American Chemical Society
ic501400n_si_002.cif (215.17 kB)

From Chromium–Chromium Quintuple Bonds to Molecular Squares and Porous Coordination Polymers

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posted on 2014-12-01, 00:00 authored by Awal Noor, Emmanuel Sobgwi Tamne, Benjamin Oelkers, Tobias Bauer, Serhiy Demeshko, Franc Meyer, Frank W. Heinemann, Rhett Kempe
Reaction of the quintuply bonded chromium­(I) dimer [ApCrCrAp] (Ap = sterically demanding 2-aminopyridinate) with pyrazine yields a chromium­(II) complex with a η44 face-on coordinated pyrazine dianion. Reaction with 4,4′-bipyridine, on the other hand, completely cleaves the metal–metal bond, leading to a chromium­(II)-based molecular square. XRD and magnetic measurements show ligand radical anions and a ferrimagnetic alignment of alternating metal and ligand magnetic moments. Controlled polymerization of the molecular square with pyrazine yields a porous coordination polymer featuring both reduced and nonreduced linkers.