Karl Peters

Bio: Karl Peters is an academic researcher from Max Planck Society. The author has contributed to research in topics: Crystal structure & Bicyclic molecule. The author has an hindex of 41, co-authored 1127 publications receiving 10416 citations. Previous affiliations of Karl Peters include University of Würzburg.

Structure refinement of the iron–aluminium phase with the approximate composition Fe2Al5

Abstract: Diiron pentaaluminide, Fe 2 Al 5 , M r =268.8, orthorhombic, Cmcm (No. 63), a=7.6559(8), b=6.4154(6), c=4.2184 (4) A, V=207. 19 (6) A 3 , Z=2, D x =4.23 (2), D m =4.20 (1) Mg m -3 , Mo Kα radiation, μ=8.2 mm -1 , F(000)=249.6, T=293 K, R=0.0229, wR=0.0270 for 137 unique reflections. The refined structure differs from the approximate structure proposed previously by an additional partially occupied atomic position

Refinement of the Fe4Al13 structure and its relationship to the quasihomological homeotypical structures

Abstract: The crystal structure of Fe 4 Al 13 was refined using single crystal diffractometer data: Pearson symbol mC102, space group C2/m; a = 15.492(2) A, b = 8.078(2) A, c = 12.471(1) A, β = 107.69(1)°; R F = 0.053, R F (W) = 0.044 for 1127 reflections and 137 refined parameters. The coordination numbers of atoms are 9, 10, 11 for iron and 10, 12, 13, 14 for aluminium. The shortest interatomic distances are: Fe − Fe − 2.902 A, Fe − Al − 2.374 A, Al-Al − 2.533 A. A preferred occupation of pentagonal prismatic coordinated positions by aluminium was found. The structural relationship between the Fe 4 Al 13 structure and chemically homologous and homeotypical structures of aluminium and gallium containing systems with the 3d transition metals is discussed

Aryl-aryl bond formation by transition-metal-catalyzed direct arylation.

Abstract: The biaryl structural motif is a predominant feature in many pharmaceutically relevant and biologically active compounds. As a result, for over a century 1 organic chemists have sought to develop new and more efficient aryl -aryl bond-forming methods. Although there exist a variety of routes for the construction of aryl -aryl bonds, arguably the most common method is through the use of transition-metalmediated reactions. 2-4 While earlier reports focused on the use of stoichiometric quantities of a transition metal to carry out the desired transformation, modern methods of transitionmetal-catalyzed aryl -aryl coupling have focused on the development of high-yielding reactions achieved with excellent selectivity and high functional group tolerance under mild reaction conditions. Typically, these reactions involve either the coupling of an aryl halide or pseudohalide with an organometallic reagent (Scheme 1), or the homocoupling of two aryl halides or two organometallic reagents. Although a number of improvements have developed the former process into an industrially very useful and attractive method for the construction of aryl -aryl bonds, the need still exists for more efficient routes whereby the same outcome is accomplished, but with reduced waste and in fewer steps. In particular, the obligation to use coupling partners that are both activated is wasteful since it necessitates the installation and then subsequent disposal of stoichiometric activating agents. Furthermore, preparation of preactivated aryl substrates often requires several steps, which in itself can be a time-consuming and economically inefficient process.

Engineering coordination polymers towards applications

Abstract: The development in the field of coordination polymers or metal-organic coordination networks, MOCNs (metal-organic frameworks, MOFs) is assessed in terms of property investigations in the areas of catalysis, chirality, conductivity, luminescence, magnetism, spin-transition (spin-crossover), non-linear optics (NLO) and porosity or zeolitic behavior upon which potential applications could be based.

Molecular self-assembly and nanochemistry: A chemical strategy for the synthesis of nanostructures

Abstract: Molecular self-assembly is the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds. Molecular self-assembly is ubiquitous in biological systems and underlies the formation of a wide variety of complex biological structures. Understanding self-assembly and the associated noncovalent interactions that connect complementary interacting molecular surfaces in biological aggregates is a central concern in structural biochemistry. Self-assembly is also emerging as a new strategy in chemical synthesis, with the potential of generating nonbiological structures with dimensions of 1 to 10(2) nanometers (with molecular weights of 10(4) to 10(10) daltons). Structures in the upper part of this range of sizes are presently inaccessible through chemical synthesis, and the ability to prepare them would open a route to structures comparable in size (and perhaps complementary in function) to those that can be prepared by microlithography and other techniques of microfabrication.