The interest for novel chalcone-based materials in nonlinear optics is dependent on strong second harmonic generation in organic systems. Chalcones are α,β-unsaturated ketones that can be easily obtained by Claisen–Schmidt condensation between ketones and aromatic aldehydes. A new 2-amino-chalcone was synthesized and its crystal molecular structure was elucidated using the single crystal X-ray diffraction technique. This compound, C₁₅H₁₂BrNO₂, crystallizes in monoclinic centrosymmetric space group C2/c with cell parameters a = 29.47(7) Å; b = 6.97(5) Å, c = 13.59(1) Å, β = 112.52(6)° and V = 2581.2(2) ų. In addition to the crystal structure, the analysis of Hirshfeld surfaces indicates the presence of hydrogen bonds of types N–H⋯O and O–H⋯O that stabilize two independent centrosymmetric dimers, and also indicates the presence of π–π stacking interactions that stabilize a supramolecular trimeric system. Being a push–pull chromophore we investigated the NLO properties of the 2-amino-chalcone asymmetric unit using the supermolecule approach in combination with an iterative electrostatic polarization scheme. The calculations were performed using the CAM-B3LYP/6-311+G(d) level of theory for both dynamic and static situations. In the presence of the embedding charges, the γ value is increased by 20% for the dynamic calculation but only 8% for the static limit. In contrast to the crystal form, when in solution the 2-amino-chalcone lacks an inversion center so that second order NLO properties do not vanish. Following this idea we computed the NLO properties using the implicit solvation approach IEF-PCM. The solvent effect on the NLO properties was to augment its values as the solvent polarity increases. We obtained for the in-crystal and in DMSO 2-amino-chalcone, γ(−2ω;ω,ω,0) = 144.12 × 10⁻³⁶ esu and 260.163 × 10⁻³⁶ esu, respectively, and therefore interesting materials for third order NLO applications.

Design, synthesis, molecular architecture and the unexpected behavior of fluorescent benzothiadiazole for selective mitochondrial and plasma membrane staining are investigated.

A selective hydrazine sensor in solution based on the 2,1,3-benzothiadiazole heterocycle is efficient forin vitroandin vivoanalyses. This sensor generates water as the only byproduct, avoiding generation of toxic compounds and interference duringin vivoapplications.