(Cobaltoceniumylamido)pyridinium hexafluoridophosphate

The title compound was prepared in a microwave-assisted synthesis and is the first example of a cobaltocenium derivative formally containing a nitrene nitrogen species.


data reports Synthesis and crystallization
In a microwave-assisted one-pot synthesis, first 9.44 g of 1-aminopyridinium iodide (4.2 mmol, 1.5 equiv.) was deprotonated with 0.67 g of potassium tert-butoxide (5.9 mmol, 2.1 equiv.) in 100 ml of EtOH solution. Subsequently, after heating for 25 min (250 W, ramp 10 min, hold for 15 min, 100 C), 1.17 g of iodo-cobaltocenium iodide (Vanicek et al., 2016) (2.8 mmol, 1 equiv.) were added and heating was continued for 40 min (250 W, ramp 10 min, hold for 30 min, 100 C). Workup: After cooling to room temperature, the mixture was transferred to a round-bottomed flask, 1.83 g of potassium hexafluoridophosphate (9.9 mmol, 3.5 equiv.) were added and the mixture was stirred for 10 min. Neutral aluminium oxide (10 g) was added and the solvent was removed on a rotary evaporator. The product was purified, using a short neutral aluminium oxide column (h = 4 cm, d = 10 cm) with CH 3 CN as eluent. The solvent was removed on a rotary evaporator. The product was further dissolved in 200 ml CH 2 Cl 2 and filtered. Toluene (20 ml) was added and the mixture was concentrated to 30 ml. Et 2 O (100 ml) was added and the product precipitated at À20 C over a period of 2 h. After filtration and washing with Et 2 O, 0.86 g of pure (cobaltoceniumylamido)pyridinium hexafluoridophosphate was obtained as an orange-red powder.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2.   The molecular structure of the title compound, with displacement ellipsoids drawn at the 50% probability level for non-H atoms. Hydrogen bond HÁ Á ÁF is represented by a green dashed line.

Figure 2
The arrangement of the molecular units of the title compound in the unit cell, with displacement ellipsoids drawn at the 50% probability level for non-H atoms along the b axis. Hydrogen bonds are represented by dashed lines (HÁ Á ÁN blue, HÁ Á ÁF green). Hydrogen atoms not involved in hydrogen bonds are omitted for clarity. (Symmetry code: x, Ày, z + 1 2 ).
Theoretical Chemistry) for the measurement of HRMS and NMR spectra.

Funding information
Funding for this research was provided by: Austrian Science Fund FWF (grant No. P33858). Table 1 Hydrogen-bond geometry (Å , ). Symmetry codes: (i) x; Ày þ 1; z þ 1 2 ; (ii) x; y; z þ 1; (iii) x; Ày; z þ 1 2 .   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. Refinement. C-bound H atoms were placed in calculated positions and constrained to ride on their parent atoms with U iso (H) = 1.2U eq (C) and a C-H distance of 0.95 Å for aromatic H atoms. Refinement was performed using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F 2 . R-factor (gt) are based on F. The threshold expression of F 2 > 2.0 sigma(F 2 ) is used only for calculating R-factor (gt).