Synthesis and crystal structure of 1,3-bis-(4-hy-droxy-phen-yl)-1H-imidazol-3-ium chloride.

ABSTRACT: Imidazolium salts are common building blocks for functional materials and in the synthesis of N-heterocyclic carbene (NHC) as ?-donor ligands for stable metal complexes. The title salt, 1,3-bis-(4-hy-droxy-phen-yl)-1H-imidazol-3-ium chloride (IOH·Cl), C₁₅H₁₃N₂O₂ ⁺·Cl^-, is a new imidazolium salt with a hy-droxy functionality. The synthesis of IOH·Cl was achieved in high yield via a two-step procedure involving a di-aza-butadiene precursor followed by ring closure using tri-methylchloro-silane and paraformaldehyde. The structure of IOH·Cl consists of a central planar imidazolium ring (r.m.s. deviation = 0.0015?Å), with out-of-plane phenolic side arms. The dihedral angles between the 4-hy-droxy-phenyl substituents and the imidazole ring are 55.27?(7) and 48.85?(11)°. In the crystal, O-H?Cl hydrogen bonds connect the distal hy-droxy groups and Cl^- anions in adjacent asymmetric units, one related by inversion (-x + 1, -y + 1, -z + 1) and one by the n-glide (x - , -y + , z - ), with donor-acceptor distances of 2.977?(2) and 3.0130?(18)?Å, respectively. The phenolic rings are each ?-? stacked with their respective inversion-related [(-x + 1, -y + 1, -z + 1) and (-x, -y + 1, -z + 1)] counterparts, with inter-planar distances of 3.560?(3) and 3.778?(3)?Å. The only other noteworthy inter-molecular inter-action is an O?O (not hydrogen bonded) close contact of 2.999?(3)?Å between crystallographically different hy-droxy O atoms on translationally adjacent mol-ecules (x + 1, y, x + 1).

SUBMITTER: Mertens RT 

PROVIDER: S-EPMC6727052 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature