Structure of Ethylene Oxide Oligomer Complexes. III. A 1:2 Complex of Hexaethylene Glycol Diethyl Ether with Mercuric Chloride

Molecular and crystal structure of a 1:2 complex of hexaethylene glycol diethyl ether CH3CH2O(CH2CH2O)6-CH2CH3 (HGE) with HgCl2 has been determined by means of X-ray diffraction. The unit cell is monoclinic with a=23.34, b=7.84, c=16.69 Å, and β=115.0°. The space group is C2/c. The unit cell contains four HGE and eight HgCl2 molecules. The HGE molecule in the complex has the conformation CH3–CH2–O–CH2–CH2–O–CH2–CH2–O–CH2–CH2–O–CH2–CH2–O–CH2–CH2–O–CH2–O–CH2–CH2–O–CH2–CH3, where T, G, and denote trans, gauche, and minus gauche, respectively, two HgCl2 molecules being coordinated with one HGE molecule. The asymmetric unit consists of a half of HGE and one HgCl2 molecule. The four oxygen atoms of either half of HGE, which are coplanar, are coordinated with one Hg atom with close interatomic distances (2.66–2.91 Å) between the O and Hg atoms, the central oxygen atom of HGE being coordinated with two Hg atoms. The HgCl2 molecule is distorted from the linear form by 4°.