[2,6-Dioxo-1,2,3,6-tetra­hydro­pyrim­idine-4-carboxyl­ato(2−)]bis(pyrazino[2,3-f][1,10]phenanthroline)cobalt(II) dihydrate

The title complex, [Co(C5H2N2O4)(C14H8N4)2]·2H2O, features a slightly distorted octa­hedral geometry for Co due to the sterical requirements of the orotic acid and pyrazino[2,3-f][1,10]phenanthroline ligands. Inter­molecular hydrogen bonding between the uncoordinated water mol­ecules and the ligand stablizes the structure of the complex

Bis(2,2′-bipyridyl-κ2 N,N′)(nitrato-κ2 O,O′)(trifluoro­acetato-κO)cadmium(II)

In the title complex, [Cd(C2F3O2)(NO3)(C10H8N2)2], the Cd(II) ion is hepta­coordinated by two chelating 2,2′-bipyridyl ligands [Cd⋯N 2.370 (6)–2.416 (6) Å], one carboxyl­ate O atom [Cd⋯O 2.290 (6) Å] from the trifluoro­acetate ligand and two O atoms [Cd⋯O 2.386 (6), 2.633 (6) Å] from a chelating nitrate anion. The trifluoro­methyl fragment is rotationally disordered between two orientations in a 0.640 (7):0.360 (7) ratio. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds contribute to the crystal packing stability

5-Benzoyl-13-bromo-4-hy­droxy[2.2]paracyclo­phane

The title compound, C23H19BrO2, was synthesized from 13-bromo-4-hy­droxy[2.2]paracyclo­phane and benzoyl chloride. The hy­droxy and carbonyl groups are involved in intra­molecular O—H⋯O hydrogen bonding. The crystal packing exhibits weak C—H⋯O inter­actions, which link the mol­ecules into sheets parallel to the bc plane

2-Methyl­benzimidazolium nitrate

In the title compound, C8H9N2 +·NO3 −, inter­molecular N—H⋯O hydrogen bonds join the mol­ecules into a chain extending along the b axis

4-Amino-12-methylsulfonyloxy-[2.2]paracyclophane

The title compound, C17H19NO3S, was synthesized from 4-benzhydrylideneamino-12-hydroxy-[2.2]paracyclophane and methanesulfonyl chloride. In the molecule, the distance between the centroids of two aromatic rings is 2.960 (5) Å. In the crystal, weak N—H...O and C—H...O hydrogen bonds link the molecules into layers parallel to the ac plane

Recent Progress in Research on [2.2]Paracyclophane-Based Dyes

In recent years, the [2.2]paracyclophane (PCP) ring has attracted extensive attention due to its features of providing not only chirality and electron-donating ability but also steric hindrance, which reduces intermolecular π–π stacking interactions and thereby improves the fluorescence properties of dyes. To date, some circularly polarized luminescence (CPL)-active small organic molecules based on the PCP skeleton have been reviewed; however, the application of the PCP ring in improving the photophysical properties of fluorescent dyes is still limited, and new molecular design strategies are still required. This review summarizes and promotes the application of PCP in fluorescent dye design, fluorescence detection, and CPL modulation. We expect that this review will provide readers with a comprehensive understanding of the PCP skeleton and lead to further improvement in fluorescent dye design

1,5-Bis[(E)-cyclopentylidene]thiocarbonohydrazide

In the title molecule, C11H18N4S, an intramolecular N—H...N hydrogen bond [N...N = 2.558 (3)Å] is observed. The two cyclopentyl rings are disordered between two conformations in 1:1 and 2:1 ratios. In the crystal structure, weak intermolecular N—H...S hydrogen bonds [N...S = 3.547 (3) Å] link pairs of molecules into centrosymmetric dimers