Eight novel silver(I) complexes constructed from ortho-hydroxyl arenesulfonic acids, [Ag(NH3)2]·(HL1) (1), [Ag2(L1)]
n
(2), [Ag2(HL2)(H2O)3]
n
(3), [Ag(HL3)(MeCN)2]
n
(4), [Ag2(HL3)2]
n
(5), [Ag2(HL4)(H2O)3]
n
(6), {(NH4)2·[Ag(NH3)2]2}·2(H
2
L5)·5H2O (7), and [Ag(H
2
L5)0.5]
n
(8) (H
2
L1 = 2-hydroxyl-5-methyl-benzenesulfonic acid; H
3
L2 = 2-hydroxyl-5-methyl-1,3-benzenedisulfonic acid; H
2
L3 = 2-hydroxyl-5-bromo-benzenesulfonic acid; H
3
L4 = 2-hydroxyl-5-bromo-1,3-benzenedisulfonic acid; H
4
L5 = 2,4-dihydroxyl-1,5-benzenedisulfonic acid), have been synthesized and characterized by elemental analysis, infrared, thermogravimetric analysis, UV–vis, photoluminescence (PL), powder and single-crystal X-ray diffraction. Complex 1 has a three-dimensional (3-D) supramolecular framework containing right-handed helical channels through the hydrogen-bonding interactions. Complex 2 exhibits a wavelike “inorgano-organic” layer structure, in which the inorganic substructures consist of Ag1 polyhedral chains linked through Ag2 dimers by sharing two vertexes and two edges. Complex 3 presents the 3-D pillared layered structure, and the inorganic layer substructures are formed by sulfonate tetrahedra bridging Ag–O chains through two vertexes. The sulfonate group in complex 4 bridges adjacent Ag(I) ions to generate a one-dimensional chain structure. Complex 5 exhibits a planar “inorgano-organic” layer structure, in which the inorganic substructures consist of chains of vertex-sharing Ag1 polyhedra and edge-sharing Ag2 polyhedra interlinked by sharing edges. Complex 6 shows a similar 3-D pillared layered structure with complex 3. In complex 7, the free water molecules, ammonium cations, and sulfonate groups form a 3-D hydrogen-bonding host network which encapsulates the [Ag(NH3)2]+ cations as guests. Complex 8 also displays a 3-D pillared layered structure with a two-dimensional (2-D) inorganic substructure formed by Ag(I) polyhedral chains interlinked by sharing edges. The structural diversities and evolutions can be attributed to the different ligands and the coordination modes of the sulfonate groups which are influenced by the hydroxyl groups. The solid-state luminescent properties have also been investigated at room temperature.
Selecting a good site for ground-based astronomy is very important. Based on the ERA-Interim global reanalysis data, this paper studied the atmospheric conditions of the Qitai Telescope (QTT) site from the aspects of absolute humidity, mixing ratio and precipitable water vapor (PWV). Error estimations of meteorological parameters are also analyzed. These primary results show that the QTT site has obvious advantages in terms of conditions with much less atmospheric water vapor than two well-known existing sites with 100-meter-aperture radio telescopes in the world. In addition, due to the influence of atmospheric water vapor on radio observations, the atmospheric transmittance for each frequency band of the site are simulated, and the atmospheric opacity is also calculated as well as Planck radiation brightness. Based on these results, the effective observational time of different bands is further estimated.
This is the fourth article in a series studying on the site-testing at Muztagh-ata site. The results of the characterization of precipitable water vapor (PWV) in the atmospheric column at Muztagh-ata site are presented. This paper studies the temporal variability of PWV, acquired from remote sensing data sets and validated by limited radiometers data, spanning a period from 2018 to 2019. The clear day PWV annual median values are 2.28 mm and 2.37 mm for 2018 and 2019 respectively. The results show that the driest seasons at Muztagh-ata site are from October to March and there are about 60 ∼ 70 days with daily median PWV less than 2 mm in this period. Atmospheric transmission in mid-infrared bands calculated by AM model confirms the IR observation potential of Muztagh-ata site.
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