction of 1,1′-ferrocenedi­carb­oxy­lic acid, 1, in the presence of LiAlH₄. The diol was treated with sodium azide in acetic acid following published procedures (Casas-Solvas et al., 2009 ▸) to give 1,1′-bis­(azido­meth­yl)ferrocene, 3 as a viscous liquid. The compound showed a strong IR absorption at 2093 cm⁻¹, indicating the formation of the desired diazide (Casas-Solvas et al., 2009 ▸). The diazide was treated with 2-ethynyl­pyridine under ‘click’ conditions (Pokharel et al., 2013 ▸) to give the title compound in 75% yield. This new tetra­dentate ligand based on ferrocene is obtained as an air-stable light-brown crystalline powder.

Structural commentary  

The asymmetric unit of the title compound contains one half of the mol­ecule since the Fe^II center is on an inversion center, as shown in Fig. 2 ▸. The symmetry in the mol­ecule was also apparent in the NMR data where only one set of signals was found for the protons and carbons of the cyclo­penta­dienyl (Cp) rings, methyl­ene groups, and the pyridyl­triazole units. The Fe—C(Cp) bond lengths are in the range 2.0349 (12)–2.0471 (13) Å [average 2.0498 (13) Å] with the Fe⋯Cp-centroid distance being 1.6550 (6) Å. The Fe—C bond to the substituted carbon [Fe—C1 2.0349 (12)] is shorter than the remaining Fe—C bond lengths, as is seen in similar 1,1′-disubstituted ferrocene derivatives (Glidewell et al., 1994 ▸). The conformation of the ferrocenyl unit is exactly staggered by inversion symmetry, and the centrosymmetry also makes the Cp—Fe—Cp linkage linear and the Cp rings parallel. The Csp ³ atom, C6, is displaced towards the Fe^II center by 0.044 (3) Å from the least-squares plane of the Cp ring. The C_Cp—Csp ³ and C_Cp—N bond lengths involving C6 are 1.4910 (19) and 1.4700 (18) Å, respectively. The pyridyl­triazole moiety is oriented exo from the Fe^II center, with the least-squares planes of the Cp and triazole rings forming a dihedral angle of 65.68 (5)°. The nitro­gen donor atoms of the pyridyl­triazole units adopt an anti conformation, as is often observed in this type of chelating ligand (Crowley & Bandeen, 2010 ▸). The pyridyl and triazole units deviate slightly from coplanarity, with the N3—C7—C9—N4 torsion angle being 167.64 (13)°.

Figure 2.

Mol­ecular structure of the title compound showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. Unlabeled atoms are generated by the symmetry operation 1 − x, 1 − y, 1 − z.

Supra­molecular features  

The crystal structure of the title compound is consolidated by inter­molecular C—H⋯N (Table 1 ▸), C—H⋯π, and π–π inter­actions (Figs. 3 ▸ and 4 ▸). The triazole carbon C8 forms a C—H⋯N inter­action, with a C⋯N distance of 3.601 (2) Å to triazole N3 (at x − 1, y, z) and the Cp carbon atom C5 forms a C—H⋯N inter­action with a C⋯N distance of 3.4240 (19) Å to triazole N2 (at x − 1, y, z). These two contacts form a ring with graph-set motif (9) (Etter et al., 1990 ▸). In addition, the triazole carbon C3 forms a C—H⋯N inter­action with a C⋯N distance of 3.4625 (19) Å to pyridyl nitro­gen N4 (at x, y + 1, z). Thus, the C—H⋯N contacts form a two-dimensional network normal to [001]. The pyridyl­triazole moieties stack in an anti-parallel fashion about inversion centers. The pyridyl moiety of one mol­ecule has a π–π interaction with the triazole moiety of another mol­ecule with a dihedral angle of 11.27 (10)° and centroid–centroid distance of 3.790 Å (symmetry operation 2 − x, −y, −z). In addition, there are also C—H⋯π inter­actions between the hydrogen atom of the pyridyl moiety with the cyclo­penta­dienyl ring [H12⋯Cp(centroid) = 2.692 Å; symmetry operation 2 − x, −y, −z;]. These two inter­actions thus form centrosymmetric dimers, illustrated in Fig. 4 ▸.

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8⋯N3i	0.95	2.68	3.601 (2)	163
C5—H5⋯N2i	0.95	2.51	3.4240 (19)	160
C3—H3⋯N4ii	0.95	2.73	3.4625 (19)	135
C12—H12⋯Cpcentroid iii	0.95	2.69	3.4861 (15)	142

Symmetry codes: (i) ; (ii) ; (iii) .

Figure 3.

The C—H⋯N network, with displacement ellipsoids at the 50% probability level.

Figure 4.

The C—H⋯π and π–π inter­actions, viewed along the a axis. Displacement ellipsoids are shown at the 50% probability level.

Database survey  

A search of the Cambridge Structural Database (Version 5.41, update of March 2020; Groom et al., 2016 ▸) for bis­(pyridyl­triazole) with a ferrocene linker gave no results. However, the structure of ferrocene attached to one methyl­ene­pyridyl­triazole, BULQIJ (Crowley et al., 2010 ▸) has been reported. The two pyridyl­triazole units connected with organic linkers, namely m-xylylene, VAJVIN (Najar et al., 2010 ▸), and p-xylylene as chloro­form solvate, FUJJOK (Crowley & Bandeen, 2010 ▸) have also been reported.

Complexation with Cu^I  

Complexation of the ligand 4 with Cu^I was performed under a nitro­gen atmosphere. When [Cu(CH₃CN)₄]PF₆ was added to a suspension of the ligand in DMF in a 1:1 ratio, the mixture was completely soluble, indicating the formation of a complex. To avoid oxidation of the complex, the resultant solution was diffused with diethyl ether vapor under nitro­gen for 3 d. Under these conditions, a bright-yellow microcrystalline solid was formed. At room temperature, the ¹H NMR spectrum of the complex showed a simple pattern containing the same set of signals for the ligand, indicative of the presence of one single species in solution. Compared to the spectrum of the free ligand, the proton signals of the complex, especially for the pyridyl­triazole coordination pocket, are shifted downfield (Fig. 5 ▸). Similar retaining of the number of signals and the coupling patterns in the ¹H NMR spectrum was observed in xylylene-linked bis­(pyridyl­triazole) ligands and their Ag^I complexes (Crowley & Bandeen, 2010 ▸). To further explore the nature of the complex in solution, we examined a MeOH/DMSO solution of the complex by positive-ion electrospray mass spectrometry (ESMS). The ESMS spectrum of the complex contains a peak at 1273.0915 corresponding to [Cu₂ L ₂](PF₆)⁺ with a similar isotopic pattern as the theoretical simulation (Fig. 6 ▸), indicating the formation of the [2 + 2] complex. Disappointingly, despite obtaining crystalline material, our attempts to obtain crystals suitable for single-crystal X-ray analysis failed.

Figure 5.

¹H NMR spectra of ligand 4 (bottom) and its Cu^I complex, 5 (top). Both spectra are clipped on the same chemical shift ranges.

Figure 6.

A portion of the high-resolution ESI–MS spectrum of complex 5

Synthesis and crystallization  

Synthesis of 1,1′-bis­(hy­droxy­meth­yl)ferrocene, 2. To a stirred solution of 1,1′-ferrocenedi­carb­oxy­lic acid (4.00 g, 14.59 mmol) in dry THF (400.0 mL), 1.0 M LiAlH₄ (58.38 mL, 58.38 mmol) was added dropwise at room temperature under N₂. The reaction vigorously produced hydrogen gas. The reaction mixture was refluxed for 2 h, by which time the starting compound was consumed, as evidenced by TLC. The reaction was again cooled to room temperature, and ethyl acetate (5 mL) and water (10 mL) were added in sequence with constant stirring. The product was extracted with ethyl acetate (4 × 150 mL). The combined organic layer was dried with anhydrous MgSO₄ and volatiles removed in vacuo to give 2 (3.46 g, 96%) as a brown solid. The analytically pure product was obtained by recrystallization from toluene upon cooling. ¹H NMR (acetone-d ₆, 400 MHz, ppm): δ 4.07 (t, 4H, ³ J = 1.6 Hz, Cp), 4.13 (t, 4H, ³ J = 1.6 Hz, Cp), 4.19 (t, 2H, ³ J = 6.0 Hz, OH), 4.30 (d, 4H, ³ J = 6.0 Hz, CH ₂). ¹³C NMR (acetone-d ₆, 100 MHz, ppm): δ 67.4, 67.7, 69.6, 89.7.

Synthesis of 1,1′-bis­(azido­meth­yl)ferrocene, 3. Caution! Organic azides with low C/N ratio are potentially dangerous. However, we did not encounter any problem during the synthesis of diazide and its subsequent derivatization. To a stirred solution of 1,1′-hy­droxy­methyl­ferrocene (1.50 g, 6.09 mmol) in glacial acetic acid (7.5 mL), sodium azide (2.23 g, 36.5 mmol) was added. The reaction was stirred for 3 h at 323 K under nitro­gen. The reaction mixture was neutralized with a saturated solution of sodium bicarbonate. The product was extracted with chloro­form (2 × 50 mL). The organic phase was dried with anhydrous MgSO₄ and the volatiles removed in vacuo to give 3 (1.50 g, 83%) as a viscous liquid. IR (ATR, cm⁻¹): 2092 (s), 1733 (w), 1240 (m). ¹H NMR (CDCl₃, 400 MHz, ppm): δ 4.10 (s, 4H, CH ₂), 4.19 (t, ³ J = 2.0 Hz, Cp), 4.22 (t, ³ J = 2.0 Hz, Cp).

Synthesis of 1,1′-bis­(pyridyl­triazolylmeth­yl)ferrocene, 4. To a stirred solution of 1,1′-bis­(azido­meth­yl)ferrocene (1.00 g, 3.34 mmol) in a mixture of DMF and water (4:1) (20 mL), Na₂CO₃ (354 mg, 3.34 mmol), CuSO₄·5H₂O (333 mg, 1.33 mmol), ascorbic acid (468 mg, 2.66 mmol), and 2-ethynyl­pyridine (862 mg, 8.36 mmol) were added in sequence. The reaction mixture was stirred for 20 h at room temperature, and then poured into an NH₃/EDTA solution (2.00 g of Na₂H₂EDTA·2H₂O in 5 mL of 28% aqueous NH₃, diluted to 100 mL with H₂O) and the mixture extracted with chloro­form (3 x 100 mL). The organic layer was collected, dried over MgSO₄, and evaporated to dryness. The crude product was purified by trituration with cold diethyl ether to give 4 (1.26 g, 75%) as a light-brown solid. X-ray quality crystals of the compound were obtained by vapor diffusion of diethyl ether into its solution in chloro­form, m.p.: decomposes above 463 K. ¹H NMR (CDCl₃, 400 MHz, ppm): δ 4.24 (t, 4H, ³ J = 2.0 Hz, Cp), 4.32 (t, 4H, ³ J = 2.0 Hz, Cp), 5.33 (s, 4H, CH ₂),7.21(td, 2H, ³ J = 5.2 Hz, ⁴ J = 2.0 Hz, Ar), 7.75 (td, 2H, ³ J = 8.0 Hz, ⁴ J = 2.0 Hz, Ar), 8.05 (s, 2H, triazole-H), 8.15 (d, 2H, ³ J = 7.6 Hz, Ar), 8.53 (d, 2H, ³ J = 4.0 Hz, Ar) ¹³C NMR (CDCl₃, 100 MHz, ppm): δ 49.8, 69.8, 70.2, 81.9, 120.3, 121.5, 122.9, 137.0, 148.4, 149.4, 150.2. HRESI–MS: m/z = 501.1416 [4+H]⁺ (calculated for C₂₆H₂₃FeN₈ 501.1442), 523.1238 [4+Na]⁺ (calculated for C₂₆H₂₃FeN₈ 523.1261).

Synthesis of Cu^I complex of 1,1′-bis­(pyridyl­triazolylmeth­yl)ferrocene, 5. To a nitro­gen-purged stirred suspension of 4 (100 mg, 0.20 mmol) in DMF (10 mL), [Cu(CH₃CN)₄](PF₆) (77 mg, 0.20 mmol) was added. The reaction produced a clear yellow solution, which was stirred for 2 h at room temperature. The reaction mixture was diffused with nitro­gen-purged diethyl ether using a cannula for 3 d. The solution was deca­nted and the product was washed with diethyl ether and dried under a slow stream of nitro­gen to give 5 (142 mg, 100%) as a yellow microcrystalline solid. A ¹H NMR sample was prepared by dissolving the compound in DMSO-d ₆ and transferring the solution into an NMR tube under nitro­gen. ¹H NMR (DMSO-d ₆, 400 MHz, ppm): δ 4.21 (br, 8H, Cp), 4.29 (br, 8H, Cp), 5.43 (s, 5.42, 8H, CH₂, 7.45 (br, 4H, Ar), 7.90 (s, 4H, triazole-H), 8.04 (br, 4H, Ar), 8.43 (br, 4H, Ar), 9.05 (br, 4H, Ar). HRESI–MS: m/z = 1273.0915 (Cu₂ 4 ₂](PF₆)⁺ (calculated for C₅₂H₄₄Cu₂F₆Fe₂N₁₆P 1273.0914), 563.0650 [Cu4](PF₆)⁺ (calculated for C₂₆H₂₂CuFeN₈ 563.0660).

Refinement  

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. All H atoms were located in difference maps and then treated as riding in geometrically idealized positions with C—H distances of 0.95 Å (0.99 Å for CH₂) and with U _iso(H) =1.2U _eq for the attached C atom.

Table 2. Experimental details.

Crystal data
Chemical formula	[Fe(C13H11N4)2]
M r	502.36
Crystal system, space group	Triclinic, P
Temperature (K)	90
a, b, c (Å)	5.7905 (3), 9.7461 (5), 10.1720 (4)
α, β, γ (°)	82.064 (3), 84.754 (4), 77.739 (4)
V (Å3)	554.44 (5)
Z	1
Radiation type	Mo Kα
μ (mm−1)	0.71
Crystal size (mm)	0.12 × 0.09 × 0.08
Data collection
Diffractometer	Bruker Kappa APEXII DUO CCD
Absorption correction	Multi-scan (SADABS; Krause et al., 2015 ▸)
T min, T max	0.857, 0.945
No. of measured, independent and observed [I > 2σ(I)] reflections	7058, 4199, 3569
R int	0.020
(sin θ/λ)max (Å−1)	0.769
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.041, 0.099, 1.06
No. of reflections	4199
No. of parameters	160
H-atom treatment	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.98, −0.29

Computer programs: APEX3 and SAINT (Bruker, 2016 ▸), SHELXS97 (Sheldrick, 2008 ▸), SHELXL2014/7 (Sheldrick, 2015 ▸), Mercury (Macrae et al., 2020 ▸) and publCIF (Westrip, 2010 ▸).

Supplementary Material

CCDC reference: 2026000

Additional supporting information: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Crystal data

[Fe(C13H11N4)2]	Z = 1
Mr = 502.36	F(000) = 260
Triclinic, P1	Dx = 1.505 Mg m−3
a = 5.7905 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.7461 (5) Å	Cell parameters from 2644 reflections
c = 10.1720 (4) Å	θ = 3.1–33.1°
α = 82.064 (3)°	µ = 0.71 mm−1
β = 84.754 (4)°	T = 90 K
γ = 77.739 (4)°	Fragment, orange
V = 554.44 (5) Å3	0.12 × 0.09 × 0.08 mm

Data collection

Bruker Kappa APEXII DUO CCD diffractometer	4199 independent reflections
Radiation source: fine-focus sealed tube	3569 reflections with I > 2σ(I)
TRIUMPH curved graphite monochromator	Rint = 0.020
φ and ω scans	θmax = 33.2°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	h = −8→8
Tmin = 0.857, Tmax = 0.945	k = −14→14
7058 measured reflections	l = −15→15

Refinement

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.099	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0526P)2 + 0.140P] where P = (Fo2 + 2Fc2)/3
4199 reflections	(Δ/σ)max < 0.001
160 parameters	Δρmax = 0.98 e Å−3
0 restraints	Δρmin = −0.29 e Å−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Fe1	0.5000	0.5000	0.5000	0.00859 (7)
N1	0.9431 (2)	0.11300 (13)	0.36213 (12)	0.0173 (2)
N2	1.1757 (2)	0.11615 (13)	0.34215 (13)	0.0203 (2)
N3	1.2663 (2)	0.03069 (13)	0.25245 (13)	0.0175 (2)
N4	0.9549 (2)	−0.19933 (13)	0.11559 (13)	0.0166 (2)
C1	0.6904 (2)	0.34473 (13)	0.39618 (12)	0.0123 (2)
C2	0.7999 (2)	0.46543 (16)	0.37622 (14)	0.0162 (3)
H2	0.9556	0.4668	0.3976	0.019*
C3	0.6341 (3)	0.58282 (15)	0.31869 (14)	0.0186 (3)
H3	0.6595	0.6765	0.2952	0.022*
C4	0.4251 (3)	0.53559 (15)	0.30257 (13)	0.0169 (3)
H4	0.2856	0.5923	0.2663	0.020*
C5	0.4585 (2)	0.38965 (14)	0.34947 (13)	0.0132 (2)
H5	0.3458	0.3316	0.3498	0.016*
C6	0.7950 (3)	0.19952 (16)	0.45781 (15)	0.0242 (3)
H6A	0.8921	0.2067	0.5308	0.029*
H6B	0.6655	0.1517	0.4970	0.029*
C7	1.0906 (2)	−0.02744 (13)	0.21606 (13)	0.0125 (2)
C8	0.8819 (2)	0.02524 (15)	0.28631 (14)	0.0156 (2)
H8	0.7300	0.0043	0.2820	0.019*
C9	1.1331 (2)	−0.13233 (13)	0.12183 (13)	0.0119 (2)
C10	1.3477 (2)	−0.16117 (14)	0.04578 (13)	0.0141 (2)
H10	1.4713	−0.1132	0.0541	0.017*
C11	1.3757 (3)	−0.26115 (15)	−0.04177 (14)	0.0166 (3)
H11	1.5178	−0.2811	−0.0965	0.020*
C12	1.1936 (3)	−0.33183 (15)	−0.04847 (14)	0.0185 (3)
H12	1.2090	−0.4018	−0.1069	0.022*
C13	0.9891 (3)	−0.29783 (16)	0.03193 (15)	0.0187 (3)
H13	0.8656	−0.3472	0.0277	0.022*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Fe1	0.00934 (12)	0.00722 (12)	0.00860 (12)	−0.00031 (8)	0.00181 (8)	−0.00256 (8)
N1	0.0209 (6)	0.0119 (5)	0.0147 (5)	0.0053 (4)	0.0018 (4)	−0.0026 (4)
N2	0.0243 (6)	0.0143 (5)	0.0223 (6)	−0.0015 (5)	0.0000 (5)	−0.0067 (4)
N3	0.0180 (6)	0.0138 (5)	0.0212 (6)	−0.0032 (4)	0.0011 (4)	−0.0060 (4)
N4	0.0155 (5)	0.0146 (5)	0.0198 (5)	−0.0033 (4)	−0.0001 (4)	−0.0029 (4)
C1	0.0141 (5)	0.0101 (5)	0.0108 (5)	0.0027 (4)	0.0007 (4)	−0.0033 (4)
C2	0.0120 (6)	0.0241 (7)	0.0148 (6)	−0.0060 (5)	0.0042 (4)	−0.0096 (5)
C3	0.0287 (7)	0.0127 (6)	0.0140 (6)	−0.0066 (5)	0.0100 (5)	−0.0036 (5)
C4	0.0191 (6)	0.0175 (6)	0.0103 (5)	0.0047 (5)	−0.0009 (5)	−0.0010 (4)
C5	0.0130 (5)	0.0163 (6)	0.0112 (5)	−0.0033 (4)	0.0012 (4)	−0.0052 (4)
C6	0.0351 (8)	0.0164 (6)	0.0128 (6)	0.0116 (6)	0.0029 (6)	−0.0020 (5)
C7	0.0135 (5)	0.0094 (5)	0.0130 (5)	0.0005 (4)	0.0005 (4)	−0.0011 (4)
C8	0.0152 (6)	0.0135 (6)	0.0148 (6)	0.0026 (5)	0.0000 (5)	−0.0001 (4)
C9	0.0134 (5)	0.0089 (5)	0.0120 (5)	−0.0001 (4)	−0.0002 (4)	−0.0005 (4)
C10	0.0149 (6)	0.0127 (6)	0.0141 (5)	−0.0018 (4)	0.0011 (4)	−0.0019 (4)
C11	0.0175 (6)	0.0181 (6)	0.0129 (6)	−0.0003 (5)	0.0019 (5)	−0.0042 (5)
C12	0.0255 (7)	0.0147 (6)	0.0154 (6)	−0.0023 (5)	−0.0018 (5)	−0.0047 (5)
C13	0.0204 (7)	0.0166 (6)	0.0211 (6)	−0.0063 (5)	−0.0026 (5)	−0.0042 (5)

Geometric parameters (Å, º)

Fe1—C1	2.0349 (12)	C2—C3	1.423 (2)
Fe1—C1i	2.0349 (12)	C2—H2	0.9500
Fe1—C2	2.0453 (13)	C3—C4	1.413 (2)
Fe1—C2i	2.0453 (13)	C3—H3	0.9500
Fe1—C5	2.0471 (13)	C4—C5	1.4145 (19)
Fe1—C5i	2.0471 (13)	C4—H4	0.9500
Fe1—C4	2.0602 (13)	C5—H5	0.9500
Fe1—C4i	2.0603 (13)	C6—H6A	0.9900
Fe1—C3	2.0614 (13)	C6—H6B	0.9900
Fe1—C3i	2.0614 (13)	C7—C8	1.3837 (18)
N1—C8	1.3466 (19)	C7—C9	1.4646 (18)
N1—N2	1.3497 (19)	C8—H8	0.9500
N1—C6	1.4700 (18)	C9—C10	1.3987 (18)
N2—N3	1.3185 (17)	C10—C11	1.3838 (19)
N3—C7	1.3656 (18)	C10—H10	0.9500
N4—C13	1.3412 (19)	C11—C12	1.388 (2)
N4—C9	1.3435 (18)	C11—H11	0.9500
C1—C5	1.4248 (19)	C12—C13	1.382 (2)
C1—C2	1.4334 (19)	C12—H12	0.9500
C1—C6	1.4910 (19)	C13—H13	0.9500
C1—Fe1—C1i	180.0	C5—C1—Fe1	70.03 (7)
C1—Fe1—C2	41.13 (5)	C2—C1—Fe1	69.83 (7)
C1i—Fe1—C2	138.87 (5)	C6—C1—Fe1	124.11 (9)
C1—Fe1—C2i	138.87 (5)	C3—C2—C1	107.90 (12)
C1i—Fe1—C2i	41.13 (5)	C3—C2—Fe1	70.34 (8)
C2—Fe1—C2i	180.0	C1—C2—Fe1	69.04 (7)
C1—Fe1—C5	40.86 (5)	C3—C2—H2	126.0
C1i—Fe1—C5	139.14 (5)	C1—C2—H2	126.0
C2—Fe1—C5	68.47 (5)	Fe1—C2—H2	126.1
C2i—Fe1—C5	111.53 (5)	C4—C3—C2	108.01 (12)
C1—Fe1—C5i	139.14 (5)	C4—C3—Fe1	69.90 (8)
C1i—Fe1—C5i	40.85 (5)	C2—C3—Fe1	69.12 (8)
C2—Fe1—C5i	111.53 (5)	C4—C3—H3	126.0
C2i—Fe1—C5i	68.47 (5)	C2—C3—H3	126.0
C5—Fe1—C5i	180.00 (7)	Fe1—C3—H3	126.5
C1—Fe1—C4	68.35 (5)	C3—C4—C5	108.52 (12)
C1i—Fe1—C4	111.65 (5)	C3—C4—Fe1	69.99 (8)
C2—Fe1—C4	67.96 (6)	C5—C4—Fe1	69.36 (7)
C2i—Fe1—C4	112.04 (6)	C3—C4—H4	125.7
C5—Fe1—C4	40.29 (6)	C5—C4—H4	125.7
C5i—Fe1—C4	139.71 (6)	Fe1—C4—H4	126.5
C1—Fe1—C4i	111.65 (5)	C4—C5—C1	108.24 (12)
C1i—Fe1—C4i	68.35 (5)	C4—C5—Fe1	70.36 (8)
C2—Fe1—C4i	112.04 (6)	C1—C5—Fe1	69.11 (7)
C2i—Fe1—C4i	67.96 (6)	C4—C5—H5	125.9
C5—Fe1—C4i	139.71 (6)	C1—C5—H5	125.9
C5i—Fe1—C4i	40.29 (5)	Fe1—C5—H5	126.2
C4—Fe1—C4i	180.00 (8)	N1—C6—C1	112.79 (12)
C1—Fe1—C3	68.63 (5)	N1—C6—H6A	109.0
C1i—Fe1—C3	111.37 (5)	C1—C6—H6A	109.0
C2—Fe1—C3	40.54 (6)	N1—C6—H6B	109.0
C2i—Fe1—C3	139.46 (6)	C1—C6—H6B	109.0
C5—Fe1—C3	67.93 (6)	H6A—C6—H6B	107.8
C5i—Fe1—C3	112.07 (6)	N3—C7—C8	108.55 (12)
C4—Fe1—C3	40.11 (6)	N3—C7—C9	122.77 (12)
C4i—Fe1—C3	139.89 (6)	C8—C7—C9	128.62 (13)
C1—Fe1—C3i	111.37 (5)	N1—C8—C7	104.22 (12)
C1i—Fe1—C3i	68.63 (5)	N1—C8—H8	127.9
C2—Fe1—C3i	139.46 (6)	C7—C8—H8	127.9
C2i—Fe1—C3i	40.54 (6)	N4—C9—C10	122.94 (12)
C5—Fe1—C3i	112.07 (6)	N4—C9—C7	115.54 (12)
C5i—Fe1—C3i	67.93 (6)	C10—C9—C7	121.50 (12)
C4—Fe1—C3i	139.89 (6)	C11—C10—C9	118.52 (13)
C4i—Fe1—C3i	40.11 (6)	C11—C10—H10	120.7
C3—Fe1—C3i	180.0	C9—C10—H10	120.7
C8—N1—N2	111.35 (11)	C10—C11—C12	119.08 (13)
C8—N1—C6	129.20 (14)	C10—C11—H11	120.5
N2—N1—C6	119.45 (13)	C12—C11—H11	120.5
N3—N2—N1	107.30 (12)	C13—C12—C11	118.35 (13)
N2—N3—C7	108.57 (12)	C13—C12—H12	120.8
C13—N4—C9	117.19 (12)	C11—C12—H12	120.8
C5—C1—C2	107.33 (12)	N4—C13—C12	123.89 (14)
C5—C1—C6	125.82 (13)	N4—C13—H13	118.1
C2—C1—C6	126.83 (14)	C12—C13—H13	118.1
C8—N1—N2—N3	0.31 (16)	N2—N1—C6—C1	88.89 (17)
C6—N1—N2—N3	−179.79 (12)	C5—C1—C6—N1	96.79 (18)
N1—N2—N3—C7	−0.34 (15)	C2—C1—C6—N1	−85.10 (18)
C5—C1—C2—C3	0.44 (14)	Fe1—C1—C6—N1	−174.35 (11)
C6—C1—C2—C3	−177.96 (12)	N2—N3—C7—C8	0.26 (16)
Fe1—C1—C2—C3	−59.84 (9)	N2—N3—C7—C9	−177.32 (12)
C5—C1—C2—Fe1	60.28 (9)	N2—N1—C8—C7	−0.15 (15)
C6—C1—C2—Fe1	−118.12 (13)	C6—N1—C8—C7	179.97 (13)
C1—C2—C3—C4	−0.26 (15)	N3—C7—C8—N1	−0.06 (15)
Fe1—C2—C3—C4	−59.29 (9)	C9—C7—C8—N1	177.33 (13)
C1—C2—C3—Fe1	59.03 (9)	C13—N4—C9—C10	0.0 (2)
C2—C3—C4—C5	−0.02 (15)	C13—N4—C9—C7	−178.92 (12)
Fe1—C3—C4—C5	−58.82 (9)	N3—C7—C9—N4	167.64 (13)
C2—C3—C4—Fe1	58.81 (9)	C8—C7—C9—N4	−9.4 (2)
C3—C4—C5—C1	0.29 (15)	N3—C7—C9—C10	−11.3 (2)
Fe1—C4—C5—C1	−58.92 (9)	C8—C7—C9—C10	171.60 (13)
C3—C4—C5—Fe1	59.21 (9)	N4—C9—C10—C11	1.4 (2)
C2—C1—C5—C4	−0.45 (14)	C7—C9—C10—C11	−179.75 (12)
C6—C1—C5—C4	177.97 (12)	C9—C10—C11—C12	−1.7 (2)
Fe1—C1—C5—C4	59.70 (9)	C10—C11—C12—C13	0.8 (2)
C2—C1—C5—Fe1	−60.15 (9)	C9—N4—C13—C12	−1.1 (2)
C6—C1—C5—Fe1	118.27 (13)	C11—C12—C13—N4	0.6 (2)
C8—N1—C6—C1	−91.24 (19)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8···N3ii	0.95	2.68	3.601 (2)	163
C5—H5···N2ii	0.95	2.51	3.4240 (19)	160
C3—H3···N4iii	0.95	2.73	3.4625 (19)	135
C12—H12···Cpcentroidiv	0.95	2.69	3.4861 (15)	142

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

Funding Statement

This work was funded by Nicholls Research Council, Nicholls State University (USA) grant .