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A series of chromophores based on benzene and thiophene moieties as π-conjugating spacers were designed and synthesized by Horner-Emmons-Wadsworth reaction and Vilsmeier-Haack reaction, followed by Knoevenagel reaction with different electron acceptors. Their structures were confirmed by 1HNMR, FT-IR, HPLC-Ms, UV-visible spectra, and the thermal properties were characterized by differential scanning calorimetry (DSC). Solvatochromic method was used to measure their nonlinear optical properties. The variation of chromophoric structures on NLO properties was investigated, indicating that the cyano substitution on the vinylene bridge of the chromophore produces a considerable red-shift of the absorption maximum, and would greatly enhance the molecular quadratic hyperpolarizability (βμ). [ABSTRACT FROM AUTHOR]

Lanthanide-doped luminescent nanoscale materials have great potential applications in biological researches. Herein, we reported a novel and mild method for one-step synthesis of chitosan/4:3+ nanocomposites. The luminescent 3+ ions and magnetic resonance imaging (MRI) contrast agent 3+ ions were incorporated to these biocompatible nanocomposites. The resultant nanocomposites exhibited strong fluorescence and attractive magnetic features. The nanocomposites also have pure hexagonal phase with uniform size of about 65 nm. FT-IR spectra revealed that these nanocomposites were successfully coated by hydrophilic chitosan, whose amine groups conferred the nanocomposites excellent dispensability in aqueous solution. Besides, the MTT assay and laser confocal microscopy images have confirmed the good biocompatibility of the nanocomposites. These results indicated that the as-prepared nanocomposites could be used as an excellent targeted imaging agent in biological fields. Lanthanide-doped luminescent nanoscale materials have great potential applications in biological researches. Here, a chitosan/ NaGdF4:Eu3+ nanocomposites have been fabricated by a novel and mild one-step synthesis method. Biocompatible chitosan is used to induce the growth of NaGdF4:Eu3+ NPs and stabilize the NPs against the formation of unexpected aggregation. The resultant nanocomposites with uniform size of about 65 nm exhibited strong fluorescence and magnetic features with excellent biocompatibility. [ABSTRACT FROM AUTHOR]