The hetereoscorpionate ligands bis(pyrazol-1-yl)acetic acid (Hbpza) and bis(3,5-dimethylpyrazol-1-yl)acetic acid (Hbdmpza) are reacted with [Sn(OAc)2] or [Sn(acac)2] to yield the corresponding Sn(II) complexes. A single crystal X-ray determination for the in solution monomeric complex [Sn(bpza)2] (1a) revealed a dinuclear molecular structure [Sn2(bpza)4] (1b), with κ3-N,N,O-coordinated bpza ligands at each of the Sn(II) and two bpza ligands μ-bridging between the Sn(II) centres. The molecular structure of [Sn(bdmpza)2] (2) exhibits a homoleptic bisligand complex with both ligands displaced by the free electron pair, which is proven by DFT calculations. Oxidation of complex 2 in an attempt to synthesize a homoleptic Sn(IV) complex leads to the formation of [Sn(bdmpza)F3] (3). In addition, homoleptic bisligand gallium complexes [Ga(bdmpza)2][ClO4] (4) and [Ga(bpza)2][GaCl4] (5) were prepared and characterized by 71Ga NMR and IR spectroscopy as well as by X-ray crystallography.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The syntheses of five 1D coordination polymers containing the sawhorse‐type unit [Ru2(µ‐OAc)2(CO)4] linked by various bridging N,N‐donor ligands are reported. Various π‐conjugated linkers, such as trans‐[1,2‐bis(N‐methyl)imidazol‐2‐yl]ethylene (trans‐bie), pyrazine (pyz), 4,4′‐bipyridine (4,4′‐bipy) and 1,2‐bis(4‐pyridyl)ethylene (bpe) as well as the aliphatic linker 1,4‐diazabicyclo[2.2.2]octane (DABCO), were applied in the syntheses. The formation of 1D coordination polymers was proven by crystal structure determinations of two of the polymeric materials. The geometries and electronic structures of all polymers were analysed further by CASSCF/CASPT2 and DFT calculations based on monomeric model compounds. Finally, first attempts regarding deposition of the 1D chain, the sawhorse fragment and/or the ligands on a highly ordered pyrolytic graphite surface, analysed by STM measurements, are also reported.

The syntheses and structures of four new bis(pyrazol‐1‐yl)acetate‐ or bis(3,5‐dimethylpyrazol‐1‐yl)acetate‐based bis‐ligand nickel(II) complexes [Ni(bdmpzmp)2] (1), [Ni(bdmpzpen)2] (2), [Ni(bdmpza)2] (3), and [Ni(bpza)2] (4) are described. The results of single crystal structure determinations reveal for all four complexes κ3‐coordination of the scorpionate ligands. The sterically hindered bis(3,5‐di‐tert‐butyl‐pyrazol‐1‐yl)acetateto (bdtbpza) ligand allows the synthesis of the nickel(II) chlorido complex [Ni(bdtbpza)Cl] (5). Furthermore, controlled formation of a novel trinuclear linear complex [Ni(bdmpza)2{Ni(acac)(bdmpza)}2] (6) [bdmpza = bis(3,5‐dimethylpyrazol‐1‐yl)acetate] by a self‐assembling reaction and alkali metal‐mediated template syntheses of [Na{Ni(acac)(bdmpza)}3]NO3 (7), [Na{Ni(acac)(bdmpza)}3]I (8) and [Li{Ni(acac)(bdmpza)}3]NO3 (9) are reported. ESI MS allowed a detailed characterization in solution and is supported by X‐ray structure analysis. Compounds 7, 8 and 9 exhibit [12‐MC‐3] metallacrown structures with a sixfold coordinated alkali metal ion in the center. The magnetic properties are studied by SQUID. Crystallographic data reveal broken symmetry in the solid state for all three [12‐MC‐3] metallacoronates 7, 8 and 9. The linear structure of [Ni(bdmpza)2{Ni(acac)(bdmpza)}2] (6) (length ≈ 2 nm) obtained through synthesis without template, as well as the molecular structure of the [12‐MC‐3] metallacoronates 7, 8 and 9 (∅ ≈ 1.3 nm) are at the nanoscale.

The reaction of bis(3,5-dimethylpyrazol-l-yl)acetic acid (Hbdmpza) with metal(II) acetates [M(OAc)(2)] (M = Mn, Co and Fe) yields a series of homoleptic first row transition metal complexes: [Mn(bdmpza)(2)] (1), [Co(bdmpza)(2)] (2) and [Fe(bdmpza)(2)] (3). Subsequent oxidation results in the formation of the trivalent complexes [Mn(bdmpza)(2)]BF4 (4), [Co(bdmpza)(2)]BF4 (5) and [Fe(bdmpza)(2)]BF4 (6). An unidentate binding of the carboxylate donor and thus kappa(3) coordination of the ligand was determined by IR spectroscopy and single-crystal X-ray diffraction experiments, which also confirm the formation of the homoleptic complexes and the preservation of the geometry during oxidation. Furthermore, the magnetic measurements exhibit that all complexes are in high-spin state with exception of the low-spin complex [Co(bdmpza)(2)]BF4 (5). The high-spin complex [Mn(bdmpza)(2)]BF4 (4) displays a Jahn-Teller distortion. In addition, the divalent and trivalent complexes show promising spectroscopic and electrochemical properties regarding their suitability as potential redox mediators for dye-sensitized solar cells (DSSCs). (C) 2016 Elsevier Ltd. All rights reserved.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

In this work, we have realized nickel oxide (NiO) electrodes that serve as photocathodes in p-type dye-sensitized solar cells (p-DSSCs) sensitized by dendronized perylenediimides (PDIs). To this end, two different approaches in terms of preparing NiO nanoparticle pastes were pursued to fabricate mesoporous electrodes on conductive fluorine doped tin oxide (FTO) glass substrates. Firstly, commercially available NiO nanoparticles were dispersed in a mixture of ethanol and terpineol. Here, in order to obtain a mesoporous network two types of ethylcelluloses (EC), that is, EC 5-15 and 30-50 mPa s, were added in 1:1 weight ratios. Following the evaporation of ethanol, the resulting pastes were spread on FTOs by doctor blading and calcinated at different temperatures. Importantly, the calcination temperature evolved as a crucial aspect in developing efficient electrodes. Nevertheless, the visual appearance of these NiO electrodes prompts a fairly heterogeneous coverage. To circumvent the aforementioned problem, a second approach en route to homogenous electrodes was investigated. In that particular case, commercial NiO nanoparticles were mixed with a mixture of EC 5-15 and 30-50 mPa s at a 1:1 weight ratio, with triacetin as a plasticizer in ethanol. In doing so, pastes containing 7 wt% EC, 3 wt% triacetin, and 3 to 20 wt% NiO nanoparticles were prepared. Most importantly, scanning electron microscopy (SEM) images corroborated the fact that the resulting electrodes revealed a dense coverage on FTOs. In addition, further characterizations ranging from UV/Vis transmission spectroscopy and conductivity measurements to Barrett-Joyner-Halenda (BJH) pore size and volume analysis were carried out. In the final step, the applicability of the new NiO photoelectrodes for p-DSSCs was successfully demonstrated by utilizing two types of PDIs, namely a symmetric 1 and a non-symmetric dendronized 2. Key aspects such as time dependence of dye uptake, hole lifetime and resistance features of the electrodes under operation conditions were investigated.