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In the quasi-trigonal-bipyramidal environment of the five-coordinate FeII atom in the title compound, [FeCl2(C14H18N6O)(CH4O)], the methanol and one of the N-atom donors of the potentially tridentate ligand are disposed axially: Fe-N(axial) is 2.149 (2) Å, Fe-N(equatorial) is 2.108 (2) Å and N-Fe-O is 174.14 (7)°.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S010827010401087X/ta1446sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S010827010401087X/ta1446Isup2.hkl
Contains datablock I

CCDC reference: 245850

Comment top

Tris(1-methyl-1H-imidazol-2yl)methanol, (mim)3COH, is a well known ligand displaying tridentate capability, as described in our accompanying paper [Batten et al., 2004a; see also references therein for examples in association with iron(II)]. Less well known is the counterpart ligand described here, in which the hydroxyl H atom is replaced by a methyl group, thus changing the bridgehead functionality to an ether rather than an alcohol. In association with iron(II), examples have been described in which (mim)3COH behaves in a bidentate or tridentate fashion; in contrast, with the present ligand all examples hitherto structurally characterized appear to have been solely bidentate. Some examples for complexes containing metals other than Fe are copper(I) (Sorrell & Borovik, 1987), copper(II) (Stibrany et al., 1996) and palladium(II) (Rüther et al., 2001), wherein the particular metal ions concerned commonly exhibit predilections for relatively low coordination numbers. In the copper(I) and palladium(II) complexes, the ligand, although three-coordinate, achieves that status by virtue of the third donor bridging in a binuclear array. In extending its coordination chemistry, we had it in mind to prepare a mononuclear species in which it was tridentate, and, given the facility with which this is achieved about iron(II) by reaction of (mim)3COH with the metal(II) chloride, the latter was reacted with the present ligand in methanol solution in a similar manner, and the resulting yellow crystals of the title compound, (I), were subjected to a single-crystal diffraction study, the results of which are reported here. \sch

The results of the X-ray study are consistent with formulation of the material as (I) (Fig. 1), with one formula unit (a neutral molecule), devoid of crystallographic symmetry, comprising the asymmetric unit of the structure. Remarkably, the iron(II) environment is quasi-trigonal-bipyramidal five-coordinate, the ligand being two- rather than three- coordinate, with one of the N donors (N11) axial and trans to the O-methanol. Interestingly (Table 1), Fe—N11 is longer than Fe—N21, despite the latter lying in an equatorial site, normally considered as more `crowded' and accommodating `bulky' ligands or lone pairs. The five-coordinate geometry, although unusual, is similar to that reported for iron(II) complexes of planar tridentate N donor ligands, e.g. FeCl2(2,6-(ArNHCH2)2C5H3N) (Ar is 2,6-Pri2C6H3; Britovsek et al., 2001).

The overall result is curious in a number of other aspects. The multidentate ligand occupies only two coordination sites, despite the obvious facility of the metal ion to accommodate similar tridentate ligands in a six-coordinate environment. Further, as our subsequent study shows, the presence of a pair of Cl ligands about the same metal ion does not preclude the attainment of six-coordination in the presence of two rather similar N,N'-bidentate ligands (Batten et al., 2004b). While the sample size thus far is limited, we conjecture that the presence of the methyl group (rather than hydroxyl) at the ligand bridgehead may confer some degree of control on the relative disposition of the three heterocycles, precluding a tridentate conformation. We note the disposition of the uncoordinated heterocycle, with the substituent directed `inwards' toward the metal, possibly precluding six-coordination, and the inherent crowding about the ether grouping if the opposite disposition (in coordinating mode) is adopted. The present disposition is presumably assisted by the intermolecular hydrogen-bond from a neighbouring methanol hydroxyl (Table 1). A further point of possible relevance is the quasi-planarity of the chelate ring [χ2 for the C3N2Fe ring is 3475, with deviations for the atoms C1 Altered - please check, C12, C22, N11, N21 and Fe of −0.032 (3), 0.104 (2), −0.044 (4), −0.072 (8), 0.043 (2) and −0.104 (3) Å, respectively. The interplanar dihedral angles to the coordinated (im) C3N2 planes are 12.24 (9) and 3.71 (9)°, and the dihedral between the pair of coordinated (im) C3N2 planes is 15.1 (1)°.

Experimental top

A solution of (mim)3COMe (0.057 g, 0.20 mmol) in methanol (5 ml) was added to a stirred solution of iron(II) chloride (0.029 g, 0.23 mmol) in methanol (5 ml). Diethyl ether (65 ml) was allowed to diffuse into the pale-yellow solution. After 1 d, a small amount of a colourless precipitate formed; the yellow supernatant was cannula filtered and light petroleum (313–333 K, 70 ml) was added. After 2 d, a yellow crystalline material was obtained. This was cannula filtered and the yellow crystals of (I) were washed with diethyl ether (3 × 2 ml).

Refinement top

The hydroxyl H atom was refined freely. The remaining H atoms were located in difference Fourier maps and placed in idealized positions, with C—H = 0.95 Å, and with Uiso(H) = 1.25Ueq(C) for CH or 1.5Ueq(C) for CH3. The largest peak in the final difference map was located 0.71 Å from the Fe atom.

Computing details top

Data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT; program(s) used to solve structure: Xtal3.5 (Hall et al., 1995); program(s) used to refine structure: CRYLSQ in Xtal3.5; molecular graphics: Xtal3.5; software used to prepare material for publication: BONDLA and CIFIO in Xtal3.5.

Figures top
[Figure 1] Fig. 1. A view of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms have arbitrary radii of 0.1 Å.
Dichloro(methanol-κO)[(methoxy)tris(1-methyl-1H-imidazol-2-yl)methane- κ2N3]iron(II) top
Crystal data top
[FeCl2(C14H18N6O)(CH4O)]F(000) = 920
Mr = 445.13Dx = 1.53 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -p 2ynCell parameters from 8192 reflections
a = 9.8803 (8) Åθ = 2.5–37.3°
b = 16.329 (1) ŵ = 1.08 mm1
c = 12.246 (1) ÅT = 150 K
β = 101.953 (2)°Prism, yellow
V = 1932.9 (3) Å30.3 × 0.25 × 0.2 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer
10108 independent reflections
Radiation source: sealed tube6646 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.063
ω scansθmax = 37.6°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1616
Tmin = 0.572, Tmax = 0.806k = 2727
39725 measured reflectionsl = 2020
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.054Hydrogen site location: difference Fourier map
wR(F2) = 0.157H atoms treated by a mixture of independent and constrained refinement
S = 1.27 w = 1/[σ2(F2) + 2.6F2]
6646 reflections(Δ/σ)max = 0.01
239 parametersΔρmax = 1.77 e Å3
0 restraintsΔρmin = 0.78 e Å3
0 constraints
Crystal data top
[FeCl2(C14H18N6O)(CH4O)]V = 1932.9 (3) Å3
Mr = 445.13Z = 4
Monoclinic, P21/nMo Kα radiation
a = 9.8803 (8) ŵ = 1.08 mm1
b = 16.329 (1) ÅT = 150 K
c = 12.246 (1) Å0.3 × 0.25 × 0.2 mm
β = 101.953 (2)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
10108 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
6646 reflections with I > 2σ(I)
Tmin = 0.572, Tmax = 0.806Rint = 0.063
39725 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0540 restraints
wR(F2) = 0.157H atoms treated by a mixture of independent and constrained refinement
S = 1.27Δρmax = 1.77 e Å3
6646 reflectionsΔρmin = 0.78 e Å3
239 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Fe0.22512 (3)0.113206 (19)0.20735 (3)0.01858 (12)
Cl10.35746 (6)0.00288 (3)0.26351 (5)0.0269 (2)
Cl20.01074 (6)0.11563 (4)0.12920 (5)0.0266 (2)
N110.2875 (2)0.12109 (12)0.04964 (17)0.0229 (7)
C120.3696 (2)0.17360 (12)0.01248 (17)0.0179 (7)
N130.4067 (2)0.14389 (12)0.08172 (17)0.0234 (8)
C1310.4942 (3)0.17943 (18)0.1526 (3)0.0357 (12)
C140.3457 (3)0.06826 (16)0.1025 (2)0.0303 (10)
C150.2720 (3)0.05523 (16)0.0219 (2)0.0304 (10)
N210.3343 (2)0.22428 (11)0.24200 (15)0.0182 (6)
C220.3900 (2)0.27337 (12)0.17655 (16)0.0162 (6)
N230.4331 (2)0.34435 (11)0.23072 (15)0.0193 (6)
C2310.4984 (3)0.41604 (15)0.1914 (2)0.0293 (10)
C240.4037 (3)0.33991 (15)0.33525 (18)0.0235 (8)
C250.3424 (2)0.26608 (14)0.34158 (17)0.0214 (8)
N310.39951 (19)0.35989 (12)0.09694 (14)0.0184 (6)
C320.3426 (2)0.32225 (12)0.02127 (15)0.0159 (6)
N330.20802 (18)0.34512 (11)0.03027 (15)0.0175 (6)
C3310.1107 (2)0.32067 (16)0.0391 (2)0.0243 (9)
C340.1786 (2)0.40064 (14)0.11668 (18)0.0215 (8)
C350.2962 (2)0.40872 (14)0.15686 (18)0.0217 (8)
C10.4155 (2)0.25780 (12)0.05945 (16)0.0159 (6)
O110.55884 (15)0.26877 (10)0.06121 (14)0.0191 (6)
C110.6467 (2)0.21387 (17)0.1356 (2)0.0294 (10)
O100.16534 (18)0.11862 (12)0.37411 (15)0.0242 (7)
C100.2313 (3)0.0819 (2)0.4763 (2)0.0306 (11)
H131A0.496810.144380.215510.07000*
H131B0.457380.231240.179650.07000*
H131C0.585070.186380.110230.07000*
H140.354040.032070.161010.02900*
H150.217900.008030.016630.04400*
H231A0.501030.459640.243030.07200*
H231B0.590550.402840.185230.07200*
H231C0.447300.433020.120780.07200*
H240.422580.380210.392210.03100*
H250.310210.246280.404630.03700*
H331A0.021350.340420.006670.04200*
H331B0.108460.262470.043700.04200*
H331C0.139400.342920.111680.04200*
H340.093180.427870.142820.02700*
H350.305960.443140.217310.03100*
H11A0.740480.224180.133140.04900*
H11B0.623690.159020.113130.04900*
H11C0.633220.221890.209400.04900*
H100.085 (4)0.132 (2)0.383 (3)0.032 (10)*
H10A0.321440.063060.472380.05000*
H10B0.241020.121700.535830.05000*
H10C0.177900.037530.494150.05000*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Fe0.01822 (13)0.01754 (13)0.02112 (14)0.00124 (10)0.00671 (10)0.00145 (10)
Cl10.0258 (2)0.0198 (2)0.0354 (3)0.00360 (17)0.0065 (2)0.0007 (2)
Cl20.0195 (2)0.0395 (3)0.0208 (2)0.0023 (2)0.00449 (16)0.0045 (2)
N110.0270 (8)0.0208 (8)0.0235 (8)0.0065 (6)0.0113 (7)0.0035 (6)
C120.0192 (8)0.0180 (7)0.0178 (7)0.0005 (6)0.0070 (6)0.0018 (6)
N130.0288 (9)0.0199 (8)0.0245 (8)0.0041 (6)0.0122 (7)0.0058 (6)
C1310.0465 (16)0.0311 (12)0.0387 (13)0.0091 (11)0.0301 (13)0.0112 (10)
C140.0382 (13)0.0243 (10)0.0319 (11)0.0068 (9)0.0153 (10)0.0122 (9)
C150.0398 (13)0.0236 (10)0.0313 (11)0.0124 (9)0.0155 (10)0.0098 (9)
N210.0200 (7)0.0191 (7)0.0164 (6)0.0007 (6)0.0059 (5)0.0002 (5)
C220.0168 (7)0.0168 (7)0.0155 (7)0.0015 (6)0.0044 (6)0.0002 (6)
N230.0233 (8)0.0172 (7)0.0173 (7)0.0014 (6)0.0041 (6)0.0017 (6)
C2310.0404 (13)0.0195 (9)0.0297 (11)0.0099 (9)0.0110 (10)0.0021 (8)
C240.0293 (10)0.0237 (9)0.0181 (8)0.0013 (8)0.0062 (7)0.0043 (7)
C250.0255 (9)0.0234 (9)0.0161 (7)0.0001 (7)0.0063 (7)0.0006 (7)
N310.0190 (7)0.0202 (7)0.0161 (7)0.0005 (6)0.0041 (5)0.0013 (5)
C320.0154 (7)0.0174 (7)0.0146 (7)0.0012 (5)0.0026 (5)0.0004 (6)
N330.0143 (6)0.0186 (7)0.0195 (7)0.0014 (5)0.0033 (5)0.0011 (6)
C3310.0153 (8)0.0304 (10)0.0282 (10)0.0005 (7)0.0070 (7)0.0005 (8)
C340.0197 (8)0.0215 (9)0.0213 (8)0.0042 (7)0.0003 (6)0.0003 (7)
C350.0259 (9)0.0200 (8)0.0178 (8)0.0011 (7)0.0019 (7)0.0017 (7)
C10.0151 (7)0.0157 (7)0.0173 (7)0.0003 (5)0.0044 (5)0.0008 (6)
O110.0127 (5)0.0204 (6)0.0243 (7)0.0008 (5)0.0040 (5)0.0030 (5)
C110.0183 (9)0.0298 (11)0.0378 (12)0.0067 (8)0.0002 (8)0.0079 (9)
O100.0209 (7)0.0322 (9)0.0214 (7)0.0056 (6)0.0087 (5)0.0070 (6)
C100.0306 (11)0.0410 (14)0.0214 (9)0.0091 (10)0.0079 (8)0.0092 (9)
Geometric parameters (Å, º) top
Fe—Cl12.3246 (7)C24—C251.359 (3)
Fe—Cl22.3290 (6)C24—H240.949
Fe—N112.149 (2)C25—H250.950
Fe—N212.1080 (18)N31—C321.330 (3)
Fe—O102.242 (2)N31—C351.381 (3)
N11—C121.324 (3)C32—N331.363 (3)
N11—C151.376 (3)C32—C11.519 (3)
C12—N131.370 (3)N33—C3311.464 (3)
C12—C11.523 (3)N33—C341.378 (3)
N13—C1311.465 (4)C331—H331A0.946
N13—C141.375 (3)C331—H331B0.953
C131—H131A0.964C331—H331C0.948
C131—H131B0.953C34—C351.359 (4)
C131—H131C0.947C34—H340.949
C14—C151.358 (5)C35—H350.950
C14—H140.946C1—O111.423 (3)
C15—H150.948O11—C111.435 (3)
N21—C221.331 (3)C11—H11A0.949
N21—C251.385 (3)C11—H11B0.951
C22—N231.359 (3)C11—H11C0.949
C22—C11.528 (3)O10—C101.418 (3)
N23—C2311.465 (3)O10—H100.85 (5)
N23—C241.372 (3)C10—H10A0.953
C231—H231A0.949C10—H10B0.967
C231—H231B0.954C10—H10C0.948
C231—H231C0.948
Cl1—Fe—Cl2126.09 (3)N23—C24—H24127.0
Cl1—Fe—N1193.80 (6)C25—C24—H24126.5
Cl1—Fe—N21114.14 (5)N21—C25—C24109.4 (2)
Cl1—Fe—O1090.05 (5)N21—C25—H25125.4
Cl2—Fe—N1194.50 (6)C24—C25—H25125.2
Cl2—Fe—N21119.66 (5)C32—N31—C35105.32 (18)
Cl2—Fe—O1086.77 (5)N31—C32—N33111.30 (17)
N11—Fe—N2184.22 (8)N31—C32—C1124.15 (18)
N11—Fe—O10174.14 (7)N33—C32—C1124.43 (18)
N21—Fe—O1090.17 (7)C32—N33—C331128.69 (17)
Fe—N11—C12131.13 (15)C32—N33—C34106.84 (18)
Fe—N11—C15120.71 (18)C331—N33—C34124.41 (18)
C12—N11—C15106.4 (2)N33—C331—H331A109.4
N11—C12—N13110.50 (19)N33—C331—H331B109.4
N11—C12—C1127.6 (2)N33—C331—H331C109.5
N13—C12—C1121.8 (2)H331A—C331—H331B109.5
C12—N13—C131130.7 (2)H331A—C331—H331C109.5
C12—N13—C14106.8 (2)H331B—C331—H331C109.4
C131—N13—C14122.4 (2)N33—C34—C35106.34 (19)
N13—C131—H131A110.8N33—C34—H34126.8
N13—C131—H131B109.2C35—C34—H34126.8
N13—C131—H131C109.4N31—C35—C34110.2 (2)
H131A—C131—H131B108.7N31—C35—H35124.9
H131A—C131—H131C109.2C34—C35—H35124.9
H131B—C131—H131C109.5C12—C1—C22114.25 (17)
N13—C14—C15106.7 (2)C12—C1—C32108.40 (15)
N13—C14—H14126.7C12—C1—O11109.67 (17)
C15—C14—H14126.6C22—C1—C32110.33 (16)
N11—C15—C14109.5 (2)C22—C1—O11108.77 (15)
N11—C15—H15125.6C32—C1—O11105.01 (16)
C14—C15—H15124.9C1—O11—C11113.58 (18)
FE—N21—C22130.94 (14)O11—C11—H11A109.6
FE—N21—C25122.34 (16)O11—C11—H11B109.2
C22—N21—C25106.13 (18)O11—C11—H11C109.4
N21—C22—N23110.28 (18)H11A—C11—H11B109.5
N21—C22—C1129.37 (18)H11A—C11—H11C109.6
N23—C22—C1120.26 (18)H11B—C11—H11C109.5
C22—N23—C231129.5 (2)FE—O10—C10128.84 (17)
C22—N23—C24107.74 (19)FE—O10—H10123 (3)
C231—N23—C24122.8 (2)C10—O10—H10106 (3)
N23—C231—H231A109.5O10—C10—H10A110.9
N23—C231—H231B109.8O10—C10—H10B109.7
N23—C231—H231C110.2O10—C10—H10C110.5
H231A—C231—H231B109.1H10A—C10—H10B107.9
H231A—C231—H231C108.9H10A—C10—H10C109.6
H231B—C231—H231C109.3H10B—C10—H10C108.2
N23—C24—C25106.5 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O10—H10···N31i0.85 (5)1.90 (5)2.745 (3)169 (4)
Symmetry code: (i) x1/2, y+1/2, z+1/2.

Experimental details

Crystal data
Chemical formula[FeCl2(C14H18N6O)(CH4O)]
Mr445.13
Crystal system, space groupMonoclinic, P21/n
Temperature (K)150
a, b, c (Å)9.8803 (8), 16.329 (1), 12.246 (1)
β (°) 101.953 (2)
V3)1932.9 (3)
Z4
Radiation typeMo Kα
µ (mm1)1.08
Crystal size (mm)0.3 × 0.25 × 0.2
Data collection
DiffractometerBruker SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.572, 0.806
No. of measured, independent and
observed [I > 2σ(I)] reflections
39725, 10108, 6646
Rint0.063
(sin θ/λ)max1)0.858
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.054, 0.157, 1.27
No. of reflections6646
No. of parameters239
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)1.77, 0.78

Computer programs: SMART (Siemens, 1995), SAINT (Siemens, 1995), SAINT, Xtal3.5 (Hall et al., 1995), CRYLSQ in Xtal3.5, BONDLA and CIFIO in Xtal3.5.

Selected geometric parameters (Å, º) top
Fe—Cl12.3246 (7)Fe—N212.1080 (18)
Fe—Cl22.3290 (6)Fe—O102.242 (2)
Fe—N112.149 (2)
Cl1—Fe—Cl2126.09 (3)Cl2—Fe—N21119.66 (5)
Cl1—Fe—N1193.80 (6)Cl2—Fe—O1086.77 (5)
Cl1—Fe—N21114.14 (5)N11—Fe—N2184.22 (8)
Cl1—Fe—O1090.05 (5)N11—Fe—O10174.14 (7)
Cl2—Fe—N1194.50 (6)N21—Fe—O1090.17 (7)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O10—H10···N31i0.85 (5)1.90 (5)2.745 (3)169 (4)
Symmetry code: (i) x1/2, y+1/2, z+1/2.
 

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