Dalton Transactions

doi: 10.1039/b818673cpmid: N/A

doi: 10.1039/b818675hpmid: N/A

doi: 10.1039/b818674jpmid: N/A

King, R. B.; Silaghi-Dumitrescu, I.

doi: 10.1039/b803958epmid: 18985236

The jellium sphere model of a volume of electrons, counterbalanced by a positive charge throughout the sphere, leads to an energy level sequence corresponding to special stabilities of bare post-transition element clusters with 20 valence electrons such as the known P4 and clusters with 40 valence electrons such as the known Ge94−, Ni@In1010−, and In117−. In this model the otherwise “external” lone pairs on the vertex atoms participate at least indirectly in the skeletal bonding. Furthermore, this model predicts the most favorable polyhedra and electron counts in some cases to be quite different than those predicted by the Wade–Mingos rules of polyhedral borane chemistry.

Clearfield, Abraham

doi: 10.1039/b807676fpmid: 18985237

The past decade has witnessed an exponential growth of metal organic framework compounds (MOFs). The defining character of these compounds is their porosity. However, in many cases no effort was made to show evidence that a stable porous structure has been achieved and that the pores may be accessed. In the present paper we describe recent work on porous pillared zirconium diphosphonates, and the newer and in many respects different characteristics of tin(iv) phosphonates. The Sn(iv) monophosphonates form spherical globules that exhibit very high surface areas. The surface area arises from their nano-sized particles that pack in a “house of cards” arrangement. Also, it is shown that the 1,4-monophenyldiphosphonic acid forms highly porous (250–400 m2 g−1) materials with Sn(iv) when prepared in alcohol–water media. This is not the case with analogous Zr(iv) compounds. The many variations in the syntheses of both the zirconium and tin aryl- and alkyldiphosphonate pillars and their combinations with spacers such as methyl- and monophenylphosphonic acid have created a variety of highly porous materials that are stable to 400 °C in air, highly stable in acid media, do not collapse when de-solvated, and can be post and presynthesis altered to include functional groups. Several new directions taken by other researchers are also described. However, it is emphasized in this presentation that the cross-linked compounds form particles that precipitate rapidly into nanoparticles that exhibit only short range order. Therefore, they differ from the more conventional MOFs in that they are not amenable to structure solution by X-ray or neutron diffraction techniques. Rather, they must be understood on the basis of modeling and indirect data from EM, NMR, and additional spectroscopic and textural studies.

Iremonger, Simon S.; Southon, Peter D.; Kepert, Cameron J.

doi: 10.1039/b816359fpmid: 18985238

Assembly of the novel homochiral ligand L(S) (where L(S) is 1,4-benzylidene-bis(S,S)-4-yl-3,5-bis(1-hydroxyethyl)-1,2,4-triazole) and AgNO3 generates a robust, porous, chiral and cationic framework that exhibits reversible guest adsorption.

Rohe, Markus; Löffler, Elke; Muhler, Martin; Birkner, Alexander; Wöll, Christof; Merz, Klaus

doi: 10.1039/b810929jpmid: 18985239

The gold-containing titanium peroxo-complex AuCl4(NH4)7[Ti4(O2)4(Hcit)2(cit)2]·12H2O 1 allows an easy reproducible access to pure Au/TiO2 composites.

Wu, Jing-Yun; Chang, Che-Hao; Thanasekaran, P.; Tsai, Chen-Chuan; Tseng, Tien-Wen; Lee, Gene-Hsiang; Peng, Shie-Ming; Lu, Kuang-Lieh

doi: 10.1039/b809489fpmid: 18985240

A triangular metalloprism, [{(CO)3Re(μ-2)Re(CO)3}3(μ3-1)2], self-assembled from Re2(CO)10, 2,4,6-tri-4-pyridyl-1,3,5-triazine (tpt, 1), and indigo (H22), represents a fairly novel example of strong face-to-face π–π interactions between the central triazine rings of the tpt ligands that bow significantly inward distorting the prismatic structure.

Hu, Li-Li; Jia, Zhong-Quan; Tao, Jun; Huang, Rong-Bin; Zheng, Lan-Sun

doi: 10.1039/b812113cpmid: 18985241

Solvothermal reaction of Co(OAc)·4HO with HL (HL = 2-((2-hydroxybenzylidene)amino)-2-hydroxymethylpropane-1,3-diol) in MeCN gave a mixed-valence pentanuclear cobalt complex [Co(HL)(HL)(OAc)]·2.5HO. Crystal structural analysis revealed that two Co() ions were linked to a central triangular Co() core through HL and HL hydroxyl groups. Magnetic measurements showed interesting magnetic properties that were assigned to spin–orbital coupling and ferromagnetic exchange interactions.

Szyrwiel, Lukasz; Jankowska, Elzbieta; Janicka-Klos, Anna; Szewczuk, Zbigniew; Valensin, Daniela; Kozlowski, Henryk

doi: 10.1039/b811224jpmid: 18985242

Multi-histidine peptide fragments of zebra-fish prion protein are effective ligands for Zn(ii) ions. Moreover the formation of a dinuclear complex species with a longer peptide can suggest the existence of the cooperative effect in the metal ion binding.