Synthesis and crystal structure of an iron triazole com­plex resulting from the unexpected ligand cleavage of a triazolium carbene precursor

Typically reactions of N-heterocyclic carbenes with transition metals are straightforward and require a carbene salt, a base strong enough to deprotonate such a salt and a metal. Yet when carbene precursors are in the form of triazolium salts, reaction may not proceed as easily as expected. In our work, we intended to obtain a triazolyl­idene com­plex of iron(II) chloride, but due to the presence of small amounts of water in the tetra­hydro­furan solvent used, bis­(aceto­nitrile)­tetra­kis­(1-benzyl-1H-1,2,4-triazole-κN⁴)iron(II) μ-oxido-bis­[tri­chlorido­ferrate(III)] aceto­nitrile disolvate, [Fe(C₉H₉N₃)₄(CH₃CN)₂][Fe₂Cl₆O]·2CH₃CN – an inter­esting anion with a linear geometry of the O atom – was formed instead of the iron carbene com­plex. Reaction proceeded via cleavage of the alkyl N-substituent of the triazolium salt. The formation of the product was confirmed by X-ray crystallography. The crystal structure and possible reaction pathways are discussed.

Computing details

Bis(acetonitrile)tetrakis(1-benzyl-1H-1,2,4-triazole-κN⁴)iron(II) µ-oxido-bis[trichloridoferrate(III)] acetonitrile disolvate

Crystal data

[Fe(C9H9N3)4(C2H3N)2][Fe2Cl6O]·2C2H3N	Z = 1
Mr = 1197.23	F(000) = 612
Triclinic, P1	Dx = 1.496 Mg m^−3
a = 8.9568 (3) Å	Cu Kα radiation, λ = 1.54184 Å
b = 12.8555 (4) Å	Cell parameters from 9907 reflections
c = 12.8951 (5) Å	θ = 3.8–70.6°
α = 116.349 (4)°	µ = 9.67 mm^−1
β = 91.178 (3)°	T = 120 K
γ = 91.622 (3)°	Block, red
V = 1329.09 (9) Å^3	0.16 × 0.11 × 0.08 mm

Data collection

Agilent SuperNova Dual source diffractometer with an Atlas detector	5052 independent reflections
Radiation source: sealed X-ray tube, SuperNova (Cu) X-ray Source	4520 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.030
Detector resolution: 5.2195 pixels mm^-1	θmax = 70.8°, θmin = 3.8°
ω scans	h = −10→9
Absorption correction: gaussian (CrysAlis PRO; Rigaku OD, 2018)	k = −15→15
Tmin = 0.618, Tmax = 0.755	l = −15→15
20380 measured reflections

Refinement

Refinement on F^2	48 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.080	H-atom parameters constrained
wR(F^2) = 0.238	w = 1/[σ^2(Fo^2) + (0.1515P)^2 + 2.6594P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.005
5052 reflections	Δρmax = 1.39 e Å^−3
328 parameters	Δρmin = −0.96 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	Occ. (<1)
C1	−0.0865 (5)	0.0122 (4)	0.2556 (4)	0.0395 (10)
C2	−0.1286 (6)	0.0155 (7)	0.3654 (5)	0.0632 (17)
H2A	−0.2378	0.0123	0.3683	0.095*
H2B	−0.0881	0.0875	0.4293	0.095*
H2C	−0.0884	−0.0513	0.3724	0.095*
C3	−0.2015 (5)	0.1852 (4)	−0.0249 (4)	0.0380 (9)
H3	−0.2195	0.1378	−0.1055	0.046*
C4	−0.1266 (6)	0.2502 (4)	0.1484 (4)	0.0465 (11)
H4	−0.0768	0.2560	0.2166	0.056*
C5	0.3342 (7)	0.1029 (6)	0.0213 (6)	0.0598 (14)
H5	0.3393	0.0643	−0.0606	0.072*
C6	0.2520 (7)	0.1631 (5)	0.1863 (5)	0.0570 (14)
H6	0.1912	0.1791	0.2507	0.068*
C7	−0.3603 (6)	0.3516 (4)	−0.0042 (5)	0.0446 (11)
H7A	−0.4543	0.3623	0.0377	0.054*
H7B	−0.3847	0.3050	−0.0879	0.054*
C8	−0.2942 (6)	0.4683 (4)	0.0164 (5)	0.0455 (11)
C9A	−0.169 (3)	0.4764 (19)	−0.0449 (16)	0.061 (5)	0.47 (4)
H9A	−0.1273	0.4067	−0.0989	0.073*	0.47 (4)
C10A	−0.104 (3)	0.5827 (19)	−0.0294 (16)	0.072 (4)	0.47 (4)
H10A	−0.0191	0.5876	−0.0705	0.087*	0.47 (4)
C9B	−0.239 (3)	0.4812 (13)	−0.076 (2)	0.066 (5)	0.53 (4)
H9B	−0.2414	0.4169	−0.1506	0.079*	0.53 (4)
C10B	−0.179 (3)	0.5884 (16)	−0.060 (3)	0.092 (8)	0.53 (4)
H10B	−0.1423	0.5983	−0.1242	0.110*	0.53 (4)
C11	−0.1725 (10)	0.6822 (7)	0.0517 (10)	0.091 (2)
H11	−0.1584	0.7546	0.0493	0.109*
C12	−0.2596 (9)	0.6738 (6)	0.1337 (9)	0.088 (2)
H12	−0.2782	0.7409	0.2030	0.105*
C13	−0.3202 (8)	0.5665 (5)	0.1144 (7)	0.0702 (17)
H13	−0.3817	0.5610	0.1711	0.084*
C14	0.4840 (9)	0.2748 (7)	0.2976 (7)	0.086 (2)
H14A	0.5872	0.2473	0.2874	0.103*
H14B	0.4431	0.2669	0.3646	0.103*
C15	0.4865 (9)	0.3973 (5)	0.3206 (7)	0.113 (2)
C16	0.6060 (7)	0.4674 (6)	0.3885 (7)	0.115 (3)
H16	0.6841	0.4343	0.4135	0.139*
C17	0.6114 (8)	0.5858 (5)	0.4200 (7)	0.125 (3)
H17	0.6931	0.6337	0.4665	0.151*
C18	0.4972 (10)	0.6342 (5)	0.3835 (7)	0.117 (2)
H18	0.5008	0.7152	0.4050	0.141*
C19	0.3776 (8)	0.5642 (7)	0.3155 (7)	0.142 (4)
H19	0.2995	0.5973	0.2906	0.170*
C20	0.3722 (8)	0.4458 (6)	0.2841 (7)	0.135 (3)
H20	0.2905	0.3979	0.2376	0.162*
C21	0.9801 (13)	0.5905 (9)	0.3572 (7)	0.109 (3)
H21A	0.8790	0.6075	0.3403	0.164*
H21B	0.9922	0.5064	0.3186	0.164*
H21C	1.0534	0.6288	0.3287	0.164*
C22	1.0033 (11)	0.6334 (7)	0.4818 (7)	0.087 (2)
N1	−0.0553 (4)	0.0083 (3)	0.1691 (3)	0.0384 (8)
N2	0.2079 (4)	0.0980 (3)	0.0779 (3)	0.0381 (8)
N3	0.4485 (6)	0.1657 (5)	0.0895 (5)	0.0684 (14)
N4	0.3935 (6)	0.2042 (5)	0.1946 (5)	0.0619 (13)
N5	−0.1165 (4)	0.1573 (3)	0.0442 (3)	0.0350 (8)
N6	−0.2107 (6)	0.3320 (4)	0.1477 (4)	0.0500 (10)
N7	−0.2572 (4)	0.2882 (3)	0.0346 (3)	0.0378 (8)
N8	1.0162 (16)	0.6712 (8)	0.5788 (7)	0.162 (6)
O1	0.5000	0.0000	0.5000	0.102 (3)
Cl1	0.50344 (15)	0.02759 (16)	0.76172 (13)	0.0665 (4)
Cl2	0.7857 (3)	0.16800 (14)	0.67204 (14)	0.0819 (6)
Cl3	0.76743 (18)	−0.13870 (15)	0.54232 (16)	0.0704 (5)
Fe1	0.0000	0.0000	0.0000	0.0316 (3)
Fe2	0.62671 (9)	0.01362 (7)	0.60932 (7)	0.0482 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.035 (2)	0.053 (3)	0.036 (2)	−0.0075 (18)	−0.0071 (17)	0.025 (2)
C2	0.046 (3)	0.119 (5)	0.040 (3)	−0.010 (3)	−0.003 (2)	0.050 (3)
C3	0.043 (2)	0.039 (2)	0.035 (2)	−0.0040 (18)	−0.0079 (18)	0.0196 (18)
C4	0.068 (3)	0.036 (2)	0.036 (2)	−0.008 (2)	−0.016 (2)	0.0176 (19)
C5	0.054 (3)	0.067 (3)	0.063 (3)	−0.014 (3)	−0.005 (3)	0.034 (3)
C6	0.059 (3)	0.061 (3)	0.054 (3)	−0.021 (3)	−0.017 (3)	0.031 (3)
C7	0.043 (3)	0.045 (2)	0.054 (3)	−0.006 (2)	−0.012 (2)	0.030 (2)
C8	0.048 (3)	0.044 (2)	0.052 (3)	−0.005 (2)	−0.013 (2)	0.029 (2)
C9A	0.060 (11)	0.069 (9)	0.063 (9)	−0.024 (8)	−0.013 (8)	0.040 (8)
C10A	0.050 (9)	0.094 (6)	0.087 (9)	−0.032 (4)	−0.027 (6)	0.056 (5)
C9B	0.087 (14)	0.055 (7)	0.074 (10)	0.000 (7)	0.009 (10)	0.045 (7)
C10B	0.080 (16)	0.096 (11)	0.141 (17)	−0.014 (9)	0.008 (14)	0.091 (12)
C11	0.089 (5)	0.060 (3)	0.142 (7)	−0.022 (3)	−0.025 (4)	0.064 (4)
C12	0.083 (5)	0.045 (3)	0.122 (7)	−0.009 (3)	−0.015 (5)	0.027 (4)
C13	0.076 (4)	0.048 (3)	0.076 (4)	−0.008 (3)	0.002 (3)	0.019 (3)
C14	0.079 (5)	0.093 (5)	0.087 (5)	−0.041 (4)	−0.035 (4)	0.045 (4)
C15	0.125 (4)	0.099 (4)	0.110 (5)	−0.029 (2)	−0.039 (3)	0.045 (3)
C16	0.099 (4)	0.096 (2)	0.120 (6)	−0.023 (4)	−0.009 (4)	0.021 (4)
C17	0.100 (5)	0.109 (2)	0.164 (7)	−0.026 (3)	−0.017 (4)	0.061 (3)
C18	0.135 (4)	0.105 (5)	0.110 (5)	−0.005 (3)	−0.004 (3)	0.047 (3)
C19	0.133 (5)	0.118 (6)	0.167 (8)	−0.023 (4)	−0.008 (4)	0.059 (5)
C20	0.142 (5)	0.106 (5)	0.160 (6)	0.010 (3)	−0.013 (4)	0.063 (4)
C21	0.131 (8)	0.107 (7)	0.054 (4)	−0.030 (6)	−0.002 (5)	0.005 (4)
C22	0.107 (5)	0.076 (4)	0.064 (4)	0.013 (4)	−0.018 (4)	0.018 (3)
N1	0.043 (2)	0.047 (2)	0.0312 (19)	−0.0060 (16)	−0.0073 (15)	0.0233 (16)
N2	0.043 (2)	0.0412 (19)	0.0365 (19)	−0.0076 (15)	−0.0071 (15)	0.0242 (16)
N3	0.056 (3)	0.081 (4)	0.078 (4)	−0.022 (3)	−0.005 (3)	0.046 (3)
N4	0.063 (3)	0.071 (3)	0.059 (3)	−0.026 (2)	−0.018 (2)	0.037 (2)
N5	0.043 (2)	0.0356 (18)	0.0288 (17)	−0.0082 (15)	−0.0074 (14)	0.0176 (14)
N6	0.074 (3)	0.039 (2)	0.036 (2)	−0.0052 (19)	−0.0122 (19)	0.0166 (17)
N7	0.044 (2)	0.0362 (18)	0.0368 (19)	−0.0101 (15)	−0.0120 (15)	0.0207 (15)
N8	0.278 (15)	0.104 (6)	0.067 (5)	0.077 (8)	−0.063 (7)	0.004 (4)
O1	0.094 (5)	0.149 (8)	0.056 (4)	0.041 (5)	−0.025 (4)	0.038 (4)
Cl1	0.0441 (7)	0.1045 (12)	0.0621 (8)	−0.0075 (7)	−0.0052 (6)	0.0479 (8)
Cl2	0.1198 (15)	0.0610 (9)	0.0535 (8)	−0.0267 (9)	0.0142 (9)	0.0164 (7)
Cl3	0.0642 (9)	0.0727 (9)	0.0908 (11)	0.0115 (7)	0.0148 (8)	0.0504 (9)
Fe1	0.0381 (5)	0.0359 (5)	0.0261 (5)	−0.0052 (4)	−0.0051 (3)	0.0193 (4)
Fe2	0.0506 (5)	0.0567 (5)	0.0406 (5)	−0.0018 (4)	−0.0114 (3)	0.0255 (4)

Geometric parameters (Å, º)

C1—N1	1.134 (6)	C12—H12	0.9500
C1—C2	1.456 (6)	C13—H13	0.9500
C2—H2A	0.9800	C14—N4	1.445 (8)
C2—H2B	0.9800	C14—C15	1.467 (10)
C2—H2C	0.9800	C14—H14A	0.9900
C3—N7	1.320 (6)	C14—H14B	0.9900
C3—N5	1.332 (6)	C15—C16	1.3900
C3—H3	0.9500	C15—C20	1.3900
C4—N6	1.313 (7)	C16—C17	1.3900
C4—N5	1.352 (6)	C16—H16	0.9500
C4—H4	0.9500	C17—C18	1.3900
C5—N3	1.326 (8)	C17—H17	0.9500
C5—N2	1.374 (7)	C18—C19	1.3900
C5—H5	0.9500	C18—H18	0.9500
C6—N2	1.315 (7)	C19—C20	1.3900
C6—N4	1.342 (8)	C19—H19	0.9500
C6—H6	0.9500	C20—H20	0.9500
C7—N7	1.467 (6)	C21—C22	1.457 (11)
C7—C8	1.503 (7)	C21—H21A	0.9800
C7—H7A	0.9900	C21—H21B	0.9800
C7—H7B	0.9900	C21—H21C	0.9800
C8—C13	1.363 (9)	C22—N8	1.126 (11)
C8—C9B	1.375 (16)	N1—Fe1	2.203 (4)
C8—C9A	1.414 (19)	N2—Fe1	2.175 (4)
C9A—C10A	1.40 (2)	N3—N4	1.331 (8)
C9A—H9A	0.9500	N5—Fe1	2.150 (4)
C10A—C11	1.41 (3)	N6—N7	1.360 (5)
C10A—H10A	0.9500	O1—Fe2	1.7349 (7)
C9B—C10B	1.39 (2)	O1—Fe2^i	1.7349 (7)
C9B—H9B	0.9500	Cl1—Fe2	2.2137 (17)
C10B—C11	1.41 (3)	Cl2—Fe2	2.2334 (18)
C10B—H10B	0.9500	Cl3—Fe2	2.2027 (18)
C11—C12	1.367 (13)	Fe1—N5^ii	2.150 (4)
C11—H11	0.9500	Fe1—N2^ii	2.175 (4)
C12—C13	1.381 (10)	Fe1—N1^ii	2.204 (4)
N1—C1—C2	178.9 (6)	C20—C15—C14	123.2 (5)
C1—C2—H2A	109.5	C15—C16—C17	120.0
C1—C2—H2B	109.5	C15—C16—H16	120.0
H2A—C2—H2B	109.5	C17—C16—H16	120.0
C1—C2—H2C	109.5	C18—C17—C16	120.0
H2A—C2—H2C	109.5	C18—C17—H17	120.0
H2B—C2—H2C	109.5	C16—C17—H17	120.0
N7—C3—N5	110.3 (4)	C17—C18—C19	120.0
N7—C3—H3	124.9	C17—C18—H18	120.0
N5—C3—H3	124.9	C19—C18—H18	120.0
N6—C4—N5	114.6 (4)	C20—C19—C18	120.0
N6—C4—H4	122.7	C20—C19—H19	120.0
N5—C4—H4	122.7	C18—C19—H19	120.0
N3—C5—N2	115.0 (6)	C19—C20—C15	120.0
N3—C5—H5	122.5	C19—C20—H20	120.0
N2—C5—H5	122.5	C15—C20—H20	120.0
N2—C6—N4	111.7 (6)	C22—C21—H21A	109.5
N2—C6—H6	124.2	C22—C21—H21B	109.5
N4—C6—H6	124.2	H21A—C21—H21B	109.5
N7—C7—C8	111.7 (4)	C22—C21—H21C	109.5
N7—C7—H7A	109.3	H21A—C21—H21C	109.5
C8—C7—H7A	109.3	H21B—C21—H21C	109.5
N7—C7—H7B	109.3	N8—C22—C21	176.3 (10)
C8—C7—H7B	109.3	C1—N1—Fe1	178.7 (4)
H7A—C7—H7B	107.9	C6—N2—C5	100.9 (5)
C13—C8—C9B	117.7 (8)	C6—N2—Fe1	132.2 (4)
C13—C8—C9A	115.1 (9)	C5—N2—Fe1	126.9 (3)
C13—C8—C7	121.7 (5)	C5—N3—N4	102.6 (5)
C9B—C8—C7	118.5 (10)	N3—N4—C6	109.8 (5)
C9A—C8—C7	120.5 (10)	N3—N4—C14	121.4 (6)
C10A—C9A—C8	122.8 (18)	C6—N4—C14	128.7 (6)
C10A—C9A—H9A	118.6	C3—N5—C4	102.6 (4)
C8—C9A—H9A	118.6	C3—N5—Fe1	128.1 (3)
C9A—C10A—C11	115.2 (15)	C4—N5—Fe1	129.3 (3)
C9A—C10A—H10A	122.4	C4—N6—N7	102.7 (4)
C11—C10A—H10A	122.4	C3—N7—N6	109.8 (4)
C8—C9B—C10B	120.1 (16)	C3—N7—C7	129.3 (4)
C8—C9B—H9B	119.9	N6—N7—C7	120.8 (4)
C10B—C9B—H9B	119.9	Fe2—O1—Fe2^i	180.00 (6)
C9B—C10B—C11	119.1 (15)	N5—Fe1—N5^ii	180.0
C9B—C10B—H10B	120.5	N5—Fe1—N2^ii	88.63 (14)
C11—C10B—H10B	120.5	N5^ii—Fe1—N2^ii	91.37 (14)
C12—C11—C10B	118.0 (9)	N5—Fe1—N2	91.37 (14)
C12—C11—C10A	119.7 (9)	N5^ii—Fe1—N2	88.63 (14)
C12—C11—H11	120.2	N2^ii—Fe1—N2	180.0
C10A—C11—H11	120.2	N5—Fe1—N1	89.09 (14)
C11—C12—C13	119.2 (8)	N5^ii—Fe1—N1	90.91 (14)
C11—C12—H12	120.4	N2^ii—Fe1—N1	90.90 (14)
C13—C12—H12	120.4	N2—Fe1—N1	89.10 (14)
C8—C13—C12	121.8 (7)	N5—Fe1—N1^ii	90.91 (14)
C8—C13—H13	119.1	N5^ii—Fe1—N1^ii	89.09 (14)
C12—C13—H13	119.1	N2^ii—Fe1—N1^ii	89.10 (14)
N4—C14—C15	110.8 (6)	N2—Fe1—N1^ii	90.90 (14)
N4—C14—H14A	109.5	N1—Fe1—N1^ii	180.0
C15—C14—H14A	109.5	O1—Fe2—Cl3	108.34 (6)
N4—C14—H14B	109.5	O1—Fe2—Cl1	109.30 (6)
C15—C14—H14B	109.5	Cl3—Fe2—Cl1	111.70 (7)
H14A—C14—H14B	108.1	O1—Fe2—Cl2	115.50 (7)
C16—C15—C20	120.0	Cl3—Fe2—Cl2	105.50 (8)
C16—C15—C14	116.7 (5)	Cl1—Fe2—Cl2	106.52 (7)
N7—C7—C8—C13	−93.8 (7)	C17—C18—C19—C20	0.0
N7—C7—C8—C9B	102.6 (16)	C18—C19—C20—C15	0.0
N7—C7—C8—C9A	66.5 (15)	C16—C15—C20—C19	0.0
C13—C8—C9A—C10A	−19 (2)	C14—C15—C20—C19	175.8 (9)
C9B—C8—C9A—C10A	84 (3)	N4—C6—N2—C5	0.0 (6)
C7—C8—C9A—C10A	179.6 (13)	N4—C6—N2—Fe1	177.7 (4)
C8—C9A—C10A—C11	0 (2)	N3—C5—N2—C6	0.4 (7)
C13—C8—C9B—C10B	15 (2)	N3—C5—N2—Fe1	−177.4 (4)
C9A—C8—C9B—C10B	−78 (3)	N2—C5—N3—N4	−0.7 (7)
C7—C8—C9B—C10B	179.1 (14)	C5—N3—N4—C6	0.7 (7)
C8—C9B—C10B—C11	1 (3)	C5—N3—N4—C14	178.1 (6)
C9B—C10B—C11—C12	−17 (3)	N2—C6—N4—N3	−0.5 (7)
C9B—C10B—C11—C10A	85 (2)	N2—C6—N4—C14	−177.6 (7)
C9A—C10A—C11—C12	21 (2)	C15—C14—N4—N3	83.4 (9)
C9A—C10A—C11—C10B	−75.7 (18)	C15—C14—N4—C6	−99.8 (9)
C10B—C11—C12—C13	15.9 (19)	N7—C3—N5—C4	0.4 (5)
C10A—C11—C12—C13	−21.6 (17)	N7—C3—N5—Fe1	178.4 (3)
C9B—C8—C13—C12	−16.3 (19)	N6—C4—N5—C3	0.0 (6)
C9A—C8—C13—C12	18.6 (18)	N6—C4—N5—Fe1	−178.0 (3)
C7—C8—C13—C12	180.0 (6)	N5—C4—N6—N7	−0.3 (6)
C11—C12—C13—C8	0.8 (13)	N5—C3—N7—N6	−0.6 (5)
N4—C14—C15—C16	−157.8 (6)	N5—C3—N7—C7	−177.5 (4)
N4—C14—C15—C20	26.3 (10)	C4—N6—N7—C3	0.5 (5)
C20—C15—C16—C17	0.0	C4—N6—N7—C7	177.7 (4)
C14—C15—C16—C17	−176.0 (8)	C8—C7—N7—C3	−122.0 (5)
C15—C16—C17—C18	0.0	C8—C7—N7—N6	61.4 (6)
C16—C17—C18—C19	0.0

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