Ferrocenylbutadiyne

Victor N Nemykin; Jason D Dorweiler; Roman I Subbotin

doi:10.1107/S1600536809005522

. 2009 Feb 21;65(Pt 3):m298–m299. doi: 10.1107/S1600536809005522

Ferrocenylbutadiyne

Victor N Nemykin ^a,^*, Jason D Dorweiler ^a, Roman I Subbotin ^a

PMCID: PMC2968460 PMID: 21582079

Abstract

The title compound, [Fe(C₅H₅)(C₉H₅)], crystallizes in a form of a π–π-stacked assembly formed as a result of strong intermolecular π–π interactions between (a) the triple bonds of two neighboring butadiyne substituents overlapping in a ‘head-to-tail’ fashion [characterized by C⋯C short contacts of 3.622 (5), 3.567 (6) and 3.556 (6) Å] and (b) the triple bonds of the butadiyne substituent and substituted cyclopendadiene ring of neighboring molecules [C⋯C = 3.474 (5) and 3.492 (6) Å]. The linear butadiyne substituent has alternating C—C triple and single bonds, while the unsubstituted cyclopentadiene ring is slightly positionally disordered (although the structure reported here was solved as non-disordered) and retains a close to eclipsed conformation.

Related literature

For the general synthesis and applications of substituted ferrocenes and related macrocycles, see: Fouda et al. (2007 ▶); Nemykin et al. (2001 ▶, 2007a ▶,b ▶, 2008 ▶); Stepnika (2008 ▶); Osakada et al. (2006 ▶). For the synthesis of the title compound, see: Yuan et al. (1993 ▶); Nemykin et al. (2007c ▶). For examples of the use of the title compound, see Bruce et al. (2004 ▶).

Experimental

Crystal data

[Fe(C₅H₅)(C₉H₅)]
M _r = 234.08
Monoclinic,
a = 7.9438 (16) Å
b = 10.332 (2) Å
c = 12.835 (3) Å
β = 97.01 (3)°
V = 1045.5 (4) Å³
Z = 4
Mo Kα radiation
μ = 1.40 mm⁻¹
T = 298 K
0.45 × 0.30 × 0.25 mm

Data collection

Rigaku AFC-7R diffractometer
Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.58, T _max = 0.70
2549 measured reflections
2411 independent reflections
2248 reflections with I > 2σ(I)
R _int = 0.052
3 standard reflections every 150 reflections intensity decay: none

Refinement

R[F ² > 2σ(F ²)] = 0.048
wR(F ²) = 0.136
S = 1.08
2402 reflections
136 parameters
H-atom parameters constrained
Δρ_max = 0.52 e Å⁻³
Δρ_min = −0.47 e Å⁻³

Data collection: AFC-7R Diffractometer Control Software (Rigaku/MSC, 1997 ▶); cell refinement: WinAFC (Rigaku/MSC, 2000 ▶); data reduction: TEXSAN (Rigaku/MSC, 2004 ▶); program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003 ▶); molecular graphics: CAMERON (Watkin et al., 1996 ▶); software used to prepare material for publication: CRYSTALS.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809005522/hg2474sup1.cif

e-65-0m298-sup1.cif^{(15.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809005522/hg2474Isup2.hkl

e-65-0m298-Isup2.hkl^{(120.7KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

Finantial support from the National Science Foundation (grant CHE-0809203) is greatly appreciated. The X-ray data were collected at the University of Minnesota Duluth X-ray crystallography facility.

supplementary crystallographic information

Comment

Ferrocene derivatives have been useful as antitumor agents (Fouda et al., 2007) and as electron transfer molecules. (Stepnika, 2008; Nemykin et al., 2001, 2007a, 2007b, 2007c, 2008; Osakada et al., 2006) The title compound represents a precursor for the preparation of butadiyne like dinuclear ferrocene molecules. (Bruce et al., 2004, Yuan et al., 1993).

There are a number of known structures of substituted ferrocenes (Stepnika, 2008, Nemykin et al., 2007a, 2007c) but this is the first reported crystal structure of a butadiyne substituted ferrocene.

The molecule crystallizes as a π-π stacked assembly in the centrosymmetric monoclinic space group P2₁/c . π-π stacked assembly formed as a result of strong intermolecular π-π interactions between (a) the triple bonds of two butadiyne substituents in molecules 'B' and 'C' (Figure 2) overlapping in 'head-to-tail' fashion and (b) the triple bonds of butadiyne substituents of a substituted cyclopendadiene ring along crystallographic b axis (Figure 2). Intermolecular π-π interactions between between the triple bonds of two butadiyne substituents (overlapping in 'head-to-tail' fashion) consists of three short contacts between C12 and C14 (3.622 (5) Å, -x, 1 - y, 1 - z), C13 and C14 (3.567 (6) Å, -x, 1 - y, 1 - z), and C13 and C13 (3.556 (6) Å, -x, 1 - y, 1 - z) carbon atoms of neighboring molecules. Intermolecular π-π interactions between between the triple bonds of butadiyne substituents and substituted cyclopentadiene ring of neighboring molecule can be characterized by two short contacts between C2 and C11 (3.474 (5) Å, -x, -y, 1 - z) and C3 and C12 (3.492 (6) Å, -x, -y, 1 - z) pairs of carbon atoms. The terminal H15 atom of the butadiyne substituent of one molecule is in close proximity to the H6 atom on the unsubstituted cyclopentadienyl ring of the other molecule. Although the unsubstituted cyclopentadiyne ring is, probably, disordered over two crystallographical positions (with disordered structure solution available from the authors on request), the unsubstituted cyclopentadiene ring retains close to eclipsed conformation of ferrocene subunit. In addition, the butadiyne substituent has alternating C—C triple and single bonds.

Experimental

The title compound was obtained as by-product of the iodination reaction of ferrocenylacetylene (Nemykin et al., 2007c). Melting point (81 ^oC, dec.). ¹H NMR (CDCl₃, tms, p.p.m.): 4.29, 5H, Cp; 4.63, 2H, α-Cp; 4.39, 2H, β-Cp; 2.39, 1H, butadiyne C—H. ¹³C (CDCl₃, tms, p.p.m.): 71.0, Cp; 60.1, α-Cp; 70.6, β-Cp; 73.5, i-Cp; 66.9, ≡C—H; 70.4, C≡C—H; 71.2, Cp—C≡C-; 81.6, Cp-C≡C–). NMR spectra are similar to those reported earlier (Yuan et al.,1993).