Synthesis and Structure of the Clusters [Hg₂(μ—SePh)₂(SePh)₂(PPh₃)₂] and [Hg₃Br₃(μ—SePh)₃] · 2 DMSO

Abstract

Neste artigo estamos apresentando a síntese do composto [Cd 8 Cl 2 (µ 4-Se) (SePh) 12 (PCy 3) 2 ]·2.5CH 3 OH pela reação de Cd(SePh) 2 com CdCl 2 e triciclohexilfosfina em metanol em um reator de aço inoxidável sob condições solvotérmicas a 130 °C. Esse composto corresponde ao último resultado de uma série sistemática de reações e visando ao crescimento de clusters moleculares a partir de Cd(SePh) 2 como reagente de partida. A importância desta síntese não está baseada somente nas propriedades do produto preparado, mas também no seu possível uso, por exemplo, no desenvolvimento de novas metodologias via estratégias "bottom up" para a obtenção de clusters a partir de uma mesma classe de reagentes-M(ER) 2 (M = metal, E = calcogênio, R = alquil ou aril). O composto apresentado neste artigo foi caracterizado por difração de raios X em monocristal, análise elementar, análise termogravimétrica e espectroscopia no UV-Vis. Estes últimos resultados foram correlacionados com dados calculados por DFT, teoria do funcional de densidade. In this article we present the synthesis of the compound [Cd 8 Cl 2 Se(SePh) 12 (PCy 3) 2 ]·2.5CH 3 OH by the reaction of Cd(SePh) 2 with CdCl 2 and PCy 3 in methanol in a stainless steel sealed reactor under solvothermal conditions at 130 °C. This compound represents the latest result of our systematic work on the growth of molecular clusters from Cd(SePh) 2 as starting material. Their importance is based not only on the properties of the new compounds, but also by their possible use, for example, in the development of new methods via a ''bottom up" strategy to obtain different clusters from single components like M(ER) 2 (M = metal, E = chalcogen, R = alkyl or aryl). The title compound was characterized by single crystal X-ray diffractometry, elemental analysis, thermogravimetrical analysis and the UV-Vis spectroscopy. These results were correlated with data calculated by DFT, density functional theory. Introduction Organylchalcogen groups bound to metal atoms to generate nanoclusters have become increasingly important due to their potential as semiconductors, among other materials and biological applications. 1-4 The unique optical and electronic properties inherent to these "quantum-confined particles" (quantum-dots) have been attributed to modifications of the electronic structure-depending upon the particle size-which lead to very different structures than those found in molecular solids or bulk materials. 5-7 Our search for new metalchalcogen-containing building blocks is of great interest for many reasons, principally because the variable size of the blocks produces tunable optoeletronic properties of the bulk products, 8-10 This emerging field-super lattices of crystalline chalcogenides-links two traditional, but distinct, areas of research: chalcogenide clusters and reticular materials. 11-19 Some authors have proposed alternative ways for the development of metal-chalcogenide clusters. Steigerwald and co-workers 20-23 have demonstrated the utility of trialkylphosphine tellurides (R...

Small Inorganic Rings in the 21st Century: From Fleeting Intermediates to Novel Isolable Entities

“…Novel Hg 2 S 2 ring motifs exist within the [(F 5 C 6 ) 2 Hg­(μ-SC 6 F 5 ) 2 Hg­(C 6 F 5 ) 2 ] 2– dianions ( 64 ), derived via [SC 6 F 5 ] − group transfer involving lanthanide thiolates (e.g., La­(SC 6 F 5 ) 3 ) and Hg­(SC 6 F 5 ) 2 ; a similar diamond core structure motif is present in the phosphonium salt (Ph 4 P) 2 [Hg 2 (SPh) 6 ] ( 65 ) . The search for new precursors to II/VI semiconductors, such as HgSe, led to the preparation of the phosphine-capped selenolate dimer [(Ph 3 P)­Hg­(μ-SePh)­SePh] 2 ( 66 ) with a slightly distorted Hg 2 Se 2 square-shaped core …”