Poly[[bis[aqua(1,10-phenanthroline)lanthanum(III)]-mu-aqua-di-mu-5-sulfonatoisophthalato] monohydrate] and poly[[[triaqualanthanum(III)]-mu-5-sulfonatoisophthalato] monohydrate].

In the two related polymeric title compounds, [[La2(sip)2(phen)2(H2O)3].H2O]n [sip is the 5-sulfonatoisophthalate trianion (C8H3O7S3-) and phen is 1,10-phenanthroline (C12H8N2)], (I), and [[La(sip)(H2O)3].H2O]n, (II), the lanthanum(III) ions are nine-coordinate, with similar distorted monocapped square-antiprism coordination geometry. The two crystal structures are very different. In (I), the sip anion acts as a pentadentate ligand, one of the coordinated water molecules lies on a twofold axis and further inversion, n-glide and translation operations generate a two-dimensional framework. In (II), the sip anion functions as a hexadentate ligand and a three-dimensional network with trinuclear 24-membered rings is developed via inversion, n-glide, twofold-screw and translation operations. Both structures also have extensive O-H...O hydrogen-bonded networks and pi-pi interactions.

[Determination of trace gold by flow injection on-line preconcentration flame atomic absorption spectrometry with trioctylamine levextrel resin].

A new method for the determination of trace amount of gold by flow injection on-line preconcentration and flame atomic absorption spectrometry with trioctylamine levextrel resin was developed. The experimental condition of Au(III) on the resin, such as the time of preconcentration, the flow rate, the elutropic time, the elutropic rate, the acidity of medium, the concentration and acidity of eluting agent was studied in this paper. The detection limit is 1.3 microg x L(-1). The enhancement factor of 24 was achieved for a loading period of 90 seconds. The recoveries of Au were 98.0%-102.0%. The developed method has been applied to the determination of trace amount of gold in water samples with satisfactory results.

[Determination of trace gold by on-line enrichment flow injection flame atomic absorption spectrometry with N1923 levextrel resin].

A new method for the determination of micro amount of gold with N1923 levextrel resin by flow injection on-line separation and flame atomic absorption spectrometry is described. Au (III) absorbed on the resin can be eluted quantitatively using sulphuric-urea solution. The absorption is carried out in 1.0 mol.L-1 HCl medium and the enhancement factor of 32 is achieved for a loading period of 90 s. The detection limit is 0.001 microgram.mL-1. The flow rate of sample injection, the time of extraction, the flow rate of enrichment, the concentration and acidity of eluting and the effect of coexistence element are studied by flame atomic absorption spectrometry. The recoveries of Au are 98.3%-101%. The developed method has been applied to the determination of trace gold in water samples with satisfactory results.

Mu1,3-azido-diazidotetrakis(1,10-phenanthroline)dicopper(II) azide tetrahydrate.

In the title compound, [Cu2(mu-(1,3)-N3)(N3)2(phen)4](N3)*4H2O (phen is 1,10-phenanthroline, C12H8N2), each of the two Cu atoms is surrounded by two N atoms of two azide anions and by four N atoms of two 1,10-phenanthroline ligands [Cu-N distances are 1.964 (3), 2.009 (3), 2.018 (3), 2.054 (3), 2.306 (3) and 2.759 (4) A], forming an elongated CuN6 octahedron. An ideally linear mu(1,3)-azide anion bridges two Cu atoms to form a dimeric structure with the central N atom located on a centre of inversion. Moreover, the adjacent dimeric units are connected by hydrogen-bond interactions to produce one-dimensional chains. A two-dimensional supramolecular array is formed by pi-pi interactions between the aromatic rings of 1,10-phenanthroline ligands of adjacent dimeric units.