Synthesis, Crystal Structures, Thermal and Magnetic Properties of New Selenocyanato Coordination Polymers with Pyrazine as Co‐Ligand

Abstract

Reaction of iron(II), cobalt(II) and nickel(II) selenocyanate with pyrazine in water at room temperature leads to the formation of the isotypic new ligand-rich 1:2 (1:2 = ratio between metal and coligand) compounds [M(NCSe) 2 (pyrazine) 2 ] n (M = Fe (1), Co (2), Ni (3)). The crystal structure of 2 was determined by X-ray single crystal analysis and those of 1 and 3 were refined from X-ray powder data with the Rietveld method. In their crystal structure the metal(II) cations are coordinated by four pyrazine co-ligands, which connect them into layers, and two terminally N-bonded selenocyanato anions in a distorted

A Rational Route to Coordination Polymers with Condensed Networks and Cooperative Magnetic Properties

“…[118,119] In this context it is noted that following investigation proved that selenocyanato coordination polymers can also be obtained and thus, a more rational access to such compounds is provided. [148,149] In order to investigate if there is any simple correlation between the structures of such compounds and their magnetic properties we exchanged pyrazine by pyrimidine and we obtained new coordination polymers of same composition and of an identical topology of the coordination network. [120,123,130,150] Investigation of their magnetic properties reveal that the ligand-rich compounds with e.g.…”

Exploration and synthesis of condensed coordination networks with modified magnetic properties

“…pyrazine, 4,49-bipyridine or 1,2-bis(4pyridyl)-ethylene. 26,29,30,[32][33][34][35][36] In the pyrazine-rich 1 : 2 compounds (1 : 2 = ratio between metal and pyrazine) of composition M(NCS) 2 (pyrazine) 2 (M = Mn, Fe, Co and Ni) the metal cations are coordinated by two terminal N-bonded thiocyanato anions and are linked by bridging pyrazine ligands into layers. 32,[37][38][39] If these compounds are heated, half of the co-ligands are removed, which enforces the formation of a 2D layer compound of composition M(NCS) 2 (pyrazine), in which the metal cations are linked by pairs of m-1,3-bridging anionic ligands.…”

Crystal structure of high-spin tetraaquabis(2-chloropyrazine-κN4)iron(II) bis(4-methylbenzenesulfonate)

“…Thus, a number of mononuclear highspin Fe II complexes with substituted pyrazines have been reported recently (Shylin et al, 2015). These heterocyclic ligands are also known for their ability to create threedimensional metal-organic framework structures, so called analogues of Hofmann clathrates with general formula Mn, Fe, Co, Ni, and L = pyrazine) in which the small-sized thiocyanate anions are terminally N-bound and therefore not involved in any magnetic exchange interactions are also known (Wriedt & Nä ther, 2011). Although 2-chloropyrazine could possess a N,N 0 -manner of coordination, it is frequently found to act as a monodentate ligand due to the bulky chlorine atom being in direct proximity to one of the nitrogen atoms (Wö hlert & Nä ther, 2013).…”