Low-temperature modification of Ba(BF₄)₂(H₂O)₃

Ba(BF₄)₂(H₂O)₃, ortho­rhom­bic, space group C222₁ at 300 K, becomes monoclinic at 280 K, space group P2₁. The spread of Ba—F distances is significantly larger in the LT modification, and one of the water mol­ecules in the LT form exhibits positional disorder.

Aqua­{μ-1,4-bis­[(1,4,7,10-tetra­aza­cyclo­dodecan-1-yl)meth­yl]benzene}(nitrato-κO)dicopper(II) tris­(nitrate) trihydrate

The title dinuclear Cu^II complex, the two Cu^II mol­ecules both have a five-coordinate square-pyramidal geometry, but the mol­ecules in the axial positions are different: a water mol­ecule and a nitrate ion. All nitrate ions, water mol­ecules, and N—H groups are involved in an inter­molecular hydrogen-bond network.

6,6′-Di­heptyl-3,3′-bis­[(pyridin-3-yl)ethyn­yl]-5H,5′H-di­pyrrolo­[1,2-b:1′,2′-g][2,6]naphthyridine-5,5′-dione

The complete mol­ecule of the title compound is generated by a crystallographic centre of symmetry. The pendant heptyl chains adopt extended conformations and the dihedral angle between the pyrrole and pyridine rings is 8.18 (15)°·In the crystal, the mol­ecules are arranged in columnar stacks propagating in the [010] direction via slipped aromatic π–π stacking inter­actions.

L-Me­thionyl-L-tyrosine monohydrate

The hydrated title compound is zwitterionic with the amine group of the me­thionyl moiety protonated and the carboxyl group of tyrosine deprotonated.

2-Amino-4-(4-meth­oxy­phen­yl)-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carbo­nitrile acetic acid monosolvate

The crystal structure of the title compound contains the host mol­ecule and acetic acid in 1:1 ratio without undergoing salt formation.