Milan Melnik

Bio: Milan Melnik is an academic researcher from University of York. The author has contributed to research in topics: Crystal structure & Copper. The author has an hindex of 26, co-authored 219 publications receiving 2513 citations. Previous affiliations of Milan Melnik include York University & Slovak University of Technology in Bratislava.

Platinum organometallic compounds: classification and analysis of crystallographic and structural data of monomeric five and higher coordinated

Abstract: Abstract Four hundred and twenty monomeric organoplatinum compounds, in which platinum atoms are five- and higher coordinated, are analyzed. The platinum atoms are found in the oxidation states +2, +3 and +4. The Pt(II) compounds by far prevail. There are wide varieties of the inner coordination spheres about the platinum centers. The Pt(II) compounds are five-coordinated (trigonal bipyramidal and square pyramidal), six-coordinated (different degrees of distortion), seven-coordinated (pentagonal bipyramidal, piano stool) and sandwiched (PtC10). The Pt(III) compound is square-planar. The Pt(IV) compounds are six- and eight-coordinated. There are several relationships between the Pt-L bond distances, covalent radii of the coordinated atom/ligand, and metallocycles, which are discussed. The trans-effect plays an important role in the inner coordination spheres about the Pt centers, especially on the Pt-L bond distances.

Structural characterization of heterometallic platinum complexes with non-transition metals. Part II: heterotrimeric complexes

Abstract: Abstract We analyzed and classified almost 100 heterotrimers of platinum with non-transition metals of the composition Pt2M (42 examples), PtM2 (48 examples), and PtMM' (6 examples). These trimers crystallized in five crystal classes: rhombohedral and tetragonal, each 1.5%; orthorhombic, 4%; triclinic, 35%; and monoclinic, 58%. There are 15 non-transition metals: Ge, Sn, Pb, Zn, Cd, Hg, Li, Na, K, Ga, In, Tl, Al, Sb, and Bi, which are partners to Pt for the creation of their respective heterotrimers. The three metal atoms form a wide variety of frameworks, with triangular and linear the most common. There is a rich variety of Pt-M bond lengths, with the mean values following the order: 2.326 Å (M=Al)<2.351 Å (Ga)<2.450 Å (Ge)<2.549 Å (Sn)<2.560 Å (Sb)<2.562 Å (In)<2.582 Å (Li)<2.658 Å (Hg)<2.738 (Pb)<2.770 Å (Tl). In the series Pt2M, the mean Pt-Pt bond distance is 2.803 Å. Correlations between structural parameters, heterometals, and donor ligands were developed and discussed.

Bis(2‐chlorobenzoato‐κO)bis(phenazone‐κO)zinc(II) 0.612‐hydrate

Abstract: The title compound, [Zn(C7H4ClO2)2(C11H12N2O)2].0.612H2O, is a mononuclear zinc(II) compound. The Zn atom lies on a crystallographic twofold rotation axis. It is coordinated in a distorted tetra­hedral arrangement by two O atoms of two phenazone mol­ecules and one carboxyl­ate O atom from each of two 2-chloro­benzoate anions. Intra­molecular O—H⋯O hydrogen bonds may be effective in the stabilization of the structure.

Shape‐Controlled Synthesis of Metal Nanocrystals: Simple Chemistry Meets Complex Physics?

Abstract: Nanocrystals are fundamental to modern science and technology. Mastery over the shape of a nanocrystal enables control of its properties and enhancement of its usefulness for a given application. Our aim is to present a comprehensive review of current research activities that center on the shape-controlled synthesis of metal nanocrystals. We begin with a brief introduction to nucleation and growth within the context of metal nanocrystal synthesis, followed by a discussion of the possible shapes that a metal nanocrystal might take under different conditions. We then focus on a variety of experimental parameters that have been explored to manipulate the nucleation and growth of metal nanocrystals in solution-phase syntheses in an effort to generate specific shapes. We then elaborate on these approaches by selecting examples in which there is already reasonable understanding for the observed shape control or at least the protocols have proven to be reproducible and controllable. Finally, we highlight a number of applications that have been enabled and/or enhanced by the shape-controlled synthesis of metal nanocrystals. We conclude this article with personal perspectives on the directions toward which future research in this field might take.