Crystal structures and supra­molecular and Hirshfeld surface analysis of three novel 2,4,6-tri­amino­pyrimidine salts

Three hydrous tri­amino­pyrimidine (TAP) salts were synthesized and structurally characterized. All three exhibit protonation at the N1 position and form R₂²(8) TAP–carboxyl­ate heterosynthons. Structural diversity arises from anion topology and hydration, yielding tetra­mers, chains and 3D frameworks. Hirshfeld analysis highlights dominant H⋯H contacts, with O⋯H and N⋯H inter­actions directing supra­molecular assembly and dimensionality.

Structures of hexa­kis­(anti­pyrine)lead(II) com­plexes: the first example of the stereochemically active and inactive 6s² lone pair for one lead(II) com­plex

Single-crystal X-ray diffraction studies on [Pb(anti)₆]X₂ (anti = antipyrine; X = OTf⁻ and ClO₄⁻) com­pounds revealed for the triflate salt, the formation of two polymorphs with both holodirected regular octa­hedral geometry (eccentricity value ɛ = 0) and hemidirected symmetry of a ψ-penta­gonal bipyramid (ɛ = 0.14). This work demonstrates, for the first time, that one lead(II) ion can exhibit both active or inactive 6s² lone-pair character in a com­plex.

Synthesis, crystal structure and green lu­mines­cence of a novel manganese(II)-based hybrid: bis­[(tert-but­oxy­carbon­yl)methyl­tri­phenyl­phospho­nium] tetra­chlorido­manganate(II)

A novel phospho­nium-based manganese(II) hybrid crystal, (TBTP)₂[MnCl₄] [TBTP is (tert-but­oxy­carbon­yl)methyl­tri­phenyl­phospho­nium], displays green lu­mi­nes­cence with a millisecond-scale lifetime (515 nm, 2.83 ms), attributed to the Mn^{2+ 4}T₁→⁶A₁ transition. Electronic structure analysis reveals a spatial separation of frontier orbitals, a structural feature that may aid in achieving the long-lived emission.

Single-crystal structure determination of psilocybin after dehydration

The structures of the hydrous and first anhydrous phases of crystalline psilocybin have been determined using single-crystal X-ray diffraction.