1,3,3,5-Tetra­methyl-1H-1,5-benzodiazepine-2,4(3H,5H)-dione

The seven-membered ring in the title compound, C13H16N2O2, adopts a boat-shaped conformation (with the C atoms of the fused-ring as the stern and the C atom bearing two methyl groups) as the prow

3-[(1-Benzyl-1H-1,2,3-triazol-5-yl)methyl]-1,5-dimethyl-1,5-benzodiazepine-2,4-dione monohydrate

In the title compound, C21H21N5O2·H2O, the seven-membered ring adopts a boat-shaped conformation with the methine C atom as the prow. In the crystal, the water mol­ecule links adjacent mol­ecules by O—H⋯O and O—H⋯N hydrogen bonds into a zigzag chain running along the c axis of the monoclinic cell

5-Chloro-1-[(E)-3-(dimethyl­amino)­acrylo­yl]-3-methyl-1H-benzimidazol-2(3H)-one–6-chloro-1-[(E)-3-(dimethyl­amino)­acrylo­yl]-3-methyl-1H-benzimid­azol-2(3H)-one (4/1)

In the reaction of 7-chloro-1,5-benzodiazepine-2,4-dione with N,N-dimethyl­formamide/dimethyl­acetal, the diazepine seven-membered ring undergoes a contraction to form the five-membered ring. The reaction yields two isomers the title compound, C13H14ClN3O2; the major component has the chlorine-atom substituent in the 5-position of the benzimidazolone ring and the minor component has the chlorine atom in the 6-position. The two isomers form a disordered co-crystal, the chloro­methyl­benzimidazolone portion of both components are disordered with respect to each other in a 4:1 ratio [the refined ratio is 0.816 (5):0.184 (5)]; the dimethyl­amino­cryloyl substitutent is ordered. The double bond of the dimethyl­amino­acryloyl substituent has an E configuration

7-Chloro-1,5-dipropargyl-1H-1,5-benzodiazepine-2,4(3H,5H)-dione

The seven-membered ring of the title compound, C15H11ClN2O2, adopts a boat-shaped conformation (with the C atoms of the fused-ring as the stern and the methyl­ene C atom as the prow). The N atoms exists in a trigonal–planar coordination; one of the acetyl­enic H atoms forms a C—H⋯O hydrogen bond to the O atom of an adjacent mol­ecule, generating a linear chain along a body diagonal

Structure and reorientational dynamics of 1-F-adamantane

The polymorphism and the dynamics of a simple rigid molecule (1-fluoro-adamantane) have been studied by means of X-ray powder diffraction and broadband dielectric spectroscopy. At temperatures below the melting point, the molecule forms an orientationally disordered Phase I with a cubic-centered structure (Phase I, Fm (3) over barm, Z = 4). This phase possesses eight equilibrium positions for the fluorine atom, with equal occupancy factors of 1/8. A solid-solid phase transition to a low-temperature tetragonal phase (Phase II, P (4) over bar2(1)c, Z = 2) reduces the statistical disorder to only four possible equivalent sites for the fluorine atom, with fractional occupancies of 1/4. The dynamics has been rationalized under the constraints imposed by the space group of the crystal structure determined by powder X-ray diffraction. The dielectric spectroscopy study reveals that the statistical disorder in Phase II is dynamic in character and is associated with reorientational jumps along the two-and three-fold axes. In the dielectric loss spectra, the cooperative (alpha) relaxation exhibits a shoulder on the high-frequency side. This remarkable finding clearly reveals the existence of two intrinsic reorientational processes associated with the exchange of the F atom along the four sites. In addition to suchPeer ReviewedPostprint (published version

Decanedioic acid (C10H18O4) - Dodecanedioic acid (C12H22O4) system: polymorphism of the components and experimental phase diagram

The experimental temperature/composition phase diagram of the binary system decanedioic acid (C10H18O4)/dodecanedioic acid (C12H22O4) was established by combining X-ray powder diffraction (XRD), differential-scanning calorimetry (DSC), infrared spectroscopy (IR), scanning electron microscopy (SEM), and thermo-optical microscopy (TOM). Both compounds crystallize in the same ordered form, C (P21/c), which is the phase that melts in both cases. The C form melts in C12H22O4 earlier than in C10H18O4 , in contrast to other unbranched-chain compounds (alkanes, alkanols, and alkanoic acids) in which the melting temperatures increase as the C-atom number rises. Contrary to what might be expected, total solid-state miscibility is not observed. The C10H18O4/C12H22O4 binary system shows a complex phase diagram. At low temperatures, a new monoclinic form, Ci (P21/c), stabilizes as a result of the disorder of composition in the mixed samples; two [C þ Ci] domains appear. Upon heating, four solid - solid and seven solid - liquid domains appear related by eutectic and peritectic invariants. All the crystallographic forms observed are isostructural

Relationship between the two-component system 1-Br-adamantane + 1-Cl-adamantane and the high-pressure properties of the pure components

The temperature-composition phase diagram of the two-component system 1-Br-adamantane and 1-Cl-adamantane has been determined by means of thermal analysis techniques and X-ray powder diffraction from the low-temperature phase to the liquid state. The crossed isopolymorphism formalism has been applied to the two-component system to infer the normal pressure properties of the orthorhombic metastable phase of 1-Cl-adamantane at normal pressure. The experimental pressure-temperature phase diagrams for the involved compounds are related to the two-phase equilibria determined at normal pressure and inferences about the monotropic behavior of the aforementioned orthorhombic phase are discussed.Peer ReviewedPostprint (author's final draft

Vers la valorisation de nouveaux materiaux a changement de phase : les alliages moleculaires (MCPAM) agents stockant de l'energie

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc