Synthesis, crystal structures, luminescent and magnetic properties of rare earth dinuclear complexes and one-dimensional coordination polymers supported by two derivatives of cinnamic acid

Conformational isomerism in trans-3-methoxycinnamic acid: From solid to gas phase

The rotational spectrum of laser ablated trans-3-methoxycinnamic acid has been observed in the 2-8 GHz range using chirped-pulse Fourier transform microwave spectroscopy coupled to a supersonic jet and adapted to support a laser ablation vaporization system (LA-CP-FTMW). Eight stable conformers were theoretically predicted to exist at B3LYP-D3BJ/6-311++(2d,p) level, all of which were experimentally detected. The experimental rotational parameters data evidence the essentially planar structures for all the conformers. The relative population distribution of conformers in the supersonic jet was investigated from relative intensity measurements. Cooling in the jet brings rotational temperatures close to 1 K for all the conformers. The theoretical predictions for the rotational constants and electric dipole moments show good agreement with the experimental constants and selection rules observed. The population distribution of conformers in the supersonic jet was found to be close to the equilibrium distribution calculated at temperatures lower than the stagnation temperature. Finally, the correlation of the observed conformers structures with those found in condensed phases was investigated.

Synthesis, characterization and supra-molecular analysis for (E)-3-(pyridin-4-yl)acrylic acid

The title compound, C8H7NO2, crystallizes as prismatic colourless crystals in space group P , with one mol-ecule in the asymmetric unit. The pyridine ring is fused to acrylic acid, forming an almost planar structure with an E-configuration about the double bond with a torsion angle of -6.1 (2)°. In the crystal, strong O-H⋯N inter-actions link the mol-ecules, forming chains along the [101] direction. Weak C-H⋯O inter-actions link adjacent chains along the [100] direction, generating an R 2 2(14) homosynthon. Finally, π-π stacking inter-actions lead to the formation of the three-dimensional structure. The supra-molecular analysis was supported by Hirshfeld surface and two-dimensional fingerprint plot analysis, indicating that the most abundant contacts are associated with H⋯H, O⋯H/H⋯O, N⋯H/H⋯N and C⋯H/H⋯C inter-actions.

Synthesis, crystal structure and Hirshfeld surface analysis of aqua(3-methoxycinnamato-κO)bis(1,10-phenanthroline-κ2 N,N′)cobalt(II) nitrate

The title compound, [Co(C10H9O3)(C12H8N2)2(H2O)]NO3 (I), crystallizes in the triclinic space group P\overline{1} with a monomeric [Co(3-meo-cin)(phen)2(H2O)]+ cation and a nitrate anion (3-meo-cin = 3-methoxy cinnamic acid) in the asymmetric unit. The CoII ion is coordinated by four N atoms from two 1,10-phenanthroline ligands and two O atoms, the first from a methoxy cinnamate ligand and the second from a coordinated water molecule, forming a distorted octahedral geometry. Discrete entities of the cation and nitrate anion are formed by water–nitrate O—H...O and phen–nitrate C—H...O hydrogen bonds. The components are further assembled into chains along the c-axis direction. Layers are than formed by slipped π–π stacking interactions parallel to the bc plane. The intermolecular interactions in the crystal structure were quantified and analysed using Hirshfeld surface analysis.