Introducing Distinct Structural and Optical Properties into Organotin Sulfide Clusters by the Attachment of Perylenyl and Corannulenyl Groups.

We report the introduction of distinct optical properties into organotin sulfide clusters by the attachment of extended polycyclic aromatic organic molecules. This was realized by the reactions of [(RNSn)4S6] (RN = CMe2CH2CMeNNH2) with 3-perylenecarbaldehyde and corannulenecarbaldehyde, respectively. The reaction with the first reactant leads to the formation of two products [(RperylSn)3S4][SnCl3] [1a; Rperyl = CMe2CH2CMeNNCH(C20H11)] and [(RperylSn)3S4Cl] (1b). Structural differences between these two compounds are reflected in their different optical absorption and luminescence behavior, yet in both cases, the main emission is red-shifted relative to 3-perylenecarbaldehyde. The second organic molecule affords the compound [(RcorSn)4Sn2S10] [2; Rcor = CMe2CH2CMeNNCH(C20H9)] with intriguing optical properties, including a broad emission with essentially no shift in λmax compared to corannulenecarbaldehyde. All compounds were obtained as single crystals, and their structures were determined by means of single-crystal X-ray diffraction. The optical properties of the highly luminescent compounds were investigated by means of emission and time-resolved photoluminescence spectroscopy measurements.

Pyrene-Terminated Tin Sulfide Clusters: Optical Properties and Deposition on a Metal Surface.

Herein, we present the synthesis of two pyrene-functionalized clusters, [(Rpyr Sn)4 S6 ]⋅2 CH2 Cl2 (4) and [(Rpyr Sn)4 Sn2 S10 ]⋅n CH2 Cl2 (n=4, 5 a; n=2, 5 b; Rpyr =CMe2 CH2 C(Me)N-NC(H)C16 H9 ), both of which form in reactions of the organotin sulfide cluster [(RN Sn)4 S6 ] (C; RN =CMe2 CH2 C(Me)N-NH2 ) with the well-known fluorescent dye 1-pyrenecarboxaldehyde (B). In contrast, reactions using an organotin sulfide cluster with another core structure, [(RN Sn)3 S4 Cl] (A), leads to formation of small molecular fragments, [(Rpyr Cl2 Sn)2 S] (1), (pyren-1-ylmethylene)hydrazine (2), and 1,2-bis(pyren-1-ylmethylene)hydrazine (3). Besides synthesis and structures of the new compounds, we report the influence of the inorganic core on the optical properties of the dye, which was analyzed exemplarily for compound 5 a via absorption and fluorescence spectroscopy. This cluster was also used for exploring the potential of such non-volatile clusters for deposition on a metal surface under vacuum conditions.

Trapping of ZnCl2 by bipyridyl-functionalized organotin sulfide clusters, and its effect on optical properties.

We report the syntheses of two new organotin sulfide clusters with heteroaromatic substituents. A phenanthroline-functionalized tin sulfide cluster [(RPhenSn)4S6] (1; RPhen = CMe2CH2C(Me)N-NC(H)C12H7N2) and a bipyridyl-terminated cluster [(R4-bipySn)4S6] (2; R4-bipy = CMe2CH2C(Me)N-NC(H)-4-C10H7N2) were obtained from reactions of the hydrazone-functionalized organotin sulfide cluster [(RNSn)4S6] (RN = CMe2CH2C(Me)N-NH2) with 1,10-phenanthroline-5-carboxaldehyde or 2,2'-bipyridine-4-carbaldehyde. 1 and 2 were tested towards their capability of trapping metal ions by means of the terminal chelating ligands. The reaction of 2 with ZnCl2 afforded the cluster compound [(R4-bipyZnCl2Sn)4S6] (5), in which four ZnCl2 units are coordinated by the heteroaromatic organic groups. We discuss the structures and demonstrate the effect of ZnCl2 trapping on optical absorption and luminescence properties.

Facile Ionic Liquid-Assisted Strategy for Direct Precipitation of Eu2+ -Activated Nanophosphors under Ambient Conditions.

This work describes a novel ionic liquid (IL)-assisted synthesis strategy for a direct and easy production of Eu2+ -doped nanoparticles (NPs), where ILs are also used as fluoride sources to avoid the use of elemental fluorine or toxic hydrofluoric acid. Up to now, the direct synthesis of Eu2+ -doped nanophosphors consisted of an enormous challenge, due to the oxidation to Eu3+ observed in hydrous solution, which is commonly used for the preparation of NPs, generating lattice defects and undesired particle growth or agglomeration by additional reducing steps at high temperatures. In contrast, ILs, unless containing ClO4- or NO3- anions, do not present an oxidizing character, allowing the direct precipitation of NPs, e.g., using Eu2+ containing starting materials. Here, the undoped and Eu2+ -doped BaFCl NPs have been prepared under atmospheric conditions for the first time using ILs as solvents and also as fluoride source, applying sonochemical and microwave-assisted approaches. In general, this method bears an enormous potential for an easy synthesis of fluoride materials compared to inconvenient solid-state methods. In addition, the IL plays the role of a strongly attached protecting shell which represents ≈7-8% of the total NPs weight.

{[Ir3(cod)3(µ3-S)2](µ3-S)SnCl}2 - a ternary Ir-Sn-S cluster with the iridium atoms in three different chemical environments.

Reactions of Sn-S clusters with [IrCl(cod)]2 afforded an Ir-Sn-S cluster with unprecedented topology, {[Ir3(cod)3(µ3-S)2](µ3-S)SnCl}2, in which two [Ir3S2] units and a central [Sn2S2] unit are connected via Ir-S and Ir-Sn bonds. Each of the crystallographically independent Ir atoms exhibits a specific chemical environment. Quantum chemical studies shed light on the electronic structure of the multinary cluster and the Ir-Sn bonds.