Open AccessStructure determination and phase transition behaviour of dimethyl sulfate
Author(s) -
Telling Mark T. F.,
Ibberson Richard M.,
Parsons Simon
Publication year - 2006
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
eISSN - 1600-5740
pISSN - 0108-7681
DOI - 10.1107/s0108768106001893
Subject(s) - monoclinic crystal system , orthorhombic crystal system , crystallography , crystal structure , phase transition , neutron diffraction , intermolecular force , phase (matter) , materials science , sulfate , crystal (programming language) , molecule , chemistry , organic chemistry , thermodynamics , physics , computer science , programming language , metallurgy
The crystal structures of phase I and phase II of dimethyl sulfate, (CH 3 O) 2 SO 2 , have been determined using complementary high‐resolution neutron powder and single‐crystal X‐ray diffraction techniques. Below its melting point of 241 K dimethyl sulfate crystallizes in an orthorhombic structure (I) in the space group Fdd2 . On cooling below ∼175 K the crystal transforms to a monoclinic structure (II) in the space group I 2/ a . The molecule is located on a twofold axis ( Z ′ = 1/2) in both structures. The phase transition is of first order with strong hysteresis. The phase transition results in changes to both the intra‐ and the intermolecular coordination environment.