Thiacalix[4]arene-protected alkynyl Agn (n = 9, 18) nanoclusters: syntheses, structural characterizations, photocurrent responses and fluorescence properties.

Two thiacalix[4]arene-protected silver(I) alkynyl nanoclusters, [Na2(H2O)2][Ag9(TC4A)(tBuCC)4(CH3OH)2(SbF6)0.5(OH)2.5]·3.5H2O·CH3OH (1, abbreviated as Ag9) and [Ag9(TC4A)(tBuCC)4(CF3COO)]2·4CH3OH (2, abbreviated as Ag18), were synthesized by the reaction of [tBuCCAg]n, p-tert-butylthiacalix[4]arene (H4TC4A), NaBH4, and AgSbF6 or CF3COOAg in the mixed solvent of methanol-trichloromethane-toluene under solvothermal conditions, respectively. Driven by SbF6- and CF3COO- with different coordination properties, the structural unit [Ag9(TC4A)(tBuCC)4]+ in both the compounds migrated in different modes, accompanied by distinct Ag⋯Ag distances. Ag9 and Ag18 exhibit similar UV-Vis absorption and diffuse reflection spectra along with contrary tendency between photocurrent responses and solid-state fluorescence. The solution stability of Ag9 and Ag18 was demonstrated by 1H NMR and MALDI-TOF mass spectrometry. The fluorescence responses of Ag9 and Ag18 towards different organic molecules were also investigated, which indicated that the polarity of solvent has a certain effect on the emission intensities of Ag9 and Ag18. This study provides a positive guide for the controlled synthesis and further study of the structure-activity relationship of thiacalix[4]arene-protected silver alkynyl nanoclusters.

Carboxylate Ligand-supported Agn (n=21 and 24) Alkynyl Clusters Induced by Single/Double Carbonate Ions.

Structural transformation is important for the study of silver cluster compounds, in which controlled synthesis of their shapes and sizes via anion template-driven is one key scientific question. In this work, the CO3 2- anion templates were captured by the [t BuC≡CAg]n system under the stimulation induced by carboxylate ligand CF3 COO- /PhCOO- , and two silver alkynyl clusters [(CO3 2- )@Ag21 (t BuC≡C)16 (CF3 COO)3 (H2 O)]⋅DMF⋅2CH2 Cl2 (1) and [(CO3 2- )2 @Ag24 (t BuC≡C)16 (PhCOO)4 ]⋅CH3 OH⋅4DMF (2) have been successfully isolated and charactered. With the increase of the number of CO3 2- templates from single to double, the outer silver atoms from twenty-one to twenty-four, accompanied by the growth of the cluster skeleton from 9.8 Š×6.9 Šof the (CO3 2- )@Ag21 unit to 10.5 Š×7.3 Šof the (CO3 2- )2 @Ag24 unit. In addition, the syntheses, structures, photocurrent responses, cyclic voltammetry characteristics, luminescence, and photodegradation of compounds 1 and 2 have been studied.

Trapping a [W10 O32 ]6- Decatungstate Anion in an Ag44 Nanowheel.

Compound [Ag44 (W10 O32 )(St Bu)24 (CF3 COO)8 ](CF3 COO)6 ⋅ 6H2 O (1) was synthesized through a one-pot method. This is the first case of isolating a new silver thiolate cluster containing a [W10 O32 ]6- template which transforms from WO4 2- polyoxoanion through a self-assembly process. The anionic nature of the reduced [W10 O32 ]6- template and the effective silver-oxygen interaction contribute to the formation of the Ag44 nanowheel in 1. The luminescence, photocatalytic activity and electrochemistry properties of 1 were studied.

A hierarchically assembled 88-nuclei silver-thiacalix[4]arene nanocluster.

Thiacalix[4]arenes as a family of promising ligands have been widely used to construct polynuclear metal clusters, but scarcely employed in silver nanoclusters. Herein, an anion-templated Ag88 nanocluster (SD/Ag88a) built from p-tert-butylthiacalix[4]arene (H4TC4A) is reported. Single-crystal X-ray diffraction reveals that C4-symmetric SD/Ag88a resembles a metal-organic super calix comprised of eight TC4A4- as walls and 88 silver atoms as base, which can be deconstructed to eight [CrO4@Ag11(TC4A)(EtS)4(OAc)] secondary building units arranged in an annulus encircling a CrO42- in the center. Local and global anion template effects from chromates are individually manifested in SD/Ag88a. The solution stability and hierarchical assembly mechanism of SD/Ag88a are studied by using electrospray mass spectrometry. The Ag88 nanocluster represents the highest nuclearity metal cluster capped by TC4A4-. This work not only exemplify the specific macrocyclic effects of TC4A4- in the construction of silver nanocluster but also realize the shape heredity of TC4A4- to overall silver super calix.

A one-dimensional infinite silver alkynyl assembly [Ag8(C[triple bond, length as m-dash]C t Bu)5(CF3COO)3(CH3CN)] n : synthesis, crystal structure and properties.

A high-yield silver alkynyl assembly [Ag8(C[triple bond, length as m-dash]C t Bu)5(CF3COO)3(CH3CN)] n (1) constructed from [AgC[triple bond, length as m-dash]C t Bu] n ligand, CF3COOAg and CH3CN auxiliary ligands with a one-dimensional infinite chain structure has been obtained in one pot. Compound 1 has been well-defined and characterized. The photocurrent properties and the temperature-sensitive luminescent properties of 1 have been investigated.

A Temperature-Sensitive Luminescent Ag42 Nanocluster Supported by TertButyl Thiol Ligands.

Compound [Ag42 S5 (StBu)25 (CF3 COO)4 (CO3 )](CO3 )0.5 ⋅CH2 Cl2 ⋅4CH3 OH⋅9DMF (1) has been obtained and well defined. It consists of a multi-shell structure involving two Ag centres, one Ag5 S5 pentagram, two Ag5 S5 pentagons and one Ag25 S15 shell. Compound 1 has been characterized by XPS, FT-IR, PXRD, TGA, NMR, MS, UV/Vis spectrum, TEM and cyclic voltammetry. Temperature-sensitive luminescent property of 1 has also been investigated.

[Linear discriminate analysis on annual and seasonal characteristics of major cations' profiles of rainwater at Zhoushan rain-sampling spot].

Rainwater samples were collected at rain-sampling Spot of Zhoushan in 2002-2003. Major cation concentrations (H+, NH4+, K+, Na+, Ca2+, Mg2+) of rainwater sample were determined. The concentration variation range and character were depicted by robust statistic analysis. Linear discriminate analysis (LDA) was used to acquire a further knowledge on the annual and seasonal characteristics of research major cations. Distribution character of samples from sample spot was clearly depicted in the new CA1-CA2 ordinates generated by linear discriminate analysis, and the reasons that caused the outliers in samples were discussed.