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A novel ratiometric colorimetric and NIR fluorescent probe for Cu 2+ was designed based on the Cu 2+ induced spirocyclic-opening reaction accompanied with activating the photo-induced transfer (PET) process of cyanine to Cu 2+ -metal ligand centers, by which well-resolved peaks and sensitivity could be obtained. The probe CyRh – Cu was also successfully applied to the determination of Cu 2+ in water samples.

Tb3+, Er3+co-doped K2GdZr (PO4)3samples were prepared by solid-state reaction method and their photoluminescence (PL) properties were investigated in ultra-violet (UV) and vacuum ultra-violet (VUV) region. The results indicate that the energy transfers from Er3+to Gd3+and from Gd3+to Tb3+required for occurring of visible quantum cutting through down-conversion are efficient. In this cooperative energy transfer process, Gd3+is used as an intermediate of energy transfer between Er3+and Tb3+. The optimal quantum efficiency (QE) of this co-doped system K2GdZr (PO4)3: Er3+, Tb3+phosphor reached to 110%, suggesting a potential visible quantum cutting phosphor in practical application.

A new rhodamine B derivative colorimetric and fluorescent sensor (1) was synthesized by condensation reaction of rhodamine B hydrazide and 2,4-dihydroxybenzaldehyde, which showed reversible and highly selective and sensitive recognition toward Cu2+ over other examined metal ions. Upon addition of Cu2+, sensor 1 exhibits remarkably enhanced absorbance intensity and color change from colorless to pink in DMSO and MeCN aqueous buffer solution or pure MeCN, and shows significant off–on fluorescence accompanied by color changes from colorless to orange in MeCN. The sensor 1 was also successfully applied to the determination of Cu2+ in water samples.

In the title compound, C16H17N3S, the aminothiourea unit is nearly planar (r.m.s. deviation = 0.0425 Å), and is twisted with respect to the tolyl and phenyl rings by 57.84 (7) and 15.88 (14)°, respectively; the tolyl and phenyl rings are twisted by 65.64 (11)° to each other. Intermolecular N—H...S and weak C—H...S hydrogen bonds are present in the crystal structure.

The asymmetric unit of the title compound, C14H14F4N2O4·H2O, contains two crystallographically independent organic molecules and two water molecules. The two 1,3-diazinane rings adopt a half-chair conformation and the dihedral angles between their mean planes and those of the benzene rings are 75.65 (4)° and 49.41 (3)° in the two molecules. The crystal structure is stabilized by intermolecular O—H...O and N—H...O hydrogen bonds.

In the title compound, C14H15F3N2O5, prepared by reaction of 2-hydroxybenzaldehyde, ethyl 4,4,4-trifluoro-3-oxobutanoate and urea, the tetrapyrimidine ring adopts a half-chair conformation. The crystal structure is stabilized by five intermolecular hydrogen bonds, three O—H...O and two N—H...O, giving cyclic dimers (through three hydrogen bonds) which are further extended into a two-dimensional network.

The title compound, C16H20F3N3O4, was prepared by reaction of 4-(dimethylamino)benzaldehyde, ethyl 4,4,4-trifluoro-3-oxobutanoate and urea. In the title molecule, the pyrimidine ring adopts a half-chair conformation and there is an intramolecular hydrogen bond (O—H...O). The crystal structure is stabilized by two types intermolecular hydrogen bonds (N—H...O and N—H...N).