(4-Benzyl-1-methyl-1,2,4-triazol-5-ylidene)[(1,2,5,6-η)-cycloocta-1,5-diene](triphenylphosphane-κP)iridium(I) tetrafluoridoborate

The cationic complex in the title salt, [Ir(C8H12)(C18H15P)(C10H11N3)]BF4, exhibits a distorted square-planar geometry around the IrI ion.

The molecular structure of the title salt, [Ir(C 10 H 11 N 3 )(C 8 H 12 )(C 18 H 15 P)]BF 4 (4), comprises an Ir I cation complex and a tetrafluoridoborate counter-anion, illustrated in Fig. 1. The coordination environment around the Ir I ion, formed by the bidentate data reports cycloocta-1,5-diene (COD), NHC, and triphenylphosphane ligands, results in a distorted square-planar environment. The Ir-C19(NHC) bond length is 2.039 (3) Å . The carbene(C19)-Ir-P bond angle is 89.52 (9) . The carbene atom, C19, deviates from the expected bond angle of an sp 2 hybridized atom with an N1-C19-N3 angle of 102.6 (3) . Fig. 2 shows the crystal packing of the complex. There is one non-covalent FÁ Á ÁH interaction between F2 of the tetrafluoridoborate anion and H20, which is connected to C20(NHC), that is significantly shorter than the sum of the van der Waals radii (Fig. 2, Table 1). An intramolecular distorted parallelstacking interaction is observed between the triazole ring and one of the phenyl rings (C7-C12) at the phosphane ( Fig. 3) with an intercentroid distance of 3.682 (2) Å and a slippage of 1.584 Å . The dihedral angle between the triazole and the phenyl phosphane ring planes is 13.0 (2) . Both intramolecular and intermolecular C-HÁ Á Á(ring) interactions impact the orientations of phenyl rings. The COD ligand and the phenyl wingtip of the triazole are oriented via an intramolecular C32-H32Á Á Á [phenyl wingtip of triazole; (C23-C28)] interaction that has an HÁ Á Ácentroid distance of 2.88 Å and a C-HÁ Á Ácentroid angle of 133 . Intermolecular, distorted perpendicular T-shaped orientations are observed between phenyl rings (Fig. 4). The Crystal packing unit-cell diagram of the title compound (4). Non-covalent interactions are shown as dotted green lines. Table 1 Hydrogen-bond geometry (Å , ). Symmetry code: (i) Àx þ 1; Ày þ 1; Àz.

Figure 3
View of the title compound (4) showing a distorted intermolecular parallel interaction between a phenyl ring (C7) of the triphenylphosphane ligand and the NHC ring.

Figure 1
The molecular entities in the crystal structure of the title compound (4). Displacement ellipsoids are drawn at the 50% probability level.

Figure 4
Views of intermolecular interactions of the title compound (4) showing Tshaped, distorted perpendicular interactions. (a) View of the near perpendicular orientation of a phenyl ring (C7) of the triphenylphosphane ligand on one moiety and the phenyl ring (C23) attached to the NHC ligand; (b) view of distorted perpendicular arranged phenyl rings that are influenced by the C9-H9Á Á Á[phenyl ring(C1)] intermolecular interactions.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2.

Figure 5
Reaction scheme showing the synthesis of the N-heterocyclic carbene (2) and the subsequent formation of the title ionic compound (4).

data-1
IUCrData (  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.003 Δρ max = 1.26 e Å −3 Δρ min = −0.46 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.