Notes. Isolation and crystal structure of [NHMe3]2[ZrCl4(OMe)(MeOH)]Cl. The first example of a linear zirconium–methoxide bond: structural and bonding implications

Abstract

Treatment of [ZrCl₄(NMe₃)₂] with boiling methanol provided colourless needle crystals which were identified by X-ray crystallography as the ‘mixed’ alcohol–alkoxide derivative [NHMe₃]₂[ZrCl₄(OMe)(MeOH)]Cl. Crystals are orthorhombic, space group P2₁2₁2₁, Z= 4, with a= 7.192(8), b= 14.578(11), c= 19.343(21)Å. 1 717 Above-background reflections were collected on a diffractometer and the structure was refined to R= 0.065. In the [ZrCl₄(OMe)(MeOH)]^– anion, the zirconium atom is octahedral being bonded to four chlorine atoms [2.480(4)–2.496(4)Å] in the equatorial plane and to two oxygen atoms in axial positions at distances of 1.847(10) and 2.264(9)Å, identified with the OMe^– and MeOH ligands respectively. The Zr–O–Me angle to the alcohol ligand is 128.6(10) and to the alkoxide 171.4(13)°. This is the first known example of a linear zirconium–methoxide bond. The structural and bonding implications are discussed.