New multi-component solid forms of anti-cancer drug Erlotinib: role of auxiliary interactions in determining a preferred conformation

Erlotinib, an anti-cancer drug, was screened for the preparation of new multi-component systems. The drug exists in two conformations. The syn conformation is observed in the cocrystals and salts with weaker acids, while the anti conformation is observed in the HCl salt. Details of the structural aspects of the new solid forms are presented.

Conformational polymorphs of iso­butyl-6-amino-5-cyano-2-methyl-4-phenyl-4H-pyran-3-carboxylate: spectroscopic, structural and DFT approach

The crystal structure of a new crystalline phase of isobutyl-6-amino-5-cyano-2-methyl-4-phenyl-4H-pyran-3-carboxylate was accurately determined by single-crystal X-ray diffraction analysis. Inter- and intramolecular hydrogen-bonding interactions exhibit various supramolecular architectures in the crystal packing and crystal cohesion is achieved by N—H⋯N, N—H⋯O and C—H⋯H—C interactions.

Crystal structure and phase transition of thermoelectric SnSe

The crystal structure of SnSe is investigated through high-resolution synchrotron powder X-ray diffraction in the range 100–855 K. The temperature dependence of the lattice constants, fractional coordinates, site occupancy factors and atomic displacement parameters is studied.

Hydrogen bonding at C=Se acceptors in seleno­ureas, seleno­amides and selones

The hydrogen-bonding ability of C=Se acceptors in selenoureas, selenoamides and selones has been probed using a combination of a Cambridge Structural Database analysis and ab initio calculations, showing that these C=Se acceptors are similar in behaviour to their sulfur analogues, and should therefore have similar use in crystal engineering as C=S acceptors.

Supramolecular hydrogen-bonding patterns of co-crystals containing the active pharmaceutical ingredient (API) phloroglucinol and N-heterocycles

The structures of five newly synthesized pharmaceutical co-crystals containing phloroglucinol and N-heterocyclic molecules are presented. A detailed analysis of the hydrogen-bonding network of all the phloroglucinol co-crystals of known structure leads to the recognition of some conserved supramolecular motifs, useful for the design of new co-crystals.

One-pot green synthesis of biologically relevant novel spiro[indolin-2-one-3,4′-pyrano[2,3-c]pyrazoles] and studies on their spectral and X-ray crystallographic behaviors

Biologically relevant spiro­[indolin-2-one-3,4′-pyrano[2,3-c]pyrazoles] derivatives were synthesized by a simple, energy-efficient and chemically sustainable method under ambient conditions with excellent yields, and the molecules were fully studied with regard to their detailed spectral and X-ray crystallographic behavior.

Silver(I) coordination polymers assembled from flexible cyclotriphosphazene ligand: structures, topologies and investigation of the counteranion effects

This paper describes the syntheses, structures and topologies of six silver coordination polymers constructed from a novel flexible cyclotriphosphazene ligand.

High-pressure studies of three polymorphs of a palladium(II) oxa­thioether macrocyclic complex

Three polymorphs of a palladium(II) macrocyclic complex were studied using high-pressure single-crystal X-ray diffraction to > 9 GPa, with one polymorph exhibiting a phase transition and conformational rearrangement.

The Z′ = 12 superstructure of Λ-cobalt(III) sepulchrate trinitrate governed by C—H⋯O hydrogen bonds

The 12-fold superstructure at T = 95 K is described as a commensurately modulated structure in superspace. Crystal packing in the Z′ = 12 superstructure is determined by short C—H⋯O hydrogen bonds.

High-temperature single-crystal X-ray diffraction study of tetragonal and cubic perovskite-type PbTiO₃ phases

A high-temperature single-crystal X-ray diffraction study of PbTiO₃ perovskite was carried out at temperatures between 298 and 928 K. Deviation from linear changes in Debye–Waller factors in the tetragonal phases was observed before the phase transition.

Anisotropic compressibility of the coordination polymer emim[Mn(btc)]

The structural response of a negatively charged metal–organic framework to pressure has been studied with single-crystal X-ray diffraction in a diamond anvil cell

New insight on bis­muth cuprates with incommensurate modulated structures

The refinement of Bi_2.27Sr_1.73CuO_6 + δ as incommensurately modulated structures showed the presence of vacancies in the oxygen site of the SrO layer, which may be the reason for oxygen content variation with annealing at different oxygen pressures. The total refined oxygen content 6.18 (1) corresponds to the results of chemical analysis.

Structural analysis of lead magnesium niobate using synchrotron powder X-ray diffraction and the Rietveld method

The contribution of the polar rhombohedral phase (R3m) in a lead magnesium niobate (PMN) sample is determined using synchrotron XRD data at room temperature. The unit-cell volume of this polar phase is a little larger than that of the paraelectric cubic phase in PMN.

Structure reinvestigation of α-, β- and γ-In₂S₃

We report on the high-resolution structure analysis of In₂S₃ powder with monochromatic synchrotron light in the temperature range between 300 and 1300 K. Three modifications could be identified with the two phase transitions taking place at 717 K and above 1049 K. Crystal structure parameters and their temperature dependence for all three phases were extracted from the diffraction data by Rietveld refinement.

Local structure in the disordered solid solution of cis- and trans-perinones

Lattice-energy minimizations are used to investigate orientational disorder in the crystal structure of cis-perinone and combined positional/orientational disorder in the solid solution of cis- and trans-perinone.