Crystal structure of chlorido­{5,10,15,20-tetra­kis­[2-(2,2-di­methyl­propanamido)­phen­yl]porphyrinato-κ4 N}iron(III)

Dennis Awasabisah; Douglas R Powell; George B Richter-Addo

doi:10.1107/S205698901500153X

. 2015 Jan 31;71(Pt 2):m42–m43. doi: 10.1107/S205698901500153X

Crystal structure of chlorido{5,10,15,20-tetrakis[2-(2,2-dimethylpropanamido)phenyl]porphyrinato-κ⁴ N}iron(III)

Dennis Awasabisah ^a,^*, Douglas R Powell ^a, George B Richter-Addo ^a

PMCID: PMC4384593 PMID: 25878847

Abstract

The title compound, [Fe(C₆₄H₆₄N₈O₄)Cl], is a five-coordinate square-pyramidal porphyrin complex with a chloride ion in the axial position, being coordinated from the protected side of the porphyrin; the Fe^III atom is displaced by 0.474 (5) Å from the 24-atom mean plane of the porphyrin core towards the chloride. The porphyrin moiety is a ‘picket-fence’ 5,10,15,20-tetrakis[2-(2,2-dimethylpropanamido)phenyl]porphyrinate (por) group. The Fe—Cl bond length is 2.221 (2) Å and the Fe—N(por) bond lengths are in the range 2.043 (5)–2.063 (5) Å. The supramolecular architecture of the crystal is sustained by C—H⋯O interactions between the pyrrolic and phenyl H atoms of one molecule and the carbonyl O atoms of the 2,2-dimethylpropanamido groups of adjacent molecules. The methyl groups of three of the four tert-butyl substituents exhibited rotational disorder over two positions. The investigated crystal was twinned by a twofold rotation about the (001) axis with a refined twin ratio of 0.4086 (16).

Keywords: crystal structure, picket-fence porphyrin, C—H⋯O interactions

Related literature

For the synthesis of (T_pivPP)FeCl (piv = ortho-pivalamido), see: Collman et al. (1975 ▸). For the crystal structures of other neutral and anionic (T_pivPP)FeCl complexes, see: Dhifet et al. (2011 ▸); Schappacher et al. (1983 ▸). For related synthetic applications of the title compound, see: Cheng et al. (2000 ▸); Nasri et al. (1997 ▸); Bominaar et al. (1992 ▸); Gismelseed et al. (1990 ▸). graphic file with name e-71-00m42-scheme1.jpg

Experimental

Crystal data

[Fe(C₆₄H₆₄N₈O₄)Cl]
M _r = 1100.53
Monoclinic,
a = 17.763 (3) Å
b = 17.652 (3) Å
c = 20.145 (4) Å
β = 110.570 (4)°
V = 5913.8 (18) Å³
Z = 4
Mo Kα radiation
μ = 0.35 mm⁻¹
T = 100 K
0.41 × 0.24 × 0.11 mm

Data collection

Bruker APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2002 ▸) T _min = 0.869, T _max = 0.962
69995 measured reflections
18970 independent reflections
9442 reflections with I > 2σ(I)
R _int = 0.077

Refinement

R[F ² > 2σ(F ²)] = 0.092
wR(F ²) = 0.280
S = 1.01
18970 reflections
788 parameters
279 restraints
H-atom parameters constrained
Δρ_max = 1.25 e Å⁻³
Δρ_min = −0.45 e Å⁻³

Data collection: SMART (Bruker, 2007 ▸); cell refinement: SAINT (Bruker, 2007 ▸); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015 ▸); molecular graphics: XP in SHELXTL (Sheldrick, 2008 ▸); software used to prepare material for publication: SHELXL2014.

Supplementary Material

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S205698901500153X/tk5357sup1.cif

e-71-00m42-sup1.cif^{(995.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S205698901500153X/tk5357Isup2.hkl

e-71-00m42-Isup2.hkl^{(1MB, hkl)}

Click here for additional data file.^{(501.3KB, tif)}

. DOI: 10.1107/S205698901500153X/tk5357fig1.tif

The molecular structure of the title compound (I), showing the atom-labelling scheme and displacement ellipsoids drawn at the 50% probability level. Disordered groups and H atoms have been omitted for clarity.

Click here for additional data file.^{(489.5KB, tif)}

. DOI: 10.1107/S205698901500153X/tk5357fig2.tif

The packing arrangement of molecules of the title compound (I).

CCDC reference: 1045127

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

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
C2H2O1ⁱ	0.95	2.43	3.310(8)	154
C7H7O2ⁱⁱ	0.95	2.35	3.228(8)	154
C12H12O3ⁱⁱⁱ	0.95	2.30	3.223(8)	163
C17H17O4^iv	0.95	2.32	3.251(8)	168
C25H25O1	0.95	2.29	2.884(12)	120
C36H36O2	0.95	2.34	2.932(11)	120
C47H47O3	0.95	2.24	2.847(11)	121
C58H58O4	0.95	2.32	2.909(11)	119

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

Acknowledgments

The authors wish to thank the National Science Foundation (CHE-1213674 and CHE-0130835) and the University of Oklahoma for funds to support this research and to acquire the diffractometer and computers used in this work.

supplementary crystallographic information

S1. Comment

The iron(III) porphyrin complex (T_pivPP)FeCl has been used as a precursor for the preparation of several (T_pivPP)Fe derivatives in our laboratory (Cheng et al., 2000) and those of several research groups (Nasri et al., 1997; Bominaar et al., 1992; Gismelseed et al., 1990). The molecular structure of the title compound is shown in Fig. 1. The complex (T_pivPP)FeCl is square pyramidal and has the chloride atom bonded to iron at the axial position. The chloride ion is coordinated at the protecting 2,2-dimethylpropanamido side of the porphyrin, in contrast to a similar structure reported (Dhifet et al., 2011) where the chloride ligand was on the opposite side of the protecting group. The Fe–Cl bond length is 2.221 (2) Å and the Fe–N(por) bond lengths are in the 2.043 (5)-2.063 (5) Å range. The iron(III) atom is displaced by 0.474 (5) Å from the 24-atom mean plane of the porphyrin core. An Fe–Cl bond length of 2.301 (2) Å and a mean Fe–N(por) distance of 2.108 (±0.015) Å were observed in the related anionic [(T_pivPP)FeCl]^– compound (Schappacher et al. 1983). Similarly, Dhifet and coworkers (Dhifet et al., 2011) determined an Fe–N(por) distance of 2.065 (2) Å, an Fe–Cl distance of 2.207 (2) and an iron displacement of 0.420 (4) Å from the 24 atom mean plane of the porphyrin macrocycle.

S2. Experimental

The (T_pivPP)FeCl complex with the chloride ion coordinated to iron at the protected side of the porphyrin was obtained serendipitously as follows: To a Schlenk tube equipped with a magnetic stirrer was added (T_pivPP)FeCl (Collman et al., 1975) (50 mg, 0.045 mmol) and toluene (10 mL). p-Fluorophenylmagnesium bromide in THF (0.05 mL, 0.05 mmol) was then added drop-wise and the mixture stirred under N₂ in the dark for 24 h. The resulting red solution was filtered into a clean Schlenk tube and the toluene solution reduced to ca 3 mL under vacuum. Hexane (10 mL) was added to the solution and placed in a -20 °C freezer overnight. The solid obtained was collected by filtration and dried in vacuo to give a black microcrystalline product. The IR (KBr) spectrum of the product shows a strong ν_CO band at 1694 cm^-1. X-ray quality crystals were obtained from slow evaporation of dichloromethane/ hexane solution of the complex at room temperature under N₂. We are unsure if the title complex with the chloride in the protected porphyrin cavity was present as a component of our bulk starting reagent (T_pivPP)FeCl.