Crystal structure of 4'-{[4-(2,2':6',2''-terpyrid-yl-4'-yl)phen-yl]ethyn-yl}biphenyl-4-yl (2,2,5,5-tetra-methyl-1-oxyl-3-pyrrolin-3-yl)formate benzene 2.5-solvate.

ABSTRACT: The title compound, C44H35N4O3·2.5C6H6 (1), consists of a terpyridine and a N-oxylpyrroline-3-formate group separated by an aromatic spacer, viz. 4-(phenyl-ethyn-yl)-1,1'-biphenyl. It crystallized in the triclinic space group P-1 with two and a half benzene solvate mol-ecules (one benzene mol-ecule is located about an inversion center), while the di-chloro-methane solvate (2) of the same mol-ecule [Ackermann et al. (2015 ?). Chem. Commun. 51, 5257-5260] crystallized in the tetra-gonal space group P42/n, with considerable disorder in the mol-ecule. In (1), the terpyridine (terpy) group assumes an all-trans conformation typical for terpyridines. It is essentially planar with the two outer pyridine rings (B and C) inclined to the central pyridine ring (A) by 8.70?(15) and 14.55?(14)°, respectively. The planes of the aromatic spacer (D, E and F) are nearly coplanar with dihedral angles D/E, D/F and E/F being 3.42?(15), 5.80?(15) and 4.00?(16)°, respectively. It is twisted with respect to the terpy group with, for example, dihedral angle A/D being 24.48?(14)°. The mean plane of the N-oxylpyrroline is almost normal to the biphenyl ring F, making a dihedral angle of 86.57?(16)°, and it is inclined to pyridine ring A by 72.61?(15)°. The intra-molecular separation between the O atom of the nitroxyl group and the N atom of the central pyridine ring of the terpyridine group is 25.044?(3)?Å. In the crystal, mol-ecules are linked by pairs of C-H?O hydrogen bonds, forming inversion dimers. The dimers stack along the c axis forming columns. Within and between the columns, the spaces are occupied by benzene mol-ecules. The shortest oxygen-oxygen separation between nitroxyl groups is 4.004?(4)?Å. The details of the title compound are compared with those of the di-chloro-methane solvate (2) and with the structure of a related mol-ecule, 4'-{4-[(2,2,5,5-tetra-methyl-N-oxyl-3-pyrrolin-3-yl)ethyn-yl]phen-yl}-2,2':6',2''-terpyridine (3), which has an ethynylphenyl spacer [Meyer et al. (2015). Acta Cryst. E71, 870-874].

SUBMITTER: Meyer A 

PROVIDER: S-EPMC4647389 | biostudies-literature | 2015 Oct

REPOSITORIES: biostudies-literature