Structure of crystalline methanol at high pressure

High-pressure crystallography

“…On the other hand, these huge pressures are comparable to the intermolecular interactions in crystal structures. Molecular crystals are formed by a very large group of organic compounds and it has already been recognized that pressure is an efficient method of generating new polymorphs (Boldyreva, 1990(Boldyreva, , 2004Allan et al, 1998;Allan & Clark, 1999;Allan et al, 2002;Boldyreva, Shakhtshneider, Ahsbahs, Sowa & Uchtmann, 2002;Boldyreva et al, 2003;Fabbiani et al, 2005;Podsiadło et al, 2005Podsiadło et al, , 2006Gajda et al, 2006;Gajda & Katrusiak, 2007;Bujak et al, 2007) and binary systems characteristic for high-pressure conditions only (Loubeyre et al, 1993(Loubeyre et al, , 1994Loubeyre, 1996;Kuhs, 2004). The higher the pressure, the further-reaching are the structural modifications.…”

High-pressure diffraction studies of molecular organic solids. A personal view

“…Later, many examples were published in the papers by several groups (Fourme, 1968;Weir et al, 1969;Fourme et al, 1971;Allan et al, 1998;Allan & Clark, 1999a,b;Allan et al, 1999Allan et al, , 2001Allan et al, , 2002aKatrusiak et al, , 2007Podsiadło et al, 2005Podsiadło et al, , 2006Lozano-Casal et al, 2005;Gajda et al, 2005Gajda et al, , 2006Oswald, Allan, Day et al, 2005;Budzianowski et al, 2005;Budzianowski & Katrusiak, 2006a,b;Budzianowski et al, 2006;McGregor et al, 2006;Bujak et al, 2007;Dziubek et al, 2007;. Sometimes, the same polymorph is formed as a result of crystallization on cooling and with increasing pressure; examples are 1,2-dichloromethane (Podsiadło et al, 2005), and carbon disulfide .…”

“…One of the examples is water -ambient-pressure and high-pressure ices differ significantly in their structures and properties (Petrenko & Whitworth, 1999). Acetone (Allan & Clark, 1999b), acetic acid (Allan et al, 1999), alcohols (Allan et al, 1998(Allan et al, , 1999(Allan et al, , 2001, benzene (Fourme, 1968;Piermarini et al, 1969;Weir et al, 1969;Fourme et al, 1971;Budzianowski & Katrusiak, 2006a), chlorotrimethylsilane (Gajda et al, 2006), 1,2-dichloromethane (Podsiadło et al, 2005), sulfuric acid (Allan et al, 2002b), phenol (Allan et al, 2002a), 2-chlorophenol and 4-fluorophenol (Oswald, Allan, Day et al, 2005; are further examples of compounds, liquid at ambient conditions, which also give different polymorphs on cooling and with increasing pressure.…”

Phase Transitions in Solid Methanol

“…Later measurements with a dilatometer (3) showed that there are actually two transitions, a first-order transition at 159 K and a second-order transition at 156 K. An amorphous phase is obtained by vapor deposition at low temperatures and this phase transforms to the a-phase on warming to 130 K (4). Yet another crystalline phase is obtained when the pressure is increased beyond 3.5 GPa at ambient temperatures (5).…”