forthcoming articles

High pressure influences the formation of the products during the photochemical reaction in crystals of (S)-(−)-1-phenyl­ethan­aminium 4-(2,4,6-tri­iso­propyl­benzoyl)­benzoate. The reason for this behaviour is the changing geometry of the molecules and their surroundings along with the change in pressure.

The field of 1D perovskites is a growing area and has a wide variety of connectivity of octahedra. A new notation is proposed to bring more concise definition to 1D perovskites.

Seleno­urea phase α is stable between 93 and 473 K, but under high-pressure up to 1.0 GPa it reveals three new forms.

The crystal structures of three 2-substituted 6,7,8,9-tetra­hydro-11H-pyrido[2,1-b]quinazolin-11-ones (mackinazolinone derivatives) are characterized using X-ray diffraction. Packing analysis and energy framework calculations contribute to the understanding of packing in the crystal and enable the the nature of the underlying inter-molecular interactions to be delineated, while additional insight into the isolated compounds is gained from quantum chemical calculations to estimate the effect of the different substituents on the chemical reactivity of mackinazolinone.

The N—H⋯O, H⋯O=P and H⋯O=C angles (X-ray data/neutron normalized) have been studied in nine new [C(O)NH](N)₂P(O)-based structures and 204 analogous structures retrieved from the Cambridge Structural Database. Some topics related to geometry and symmetry are addressed.

A pseudocubic parameterization of the O₄ tetrahedra of quartz and its structural analogue GeO₂ at variable temperatures allows direct calculation of tetrahedral tilt angle, the microscopic order parameter of the α↔β phase transition. The crystal structures at interpolated or extrapolated temperatures can also be predicted.