Publications by authors named "Maximilian Klein"

Background: Each year there are 7.3 million emergencies for the German rescue service, trend rising and around 59% of the emergency patients are treated by paramedics only; however, most of the studies focus on physicians, while their practical skills at the scene are rarely necessary. Accordingly, the responsibility for the patient lies with the paramedics most of the time.

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Five coordination polymers formed from combinations of copper(II) acetate and 4'-(4-alkyloxyphenyl)-3,2':6',3''-terpyridines with methoxy (), -butoxy (), -pentyloxy () and -heptyloxy () substituents are reported. Reaction of with Cu(OAc)∙HO leads to the 1D-polymer [Cu(μ-OAc)()] in which {Cu(-OAc)} paddle-wheel units are connected by ligands , or [{Cu(μ-OH)(μ-OAc)(μ-OAc)(AcO-κO)()}2MeOH] in which centrosymmetric tetranuclear clusters link pairs of ligands to give a double-stranded 1D-polymer. Layering solutions of Cu(OAc)∙HO (in MeOH) over , or (in CHCl) leads to the assembly of the 1D-polymers [2{Cu(μ-OAc)()}1.

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The synthesis and characterization of 4'-(4-methoxyphenyl)-3,2':6',3″-terpyridine () (IUPAC PIN 2-(4-methoxyphenyl)-1,2:2,3-terpyridine) are described, and its coordination behaviour with cobalt(II) thiocyanate has been investigated. In a series of experiments, crystals were grown at room temperature by layering a MeOH solution of Co(NCS) over a CHCl solution of using 1:1, 1:2 or 2:1 molar ratios of metal salt-to-ligand. Crystals harvested within 2-3 weeks proved to be the 1D-coordination polymer [Co()(NCS)(MeOH)] and powder X-ray diffraction (PXRD) confirmed that the crystals selected for single-crystal X-ray diffraction were representative of the bulk samples.

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The syntheses and characterizations of three new ligands containing two 4,2':6',4″-tpy or two 3,2':6',3″-tpy metal-binding domains are reported. The ligands possess different alkyloxy functionalities attached to the central phenylene spacer: -pentyloxy in , 4-phenyl--butoxy in , benzyloxy in . Crystal growth under ambient conditions has led to the formation of {[Co(NCS)₂()]·0.

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We probe the effect of heteroatom substitution on the spin crossover (SCO) properties of dinuclear materials of the type [Fe(NCX)(R-trz)]·S (X = S, Se; S = solvent; R-trz = (E)-N-(furan-2-ylmethylene)-4H-1,2,4-triazol-4-amine (furtrz); (E)-N-(thiophen-2-ylmethylene)-4H-1,2,4-triazole-4-amine (thtrz)). For the furtrz family ([Fe(NCX)(furtrz)]·furtrz·MeOH; X = S (furtrz-S) and X = Se (furtrz-Se)) gradual and incomplete one-step SCO transitions are observed (furtrz-S (T = 172 K) and furtrz-Se (T = 205 K)) and a structural evolution from [HS-HS] to [HS-LS] per dinuclear species. Contrasting this, within the thtrz family ([Fe(NCX)(thtrz)]·4MeOH; X = S (thtrz-S) and X = Se (thtrz-Se)) more varied SCO transitions are observed, with thtrz-S being SCO-inactive (high spin) and thtrz-Se showing a rare complete two-step SCO transition (T = 170, 200 K) in which the Fe sites transition from [HS-HS] to [HS-LS] to [LS-LS] per dinuclear unit with no long range ordering of spin-states at the intermediate plateau.

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In this study we exploit the flexible nature of porous coordination polymers (PCPs) with integrated spin crossover (SCO) properties to manipulate the multistability of spin-state switching profiles. We previously reported the two-dimensional Hofmann-type framework [Fe(thtrz)Pd(CN)]·EtOH,HO (1·EtOH,HO), N-thiophenylidene-4 H-1,2,4-triazol-4-amine), displaying a distinctive two-step SCO profile driven by extreme elastic frustration. Here, we reveal a reversible release mechanism for this elastic frustration via stepwise guest removal from the parent phase (1·EtOH,HO → 1·HO → 1·Ø).

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A comparative investigation of crystal growth from solution and on-surface assembly in vacuo between copper and three 4'-(2-R-pyrimidin-5-yl)-4,2':6',4''-terpyridines, with R = H (1), Me (2), or Et (3), is presented. In solution, ligand 3 combines with copper(II) acetate or copper(I) triflate in MeOH solution to give [Cu(OAc)(3)] or {[Cu(3)(OMe)(MeOH)][CFSO]·MeOH}. In [Cu(OAc)(3)], paddle-wheel {Cu(μ-OAc)} nodes direct the assembly of one-dimensional (1D) zigzag chains which pack into two-dimensional (2D) sheets.

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A comparative investigation of the coordination assemblies formed between Co(NCS)₂ and two monotopic 4,2':6',4''-terpyridine (4,2':6',4"-tpy) ligands or two related ditopic ligands is reported. Crystals were grown by layering MeOH solutions of Co(NCS)₂ over a CHCl₃ or 1,2-C₆H₄Cl₂ solution of the respective ligand at room temperature. With 4'-(2-methylpyrimidin-5-yl)-4,2':6',4"-terpyridine (), the 1D-coordination polymer {[Co₂(NCS)₄(MeOH)₄()₂]∙2MeOH∙8H₂O} assembles with coordinating only through the outer N-donors of the 4,2':6',4"-tpy unit; coordination by the MeOH solvent blocks two cobalt coordination sites preventing propagation in a higher-dimensional network.

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With the aim of improving the photoconversion efficiencies of heteroleptic [Cu(Lanchor)(Lancillary)](+) dyes in n-type dye-sensitized solar cells (DSCs), the previously favoured anchor ((6,6'-dimethyl-[2,2'-bipyridine]-4,4'-diyl)bis(4,1-phenylene))bis(phosphonic acid) (1) has been replaced by analogues 2 and 3 containing 2-thienyl spacers between the 2,2'-bipyridine metal-binding domain and the phosphonic acid anchoring groups. The synthesis and characterization of 2 and 3 (2-thienyl spacer with phosphonic acid in the 5- and 4-positions, respectively) are reported. A stepwise, on-surface method was used to assemble [Cu(Lanchor)(Lancillary)](+) dyes onto FTO/TiO2 electrodes with Lanchor = 1, 2 or 3, and Lancillary = 6,6'-bis(trifluoromethyl)-2,2'-bipyridine (4), 6-trifluoromethyl-2,2'-bipyridine (5), 6,6'-dimethyl-2,2'-bipyridine (6), and 6-methyl-2,2'-bipyridine (7).

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The abrupt and hysteretic two-step spin crossover in a new triazole-based 2-D Hofmann-type complex shows a record breaking 120 K intermediate plateau (IP) region stabilized by negative cooperative interactions.

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The regulation and function of lysosomal hydrolases during yolk consumption and embryogenesis in zebrafish are poorly understood. In an effort to better define the lysosomal biochemistry of this organism, we analyzed the developmental expression, biochemical properties, and function of several glycosidases in zebrafish eggs, embryos, and adult tissues. Our results demonstrated that the specific activity of most enzymes increases during embryogenesis, likely reflecting a greater need for turnover within the embryo as yolk-derived nutrients are depleted.

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